Toxoplasma gondii and Coxiella burneti antibodies among Brazilian slaughterhouse employees.

Previous studies have indicated toxoplasmosis and Q fever are potential hazards to persons who handle raw meat or who work in slaughterhouses. The prevalence of antibodies to T. gondii and C. burneti was studied among 144 employees of an abattoir in Belo Horizonte, Brazil, to determine what environmental factors may be associated with the occurrence of these agents among persons who handle meat but who have not reported having toxoplasmosis or Q fever. Seventy-two per cent of the 144 employees were serologically positive to T. gondii and 29% were serologically positive for C. burneti. The highest prevalence of antibodies to T. gondii (92%) occurred among meat inspectors, who also had a geometric mean titer (GMT) of 1400. The prevalence levels of antibodies to T. gondii for employees who handled meat in the deboning and sausage departments were 80% and 79% with GMT's of 412 and 340, respectively. These levels exceeded the antibody prevalences of 60% and 65% and GMT's of 168 and 120 for employees who worked with cattle in the corrals or who worked on the killing floor, respectively. Conversely, the prevalence of antibodies to C. burneti was highest (40%) among employees working in the corrals and who were exposed to dust and hides. A similar prevalence of antibodies to C. burneti was found in employees on the killing floor (36% positive) who were exposed to hides and viscera, but employees handling meat in the deboning or sausage section had prevalence levels of 20% and 14% respectively. Serologic testing of zebu cattle processed at the abattoir indicated that 10% of 124 tested had antibodies to T. gondii and 29% of 156 tested had antibodies to C. burneti. These levels in cattle are probably adequate to expose (and infect) persons who process meat daily. Continuous daily exposures to chronically infected cattle may result in sporadic undiagnosed illnesses or seroconversions from subclinical infections.