GENETICS, METABOLISM AND HOST-SPECIFICITY OF PNEUMOCYSTIS-CARINII

Pneumocystis carinii is a major cause of severe pneumonia in immunosup pressed individuals, especially in those with human immunodeficiency v irus (HIV) infection during their period of progression to acquired im munodeficiency syndrome (AIDS), and constitutes a worldwide problem to public health. Recently, significant advances in the development of e xperimental animal models of P. carinii infection, as well as in our k nowledge of the genetic diversity and taxonomy of P. carinii, have bee n made. These advances may contribute to our understanding of the tran smission of P. carinii pneumonia (PCP) and to the development of new p revention and control strategies. This paper addresses questions relat ing to the epidemiology of PCP including the detection of the parasite in the environment and in patients, the mechanism of genetic variatio n of the major surface glycoprotein (MSG) of P. carinii, and host-rela ted genetic variation among isolates of this organism, emphasizing phe notypic expression and its impact on epidemiology and taxonomy.