Coxiella burnetiiSeroprevalence and Risk for Humans on Dairy Cattle Farms, the Netherlands, 2010–2011

B Schimmer,J.L.A Hautvast,E Van Engelen,N Schotten,Y.T.H.P Van Duijnhoven,P.M Schneeberger

doi:10.3201/eid2003.131111

Abstract

Q fever, caused by Coxiella burnetii, is a recognized occupational infection in persons who have regular contact with ruminants. We determined C. burnetii seroprevalence in residents living or working on dairy cattle farms with >50 adult cows and identified risk factors for seropositivity. Serum samples from farm residents, including employees, were tested for C. burnetii IgG and IgM; seroprevalence was 72.1% overall and 87.2%, 54.5%, and 44.2% among farmers, spouses, and children, respectively. Risk factors included farm location in southern region, larger herd size, farm employment, birds in stable, contact with pigs, and indirect contact with rats or mice. Protective factors included automatic milking of cows and fully compliant use of gloves during and around calving. We recommend strengthening general biosecurity measures, such as consistent use of personal protective equipment (e.g., boots, clothing, gloves) by farm staff and avoidance of birds and vermin in stables.

Highlights

Qfever, caused by Coxiella burnetii, is a recognized occupational infection in persons who have regular contact with ruminants
In 2009–2010, a program was implemented to cull pregnant dairy goats and sheep on farms with C. burnetii–positive animals identified through a national bulk tank milk (BTM) screening [4]
Compared with nonparticipating farms, participating farms were a median of 1.5 km closer to small ruminant farms with C. burnetii–positive BTM samples (Table 1)

Summary

Introduction

Qfever, caused by Coxiella burnetii, is a recognized occupational infection in persons who have regular contact with ruminants. We determined C. burnetii seroprevalence in residents living or working on dairy cattle farms with >50 adult cows and identified risk factors for seropositivity. C. burnetii seroprevalence estimates for dairy cattle farm residents in the Netherlands are outdated, and risk factors associated with seropositivity are seldom studied. This lack of data inhibits accurate assessment of the public health risk. To inform control measures and provide advice for persons living/working on a dairy cattle farm (DCF), we conducted a cross-sectional study to investigate the seroprevalence of C. burnetii antibodies in DCF residents/ workers and identified participant-based and farm-based risk factors for seropositivity. The study was approved by the Medical Ethics Committee of the University Medical Centre Utrecht (no. 09–189/K)

Methods

Results

Conclusion