The baseline characteristics and interim analyses of the high-risk sentinel cohort of the Vietnam Initiative on Zoonotic InfectiONS (VIZIONS).

Juan Carrique-Mas ,Karen Saylors,Dinh V Tan,Heiman Wertheim,Juliet E Bryant,Pham V Lao,Hoang Van V Duong,Mark Woolhouse,Guy Thwaites,Maia A Rabaa,Stephen Baker,Behzad Nadjm,Nguyen Canh Tu ,Trần Khánh Toàn ,Nguyễn Thị Kim Chúc ,Vo Be Hien ,Nguyen Khac Chuyen ,Ngô Thị Hoa ,Nguyen T.y ,Ngo Tri Tue ,Navarro-Zambrana An ,James I Campbell ,Nguyễn Văn Cường

doi:10.1038/srep17965

Abstract

The Vietnam Initiative for Zoonotic Infections (VIZIONS) includes community-based ‘high-risk sentinel cohort’ (HRSC) studies investigating individuals at risk of zoonotic infection due to occupational or residential exposure to animals. A total of 852 HRSC members were recruited between March 2013 and August 2014 from three provinces (Ha Noi, Dak Lak, and Dong Thap). The most numerous group (72.8%) corresponded to individuals living on farms, followed by slaughterers (16.3%) and animal health workers (8.5%). Nasal/pharyngeal and rectal swabs were collected from HRSC members at recruitment and after notifying illness. Exposure to exotic animals (including wild pigs, porcupine, monkey, civet, bamboo rat and bat) was highest for the Dak Lak cohort (53.7%), followed by Ha Noi (13.7%) and Dong Thap (4.0%). A total of 26.8% of individuals reported consumption of raw blood over the previous year; 33.6% slaughterers reported no use of protective equipment at work. Over 686 person-years of observation, 213 episodes of suspect infectious disease were notified, equivalent of 0.35 reports per person-year. Responsive samples were collected from animals in the farm cohort. There was noticeable time and space clustering of disease episodes suggesting that the VIZIONS set up is also suitable for the formal epidemiological investigation of disease outbreaks.

Highlights

Southeast Asia is considered a ‘hotspot’ for emerging infectious diseases
There were two categories of high-risk sentinel cohort’ (HRSC) members represented in only one province each: restaurant workers of restaurants specialized in exotic animal meat (n = 15, Ha Noi) and rat traders (n = 5, Dong Thap)
Interviews for baseline questionnaire were conducted on 420 individuals (128, 162 and 130 from Ha Noi, Dak Lak, and Dong Thap, respectively) since only the head of the household was interviewed on farms

Summary

Introduction

Southeast Asia is considered a ‘hotspot’ for emerging infectious diseases. Over recent years this region (including southeast China) has witnessed the emergence of major outbreaks of severe zoonotic disease such as SARS, nipah virus and avian influenza[1,2]. Epicentre of highly pathogenic avian influenza (HPAI)[4] The reasons for this high incidence of emerging zoonoses in southeast Asia are complex, and likely to include multiple demographic, geographical, climatic, economic and cultural factors as well as agricultural practices that create an environment conducive to the emergence and propagation of zoonotic diseases[5]. The community component, termed ‘a high-risk sentinel cohort’ (HRSC), focuses on individuals perceived to be at high risk of infection with zoonotic pathogens because of their occupational or residential exposure[6]. These cohorts include people living on farms (including farms raising non-domestic or ‘exotic species’ – termed ‘exotic animal farms’), slaughterers (pigs and poultry), animal health workers, restaurant workers and rat traders. The aims of this report are: (a) To describe the methodologies used for recruitment of HRSC members and associated data collection; (b) to describe the demographic characteristics and high-risk exposures (i.e. contact with animals, slaughtering and consumption) among the HRSC members across the three provinces; and (c) to provide a current update report on the episodes of clinical disease reported

Objectives

Methods

Results

Conclusion