HUMAN PROTOTHECOSIS AND ENVIRONMENT

Protothecosis are uncommon infections caused by Prototheca, considered to be achlorophylous algae. Nearly 80 human cases are reported in the literature since the first case described by Davies and Wakelin in 19 64 in Sierra Leone (11). The disease have been identified in Europe, A sia (Japan, Thailand, China), Oceania and in the United States with 40 cases, particularly in the Southeast. Clinically, three clinical mani festations can be observed: 1) cutaneous lesions: papules, plaques or eczematoid, papulo-nodular areas of the extremities, 2) olecranon burs itis which occurred in 25% of cases, 3) systemic protothecosis. An imm unosuppressive factor local or general can be found in half of the cas es and the first description of algal meningitis was reported in a pat ient with AIDS in association with Cryptococcus neoformans. Because th e disease is clinically not suspected, the diagnosis is often provided by histology showing a dermic granuloma with endospores. The caracter istic feature of protothecosis in tissues is the presence of specific mature sporangia of Prototheca wickerhamii with the pattern of morula. The organism was PAS, Grocott and mucicarmin positive. The ecology wa s studied by Clark (7), Pidoux (23), Pore (25) and Sudman (27). Protot heca are ubiquitous inhabitants of sewages and are found in slime flux and animal wastes contaminating different aquatic systems. The transm ission generally occurred by traumatic inoculation. Prototheca are als o found in the digestive system of man and animals without never invas ion of the epithelium and mucosae in experimental models. The pathogen icity and virulence are moderate and they are considered as rare oppor tunistic agents.