Serologic and behavioral risk survey of workers with wildlife contact in China

Abstract

We report on a study conducted in Guangdong Province, China, to characterize behaviors and perceptions associated with transmission of pathogens with pandemic potential in highly exposed human populations at the animal-human interface. A risk factor/exposure survey was administered to individuals with high levels of exposure to wildlife. Serological testing was performed to evaluate prior infection with several wildlife viral pathogens. Follow up serology was performed on a subset of the cohort as well as close contacts of individuals. 1,312 individuals were enrolled in the study. Contact with a wide range of wildlife species was reported in both occupational and occasional contexts. The overall proportion of individuals seropositive to any of the tested wildlife pathogens was approximately 4.0%. However, persons employed as butchers demonstrated a seropositivity of 9.0% to at least one pathogen of interest. By contrast, individuals working as hunters had lower rates of seropositivity. Among the study population, a number of other behaviors showed correlation with seropositivity, including contact with particular wildlife species such as field rats. These results demonstrate the need to further explore zoonotic risks of particular activities regarding wildlife contact, and to better understand risks of persons working as butchers with wildlife species.

Fig 1. Prefecture maps of Guangdong Province, China.

A) 1,267 participants were enrolled at Dabu, Jiaoling, Pingyuan, Lianping, Heping, Lianshan, Lianzhou, Yunfu, Yunan, Xinyi, Deqing and Fengkai (areas colored black). Number of respondents at each prefecture is bracketed; (B) In the brackets, in total 43 (left) seropositive respondents and 45 (right) close contacts of theirs were enrolled in the follow-up phase at Xinyi, Yunan, Fengkai, Lianshan, Lianzhou, Pingyuan, Jiaoling and Dabu (areas colored black). Together, 88 individuals participated in the follow up phase.

Fig 2. Flow diagram of recruitment and enrollment.

12 prefectures were selected after primary investigation by visiting over 20 prefectures. Totally 1,267 individuals were enrolled, and serological tests and behavioral interviews were conducted. In the follow up study, 43 respondents showing seropositive results to SARS virus, hantavirus, and/or bunyavirus in the enrollment phase and 45 of their close contacts were enrolled. Additionally, 52 respondents showing indeterminate or positive results were excluded in the follow up study since they moved to other locations between the two study phases. Another round of serological analysis and behavioral investigation were conducted to 88 respondents in the follow up study.