Surveillance for outbreaks of gastroenteritis in long-term care facilities, Australia, 2002-2008.
BACKGROUND
Each year in Australia, health departments investigate hundreds of gastroenteritis outbreaks. Long-term care facilities (LTCFs) for elderly persons are a common setting for these outbreaks and can result in potentially serious outcomes.


METHODS
We established surveillance for gastroenteritis outbreaks in 2001, and analyzed data on outbreaks occurring from 1 July 2002 through 30 June 2008 to estimate the incidence in Australian LTCFs and residents. We summarized outbreaks by mode of transmission and etiological agent. We used negative binomial regression to examine variation in the number of fecal specimens collected in outbreaks-a marker of investigation intensity.


RESULTS
During surveillance, 3257 (52%) of 6295 outbreaks of gastroenteritis and foodborne disease in Australia were reported in LTCFs. These outbreaks affected 84,769 people, with 1577 people hospitalized and 209 deaths. There were 0.19 (95% confidence interval, 0.14-0.26) residents affected per 1000 bed days and 16.8 (95% confidence interval, 12.4-22.7) outbreaks per 100 LTCFs annually. LTCF outbreaks were most commonly transmitted from person to person. Only 43 (1.3% ) of 3257 outbreaks were foodborne, although 47 (6.4%) of 733 residents were hospitalized and 20 (2.7%) of 733 died. Norovirus was responsible for 1136 (35%) of all 3257 outbreaks. Higher numbers of fecal specimens per outbreak were collected in 4 Australian States, in later years of surveillance, and where the etiology was identified.


CONCLUSIONS
Norovirus outbreaks spread from person to person are common in LTCFs, although clinicians should be alert for foodborne outbreaks with more serious consequences. There is a need to identify effective infection control measures to assist facilities in managing outbreaks of gastroenteritis.
Kirk
Martyn D
MD
Australian Government Department of Health and Ageing, National Centre for Epidemiology and Population Health, The Australian National University, OzFoodNet, Canberra, Australia. martyn.kirk@anu.edu.au
Fullerton
Kathleen E
KE
Hall
Gillian V
GV
Gregory
Joy
J
Stafford
Russell
R
Veitch
Mark G
MG
Becker
Niels
N
D001315:Australia / Q000453:epidemiology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission / Q000821:virology; D004196:Disease Outbreaks; D005517:Foodborne Diseases / Q000453:epidemiology / Q000382:microbiology / Q000821:virology; D005759:Gastroenteritis / Q000453:epidemiology* / Q000382:microbiology / Q000821:virology; D006801:Humans; D015994:Incidence; D008134:Long-Term Care; D029322:Norovirus / Q000302:isolation & purification