title: Elucidating the aetiology of human Campylobacter coli infections.
abstract: There has been little research on the determinants of Campylobacter coli infection, despite its contributing up to 10% of human Campylobacter infections. A case-control and two case-case study methods explored the aetiology of C. coli over a one year period across Scotland. The case-control multivariate model found an increased risk of C. coli infection in people older than 19 years (O.R. = 3.352), and during the summer months (O.R. = 2.596), while residing in an urban area decreased the risk (O.R. = 0.546). The first case-case study compared C. coli and C. jejuni cases and also showed a higher risk of C. coli during the summer (O.R. = 1.313) and in people older than 19 years (O.R. = 0.791). Living in an urban area was associated with a reduced risk of infection (O.R. = 0.769). Multi-locus sequence typing (MLST) indicated that sheep and chicken C. coli sequence types (STs) were most frequently found in humans whilst those from cattle and pigs were rarer. MLST diversity was high in isolates from pigs and chicken, intermediate in human isolates, and low in ruminant isolates. The second case-case study used MLST data to ascribe putative sources of infection to the cases. The putative source for 40% of cases was chicken, with 60% acquired from other sources (ruminants 54% and pigs 6%). The case-case analysis also showed that female gender was a risk factor (O.R. = 1.940), which may be explained by females being more likely to prepare poultry in the home. These findings indicate differences between the aetiology of C. coli and C. jejuni infections: this should be taken into account by public health professionals when developing strategies to reduce the burden of human campylobacteriosis.
authors.affiliation: School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom.
authors.forename: Francois
authors.initials: F
authors.lastname: Roux
authors.forename: Emma
authors.initials: E
authors.lastname: Sproston
authors.forename: Ovidiu
authors.initials: O
authors.lastname: Rotariu
authors.forename: Marion
authors.initials: M
authors.lastname: Macrae
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Sheppard
authors.forename: Paul
authors.initials: P
authors.lastname: Bessell
authors.forename: Alison
authors.initials: A
authors.lastname: Smith-Palmer
authors.forename: John
authors.initials: J
authors.lastname: Cowden
authors.forename: Martin C J
authors.initials: MC
authors.lastname: Maiden
authors.forename: Ken J
authors.initials: KJ
authors.lastname: Forbes
authors.forename: Norval J C
authors.initials: NJ
authors.lastname: Strachan
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000818:Animals; D002169:Campylobacter Infections / Q000382:microbiology*; D017000:Campylobacter coli / Q000145:classification / Q000235:genetics / Q000502:physiology*; D016123:Campylobacter jejuni / Q000145:classification / Q000235:genetics / Q000502:physiology*; D016022:Case-Control Studies; D002645:Chickens; D002648:Child; D002675:Child, Preschool; D005260:Female; D054884:Host-Pathogen Interactions; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D058885:Multilocus Sequence Typing / Q000379:methods*; D012307:Risk Factors; D012606:Scotland; D012621:Seasons; D013045:Species Specificity; D055815:Young Adult