Dr. Holló Ferenc szerk.: Parasitologia Hungarica 3. (Budapest, 1970)
discrepancy between the prevalence of the infection and that of the disease, the role of the immunological state of the host is emphasised even by those who consider this protozoon pathogenic in man, A number of aspects of Toxoplasma infection can be elucidated by knowledge of some relevant epidemiological parameters, such as: environment, time relations, personal features (MacMAHON et al., I960). Surveys in different countries have revealed varying degress of prevalence ranging from 0 (Alaska) to 96 # (Guatemala). Prevalence in our country is slight. (However, it must be borne in mind that conclusions reached by comparing results of various countries are only approximate owing to the diverse diagnostic tests employed. Por instance, age groups of population are of basic importance because of the significant difference in prevalence at different ages. (Two inferences are, however, reasonable. Toxoplasma infection is more common in countries with a hot or à warm and humid climate than in those with a cold or a warm but dry one (WRIGHT, 1957; HARTLEY, 1966). There is evidence also to suggest that the higher an area above sea level the lower is the prevalence (GIBSON and COLEMAN , 1958; WALTON et al., 1966; WALLS and KAGAN, 1967). The incident among rural inhabitants does not exceed that among town dwellers as one would expect in the case of a zooanthroponosis . This is explicable both by increased urbanization in this century (migration mainly within the country) and by pet-keeping fashion in towns (as observed also in the present study). We are not aware of any particular influence of a „time" factor in the epidemiology of toxoplasmosis at present. It is true, nevertheless, that such a possibility was raised by ROBERTSON (i960) who observed an extreme accumulation of connatal toxoplasmosis in Lincolnshire (England) during a period of 3 years. A characteristic seasonal increase of toxoplasmosis in animals has been reported also (HARTLEY, 1966).
