title: Campylobacter immunity and coinfection following a large outbreak in a farming community.
abstract: An outbreak of campylobacteriosis affected approximately one-half of 165 people attending an annual farmers' dance in Montrose, Scotland, in November 2005. Epidemiological investigations, including a cohort study (n = 164), identified chicken liver paté as the most likely vehicle of infection. Paté preparation involved deliberate undercooking of chicken livers by flash-frying, followed by mechanical homogenization. Typing of 32 Campylobacter strains (isolated from submitted stools) by multilocus sequence typing identified four distinct clades of Campylobacter jejuni. There was good agreement when isolates were typed by Penner serotyping, pulsed-field gel electrophoresis, and flaA short variable region sequencing but poorer agreement with phage and antibiotic susceptibility testing. At least three attendees were coinfected with two Campylobacter strains each. The outbreak was probably due to several livers contributing Campylobacter strains that survived undercooking and were dispersed throughout the paté. The study highlights improper culinary procedures as a potential human health risk and provides a striking counterexample to the "dominant outbreak strain" view of point source outbreaks of food-borne infections. It also demonstrates that previous exposure to biologically plausible sources of Campylobacter may confer protection against subsequent infection.
authors.affiliation: Department of Medical Microbiology, School of Medicine, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom.
authors.forename: K J
authors.initials: KJ
authors.lastname: Forbes
authors.forename: F J
authors.initials: FJ
authors.lastname: Gormley
authors.forename: J F
authors.initials: JF
authors.lastname: Dallas
authors.forename: O
authors.initials: O
authors.lastname: Labovitiadi
authors.forename: M
authors.initials: M
authors.lastname: MacRae
authors.forename: R J
authors.initials: RJ
authors.lastname: Owen
authors.forename: J
authors.initials: J
authors.lastname: Richardson
authors.forename: N J C
authors.initials: NJ
authors.lastname: Strachan
authors.forename: J M
authors.initials: JM
authors.lastname: Cowden
authors.forename: I D
authors.initials: ID
authors.lastname: Ogden
authors.forename: C C
authors.initials: CC
authors.lastname: McGuigan
mesh_terms: D015373:Bacterial Typing Techniques; D001434:Bacteriophage Typing; D002169:Campylobacter Infections / Q000453:epidemiology* / Q000276:immunology* / Q000382:microbiology; D016123:Campylobacter jejuni / Q000145:classification / Q000276:immunology* / Q000302:isolation & purification*; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005243:Feces / Q000382:microbiology; D005408:Flagellin / Q000235:genetics; D005838:Genotype; D006801:Humans; D008461:Meat Products / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D012606:Scotland / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D012703:Serotyping
chemical_list: D004269:DNA, Bacterial; D005408:Flagellin; C067138:flaA protein, bacteria