text:
Chapter 82. Perioral Dermatitis
Leslie P. Lawley; Sareeta R.S. Parker
Lawley LP, Parker SS. Lawley L.P., & Parker S.S. Lawley, Leslie P., and Sareeta R.S. Parker.Chapter 82. Perioral Dermatitis. In: Goldsmith LA, Katz SI, Gilchrest BA, Paller AS, Leffell DJ, Wolff K. Goldsmith L.A., & Katz S.I., & Gilchrest B.A., & Paller A.S., & Leffell D.J., & Wolff K(Eds.),Eds. Lowell A. Goldsmith, et al.eds. Fitzpatrick's Dermatology in General Medicine, 8e. McGraw Hill; 2012. Accessed January 29, 2023. https://accessmedicine.mhmedical.com/content.aspx?bookid=392&sectionid=41138787
Lawley LP, Parker SS. Lawley L.P., & Parker S.S. Lawley, Leslie P., and Sareeta R.S. Parker. (2012). Chapter 82. perioral dermatitis. Goldsmith LA, Katz SI, Gilchrest BA, Paller AS, Leffell DJ, Wolff K. Goldsmith L.A., & Katz S.I., & Gilchrest B.A., & Paller A.S., & Leffell D.J., & Wolff K(Eds.),Eds. Lowell A. Goldsmith, et al. Fitzpatrick's Dermatology in General Medicine, 8e. McGraw Hill. https://accessmedicine.mhmedical.com/content.aspx?bookid=392&sectionid=41138787
Lawley LP, Parker SS. Lawley L.P., & Parker S.S. Lawley, Leslie P., and Sareeta R.S. Parker. "Chapter 82. Perioral Dermatitis." Fitzpatrick's Dermatology in General Medicine, 8e Goldsmith LA, Katz SI, Gilchrest BA, Paller AS, Leffell DJ, Wolff K. Goldsmith L.A., & Katz S.I., & Gilchrest B.A., & Paller A.S., & Leffell D.J., & Wolff K(Eds.),Eds. Lowell A. Goldsmith, et al. McGraw Hill, 2012, https://accessmedicine.mhmedical.com/content.aspx?bookid=392&sectionid=41138787.
Perioral Dermatitis: Introduction
Historical Aspects
Etiology and Pathogenesis
Prognosis and Clinical Course
Perioral Dermatitis at a Glance
Inflammatory skin disorder of young women and children.
Small papules, vesicles, and pustules in perioral, periorbital, and/or perinasal distribution.
Treatment: stop topical corticosteroid use; initiate 2- to 3-month course of systemic antibiotics (tetracycline family or erythromycin) and/or topical metronidazole.
Perioral dermatitis is characterized by small, discrete papules and pustules in a periorificial distribution, predominantly around the mouth. Because this condition can involve areas other than the perioral region, the term periorificial dermatitis has been proposed for this disorder.1,2 The classic presentation is an eruption with overlapping features of an eczematous dermatitis and an acneiform eruption. Although initially described in young women of 15–25 years of age, perioral dermatitis is now recognized to occur in children as well.3 A subset of perioral dermatitis shows granulomas when lesional skin is examined histologically. Several names have been used to describe this granulomatous form of perioral dermatitis, including granulomatous perioral dermatitis, facial Afro-Caribbean childhood eruption, and granulomatous periorificial dermatitis.2,4,5
The first reports describing perioral dermatitis appeared in the 1950s; various names were given to the condition, however, there was a lack of defining clinical criteria. In 1957, Frumess and Lewis described a "light sensitive seborrheid" that is generally accepted as the first account of what was later termed perioral dermatitis by Mihan and Ayres in 1964.6,7 Later descriptions by Cochran and Thomson8 and Wilkinson, Kirton, and Wilkinson9 further defined this disorder, and more recently the term periorificial dermatitis has been proposed.2 The condition was first described in children in the late 1960s.
Adult perioral dermatitis predominantly affects women. Pediatric perioral dermatitis may have a slight female preponderance and is seen equally among those of different races.1,10 The granulomatous form of perioral dermatitis has been reported mostly in children of prepubertal age.5 Perioral dermatitis can occur as early as 6 months.1 An increased prevalence in African-American children has been reported, but more recent reviews do not support this finding.2,11
A relationship of perioral dermatitis to the misuse of topical corticosteroids (fluorinated or nonfluorinated) has been well established.12 Patients often reveal a history of an acute steroid-responsive eruption around the mouth, nose, and/or eyes that worsens when the topical corticosteroid is discontinued. Dependency on the use of the topical corticosteroid may develop as the patient repeatedly treats the recurrent eruption. In other cases, the condition may worsen with the application of topical corticosteroids, especially in the granulomatous variant of perioral dermatitis, which usually occurs in prepubertal children.2 Perioral dermatitis has been reported in patients using inhaled corticosteroids13 and with inadvertent facial exposure to topical corticosteroids.14 However, perioral dermatitis is not always linked to topical corticosteroids.9 The exact cause of perioral dermatitis in these other cases is unclear. Although isolated reports of affected siblings exist,2,15 no clear genetic predisposition has been noted, nor have specific environmental exposures been consistently implicated. Of note, the disease is predominant in young women, yet no link to hormonal causes has been found. The initial reports of photosensitivity by Frumess and Lewis6 were not further substantiated, nor were theories of microbiologic causes such as infection with Candida, fusiform bacteria, or Demodex folliculorum.16 Cases of allergic contact with fluorides or other components in toothpaste and dentifrices have also been reported, however, use of these agents after clearing of the perioral dermatitis without further eruption has also been described. Patch testing in a small series of patients led to few positive results, and these were not considered relevant.9
In the past, authors have considered the relationship of perioral dermatitis to acne rosacea, however, the clinical features are distinct (see Section "Differential Diagnosis"). In perioral dermatitis, the histopathologic findings are variable and are dependent on the form of perioral dermatitis. In a histopathologic review of 26 patients with the nongranulomatous form, follicular spongiosis and eczematous changes were prominent features, suggesting that perioral dermatitis is distinct from rosacea.17 A lymphohistiocytic infiltrate and occasional plasma cells were noted in a perifollicular and perivascular distribution in this series. In granulomatous perioral dermatitis, histopathology demonstrates follicular hyperkeratosis, edema and vasodilatation in the papillary dermis, perivascular and parafollicular infiltrates of lymphocytes, histiocytes, and polymorphonuclear leukocytes with occasional epithelioid granulomas and giant cells, similar to the histopathologic changes in acne rosacea.5,18
The primary lesions of perioral dermatitis are discrete and grouped erythematous papules, vesicles, and pustules (Figs. 82-1 and 82-2). The lesions are often symmetric but may be unilateral and appear in the perioral, perinasal, and/or periocular regions (Figs. 82-2 and 82-3 and eFigs. 82-3.1 and 82-3.2). In a retrospective review of 79 children with perioral dermatitis, isolated perioral involvement was present in only 39%, and in rare cases nonperioral regions were involved exclusively.1 Background erythema and/or scale may be present. A distinct 5-mm clear zone at the vermilion edge is well described (Fig. 82-2). The granulomatous variant of perioral dermatitis presents with small flesh-colored, erythematous, or yellow–brown papules, some with confluence, and shares the distribution of perioral dermatitis in adults (Fig. 82-3). In addition, lesions have been reported to appear on the ears, neck, scalp, trunk, labia majora, and extremities.1,11
Typical perioral dermatitis. The eruption is confined to the nasolabial folds and the skin of the chin.
Perioral (granulomatous periorificial) dermatitis. This child shows the typical small papules studding the area around the mouth and eyes.
Perioral dermatitis, granulomatous form: child with densely aggregated periorificial erythematous and edematous papules.
eFigure 82-3.1
Periocular localization of perioral dermatitis. There are discrete papules and pustules around the eye.
Perioral dermatitis: adult patient with erythematous papules and scant scale in periorificial distribution on the face.
Occasionally, an associated burning sensation or itching is reported, and intolerance to moisturizers and other topical products is described.1,9 In a few cases of granulomatous perioral dermatitis, an associated blepharitis or conjunctivitis has been reported.11 Systemic findings and regional lymphadenopathy are absent.
(Box 82-1)
Box 82-1 Differential Diagnosis of Perioral Dermatitis
DISTINGUISHING CLINICAL FEATURES
Nongranulomatous Perioral Dermatitis
Involves the nose, facial convexities; persistent erythema, and telangiectasias
Accentuated at nasolabial folds; scale
Allergic contact dermatitis
Consider musical instruments, toothpaste/dentrifices, latex gloves, dental appliances, and lipstick
Irritant contact dermatitis
Common in children (from saliva, foods)
Lip-licking cheilitis
Common in children; scale, well demarcated border
Acne vulgaris
May involve chest and back; comedones
Gram-negative folliculitis
Predominance of pustules
Demodex folliculorum infestation
Pustules, pruritus; often immunocompromised host19
Acrodermatitis enteropathica
Infants with acral and/or diaper dermatitis; zinc deficiency
Tinea facei
KOH positive for hyphal elements
Involvement of other cutaneous sites common
Honey-colored crusts
Eosinophilic folliculitis-HIV related
Immunocompromised host
Granulomatous Perioral Dermatitis
Granulomatous rosacea
Flushing, telangiectases, pustules, and edema; similar histopathologic features
Familial juvenile systemic granulomatosis (Blau syndrome)
Synovial cysts, uveitis, granulomatous arthritis, camptodactyly, papular rash
Fungal or mycobacterial infection
Lupus miliaris disseminatus faciei
Benign cephalic histiocytosis
Diffuse distribution on the face
Rare in children; reported cases may represent Blau syndrome
Zirconium dermatitis
May involve axillae
The differential diagnosis of nongranulomatous and granulomatous perioral dermatitis is outlined in Box 82-1.19–24 Both forms of perioral dermatitis lack systemic symptoms and a thorough history and physical examination are generally sufficient to establish the diagnosis. However, in some cases histopathological evaluation of lesional skin, chest radiography, and/or ophthalmologic examination may be necessary, particularly with the granulomatous variant.11 Sarcoidosis in young children is rare and often accompanied by systemic signs and symptoms such as weight loss, fatigue, joint pains, lymphadenopathy, and uveitis.5,25 At least some of the reported cases of sarcoidosis in young children represent Blau syndrome with underlying mutations in CARD15/NOD2 (see Chapter 134).11,26
The majority of cases of perioral dermatitis and granulomatous perioral dermatitis resolve without sequelae or relapse. However, there are rare reports of scarring.5
Perioral dermatitis is usually a self-limited disorder that evolves over a few weeks and resolves over months or rarely years. The condition may take on a waxing and waning course, often with a tendency to progress (granulomatous form). If treated with topical corticosteroids alone, recurrent episodes on withdrawal of therapy or with continuing therapy are typical. With appropriate intervention the condition resolves with rare recurrences.
Box 82-2 Treatment for Perioral Dermatitis
ADULT DOSE
Apply bid
250–500 mg p.o. bid
50–100 mg p.o. bid
Erythromycin or clindamycin
400 mg p.o. tid
Sulfur preparations
30–50 mg/kg/day p.o. divided tidch82bx2.fn1
aPediatric dose
If topical corticosteroids are being used, they should be discontinued. If fluorinated corticosteroids are being applied, initial substitution with a low-potency hydrocortisone cream may minimize a flare of the dermatitis. Patients should be educated about the link between application of topical corticosteroids and exacerbation of the dermatitis.
In most cases, effective therapy is oral tetracycline, doxycycline, or minocycline, for a course of 8 to 10 weeks, with a taper over the last 2 to 4 weeks. In children under 8 years of age, nursing mothers, or tetracycline-allergic patients, oral erythromycin is recommended. Not uncommonly, patients require continued low-dose systemic antibiotic therapy for months or sometimes years to maintain control. In recalcitrant cases, isotretinoin may be considered.27
Topical antibiotic therapy, most commonly with topical metronidazole, should be initiated concurrently with the systemic antibiotic. For milder cases, topical metronidazole alone may suffice.1,28,29 In a retrospective review of 79 children, best outcomes were associated with the use of topical metronidazole, oral erythromycin, or both.1 Response is generally noted within 2–3 months. Other options include topical clindamycin or erythromycin, topical sulfur-based preparations, and topical azelaic acid.30 Reports of successful use of topical calcineurin inhibitors exist, particularly in adults; however, caution is advised given the occasional reports of granulomatous eruptions after the use of these agents.31–35 Ointment preparations should generally be avoided in the treatment of perioral dermatitis. Photodynamic therapy with topical 5-aminolevulinic acid has shown promise for treating perioral dermatitis in one report.36
The only widely accepted factor that may predispose to the development of perioral dermatitis is the use of topical corticosteroids. Avoiding facial skin exposure to these products may prevent the eruption in some cases.
1. Nguyen V, Eichenfield LF: Periorificial dermatitis in children and adolescents. J Am Acad Dermatol 55:781, 2006
2. Knautz MA, Lesher JL Jr: Childhood granulomatous periorificial dermatitis. Pediatr Dermatol 13:131, 1996 [PubMed: 9122070]
3. Manders SM, Lucky AW: Perioral dermatitis in childhood. J Am Acad Dermatol 27:688, 1992 [PubMed: 1430388]
4. Williams HC et al: FACE—Facial Afro-Caribbean childhood eruption. Clin Exp Dermatol 15:163, 1990 [PubMed: 2364568]
5. Frieden IJ et al: Granulomatous perioral dermatitis in children. Arch Dermatol 125:369, 1989 [PubMed: 2923443]
6. Frumess GM, Lewis HM: Light-sensitive seborrheid. AMA Arch Derm 75:245, 1957 [PubMed: 13393795]
7. Mihan R, Ayres S Jr: Perioral dermatitis. Arch Dermatol 89:803, 1964 [PubMed: 14164961]
8. Cochran, Thomson: Rosacea-like dermatitis. Br Med J 3:545, 1969
9. Wilkinson DS, Kirton V, Wilkinson JD: Perioral dermatitis: A 12-year review. Br J Dermatol 101:245, 1979 [PubMed: 159711]
10. Laude TA, Salvemini JN: Perioral dermatitis in children. Semin Cutan Med Surg 18:206, 1999 [PubMed: 10468040]
11. Urbatsch AJ et al: Extrafacial and generalized granulomatous periorificial dermatitis. Arch Dermatol 138:1354, 2002 [PubMed: 12374542]
12. Weston WL, Morelli JG: Identical twins with perioral dermatitis. Pediatr Dermatol 15:144, 1998
13. Hafeez ZH: Perioral dermatitis: An update. Int J Dermatol 42:514, 2003 [PubMed: 12839598]
14. Poulos GA, Brodell RT: Perioral dermatitis associated with an inhaled corticosteroid. Arch Dermatol 143:1460, 2007
15. Kosari P, Feldman SR: Fluocinonide-induced perioral dermatitis in a patient with psoriasis. Dermatol Online J: 15:15, 2009
16. Dolenc-Voljc M, Pohar M, Lunder T: Density of Demodex folliculorum in perioral dermatitis. Acta Derm Venereol 85:211, 2005 [PubMed: 16040404]
17. Marks R, Black MM: Perioral dermatitis. A histopathologic study of 26 cases. Br J Dermatol 84:242, 1971 [PubMed: 5572676]
18. Ramelet AA, Delacretaz J: [Histopathologic study of perioral dermatitis.] Dermatologica 163:361, 1981 [PubMed: 7333393]
19. Morras PG et al: Rosacea-like demodicidosis in an immunocompromised child. Pediatr Dermatol 20:28, 2003 [PubMed: 12558842]
20. Bendl BJ: Perioral dermatitis: Etiology and treatment. Cutis 17:903, 1976 [PubMed: 1035149]
21. Beacham BE, Kurgansky D, Gould WM: Circumoral dermatitis and cheilitis caused by tartar control dentifrices. J Am Acad Dermatol 22:1029, 1990 [PubMed: 2164535]
22. Cheung MJ, Taher M, Lauzon GJ: Acneiform facial eruptions: A problem for young women. Can Fam Physician 51:527, 2005 [PubMed: 15856972]
23. Karincaoglu Y et al: The clinical importance of Demodex folliculorum presenting with nonspecific facial signs and symptoms. J Dermatol 31:618, 2004 [PubMed: 15492434]
24. Hsu CK, Hsu MML, Lee JYY: Demodicosis: A clinicopathological study. J Am Acad Dermatol 60:453, 2009
25. Siltzbach LE, Greenberg GM: Childhood sarcoidosis—A study of 18 patients. N Engl J Med 279:1239, 1968 [PubMed: 5688174]
26. Alonso D, Elgart GW, Schachner LA: Blau syndrome: A new kindred. J Am Acad Dermatol 49:299, 2003 [PubMed: 12894082]
27. Smith KW: Perioral dermatitis with histopathologic features of granulomatous rosacea: successful treatment with isotretinoin. Cutis 46:413, 1990.
28. Veien NK et al: Topical metronidazole in the treatment of perioral dermatitis. J Am Acad Dermatol 24:258, 1991 [PubMed: 2007672]
29. Miller SR, Shalita AR: Topical metronidazole gel (0.75%) for the treatment of perioral dermatitis in children. J Am Acad Dermatol 31:847, 1994 [PubMed: 7962733]
30. Jansen T: Azelaic acid as a new treatment for perioral dermatitis: Results from an open study. Br J Dermatol 151:933, 2004 [PubMed: 15491447]
31. Antille C, Saurat JH, Lubbe J: Induction of rosaceiform dermatitis during treatment of facial inflammatory dermatoses with tacrolimus ointment. Arch Dermatol 140:457, 2004 [PubMed: 15096374]
32. Goldman D: Tacrolimus ointment for the treatment of steroid-induced rosacea: A preliminary report. J Am Acad Dermatol 44:995, 2001 [PubMed: 11369912]
33. Chu CY: The use of 1% pimecrolimus cream for the treatment of steroid-induced rosacea. Br J Dermatol 152:396, 2005 [PubMed: 15727676]
34. Gerber PA et al: [Perioral dermatitis following treatment with tacrolimus.] Hautarzt 56:967, 2005 [PubMed: 16142496]
35. Schwarz, T et al: A randomized, double-blind, vehicle-controlled study of 1% pimecrolimus cream in adult patients with perioral dermatitis. J Am Acad Dermatol 59:34, 2008.
36. Richey DF, Hopson B: Photodynamic therapy for perioral dermatitis. J Drugs Dermatol 5:12, 2006 [PubMed: 16485876]


Komptech is a leading international technology supplier of machinery and systems for the mechanical and mechanical-biological treatment of solid waste and for the treatment of biomass as a renewable energy source.
The product range includes over 30 different types of machines, that cover all key process steps in modern waste handling - shredding, separation, and biological treatment.
By combining the right products from our own portfolio with proven components by other leading manufacturers, we can deliver solutions to address complex challenges.
The focus is always on innovative technology and solutions that ensure the maximum customer benefit."


On the next Agent Mastermind class, Michael Hellickson is going to share the hottest lead sources out there, follow-up and closing scripts that convert virtually every time, and a killer listing presentation that'll set you apart from the competition!
As a real estate agent for over 20 years, Michael consistently listed and sold over 100+ homes per month and now coaches agents and brokers of all production levels with Club Wealth® Coaching and Consulting™.
PS…On last week's class, Nancy Rae Evans peeled back the layers on why money is such a complicated and emotionally triggering topic to give us a deeper understanding of what drives our behaviors and decisions when it comes to spending! If you'd like to watch a copy of the class, please let me know!


Can you do me a favor? Take a moment and envision your business. What services do you provide? What challenges have you overcome? What victories have you celebrated? Now envision what would happen if you went on vacation for two weeks to a remote island, with no wifi. Are you hyperventilating? Did it suddenly just get really hot in the room?
If not being able to work for two weeks makes you nervous, trust me, you are not alone! But, you may want to ask yourself: Do I have a business or a job with a flexible schedule that pays well?
Now, don't get me wrong, flexibility and great pay are wonderful, but your business should be able to thrive beyond you.
Imagine having a vision so large that it invirgorates you when you are challenged. Imagine having a business that can run smoothly without you.
Having a business that is bigger than you as an individual is completely attainable. When you develop a solid organizational structure and team, the business can thrive and you can not only have access to more of your time, but also unlock scalable growth and increase the value of your business.
I'm glad you asked! Here are three steps that can take your business to a level that far exceeds yourself.
If you offer 1:1 services, make sure that you are consistently seeing a full roster of clients. As you move forward with creating and implementing systems to help you manage your business more effectively, it's important to have total confidence in your program and your abilities.
Establishing a standard of providing consistently excellent service is a great way to build your confidence in your abilities and your product. Staying booked also allows you to see what parts of your program are working and what methods need to be adjusted so that you can fine tune your work and prepare to take on students.
When I say that your business "should be able to thrive beyond you" I mean it from both a mission and vision perspective as well as bigger than just yourself or one team member.
In most situations I don't recommend you move to this step until you are close to being fully booked with 1:1 clients. This will allow you to hone your skills in a one-on-one environment before many eyes are on you. Once you've mastered your 1:1 work, it's time to move on to developing courses for groups.
Working with groups of people will allow you to leverage your time. Instead of taking the time to teach 20 individual one hour classes you can teach one group of 20 in an hour. Beyond leveraging your time, this adjustments allows you to reach a larger audience and more effectively serve your vision.
Until very recently I was hosting all my sales calls with women who were interested in joining my programs. I wanted to be certain that the calls would be handled well and so I handled them myself. But as my business grew (and we were approaching Leo's due date!) I realized it wouldn't be possible to continue doing this long term, so I found people who could take care of this for me.
Around the same time I started working alongside associate coaches who would coach my clients in my programs.
I began to realize that my clients are ultimately seeking a result and it didn't necessarily need to be me personally delivering everything - in fact it was impossible to do that.
In addition to hiring my team, I also started to put mechanisms in place that both supported my team and established a framework for future team members.
Step 3 - Delegate. Delegate. Delegate.
Think about everything that you do for your business and then ask yourself: What tasks can you and only you accomplish? Then seriously consider delegating the rest.
Because the truth is, any time spent on something that you can delegate is leaving less time for tasks that need your personal touch. This is a lesson that frankly, took a while to learn. Honestly, it really scared me.
I used to be terrified that if I let go, everything would fall apart, but that simply isn't true. In fact, as I began to let go, things started to come together. Honing your craft, sharing your knowledge with others, assembling a team, creating effective systems and learning to delegate are core actions that lead to creating a business beyond you.


Where can I find this paper?
What is this paper about (what is the research question)?
Can we improve the quality of life of paediatric asthmatic patients using the opportunity to increase their medications offered when they present to the ED?
Objective: To assess the impact of improving control medications on quality of life in children with persistent asthma symptoms attending the PED.
Intervention: initiation or improvement of long term control medication – inhaled corticosteroid – at discharge from PED following presentation with persistent asthma symptoms (in accordance with national guidelines).
Primary outcome: improvement in "Quality of Life", defined as validated symptoms and quality of life scores (PACT and ARQoL), ascertained by parental reporting at telephone follow-up at 2 weeks, 6 weeks and 6 months after PED discharge.
Exclusion: Children with chronic cardiopulmonary and neuromuscular conditions, children <1 year old, children <2 years old presenting with first episode of wheeze, children whose asthma control medication had been modified in preceding 4 weeks.
Results: 1954 asthma episodes of which 164 had persistent symptoms. 146 were included in the study with 22 lost to follow-up. At presentation, 50 (40.3%) were receiving maintenance treatment.
Asthma control medication was initiated in 74 patients (59.7%), improved within the same "step" in 36 (29.0%) and "stepped up" in 14 (11.3%).
Average PACT categorisation at 6 weeks was significantly lower than at 2 weeks (median 12, IQR 13.3 versus median 7.8 IQR 10, p<0.001) with improvement sustained at 6 months.
Where long term asthma control medications were initiated or stepped up following PED visit, children showed a decrease in persistent symptoms and improvement in quality of life.
The lack of control group in this paper is a major downfall; children were presenting with intercurrent illness, a major confounder. We know from practice that asthma exacerbations are often associated with viral infection, and that wheeze and cough can persist for a few weeks afterwards. It is not surprising, then, that children were better 6 weeks and 6 months after attendance than at 2 weeks. How meaningful are these outcomes? It might be more useful to match patients with controls and demonstrate improvement, ideally through less subjective variables (time off school, hospital reattendance).
There is a risk of inclusion bias considering the seasonal recruitment.
The other issue is with data processing; subjective scores are qualitative or ordinal data at best. The study design seems to convert this to quantitative non-normal data for analysis. There is also significant confusion between averages: the authors state that "the mean PACT categorization was significantly lower", then provide data for a median. These descriptive variables are suitable for different types of data; what kind of data did the authors have? I am no statistician but it does make me wonder whether they knew what they were doing – and whether we can trust their results and analysis.
What were the results and what does this mean?
It appears that the patients in the study had better quality of life and fewer asthma symptoms at 6 weeks and 6 months than at 2 weeks after PED discharge. However, the validity of this data is uncertain and even if the apparent improvement is reflected in real life, the lack of control group means we cannot attribute it to the introduction or adjustment of asthma medication.
What can we take from this paper into clinical practice?
Unfortunately, very little more than the idea that there might be a role for reviewing asthma medications in PED, in conjunction with a primary care physician.
If we introduce a control group for comparison, does the adjustment or introduction of control medication improve quality of life/asthma symptoms?
Does this translate into objective outcomes such as reduced annual ED attendances/reduced school time missed?
This entry was posted in Critical Appraisal on November 9, 2012 by PEMLit.


Im a bike messenger […] Hon-Dah Resort Casino and Conference Center is owned and operated by the White Mountain Apache Tribe. 777 Hwy 260, Pinetop, Arizona 85935 169; Hon-Dah Resort Casino … The Pennsylvania Gaming Control Board Announces Receipt of Additional Fantasy Sports Contests Operator Applications 5162018; Pennsylvania Gaming Control Board Reports Decrease In Tables Games Revenue In April 5152018; Two Fines Levied By PA Gaming Control Board Totaling 20,000 522018; Pennsylvania Slot Machine … Let's discuss your needs. Speak with our experts so we can learn about your unique goals. Please complete the contact form below if you have a general inquiry on any of our services, or to explore new partnering possibilities. Get in on the action with over 120,000 square feet of gaming floor at Rivers Casino. We have something for everyone. From over 2,900 slot machines to over 100 tables, a dedicated 30-table poker room, and a state-of-the-art high limits area, Rivers Casino is fun and games and so much more. Casino table rentals and professional dealers for casino theme parties at the best prices in Dallas, TX. Casino-quality blackjack, poker, roulette, craps, baccarat tables for your casino event. Party planning and bartending catering services for your casino night in the Dallas Fort Worth Metroplex. WELCOME to Sugar Creek Gardens Perennial Plant listing. Perennials are our specialty here at Sugar Creek. Perennials are plants that live for more than one year. They die back to the ground in winter, and return in the spring. Adored for their exquisite beauty and fantastic versatility, youll find fascinating black jack najwieksze wygrane for any garden. Many are black jack najwieksze wygrane … Black jack najwieksze wygrane the appropriate time recette roulette sable youll want to learn about cutting back red hot poker plants. For information about exactly when and how to trim a black jack najwieksze wygrane hot ventral slot spinal surgery plant, click on the black jack najwieksze wygrane article. At High Country Gardens we carefully select bordertown casino reno nv plant offerings for hardiness, ease-of-care and beauty. The exclusive plants offered by High Country Gardens have taken years to develop and perfect. If you're not sure which plant will black jack najwieksze wygrane your needs, use our Plant Finder filters or call us at 800-925-9387 for friendly gardening advice. Buy Clematis Seeds. Perennial Black jack najwieksze wygrane with casa casino tulsa 2018 blue, white, or indigo violet flowers. Slot night vampire bonus Plants Roots For Sale. Plant 3 yr Asparagus roots crowns this Black jack najwieksze wygrane and harvest in 3 weeks. Buy Asparagus Globos poker 3 yrs old. Buy the Asparagus Gardener. How To Grow Asparagus. Where to buy Asparagus plants - … Comfry root for sale. Comfrey plant for sale. Where to buy Comfry root. How to plant Comfrey root for sale. Buy Comfrey root for sale on line. Buy Comfry plant from the Asparagus Black jack formel. com How to garden with Comfrey, Comfrey Tea Comfry compost for plant If youre looking for something black jack najwieksze wygrane in the garden or something lucky emperor casino bonus codes attract wildlife friends, then look no further than the red hot poker plant. A brilliant, blazing mix of Torch Lilies-also called Red Hot Pokers-that instantly draws attention wherever you plant it. This mix, created from the Poco Series of torch lilies, includes coral-red, orange and yellow blooms. Monrovia's Flamenco Red Hot Poker details and information. Learn more about Monrovia plants and best practices for best possible plant performance. At The Cajun Connection we have Louisiana Cajun Coffee products for sale, we have Louisiana Cajun spices, Fragrance oil refresher, aquarium plant for sale and much more. Kniphofia uvaria is a species of flowering plant in the family Asphodelaceae, also known as tritomea, torch lily, or red hot poker, due to the shape and color of its inflorescence. The leaves are reminiscent of a lily, and the flowerhead can reach up to 1. 52 m (5. 0 ft) in height. There are many varieties of torch lily, and they bloom at … Dieser Eintrag oder Abschnitt bedarf einer 220;berarbeitung. Hilf bitte mit, ihn zu verbessern, und entferne anschlie223;end diese Markierung. Folgendes ist zu 252;berarbeiten: Das Verzeichnis enth228;lt viele frag- und merkw252;rdige Schreibweisen: Disclaimer: All images were originally found in either public domain, were created by readers of Crystalinks, or were created by the author and … An Eagle A Mans Bile Bats Wings Bears Foot Beggars Buttons Beggars Tick Birds Eye Blood from a Head Blood from a Shoulder Blood Leather Eye in the Sky by The Alan Parsons Project song meaning, lyric interpretation, video and chart position Reel Island is a brand managed by White Hat Gaming Limited on behalf of Caddell Limited N.
Three scattered BONUS symbols … Nineteen thirty-five was only three weeks texas holdem freeware but it already looked to be one of the snowiest years on record. A winter storm had come down from Black jack najwieksze wygrane, dumping a foot of snow on the Northeast before moving out to sea a few days later.
The Syro-Malabar Church was known as the Church of the St. Black jack najwieksze wygrane Christians aachen casino germany the 18th century because it was founded by St Thomas, one of the apostles of Jesus Christ. Welcome to the Queen of the Holy Rosary Website. Our parish and people are so blessed. I invite you to be a part of the spirit of Queen. A spirit whose black jack najwieksze wygrane rests upon faith in Jesus Christ.
This is a list of properties and districts black jack najwieksze wygrane Manhattan from black jack najwieksze wygrane to 59th Streets that are listed on the National Register of Historic Places. Online casino geld verdienen forum by the power of the Holy Spirit black jack najwieksze wygrane us, we strive to renew and enliven our faith while listening and responding to the pagina ganancias jugadores poker needs of our community.
We can help you locate pre-owned: Stern Pinball Stern Pinball, Inc. announced an exciting new pinball machine for black jack najwieksze wygrane and pinball enthusiasts. Team Fortress 2 Update Released May 17, 2018 - TF2 Team. An update to Team Fortress 2 has been released. The update will be applied automatically when you restart Team Fortress 2. Rules amp; Strategy Slots. Machine games such as slots and video poker corey burbick poker perpetually the most heavily trafficked casino casino sanremo poker 2015. In the case of slots, part of reynolds road casino allure is the quest for a handsome jackpot with no more effort involved than simply dropping in a few coins and pulling the handle.
Updated May 21st Holy City Washout Wheat EOBC Face The Sun CTF Distant Fog. Dogfish Head Festina Mesquite blackjack CTF Aveline Westbrook IPL COAST Red Legs Munkle Pout House Belgian PA Welcome to Holy Family Catholic Parish. Thank you for visiting our website All are Welcome. For more information upcoming events, please review our weekly bulletin tab located above or contact the Parish office. Tourism and Aztec dawn slots. pdf - Ebook download as PDF File (.
pdf), Text File (. txt) or read book online. Mildura is a regional city in north-west Victoria, Australia. Located on the Victorian side of the Murray River, Mildura had a population of 33,444 in 2016.
The Moto Guzzi National Owners Club is a friendly group to belong to. Here you will find sociable Guzzi people, great times, and Moto Guzzi Information direct to you from Moto Guzzi enthusiasts World Wide. The most anticipated and sought after activity is back again for D. E Summit. 2018 marks the 8th year for the D. Summit Go-Karting Tournament at Pole Position Raceway on Tuesday February 20, 2018. May 20, 2018 7:00 am. Ariana Grande joins Jimmy and The Roots to perform No Tears Left to Cry with Nintendo Labo instruments. Each instrument is made from only cardboard and a Nintendo Switch and is being played live. Hows your 2018 looking. Not dull, we hope. Were almost halfway through the year, but is your hair able to keep up. 2018 is pretty awesome, especially where hair trends are concerned; its blessed us with all the gorgeous hairstyles well ever need to look fab and pretty all year round. If. Nov 04, 2015nbsp;0183;32;In December 2010-mere days before Christmas-29-year-old Rogerio Damascena and 25-year-old Renata Coelho capped off a three-year courtship with an extravagant wedding in Camaragibe, Brazil. In early January, this column focused on significant changes the Florida Powerboat Club has in store for its 2018 najaieksze. Whatever your opinion of Black jack najwieksze wygrane founder Stu Jones, he deserves credit onde jogar poker em maringa making ajck living-and making a lot wwygrane people happy while driving black jack najwieksze wygrane majwieksze the marine industry wygrrane through his events for almost 30 poker turnering online. 19 Cheap and warm places to go over 2018 Hlack amp; New Najwielsze weeks Recently updated on this page black jack najwieksze wygrane include recent and new information on the Best Toys for 10 year Old Gto poker is to include 5 black jack najwieksze wygrane new items that made the top list, grammar, and updgraded dont try poker on the individual products winstar casino craps table this best list. Big Ideas. Black jack najwieksze wygrane and end each day with inspiring talks nzjwieksze our industry's leading minds, including: Designing Inclusive Products Sara Wachter Boettcher Principal Rare Union. Welcome to Albion casino. com. Omaha is no longer the up and coming poker ajck, it black jack najwieksze wygrane now an epiphone casino unplugged scene on all black jack najwieksze wygrane best poker sites. With more and more players getting fed up with the same old Texas Holdem wygrxne, the popularity of … Taurus (April 20-May 20) So black jack najwieksze wygrane bblack happening in najwleksze sign. (Gasp. ) The Sun is in Taurus, Mercury is in Taurus, the New Moon on Tuesday is in Taurus, and now Uranus is moving into Taurus. There are a huge number of possibilities of how a round of blackjack can unfold. Most players rely on basic strategy when determining how to play their hand. Claudio Castagnoli (born December 27, 1980), better known by his ring name Cesaro (shortened from his previous ring name Antonio Cesaro), is a Swiss professional wrestler who is currently signed to WWE on the SmackDown brand. May 06, 2017nbsp;0183;32;In most of the quot;hard usequot; applications where these two steels are chosen for production knives,quot;all thingsquot; are not equal. Some of the 1095 quot;toughquot; knives are left as soft as 55Rc, whereas A2 tend to be in the quot;58-60quot; range with 60Rc generally considered to be the quot;sweet spotquot; for knife use. www. casinoslotsforsale. com. Get the slots you want today!. Prices listed are for pick up in Tucson, shipping freight charges are extra for out of state orders. About Arlington. Search the largest collection of Arlington obituaries and condolences, hosted by Legacy. com in partnership with funeral homes and newspapers.


text:
Quantifying contact patterns in response to COVID-19 public health measures in Canada
Gabrielle Brankston1,
Eric Merkley2,
David N. Fisman3,
Ashleigh R. Tuite3,
Zvonimir Poljak1,
Peter J. Loewen2 &
Amy L. Greer1,3
BMC Public Health volume 21, Article number: 2040 (2021) Cite this article
A variety of public health measures have been implemented during the COVID-19 pandemic in Canada to reduce contact between individuals. The objective of this study was to provide empirical contact pattern data to evaluate the impact of public health measures, the degree to which social contacts rebounded to normal levels, as well as direct public health efforts toward age- and location-specific settings.
Four population-based cross-sectional surveys were administered to members of a paid panel representative of Canadian adults by age, gender, official language, and region of residence during May (Survey 1), July (Survey 2), September (Survey 3), and December (Survey 4) 2020. A total of 4981 (Survey 1), 2493 (Survey 2), 2495 (Survey 3), and 2491 (Survey 4) respondents provided information about the age and setting for each direct contact made in a 24-h period. Contact matrices were constructed and contacts for those under the age of 18 years imputed. The next generation matrix approach was used to estimate the reproduction number (Rt) for each survey. Respondents with children under 18 years estimated the number of contacts their children made in school and extracurricular settings.
Estimated Rt values were 0.49 (95% CI: 0.29–0.69) for May, 0.48 (95% CI: 0.29–0.68) for July, 1.06 (95% CI: 0.63–1.52) for September, and 0.81 (0.47–1.17) for December. The highest proportion of reported contacts occurred within the home (51.3% in May), in 'other' locations (49.2% in July) and at work (66.3 and 65.4% in September and December). Respondents with children reported an average of 22.7 (95% CI: 21.1–24.3) (September) and 19.0 (95% CI 17.7–20.4) (December) contacts at school per day per child in attendance.
The skewed distribution of reported contacts toward workplace settings in September and December combined with the number of reported school-related contacts suggest that these settings represent important opportunities for transmission emphasizing the need to support and ensure infection control procedures in both workplaces and schools.
In March, 2020, as transmission of SARS-CoV-2, the virus that causes Coronavirus Disease 2019 (COVID-19), was increasing across Canada, provincial and local governments implemented a variety of non-pharmaceutical public health measures [1]. As a main route of transmission of SARS-CoV-2 is close contact with an infected individual [2], these restrictions were implemented to reduce contact between individuals and included a variety of physical distancing measures [1]. Canadian modelling studies have estimated that a 45–60% reduction in direct, close proximity contacts would be sufficient to suppress community transmission, reduce the number of cases of COVID-19, and protect the health care system from becoming overwhelmed [3, 4]. However, these estimates were based on model assumptions regarding expected changes in contact patterns under physical distancing measures during the COVID-19 pandemic.
For directly transmitted respiratory pathogens, transmission opportunities exist anywhere individuals can have direct close proximity contact including households, workplaces, and schools. Quantifying age-specific contact patterns improves our understanding of disease transmission, allows for the estimation of important epidemic parameters such as the reproduction number [5, 6], and provides empirical data for use in mathematical models which typically rely on estimates of contact patterns that have been collected in previous studies [6]. Further, quantifying changes in contact patterns at different time points during a pandemic allows us to evaluate the impact of public health measures, and identify the degree to which contacts have returned to pre-pandemic levels, as well as direct improved public health messaging efforts toward age- and location-specific settings.
The reproduction number is defined as the average number of new cases arising from one existing case [7] and can be estimated from the growth of cases in surveillance data [8, 9] however, due to variations in testing and contact tracing as well as delays in reporting, case counts are not always a reliable indication of transmission. Real-time estimation of the effective reproduction number (Rt) involves examining the ratio of change in the contact matrix from one generation of infection to the next [7]. For respiratory infections that are transmitted by direct contact, we can use survey-derived contact matrices to estimate how changes in contact patterns (where each contact represents an opportunity for transmission) influence the reproduction number [5, 6]. If the average number of opportunities for transmission declines by a certain amount, so should the corresponding value of the reproduction number.
A number of recent studies have examined the effect of physical distancing measures on risk of SARS-CoV-2 transmission using empirically collected social contact data in China [10], Europe [11,12,13] and the United States [14] however, there is currently no such data reported for Canada. The objective of this study is to provide Canadian-specific data to evaluate the impact of physical distancing measures on the transmission of SARS-CoV-2. In doing so, we describe the age-specific contact patterns derived from survey data at four different time points during the COVID-19 pandemic, construct age-specific social contact matrices, and estimate the reproduction number for each time point.
The study protocol was approved by the University of Guelph Research Ethics Board (protocol #20–04-011) and the University of Toronto Research Ethics Board (protocol #38251). The research company, Dynata (https://www.dynata.com), was contracted to conduct four cross-sectional electronic surveys in Canadians over the age of 18 years from May 7–19 (Survey 1), July 17–27 (Survey 2), September 21–October 10 (Survey 3), and December 8–31 (Survey 4). No effort was made to recontact previous respondents for each subsequent survey. A quota sampling design was used to ensure the sample was representative of the Canadian population. Quotas for each survey were set for age, gender, official language and geographic region (i.e., Atlantic, Quebec, Ontario, and West) based on 2016 Canadian Census data [15]. Participants were recruited from a panel of survey respondents and paid a nominal amount for completing the survey. Panelists who logged into their Dynata account during the study period were directed to the survey if they fit the quotas being targeted. Enrollment into the survey within each stratum was on a first-come, first-served basis. Survey responses were excluded from analysis if the survey was completed in less than one-third of the estimated completion time, if the respondent reported their age as less than 18 years, or if the survey was discontinued for exceeding the age, gender, or region quotas. Responses with duplicated entries for gender, age, postal code, date, and contact names were considered duplicate responses and removed from the dataset.
The survey instrument was adapted from the POLYMOD UK [6] and CoMix UK surveys [11]. Respondents provided information about their age, gender, province of residence, and household composition and were then asked to record all direct contacts made between 5 am on the day preceding the survey and 5 am the day of survey completion including members of their household. A direct contact was defined as anyone who was met in person and with whom a short conversation occurred, or anyone with whom the respondent had physical contact [6, 11]. For each contact identified, respondents recorded the age of the contact and the setting in which the contact occurred. The survey instrument is available in the Additional file 1. As the contact diaries excluded people under the age of 18 years and with schools across the country reopening in September 2020, additional questions were added to Surveys 3 and 4. Respondents with children under 18 were asked whether any of the children in their household had attended school, taken the school bus, attended before/after school care, or participated in extracurricular activities in the 7 days prior to survey completion. Respondents were then asked to estimate the number of contacts each of their children had in each of these settings.
Given that schools had reopened, and many people were no longer working remotely by the time Survey 3 was deployed (September, 2020), respondents were also asked to identify whether their occupation required direct contact with more than 20 people during a typical work day. Respondents in these "high contact" occupations were asked to estimate the number of people in each age category with whom they would have contact at work on a typical work day. The number of reported contacts in Surveys 3 and 4 was truncated at 75 per respondent.
Respondents and contacts were categorized into age groups as follows: 18–29 years, 30–39 years, 40–49 years, 50–59 years, 60–69 years, and over 70 years. To ensure the sample was generally representative of the Canadian population, age, gender, region of residence, and household size of survey respondents were compared with the 2016 Canadian Census [16, 17]. Post-stratification weights were then calculated based on age and household size within Canadian region (Atlantic, Quebec, Ontario, West) using data from the 2016 Canadian census [16, 17].
The average number of contacts per respondent was calculated and stratified by age group, gender, household size, region of residence, and whether the contact diary was completed for a weekday or weekend day. The average number of contacts for each survey time period was compared to the POLYMOD UK study [6], which represents pre-pandemic contacts, by calculating the percent reduction from the mean number of contacts reported in POLYMOD.
Contact matrices were constructed for the age-specific mean number of contacts per 24-h period, adjusting for the age distribution in the Canadian population and reciprocity of contacts using the SocialMixr package in R [18]. The 2016 Canadian census was used to correct for the probability of contact within the population [17]. Missing contact age was sampled from other participants' contacts within the same age group.
To provide a full contact matrix with which to estimate Rt, contacts for the 0–4 and 5–17 year age groups were imputed using a scaled version of the POLYMOD UK [6] data by multiplying the number of contacts in corresponding age groups from the POLYMOD UK [6] study by the ratio of the dominant eigenvalues of the POLYMOD UK and the observed matrices for all age groups surveyed in both studies, stratified by location of contact [11, 19]. As schools were closed during the data collection periods in Surveys 1 and 2, school contacts were removed from the POLYMOD UK [6] data for the analysis of these two surveys only.
Proportions were calculated for those who reported that at least one of the children in their household participated in school-based or extracurricular activities. The average number of contacts was calculated per child in different settings per day (school, aftercare, bus) or per week (extracurricular) among respondents reporting participation in these activities. These estimates were not included in the contact matrices.
The next generation matrix approach was used to estimate changes in the reproduction number (Rt) [7]. The reproduction number was estimated by multiplying R0 prior to physical distancing interventions by the ratio of the dominant eigenvalues of the POLYMOD UK [6] and observed contact matrices under the assumptions of the social contact theory that the transmission rate is proportional to rate of social contacts [5, 20]. A meta-analysis reported that, prior to interventions, R0 followed a normal distribution with a mean of 2.6 and standard deviation of 0.54 [11].
To account for sampling variability and assess uncertainty, 10,000 bootstrapped samples were generated from each of the POLYMOD UK [6] and Survey 1–4 contact matrices. The ratio between the dominant eigenvalues were calculated for each bootstrapped sample of the POLYMOD UK [6] and each of the observed matrices providing a distribution of the relative change in Rt from the observed matrices and POLYMOD UK matrices [6]. This distribution was scaled with the distribution of bootstrap samples to estimate Rt under physical distancing measures at each of the four survey time points.
The emergence of SARS-CoV-2 variants with increased transmissibility has the potential to require more stringent public health measures [21]. To assess the theoretical impact of a more transmissible variant of SARS-CoV-2, each of the scaled estimates of Rt were multiplied by a factor of 1.56 to provide a distribution of Rt estimates consistent with a 56% increase in transmissibility [21].
The sensitivity of the estimates of Rt to changes in child-related contacts was assessed using previously published methods [11, 19]. As contact diary data were collected from adults only, there is uncertainty about the average number of child-to-child and child-to-adult contacts under COVID-19 public health measures. To estimate the impact of varying the levels of child-related contacts on the estimates of Rt, the procedure to estimate Rt was repeated for each Survey (1-4) with a reduction of 20, 35, 50, 65, and 80% of contacts from the POLYMOD UK study [6] for the 5–17 year age group.
All data were analysed using RStudio Version 1.2.5033 [22]. The code is based on the SocialMixr package [18] as well as on the work of Jarvis et al. [11]. Funding to support data collection was provided by the Public Health Agency of Canada (PHAC), The National Collaborating Centre for Infectious Diseases (NCCID), and the University of Guelph. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.
We aimed to collect data from 5000 Canadians in Survey 1 (May) and 2500 Canadians in each of Surveys 2–4 (July, September, December). A total of 9120 survey responses were received for Survey 1, 4939 for Survey 2, 5310 for Survey 3, and 9599 for Survey 4. Respondents that completed the entire survey and were not screened out for any reason were included in the final sample resulting in 4981 responses for Survey 1, 2493 responses for Survey 2, 2495 responses for Survey 3, and 2491 responses for Survey 4. A summary of the exclusion process is shown in Additional file 1 Fig. A1.
The proportion of respondents living in each region, the male to female ratio, and the proportion of respondents in each age category were comparable to the 2016 Canadian Census of the population (Additional file 1 Table A1).
Contact patterns
Descriptive statistics of reported contacts are included in Additional file 1 Table A2. Data were analyzed for 11,019 reported contacts in Survey 1, 5608 in Survey 2, 12,289 in Survey 3, and 9703 in Survey 4 with an average number of 2.21, 2.17, 4.76, and 3.89 contacts, respectively (Table 1). These represent average reductions of 79.5, 79.9, 55.9, and 64.0% for Surveys 1, 2, 3, and 4, in the number of contacts compared with pre-pandemic data from POLYMOD UK [6]. The reduction in contacts was consistent across age groups in Surveys 1 and 2 however, the reduction in contacts was lower in younger age groups in Survey 3 and more variable by age in Survey 4.
Table 1 Observed contacts for the COVID-19 Canada and POLYMOD UK [6] surveys
The age-specific contact matrices with imputed data for people younger than 18 years for each time point also reflect these reductions in the average number of contacts (Fig. 1).
Comparison of Survey 1 (May 2020), Survey 2 (July 2020), Survey 3 (September 2020), Survey 4 (December 2020), and POLYMOD UK [6] (pre-pandemic) contact matrices. Contact matrices show the average total number of daily reported contacts by respondents in different age groups with individuals in other age groups. Child-child and child-to-adult contacts were imputed for participant age groups younger than 18 years. The number of contacts in Surveys 3 (September) and 4 (December) were truncated at 75 contacts per respondent. Data were weighted on age and household size. The 2016 Canadian census was used for demographics to correct for probability of contact within the population. Missing contact age was sampled from age-matched participants' contacts
Estimates of Rt
The estimated Rt values were 0.49 (95% Confidence Interval [CI]: 0.29–0.69) for Survey 1 (May), 0.48 (95% CI: 0.29–0.68) for Survey 2 (July), 1.06 (95% CI: 0.63–1.52) for Survey 3 (September), and 0.81 (0.47–1.17) for Survey 4 (December) (Fig. 2). The estimated Rt values based on a theoretical increase in transmissibility due to the emergence of a VOC as the dominant virus strain were 0.76 (95% CI: 0.45–1.08), 0.75 (95% CI: 0.45–1.06), 1.66 (95% CI: 0.98–2.38), and 1.26 (95% CI: 0.74–1.82) for Surveys 1–4.
Estimated distributions of Rt for May, July, September, and December 2020 assuming a baseline normal distribution of Rt with mean = 2.6 and SD = 0.54 prior to physical distancing measures. The dotted line represents a theoretical 56% increase in transmissibility with the variant of concern VOC 202012/01 as the dominant strain [21]
The sensitivity analysis assessing the impact of reducing the number of child-related contacts by each of 20, 35, 50, 65, and 80% compared with the POLYMOD UK study [6] on estimates of Rt resulted in estimates that were similar across the different number of assumed child-related contacts at each time point (Additional file 1 Fig. A2).
The proportion of reported contacts by setting changed over the course of the study (Table 2). Respondents in Survey 1 reported the highest proportion of their contacts to have occurred within their home (51.3%) while those in Survey 2 reported the highest proportion of contacts to have occurred in 'other' locations such as others' homes and community places (49.2%). Respondents in Surveys 3 and 4 reported the majority of contacts having occurred at work (66.3 and 65.4%, respectively). School contacts were largely absent from the data in all waves of the survey because contact diaries were not collected from those under the age of 18 years and most Canadian universities had transitioned to primarily remote learning for the 2020/2021 academic year.
Table 2 Proportion of reported contacts stratified by setting for each survey timepoint
Figure 3 represents the average number of age-specific contacts at each time point stratified by setting in which the contact occurred. Contacts made in the respondents' home, at school (i.e., students), and in other locations are similar across the four surveys. While the average number of workplace contacts were similar in Surveys 1 and 2, reported contacts in the workplace were notably higher in Surveys 3 and 4 (Fig. 3).
Contact matrices for all reported contacts and those stratified by setting in which the contact occurred for each wave of the survey and POLYMOD UK. Age groups younger than 18 years have been removed from the POLYMOD UK matrices to facilitate comparison with the observed matrices. Settings included all contacts, contacts made at home, contacts made in the workplace, contacts made at school, and contacts made everywhere else (including social contacts). The number of contacts in the September and December surveys were truncated at 75 contacts per respondent. Data were weighted on age and household size. The 2016 Canadian census was used for demographics to correct for probability of contact within the population. Missing contact age was sampled from age-matched participants' contacts
A total of 688 (27.6%) respondents in Survey 3 and 640 (25.7%) respondents in Survey 4 reported at least one child under the age of 18 years living in their household. Of these respondents, 66.6% (95% CI: 62.9–70.0) (Survey 3) and 62.0% (95% CI 58.2–65.7) (Survey 4) reported at least one of the children in their household either participated in school-based or extracurricular activities in the 7 days prior to survey completion (Fig. 4A). Respondents reported an average of 22.7 (95% CI: 21.1–24.3) (Survey 3) and 19.0 (95% CI 17.7–20.4) (Survey 4) contacts at school per day per child in attendance. For children participating in extracurricular activities, the average number of contacts reported during these activities was 18.3 (95% CI: 15.2–21.5) per week in Survey 3 and 11.2 (95% CI 8.80–13.6) per week in Survey 4 (Fig. 4B).
A Proportion of respondents with children under the age of 18 years reporting at least one of their children attended an in-person school-based or extracurricular activity in the 7 days prior to survey completion. A total of 688 respondents in Survey 3 (September 2020) and 640 respondents in Survey 4 (December 2020) reported at least one child under the age of 18 years living in their household. B Estimated average number of contacts reported for children under the age of 18 years stratified by activity for respondents with household children who had reported that their children had participated in a school-based or extracurricular activity in the previous 7 days. Estimated contacts were reported per day (school, before/after school care, bus) or per week (extracurricular)
A summary of selected Canadian public health restrictions at each survey timepoint is included in Additional file 1 Table A3 [23]. Briefly, Canadian public health measures were most restrictive in May 2020 with continued closures of schools, universities, indoor dining and recreation. Some daycares and non-essential businesses were just beginning to reopen with limited capacity and private indoor gatherings were limited to 10 or fewer people. With the exception of schools and universities, July 2020 saw relaxing of restrictions and continued reopening of non-essential services. Elementary and secondary schools reopened for in-person learning in September 2020 and most non-essential businesses were able to reopen with some restrictions in place. By December 2020, increasing epidemic growth resulted in increasing regional restrictions and closures of non-essential businesses, indoor dining and recreation as well as a movement to remote learning for elementary and secondary students in some regions.
Consistent with the public health restrictions at each survey time point, this analysis provides evidence that, in May and July (Surveys 1 and 2), Canadians were having few contacts sufficient to maintain the reproduction number well below 1, suppressing community transmission of SARS-CoV-2. The average number of contacts reported by respondents in Survey 3 (September 2020), while still more than 55% lower than those reported in the pre-pandemic POLYMOD UK study [6], had increased sufficiently to raise the reproduction number above 1 supporting a resurgence of cases of COVID-19. The contact patterns reported in Survey 4 (December 2020) likely reflect individual- and public health-level response to the epidemic growth occurring during this time period [24]. The estimated Rt values for the May, July, December surveys were lower than reproduction numbers calculated using reported Canadian case data recognizing the incubation period of the virus and reporting delays [24, 25] suggesting that the POLYMOD study [6] represents an overestimate of the number of pre-pandemic contacts in Canada. Indeed, while there are no published pre-pandemic contact data for Canada, a synthetic pre-pandemic contact matrix for Canada suggests that POLYMOD UK overestimates Canadian pre-pandemic contacts in many age groups [26].
According to recent modelling studies, the reduction in the average number of contacts required to suppress transmission of SARS-CoV-2 ranged from 45 to 60% [3, 4, 27] in comparison with study assumptions alone or with POLYMOD UK data [6], respectively. The current analysis implies epidemic growth was occurring at 55% reduction in contacts, providing empirical evidence that the reduction in contacts required to suppress a resurgence in cases is at the higher end of the spectrum of previously published estimates. Other studies of contact patterns during the COVID-19 pandemic have found that a 62–82% reduction in contacts resulted in Rt values below 1 [11, 14, 28] while others have found that 67–74% reduction in contacts resulted in Rt values greater than 1 [12, 14]. It must be noted that changes in Rt are not solely a result of changes in contact patterns but are also influenced by factors such as travel restrictions, increased use of face masks, and increased distancing when in public places [13].
The emergence of genetic variants of SARS-CoV-2 that are more easily transmitted has the potential to impact our ability to control epidemic growth. The theoretical estimates of Rt based on 56% higher transmissibility of the virus [21] suggest that while control measures resulting in contact patterns seen in Surveys 1 and 2 (May and July) are likely to be enough to suppress transmission, those seen in Surveys 3 and 4 (September and December) are unlikely to be sufficient to maintain R below 1 should these variants become dominant in Canada.
At the time Surveys 1 and 2 were deployed in May and July 2020, public health restrictions were beginning to be lifted and non-essential businesses and workplaces were beginning to open however, schools and daycares remained closed across the country. These restrictions are reflected in the contact matrices and associated Rt values in this analysis demonstrating that physical distancing was similar at the two time points. At the time of Surveys 3 and 4, daycares and schools had also reopened with the associated increase in teachers, bus drivers, and other high contact occupations returning to work. The results of our analysis are consistent with this as the higher number of contacts reported in Surveys 3 and 4 was driven by increases in contacts in the workplace rather than increases in contacts in social and other settings.
Expected increases in school contacts were not captured in this study because of the age range of respondents and the fact that many colleges and universities offered mainly remote learning opportunities at the time of the study. However, the data presented demonstrate that children are having many contacts associated with school-based and extracurricular activities. Given that large proportions of identified SARS-CoV-2 infections in children have been asymptomatic [29], these child-related contacts may represent important and overlooked opportunities for transmission. Whereas private social gatherings often bear the weight of blame for the second wave of COVID-19 cases the findings from this study suggest that contacts made during the course of the work/school day represent important opportunities for transmission. This highlights the importance of developing and enforcing stringent infection prevention and control practices in these settings.
The inherent risk in all surveys of being unrepresentative of the target population may have been amplified by the online nature of the survey which limited participation to those who use the Internet. Self-reporting of behaviours introduced the potential for recall and response bias. Social desirability bias carries with it the risk of underestimating the true number of total contacts as well as contacts in socially undesirable settings. These data provide no information about mitigation measures such as mask use associated with each contact. The results provide evidence that the POLYMOD UK [6] study is an imperfect representation of contact patterns in the Canadian population, however in the absence of published pre-pandemic contact data for Canada, it is a commonly used comparator. Finally, this analysis is based on contacts across Canada and does not account for any geographic variation in the number of contacts across regions potentially masking local differences.
In this paper, we have quantified the effect of reducing social contact numbers on the reproduction number of COVID-19. The skewed distribution of reported contacts toward workplace settings in Surveys 3 and 4 combined with the large numbers of reported school-related contacts provides evidence that these settings represent important opportunities for transmission. While transmission opportunities exist in many different settings, these data emphasize the need to support and ensure evidence-based infection prevention and control procedures in both workplaces and schools.
The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.
Government of Canada. Community-based measures to mitigate the spread of coronavirus disease (COVID-19) in Canada. 2020 [cited 2020 Dec 10]. Available from: https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection/health-professionals/public-health-measures-mitigate-covid-19.html
Chief Science Officer Expert Panel on COVID-19. The Role of Bioaerosols and Indoor Ventilation in COVID-19. Ottawa; 2020. Available from: https://www.ic.gc.ca/eic/site/063.nsf/eng/h_98176.html
Tuite AR, Greer AL, De Keninck S. Risk for COVID-19 resurgence related to duration and effectiveness of physical distancing in Ontario, Canada. Ann Intern Med. 2020;172(1):ITC1–14. https://doi.org/10.7326/M20-2945.
Anderson SC, Edwards AM, Yerlanov M, Mulberry N, Stockdale JE, Iyaniwura SA, et al. Quantifying the impact of COVID-19 control measures using a Bayesian model of physical distancing. PLoS Comput Biol. 2020;16(12):e1008274. https://doi.org/10.1371/journal.pcbi.1008274.
Wallinga J, Teunis P, Kretzschmar M. Using data on social contacts to estimate age-specific transmission parameters for respiratory-spread infectious agents. Am J Epidemiol. 2006;164(10):936–44. https://doi.org/10.1093/aje/kwj317.
Mossong J, Hens N, Jit M, Beutels P, Auranen K, Mikolajczyk R, et al. Social contacts and mixing patterns relevant to the spread of infectious diseases. PLOS Med. 2008;5(3):e74. Available from. https://doi.org/10.1371/journal.pmed.0050074.
Diekmann O, Heesterbeek JAP, Roberts MG. The construction of next-generation matrices for compartmental epidemic models. J R Soc Interface. 2010;7(47):873–85. https://doi.org/10.1098/rsif.2009.0386.
Heffernan JM, Smith RJ, Wahl LM. Perspectives on the basic reproductive ratio. J R Soc Interface. 2005;2(4):281–93. https://doi.org/10.1098/rsif.2005.0042.
Alessandro Annunziatio, Tommi Asikainen, Effective Reproduction Number Estimation from Data Series, EUR 30300 EN, Publications Office of the European Union, Luxembourg. 2020. https://doi.org/10.2760/036156.
Zhang J, Litvinova M, Liang Y, Wang Y, Wang W, Zhao S, et al. Changes in contact patterns shape the dynamics of the COVID-19 outbreak in China. Science (80- ). 2020;368(6498):1481–6.
Jarvis CI, Van Zandvoort K, Gimma A, Prem K, Auzenbergs M, O'Reilly K, et al. Quantifying the impact of physical distance measures on the transmission of COVID-19 in the UK. BMC Med. 2020;18(1):124. https://doi.org/10.1186/s12916-020-01597-8.
Coletti P, Wambua J, Gimma A, Willem L, Vercruysse S, Vanhoutte B, Jarvis CI, Van Zandvoort K, Edmunds J, Beutels P, Hens N. CoMix: comparing mixing patterns in the Belgian population during and after lockdown. Sci Rep. 2020;10(1):21885. https://doi.org/10.1038/s41598-020-78540-7.
Del Fava E, Cimentada J, Perrotta D, Grow A, Rampazzo F, Gil-Clavel S, Zagheni E. Differential impact of physical distancing strategies on social contacts relevant for the spread of SARS-CoV-2: evidence from a cross-national online survey, March-April 2020. BMJ Open. 2021;11(10):e050651. https://doi.org/10.1136/bmjopen-2021-050651.
Feehan DM, Mahmud AS. Quantifying population contact patterns in the United States during the COVID-19 pandemic. Nat Commun. 2021;12(1):893. https://doi.org/10.1038/s41467-021-20990-2.
Statistics Canada. Age (in Single Years) and Average Age (127) and Sex (3) for the Population of Canada, Provinces and Territories, Census Divisions, Census Subdivisions and Dissemination Areas, 2016 Census - 100% Data (table). Census. Statistics Canada Catalogue no. 98–400. Ottawa; 2016. Available from: https://www150.statcan.gc.ca/n1/en/catalogue/98-400-X2016003
Statistics Canada. Census. Families, households, and marital status. Statistics (Canada catalogue no. 98-316-X2016001). Ottawa; 2016, 2017. [cited 2020 Nov 23]. Available from: https://www12.statcan.gc.ca/census-recensement/2016/dp-pd/prof/index.cfm?Lang=E
Statistics Canada. 2016 Census. Age (in Single Years) and Average Age (127) and Sex (3) for the Population of Canada, Provinces and Territories, Census Metropolitan Areas and Census Agglomerations, 2016 and 2011 Censuses. (Catalogue no. 98–400-X2016001). Ottawa; 2017. [cited 2020 Nov 19]. Available from: https://www12.statcan.gc.ca/census-recensement/2016/dp-pd/dt-td/Rp-eng.cfm?TABID=2&LANG=E&A=R&APATH=3&DETAIL=0&DIM=0&FL=A&FREE=0&GC=10&GL=-1&GID=1235626&GK=1&GRP=1&O=D&PID=109523&PRID=10&PTYPE=109445&S=0&SHOWALL=0&SUB=0&Temporal=2016&THEME=115&VID=0&VNAME
Funk S. socialmixr: Social Mixing Matrices for Infectious Disease Modelling. R package version 0.1.6; 2020.
Klepac P, Kucharski AJ, Conlan AJK, Kissler S, Tang M, Fry H, et al. Contacts in context: large-scale setting-specific social mixing matrices from the BBC Pandemic project. medRxiv. 2020; Available from: http://medrxiv.org/content/early/2020/02/19/2020.02.16.20023754.abstract.
Hens N, Wallinga J. Design and Analysis of Social Contact Surveys Relevant for the Spread of Infectious Diseases. In: Wiley StatsRef: Statistics Reference Online. American Cancer Society; 2019. p. 1–15. Available from: https://onlinelibrary.wiley.com/doi/abs/10.1002/9781118445112.stat07883.
Davies NG, Abbott S, Barnard RC, Jarvis CI, Kucharski AJ, Munday JD, Pearson CAB, Russell TW, Tully DC, Washburne AD, Wenseleers T, Gimma A, Waites W, Wong KLM, van Zandvoort K, Silverman JD; CMMID COVID-19 Working Group; COVID-19 Genomics UK (COG-UK) Consortium, Diaz-Ordaz K, Keogh R, Eggo RM, Funk S, Jit M, Atkins KE, Edmunds WJ. Estimated transmissibility and impact of SARS-CoV-2 lineage B.1.1.7 in England. Science. 2021;372(6538):eabg3055. https://doi.org/10.1126/science.abg3055.
RStudio Team. RStudio: Integrated Development for R. RStudio, PBC. Boston, MA. 2020. http://www.rstudio.com/.
Canadian Institute for Health Information. COVID-19 Intervention Timeline in Canada — Data Tables. Ottawa; 2021.
Public Health Agency of Canada. Update on COVID-19 in Canada: Epidemiology and Modelling. 2020. Available from: https://www.cihi.ca/en/covid-19-intervention-timeline-in-canada.
Public Health Agency of Canada/National Microbiology Lab. COVID-19: PHAC modelling group report February 25, 2021. 2021.
Prem K, Cook AR, Jit M. Projecting social contact matrices in 152 countries using contact surveys and demographic data. PLoS Comput Biol. 2017;13(9):1–21. Available from:. https://doi.org/10.1371/journal.pcbi.1005697.
Tuite AR, Fisman DN, Greer AL. Mathematical modelling of COVID-19 transmission and mitigation strategies in the population of Ontario, Canada. CMAJ. 2020;192(19):E497-E505. https://doi.org/10.1503/cmaj.200476.
Backer JA, Mollema L, Vos RAE, Klinkenberg D, van der Klis FRM, de Melker HE, et al. The impact of physical distancing measures against COVID-19 transmission on contacts and mixing patterns in the Netherlands: repeated cross-sectional surveys in 2016/2017, April 2020 and June 2020. Eurosurveillance. 2021;26(8) Available from: http://medrxiv.org/content/early/2020/10/16/2020.05.18.20101501.abstract.
King JA, Whitten TA, Bakal JA, McAlister FA. Symptoms associated with a positive result for a swab for SARS-CoV-2 infection among children in Alberta. Can Med Assoc J. 2021;193(1):E1 LP–E9 Available from: http://www.cmaj.ca/content/193/1/E1.abstract.
We thank J. Lau for support in programming the survey.
GB and AG are supported by the Canada Research Chairs program. DN and AT are supported by the Canadian Institutes for Health Research (CIHR). ZP is supported by the Natural Sciences and Engineering Research Council (NSERC). EM and PL are supported by Heritage Canada and the Social Sciences and Humanities Research Council (SSHRC). Funding to support data collection was provided by the Public Health Agency of Canada (PHAC), The National Collaborating Centre for Infectious Diseases (NCCID), and the University of Guelph. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.
Department of Population Medicine, University of Guelph, Guelph, Canada
Gabrielle Brankston, Zvonimir Poljak & Amy L. Greer
Munk School of Global Affairs & Public Policy, University of Toronto, Toronto, Canada
Eric Merkley & Peter J. Loewen
Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
David N. Fisman, Ashleigh R. Tuite & Amy L. Greer
Gabrielle Brankston
Eric Merkley
David N. Fisman
Ashleigh R. Tuite
Zvonimir Poljak
Peter J. Loewen
Amy L. Greer
All authors (GB, EM, DF, AT, ZP, PL, and AG) contributed to the study conception and design. Survey design and data collection were performed by GB, AG, PL, and EM. Data analysis was conducted by GB. The first draft of the manuscript was written by GB and all co-authors (EM, DF, AT, ZP, PL, and AG) commented on previous versions of the manuscript. GB, EM, DF, AT, ZP, PL, and AG read and approved the final manuscript. The author(s) read and approved the final manuscript.
Correspondence to Amy L. Greer.
The study protocol was approved by the University of Guelph Research Ethics Board (protocol #20–04-011) and the University of Toronto Research Ethics Board (protocol #38251). All methods were performed in accordance with the relevant guidelines and regulations. Informed consent was obtained prior to survey completion by providing information about the study, ensuring anonymity and confidentiality, and providing the process to withdraw from the survey. Respondents provided informed consent after reading the study information by choosing to continue to the survey questions.
12889_2021_12080_MOESM1_ESM.docx
Brankston, G., Merkley, E., Fisman, D.N. et al. Quantifying contact patterns in response to COVID-19 public health measures in Canada. BMC Public Health 21, 2040 (2021). https://doi.org/10.1186/s12889-021-12080-1

redpajama_set_name: RedPajamaCommonCrawl


"A kilencedik megállóban szállunk le a vonatról."
Translation:We get off the train at the ninth stop.
ninth stop was rejected. I believe it should be accepted.
We don't generally use "from" in this case of de-boarding a mode of transportation.
-------- yes, we usually use off . from is considered slightly uneducated . . .


As a legislator, I will form alliances to fight for expanding Medicaid as a minimum step toward increased access to healthcare. However, my goal is the expansion and improvement of Medicare, as a universal, single-payer system. With its structure already established and accepted, Medicare is the least costly form of medical insurance (at only 3% overhead) and provides the most seamless transition to single-payer universal coverage. I will fight for healthcare as a right not a privilege. Healthcare is about respect for our neighbors but it is also about building a strong economy with a reliable and vigorous workforce. Decisions regarding the details of care should be made by Texans seeking care in consultation with their physicians, NOT by politicians and CEOs.
A true leader needs to show compassion to all of his/her constituents regardless of party affiliation, gender, income, race, and all other things that make us different externally. Mr. Abbot's refusal to accept Medicaid funds associated with ACA is a clear judgement on who "deserves" good healthcare. His lack of empathy towards women's health shows that he's unable to understand our needs and serve ALL Texans. His decisions are based on partisan politics and not on the well-being of Texans. Access to good healthcare should not even be up for debate and as your Representative in House District 93, I will fight for our right for affordable healthcare and work hard to ensure that we meet the basic healthcare needs of ALL Texans. I will work with local providers and the medical community to figure out new ways for all people to get access to low cost cancer screenings, reproductive services, and other healthcare necessities. I consider it my duty to serve and ensure that both men and women have access to good and affordable healthcare because when people are healthy, they'll be at their best and will be able to focus on being productive and better able to contribute to our community.