Epidemiology of zoonoses in slaughterhouse workers in western Kenya
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Date
29/06/2015Author
Cook, Elizabeth Anne Jessie
Metadata
Abstract
Slaughterhouses are places where animals are slaughtered for food. In developing
countries a lack of appropriate facilities and limited resources mean the slaughter
industry is poorly regulated. Poor hygiene practices in slaughterhouses can result in
the transmission of diseases from animals to people called zoonoses. Slaughterhouse
workers are generally considered at increased risk of being exposed to such diseases
due to their close contact with animals and animal products.
The aims of this study were: to assess the current conditions in slaughterhouses and
the knowledge, attitudes and practices of workers in ruminant and pig
slaughterhouses in western Kenya; to determine the exposure of slaughterhouse
workers to different zoonotic pathogens; to investigate the risk factors associated
with exposure to these pathogens and to quantify the risk of zoonotic disease
exposure for slaughterhouse workers compared to the general population.
Slaughterhouses in western Kenya were visited between May 2011 and October
2012. Seven hundred and thirty-eight workers were recruited from 142
slaughterhouses. Overall, the slaughterhouses lacked facilities, with 65% (95% CI
63–67%) of slaughterhouses having a roof, cement floor and solid sides, 60% (95%
CI 57–62%) had a toilet and 20% (95% CI 18–22%) hand-washing facilities. Less
than half of workers 32% (95% CI 29–34%) wore personal protective clothing.
Antemortem inspection was practiced at 7% (95% CI 6–8%) of slaughterhouses and
18% (95% CI 16–19%) of workers reported slaughtering sick animals.
Slaughterhouse workers were screened for five zoonotic diseases. The unadjusted
seroprevalence of the zoonotic diseases were: brucellosis 0.1% (95% CI 0.007–
0.8%); leptospirosis 13.4% (95% CI 11.1–16.1%); Q fever 4.5% (95% CI 3.2–6.2%);
Rift Valley fever (RVF) 1.2% (95% CI 0.6–2.3%); taeniasis 1.8% (95% CI 1.0–
3.0%); and cysticercosis 2.6% (95% CI 1.7–4.0%).
Risk factors for leptospirosis and Q fever were examined by multivariable logistic
regression. Risk factors associated with leptospirosis seropositivity included: having
wounds (OR 2.7; 95% CI 1.4–5.3); smoking at work (OR 1.8; 95% CI 1.1–3.0);
eating at work (OR 2.1; 95% CI 1.2–3.6); and cleaning the intestines (OR 3.8; 95%
CI 1.8–8.2). Protective factors were: working at a slaughterhouse where antemortem
inspection was performed (OR 0.6; 95% CI 0.4–0.9). The risk factors significantly
associated with Q fever seropositivity included: being intoxicated at work (OR 3.2;
95% CI 1.1–9.4).
The odds ratio for leptospirosis seropositivity in slaughterhouse workers was
determined to be 2.3 (95% CI 1.6–3.4) times that of the community. For Q fever the
odds ratio for seropositivity in slaughterhouse workers was 1.9 (95% CI 1.0–3.8)
times that of the community.
This is the first report of a range of zoonotic pathogens in slaughterhouse workers in
Kenya. This study indicated the potential risk factors for zoonotic disease exposure
in slaughterhouses. The current working conditions in slaughterhouses in western
Kenya are far below the recommended standard. Improvements need to be made to
facilities and practices in all slaughterhouses. Training is recommended to improve
awareness for workers, managers and inspectors of the risks of zoonotic disease
exposure and methods to reduce it.