Parasites of Laboratory Animals Transmissible to Man

Abstract

SUMMARYAn assessment is made of the hazards to man from parasites of laboratory animals. The chief danger arises from gastrointestinal helminths and protozoa of primates and tapeworms of rodents and prevention of infection depends on the adoption of normal hygienic measures for disposal of the faeces and bedding of experimental animals. Simian malaria constitutes a possible danger in those parts of the world where suitable vectors exist and in these areas the screening of animal houses against mosquitoes is necessary. Many ectoparasites of laboratory animals are capable of establishing themselves on human beings but their tenure is usually short. Infestation of man can be prevented only by control of the ectoparasites in the laboratory animals and this is desirable for the welfare of the animals themselves. The possibility of human infection with the parasites of laboratory animals can be greatly reduced by a period of quarantine immediately following arrival, during which examination is made for the presence of parasites and appropriate treatment given to remove any found to be pres~nt.A survey carried out at 5000 laboratories in the United States by Sulkin & Pike (1951) revealed 1342 infections that had been acquired in the laboratory but circumstances connected with the survey suggest that only part of the total was revealed. Thirty-nine were parasitic infections, the rest being bacterial, viral or rickettsial in origin.Of the parasitic infections, 18 were amoebiasis; none of these could be definitely proved to have been acquired in the laboratory, although 11 were probably, and seven were possibly, acquired there. There were nine cases of malaria of which four were definitely acquired in the laboratory, three probably and two possibly.The other 12 cases were caused by various helminths and protozoa.Four of these cases were definitely of laboratory origin, four of probable laboratory origin and four were possibly acquired there. Thirty-seven of the total occurred in trained scientific personnel.Nine bf these were the result of accidents, of which the most common was the bite of an animal or ectoparasite, five were acquired by contact with infected animals or ectoparasites, 17 from clinical specimens, six by working with the agent, one by airborne infection and the final case was of unknown origin. The number of parasitic infections known to have been acquired in the laboratory is small and few, if any, have been acquired from laboratory at SAGE