You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
infection reported to the new south wales health department identified a probable s. enterica var .
java outbreak in a single local government area ( population 57,000 ) , and an investigation was initiated .
we defined a case - patient as a person reported to health authorities during 20072009 who had had diarrhea for at least 24 hours , either lived in or had visited the local government area during the 7 days before the onset of diarrhea , and had provided a fecal sample from which s. enterica var .
seventy - five case - patients were identified : ages ranged from 1 month through 60 years ( median age 2 years , 10 months . ) ; 34 were female .
all isolates were sensitive to ampicillin , streptomycin , tetracycline , chloramphenicol , sulfathiazole , and spectinomycin .
results of phage typing by using standard techniques ( 7 ) were available for 74 isolates ; 54 were classified as phage type dundee , 19 as a uniform 
reactions do not conform ,  which closely resembled dundee , and 1 as untypeable .
seventy - two isolates underwent multilocus variable number tandem repeat analysis ( mlva ) typing ( 8) ; 69 were classified as 1-(12 - 17)-0 - 0 - 493 and 3 as distinctly different types .
this mlva type was unique to case - patients from this outbreak ; it was not seen in isolates from other parts of new south wales .
after an extensive investigation involving case - patient interviews and food and environmental sampling during 2007 and early 2008 , exposure to playground sand at public parks and childcare centers was identified as the likely immediate source of the outbreak .
java was isolated from 50 of 207 sand samples taken from 39 locations ; no other salmonella serotypes were detected .
all 19 playgrounds with sandboxes from within the local government area were sampled , regardless of whether they were linked to case - patients .
all 35 playground isolates came from 6 playgrounds that had received sand from a central depot within the past 12 months .
were isolated from surface and deep ( as far as 50 cm below the surface ) sand samples . despite multiple samples being taken
antimicrobial drug sensitivity testing , phage typing , and mlva typing of isolates produced results indistinguishable from those of the outbreak strain .
one contaminated playground was closed to human access , left undisturbed , and sequentially sampled every 3 months .
nine months passed before all samples taken from this playground were clear of the bacterium . to confirm the hypothesis that sand from playgrounds contaminated with s. enterica var .
java was the immediate source of the outbreak , we performed an age - matched case  control study of case - patients 1 month to 4 years of age involving 16 case - patients and 32 controls during may 2008 .
exposure to playgrounds with contaminated sand within 7 days of symptom onset was associated with illness ( matched odds ratio 3.7 , 95% ci 1.112.1 ) . in may 2008 ,
a substantial reduction in the number of case - patients reported occurred ( figure 1 ) , although new case - patients continued to be reported throughout the study period .
number of cases of salmonella enterica variant java infection and month of onset in children playing in sandboxes , australia , 20072009 . to better characterize the distribution of the bacterium in the local ecosystems
, we collected fecal and cloacal samples from 261 free - ranging animals of various species ( table ) .
java were identified : most were from a marsupial species native to the local area , the long - nosed bandicoot , perameles nasuta ( figure 2 ) .
the australian registry of wildlife health had no recorded evidence of disease associated with the isolation of s. enterica var .
java from long - nosed bandicoots ( k. rose , taronga conservation society australia , pers . comm . ) . * with the exceptions of samples from 1 bandicoot that reacted but did not conform ( pt rdnc / a001 ) , and 1 dog that was not tested , all phage types were dundee .
long - nosed bandicoot ( perameles nasuta ) . photograph courtesy of taronga zoo , sydney , new south wales , australia .
java from playground sand with the same phage type , mlva pattern , and antibiogram as that of human isolates supported the hypothesis that ingestion of sand from playgrounds was the human exposure pathway for this outbreak . the case  control study found an association between infection in humans and exposure to at least 1 playground where an s. enterica var .
java isolate was found in the sand ; these findings confirmed sand as the immediate source of infection .
although sand from the central depot was a common factor in all contaminated playgrounds where case - patients contracted the illness , the infection source for this facility remains unknown .
it was located in a wild bushland setting , and it is feasible that transmission of the bacterium from local wildlife occurred .
native animals and wildlife have been implicated in previous community - wide outbreaks of salmonellosis ( 9,10 ) . the isolation of s. enterica var .
java of common phage and mlva types from human , animal , and environmental samples implies that the organism can survive within multiple ecosystems .
the organism probably has multiple transmission pathways , involving interactions among humans , animals , and the environment .
the persistence of the bacterium in playground sand for up to 9 months demonstrates that the organism can survive for a relatively long period in this environment and might provide information about the natural history of the bacterium and how it can infect humans .
java with the outbreak phage type and mlva typing in cloacal swab specimens from 31% of native long - nosed bandicoots sampled ( table ) ; illness in the animals was not apparent .
it is unclear whether the bacterium has a predilection for this species or whether the bandicoot exhibits a particular behavior that predisposes it to being colonized .
the study identifies accidental sand ingestion as a previously unrecognized pathway for humans acquiring illness caused by s. enterica var .
java and provides further evidence for the need to manage this medium in playgrounds to protect public health . the emergence of human disease caused by s. enterica var .
java from this environmental source and the local colonization of wildlife with the same bacterium highlights the consequences of the interface between human and wildlife health .
further research and a more extensive systematic sampling program that includes the local government area that was the focus of this study are required to better understand the ecology of s. enterica var .
ultimate control of the outbreak might require a strategy that involves altering human behavior , the environment , and wildlife habitat .
a community outbreak of gastroenteritis in australia during 20072009 was caused by ingestion of playground sand contaminated with salmonella enterica paratyphi b , variant java . 
 the bacterium was also isolated from local wildlife . 
 findings support consideration of nonfood sources during salmonellosis outbreak investigations and indicate transmission through the animal  human interface .