title: A windy day in a sheep saleyard: an outbreak of Q fever in rural South Australia.
abstract: In December 2004, the Department of Human Services investigated an outbreak of Q fever in South Australia. A case-control study tested an association between attending a local saleyard and human illness. A case was defined as a person with clinical illness and evidence of seroconversion or high phase II IgM. Controls were selected from a database of community controls matched on sex, age group and postcode. Matched analysis of the first 15 cases with 45 controls indicated that contracting Q fever was associated with attending the saleyard on one particular day (adjusted odds ratio 15·3, 95% confidence interval 1·7-undefined, P = 0·014). Saleyard conditions were windy and conducive for airborne dispersal of contaminated particles. In total, 25 cases were detected. Of these, 22 cases had attended a local saleyard on the same day. This outbreak suggests cases were probably infected by a single exposure at a saleyard from infected sheep and dust. The investigation resulted in an increase in the local uptake of Q fever vaccination and extension of the Australian national vaccination programme.
authors.affiliation: National Centre for Epidemiology and Population Health,Australian National University,Canberra,Australia.
authors.forename: B A
authors.initials: BA
authors.lastname: O'Connor
authors.affiliation: Communicable Disease Control Branch, Department of Human Services,South Australia,Australia.
authors.forename: I G
authors.initials: IG
authors.lastname: Tribe
authors.affiliation: Communicable Disease Control Branch, Department of Human Services,South Australia,Australia.
authors.forename: R
authors.initials: R
authors.lastname: Givney
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000822:Animal Husbandry; D000818:Animals; D016022:Case-Control Studies; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D004391:Dust; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D011778:Q Fever / Q000453:epidemiology*; D012424:Rural Population; D012756:Sheep; D012988:Soil Microbiology; D013021:South Australia / Q000453:epidemiology; D014919:Wind; D055815:Young Adult
chemical_list: D004391:Dust