Results of FilmArray® Gastro-intestinal Panel and Serum Procalcitonin in Acute Colitis and Infectious Diarrhea in the ER
Results of FilmArray® Gastro-intestinal Panel and Serum Procalcitonin in Acute Colitis and Infectious Diarrhea in the ER
Acute diarrhea and acute colitis of infectious origin are common reasons for consultation at
 the emergency department. The current etiological diagnostic approach is limited to the
 determination of markers of inflammation, such as CRP and blood leukocytes, which lack
 specificity and sensitivity for bacterial infection. The stool culture can detect bacterial
 pathogens in the stool with a result at least 48 hours later and a positivity rate <50%.

 This study will describe the procalcitonin (PCT) concentrations (a biomarker of bacterial
 infection) in this population to evaluate its usefulness depending on the viral or bacterial
 etiology identified by stool multiplex gastro-intestinal PCR panel (GI panel) and stool
 culture.

 The investigators hypothesize that PCT levels will be higher if the GI panel or the stool
 culture identifies a bacteria or a parasite, as it is the case in respiratory tract
 infections. If there is a detection of a virus by the GI panel or both the stool culture and
 the GI panel are negative, the investigators expect that PCT values will be lower or
 negative.

 the investigators will include the patients admitted to the ED with a suspicion of infectious
 diarrhea or acute colitis in order to have a large representative panel of infectious
 diarrhea etiologies.

 Only the patients having a blood sample prescribed as the routine care will be included. The
 blood sample is useful for dosing CRP and whole blood cell count (WBC), which are part of
 current biologic analyses performed in this context. After getting the patient's consent, the
 investigator will add the PCT dosage in blood sampling and will ask the patient to provide a
 stool sample, in order to have a stool culture and to perform an extended investigation for
 the pathogens through multiplex PCR technology (Filmarray ®GI panel).

 The physician will be asked if all these results (the ones ordered currently together with
 the dosage of PCT and the GI panel) will change his/her decision to start an antibiotic.

 Patients will receive a phone call at day 15 after their initial admission in the emergency
 department and will be asked if he/she has consulted a new physician or if a new treatment by
 antibiotics was started.

 Data collection procedures: Data from the medical file will be collected by the investigators
 and the emergency department clinical research assistant. All the data will be pseudonymized.
 The collection will be done at the day of admission in the emergency department and after the
 phone interview at Day15.
Acute diarrhea and acute colitis of infectious origin are common reasons for consultation at
 the emergency department. The current etiological diagnostic approach is limited to the
 determination of markers of inflammation, such as CRP and blood leukocytes, which lack
 specificity and sensitivity for bacterial infection. The stool culture can detect bacterial
 pathogens in the stool with a result at least 48 hours later and a positivity rate <50%.

 This study will describe the procalcitonin (PCT) concentrations (a biomarker of bacterial
 infection) in this population to evaluate its usefulness depending on the viral or bacterial
 etiology identified by stool multiplex gastro-intestinal PCR panel (GI panel) and stool
 culture.

 The investigators hypothesize that PCT levels will be higher if the GI panel or the stool
 culture identifies a bacteria or a parasite, as it is the case in respiratory tract
 infections. If there is a detection of a virus by the GI panel or both the stool culture and
 the GI panel are negative, the investigators expect that PCT values will be lower or
 negative.

 The investigators will include the patients admitted to the ED with a suspicion of infectious
 diarrhea or acute colitis in order to have a large representative panel of infectious
 diarrhea etiologies.

 Only the patients having a blood sample prescribed as the routine care will be included. The
 blood sample is useful for dosing CRP and whole blood cell count (WBC), which are part of
 current biologic analyses performed in this context. After getting the patient's consent, the
 investigator will add the PCT dosage in blood sampling and will ask the patient to provide a
 stool sample, in order to have a stool culture and to perform an extended investigation for
 the pathogens through multiplex PCR technology (Filmarray ®GI panel).

 The physician will be asked if all these results (the ones ordered currently together with
 the dosage of PCT and the GI panel) will change his/her decision to start an antibiotic.

 Patients will receive a phone call at day 15 after their initial admission in the emergency
 department and will be asked if he/she has consulted a new physician or if a new treatment by
 antibiotics was started.

 Data collection procedures: Data from the medical file will be collected by the investigators
 and the emergency department clinical research assistant. All the data will be pseudonymized.
 The collection will be done at the day of admission in the emergency department and after the
 phone interview at Day15.

 Statistical justification for sample size: This will be a pilot study to describe the results
 of PCT concentration and multiplex GI panel. As to our knowledge, there is no published study
 reporting PCT concentrations in this population. This preclude a sample, size calculation.
 The investigators will include as much patients as possible during one year in order to cover
 the epidemiological seasonal variations and to obtain a convenient sample of at least 100
 patients.

 Statistical methods description: Clinical and biological data will be reported as median and
 interquartile range or mean +/- SD. PCT values will be reported as median and IQR,
 respectively if a there is a viral infection, a documented infection (bacterium or parasite)
 or no pathogen identified by GI panel and/or stool culture (bacteria). Patient's
 characteristics and PCT results will be compared in all groups, using as a reference, the
 group where no pathogen is observed. A sub-group analysis will be performed on colitis and
 acute diarrhea respectively, to find out if there is any difference with the variables
 analyzed as both pathologies are not managed in the same way.
Inclusion Criteria:

 Inclusion criteria for patients presenting an acute diarrhoea :

 1. Patients over 18 years of age,

 2. Signed informed consent form

 3. Having a social security insurance,

 4. Attending the emergency department for Acute diarrhoea (at least three loose or liquid
 stools a day for less than 15 days)

 5. For whom a blood test in the emergency department is ordered as a standard of care

 Inclusion criteria for patients presenting an infectious colitis :

 1. Patients over 18 years of age,

 2. Signed informed consent form

 3. Having a social security insurance,

 4. Attending the emergency department for a documented colitis presumed to be of
 infectious origin, for whom a blood test in the emergency department is planned,
 defined by:

 1. at least one of the following symptoms: abdominal pain, fever, diarrhoea and

 2. Elevated white blood cell count (> 10.000/mm3) or CRP (> 10 mg/l) and

 3. An abdominal CT scan showing a thickening of at least segmental colonic walls.

 Exclusion Criteria:

 1. Recent abdominal surgery of less than one month

 2. Pregnancy

 3. Inflammatory bowel disease

 4. Patients under curatorship or guardianship