title: Dog-associated risk factors for human plague.
abstract: Plague is a rare but often fatal zoonosis endemic to the western United States. Previous studies have identified contact with pets as a potential risk factor for infection. We conducted a matched case-control study to better define the risks associated with pets at both the household and individual levels. Using a written questionnaire, we surveyed nine surviving plague patients, 12 household members of these patients, and 30 age- and neighbourhood-matched controls about household and individual exposures. Overall, 79% of households had at least one dog, 59% had at least one cat and 33% used flea control, with no significant differences between case and control households. Four (44%) case households reported having a sick dog versus no (0%) control households [matched odds ratio, (mOR) 18.5, 95% confidence interval (CI) 2.3-infinity], and four (44%) patients reported sleeping in the same bed with a pet dog versus three (10%) controls (mOR 5.7, 95% CI 1.0-31.6). Within case households with multiple members, two (40%) of five patients slept with their dogs versus none (0%) of 12 healthy family members (P=0.13). The exposures to cats were not significant. Sleeping in the same bed as a pet dog remained significantly associated with infection in a multivariate logistic regression model (P=0.046). Our findings suggest that dogs may facilitate the transfer of fleas into the home and that activities with close extended contacts with dogs may increase the risk of plague infection.
authors.affiliation: Division of Vector-Borne Infectious Diseases, Centers for Disease Control and Prevention, Bacterial Diseases Branch, Fort Collins, CO, USA. lgould@cdc.gov
authors.forename: L Hannah
authors.initials: LH
authors.lastname: Gould
authors.forename: J
authors.initials: J
authors.lastname: Pape
authors.forename: P
authors.initials: P
authors.lastname: Ettestad
authors.forename: K S
authors.initials: KS
authors.lastname: Griffith
authors.forename: P S
authors.initials: PS
authors.lastname: Mead
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000822:Animal Husbandry / Q000379:methods; D000818:Animals; D016022:Case-Control Studies; D002648:Child; D004283:Dog Diseases / Q000635:transmission*; D004285:Dogs; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000382:microbiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010930:Plague / Q000635:transmission* / Q000662:veterinary*; D012307:Risk Factors; D005423:Siphonaptera / Q000382:microbiology*; D015010:Yersinia pestis / Q000302:isolation & purification; D015047:Zoonoses