Occupational Exposure to Animals and Risk of Zoonotic Illness in a Cohort of Farmers, Farmworkers, and Their Families in England.* Daniel Rh. Thomas, Principal Scientist, Communicable Disease Surveillance Centre (CDSC) Wales, Abton House, Wedal Rd., Cardiff, Wales, UK CF4 3QX, phone 029-20521-997, fax 029-20521-987, e-mail daniel.Thomas@phls.wales.nhs.uk; Roland L. Salmon, Consultant Epidemiologist, CDSC Wales, Cardiff, Wales, UK; Tim J. Coleman, Director, Public Health Laboratory, Hereford, UK; Peter Morgan-Capner, Director, PHLS North West, Preston, Lancashire, UK; Margaret Sillis, Consultant Clinical Scientist, Public Health Laboratory, Norwich, UK; E. Owen Caul, Deputy Director, Public Health Laboratory, Bristol, UK; Kenton L. Morgan, Professor of Veterinary Epidemiology, University of Liverpool, UK; Giles A. Paiba, Veterinary Research Officer, University of Bristol, UK; Malcolm Bennett, Reader, University of Liverpool, UK; C. Donald Ribeiro, Consultant Microbiologist, Public Health Laboratory, Cardiff, UK; Graham Lloyd, Head of Viral Diagnosis, Centre for Applied Microbiology and Research, Potion Down, UK; Susan M. Kench, Research Assistant, Public Health Laboratory, Hereford, UK; Diane Meadows, Research Nurse, Public Health Laboratory, Preston, UK; Pamela Softley, Research Assistant, Public Health Laboratory, Norwich, UK; and Rachel M. Chalmers, Senior Scientist, CDSC Wales, Cardiff, Wales, UK.
We recruited a representative population-based sample of 606 farmers, farmworkers, and their families from three areas of England. By defining and measuring animal exposure (type, frequency, and species range) we were able not only to measure the incidence and prevalence of markers of exposure to zoonotic organisms in this sentinel group, but also to determine the risk of exposure to zoonotic organisms associated with a variety of defined occupational exposures. Prevalence of antibodies to Coxiella burnetii (the cause of Q fever) (29.2%) and toxoplasma (50.2%) were high; whereas, prevalence of antibodies to Borrelia burgdorferi (the cause of Lyme disease) (0.2%), leptospira (0.2%), and brucella (0.7%) were low. The cohort was also exposed to hantavirus (seroprevalence 4.7%), orthopoxvirus (0.7%), parapoxvirus (4.5%), Bartonella spp. (2.0%) Ehrlichia chaffeensis (0.2%), human granulocytic ehrlichiosis agent (l.5%), and Echinococcus granulosis 3/202 (1.5%). Coxiella seropositivity was associated with exposure to dairy cattle (odds ratio: 1.48, 95% confidence interval: 1.03-2.12); cowpox with exposure to rats (odds ratio: 18.7, 95% confidence interval: 1.7-201.8). Self reported clinical orf (contagious pustular dermatitis) was associated with exposure to sheep (risk ratio: 7.64, 95% confidence interval: 1.93-30.26) and rats (risk ratio 4.54, 95% confidence interval: 1.16-17.70); ringworm (dermatophytosis) with cattle (risk ratio: 1.76; 95% confidence interval: 1.17-2.64).
*Presented, in part, at the Fourth International Symposium "Rural Health and Safety in a Changing World" held October 18-22, 1998, in Saskatoon, Saskatchewan, Canada.