Endemic Pneumocystis Carinii Pneumonia

The entity of interstitial plasma cell pneumonia due to Pneumocystis carinii has received increasing attention during the past 10 years. Extensive studies and reviews concerning this problem, its epidemiology and pathogenesis (Ahvenainen, 1957; Bachmann, 1954; Cahalane, 1962; Jirovec, 1 960a and b; Muller and Vietor, 1957), its clinical course and picture (Berdnikoff, 1959; Dvorak and Jirovec, 1953; Gajdusek, 1957; Gerrard, 1958; Holland and Ward, 1962; White, Saxton and Dawson, 1961) as well as the radiological features (Falkenbach, Bachmann and O'Loughlin, 1961; Feinberg, Lester and Burke, 1961; White et al., 1961) have been published. The pathological and morphological changes are equally well defined by a thickening of the alveolar septa due to a plasmacellular infiltration as well as by a specific proteinrich exudate containing small foamy vacuoles with the protozoal bodies (Le Tan Vinh, Vialatte, Pellerin and Sinna, 1960; Vanek and Jirovec, 1952; Stopka, Wunderlich and Carlson, 1957). These parasites hiave also been found in reticuloendothelial cells outside the lung (Zandanell, 1954). Histochemical studies (Ricken, 1958; Opferkuch and Ricken, 1959; Opferkuch, 1959; Nitschke and Heyn, 1960), ultra-thin sections (Timmel, 1960), and studies with the electron miscroscope (Pliess and Seifert, 1959; Timmel, 1960; Bommer, 1961) have confirmed the protozoal character of the parasite. Although there were doubts whether Pneumocystis carinii was the aetiological agent in plasmacellular pneumonia, it now seems well accepted that it does cause this disease in debilitated children and occasionally in debilitated adults (Jirovec, 1959; Rubin and Zak, 1960; White et al., 1961). Primary cases in adults have been reported (Kaftori, Bassan, Gellei and1 Griffel, 1962; Lyons, Vinijchaikul and Hennigar, 1961). Pneumocystis was first seen by