Risk for allergic and non-allergic health problems. The Veterinary Health Study- Part I

Veterinarians are potentially exposed to a range of animal-related allergens.
Few studies looked at allergies among veterinarians but prevalence rates
ranging from 17 to 66% for self-reported atopic and allergic diseases have been
described. More studies assessed the prevalence of allergies in laboratory
animal workers and demonstrated prevalence rates of animal-related allergies
from 11 to 44%. Increasing exposure intensity to laboratory animals is
associated with an increased likelihood of IgE-mediated sensitisation and
prolonged exposure resulted in allergy, accelerated lung function decline and
irreversible respiratory disease. Laboratory animal workers that develop
allergies to one animal species are at risk of developing allergy to other
species as well.
Besides exposure to allergens, veterinarians have an increased exposure to
infectious agents like zoonoses (e.g. mycosis, brucellosis, psittacosis) and
other non-direct pathogenic microbial bio-aerosols. Reported prevalence rates
of zoonotic diseases in veterinarians range between 4 to 17%. A Dutch survey
among veterinarians showed that the mean dust and endotoxin exposure was high
in swine, poultry and cattle practitioners and relatively low in companion
animal practitioners.
The prevalence of allergic and non-allergic diseases occurring during
veterinary study, when first exposure takes place, is not known. A study in
animal-health technology apprentices starting exposure to laboratory animals
showed an incidence of 8.9% of work-related sensitisation and an incidence of
occupational asthma of 2.7%. Sensitisation, symptoms and disease occurred in
the first 2 to 3 years after exposure to laboratory animals began and
predictors of sensitisation were atopy, nasal and respiratory symptoms in the
pollen season and number of contact hours with rodents.

The main aim of this study is to assess the prevalence of allergic and
non-allergic health problems in veterinary students in different phases of the
veterinary education. On later stage, genetic predisposition for allergies will
be studied. In the light of the GABRIEL study, a multidisciplinary study to
identify the genetic and environmental causes of asthma in the European
Community, DNA will be analyzed for asthma specific genetic polymorphism.

An epidemiological cross-sectional study will invite all veterinary students
(n=1500) to fill out a standardized health questionnaire and a single blood
draw. Blood will be analysed on atopic status by IgE and IgG4 serology to a
range of common and veterinary-specific allergens. Past and present zoonotic
infections will be determined by IgG serology. Leucocytes of participants will
be isolated and stored to allow genotyping of innate immunity pathways such as
polymorphisms in toll-like receptors, CD14, CR3 and Myd88. Leucocytes of
participants will be stored to allow genotyping of innate immunity in a later
stage and analyze asthma specific genetic polymorphisms in the light of the
GABRIEL study.

Study participation by completing the questionnaire and giving blood once is
unlikely to be associated with significant health risks and will cause no
significant burden.