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TOXOPLASMA GONDII
Author(s) -
HENRIQUE CARNEIRO,
DE OLIVEIRA,
Helene Santos Barbosa,
Maria Ignez,
minha esposa,
Angélica B. Carneiro,
meu sogro George
Publication year - 1962
Publication title -
medical journal of australia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 131
eISSN - 1326-5377
pISSN - 0025-729X
DOI - 10.5694/j.1326-5377.1962.tb27011.x
Subject(s) - citation , toxoplasma gondii , computer science , information retrieval , world wide web , medicine , immunology , antibody
IN general, the more intimate the host-parasite relationship, the more highly specific is the parasite in the choice of its host. The causative organism of toxoplasmosis is a complete exception to this, as to many other generalizations. For Toxoplasma gondii, an obligatory intracellular parasite, is in many ways a remarkable organism. It is the only species in its genus, and the only organisms which can be regarded as being in any way closely related to it are a few obscure protozoon parasites which systematists have classified as a separate group within the class Sporozoa. It is one of the most successful parasites known; it is extremely well adjusted to a parasitic life, because for the most part it multiplies within its host without causing any noticeable disturbance to the host organism; it parasitizes an astonishingly wide range of hosts, it occurs commonly in many of them, and it is of almost world-wide distribution. (So far as we know it has not yet been recorded from Antarctica, but that may well be because no one has yet looked for it in the native inhabitants of that region.) Though Toxoplasma gondii was described over 50 years ago, and a good deal was found out about its occurrence in animals, it was not until 1939 that it was definitely recognized as a parasite of man, in the first instance as the cause of a severe and frequently lethal infection acquired in utero. During the next 10 years the true epidemiological picture was filled out, and it was gradually realized that infection with T. gondii was an extremely common and usually symptomless state of a1fairs, but that on rare occasions it could be the cause of acute illness in all age groups. Serological surveys commonly show a steadily rising incidence of positive results from childhood up to the fifth or sixth decade, though, strangely enough, the way in which the infection is transmitted still evades detection. The principal Australian surveys are those of Alison Garven,' who examined 1000 specimens of serum from persons of various ages in Melbourne and Sydney, and found an incidence of positive results rising to 34% among those aged 50 years and over, and of Ian Cook," who found a positive incidence of 27% among Queenslanders of European origin over 15 years of age.