A VERY UP-TO-DATE STAGE IN THE FATE OF IN FECTIOUS-DISEASES, PARASITIC AND FUNGAL OPPORTUNISTIC

Opportunistic parasitosis and mycosis are becoming ever more widesprea d, mainly under the influence of major immunodeficiencies, either acqu ired (AIDS) or therapeutic. In this general overview, their main aspec ts, both clinical and epidemiological, are underlined. In terms of epi demiology, three types of phenomena have been observed : 1) emergence of human parasitosis unknown before (microsporidiosis due to Enterocyt ozoon bieneusi. Encephalitozoon hellem or Septata intestinalis); 2) am ong the human parasites already known, identification of very pathogen ic strains (Toxoplasma gondii, Aspergillus fumigatus. Cryptococcus neo formans); 3) origin probably or certainly nosocomial of certain infect ions (pneumocystosis; toxoplasmosis and visceral leishmaniasis transmi tted during bone-marrow or organ transplantations). The development of deep mycosis (invasive aspergillosis) is particulary promoted by gran ulopenia and alterations in the phagocytosis. On the other hand, oppor tunistic protozoosis (toxoplasmosis and leishmaniasis) and helminthias is (strongyloidosis due to Strongyloides stercolaris) are related, abo ve all, to disorders in cellular immunity (deficit of CD4+, mainly). F inally, several of these infections may be characterised by a variety of clinical pictures and outcome, depending on the contributory factor s (immunodeficit or not) which led to the development of the infection .