[Toxoplasmosis. A common infection, not very often recognized clinically]

Epidemiological survey and microscopical diagnosis point out that toxoplasmosis is a cosmopolitan infection usually with percentages of positivity higher than 20 per cent. Even in places with prosperous economical conditions the human infections can be relatively high due to the habit of eating raw meat or not properly exposed to temperatures lethal to Toxoplasma gondii. But sometimes they can be explained by cultural patterns or to individual psicological factors in relation to cats, the definitive hosts and important sources of parasites. It is explained how to infections occur and terms are defined. Even now in some circumstances the source of infection is not known. A discussion is presented on the diagnosis. The taxonomy of the parasite is presented in brief.