Gm. Liss et al., OCCUPATIONAL EXPOSURE TO MYCOBACTERIUM-BOVIS INFECTION IN DEER AND ELK IN ONTARIO, Canadian journal of public health, 85(5), 1994, pp. 326-329
In late 1991, two herds of deer and elk were depopulated at a slaughte
ring plant in Ontario, followed by processing of infected animals at a
rendering plant. We conducted a questionnaire plus tuberculin skin-te
st survey of 104 exposed slaughtering and rendering plant workers, and
government veterinarians and inspectors. Overall, 17 participants wer
e skin-test positive; one of 51 initially skin-test negative subjects
tested a second time three months later became positive, consistent wi
th the risk associated with occupational exposure during the depopulat
ion of tuberculous elk previously observed in Alberta. Deer farming is
widespread, with 263 herds in Ontario. The likely route of transmissi
on is through aerosols. Possible reasons for the low conversion rate i
nclude the use of respiratory protection, absence of a tanning plant,
an enclosed rendering plant process, and late skin testing which may h
ave underestimated the number of conversions. Recommendations for prev
ention are summarized; in particular, respiratory protection for work
with infected herds should probably include high efficiency particulat
e face masks.