The clinical epidemiology of pulmonary cryptococcosis in non-AIDS patients at a tertiary care medical center.

Abstract

Cryptococcus neoformans is a ubiquitous saprophytic fungus with worldwide distribution. It has been found in nature, primarily in association with bird droppings, but nonavian sources have been described as well (10). Although the lungs are thought to be the portal of entry for cryptococcus, pulmonary infection is uncommon. The organism is trophic to the central nervous system and the vast majority of recognized infections involve meningitis. Before the acquired immunodeficiency syndrome (AIDS) epidemic (1980), cryptococcosis was a rare infection, and pulmonary disease was described in 10%–45% of patients with cryptococcal meningitis (2). However, the true incidence of pulmonary cryptococcosis (PC) was not known, but was much lower than meningitis. Most PC cases were identified histologically and often at autopsy, with only about 20% diagnosed by culture (2, 3, 13). In recent years, many of the reports of cryptococcal infection have been in the human immunodeficiency virus (HIV)-positive population, and little is known of the disease in non-AIDS patients, particularly pulmonary involvement. At our institution, a tertiary care medical center with a large transplant program, sporadic cases of PC have occurred in solidorgan transplant recipients as well as in patients with a variety of different medical conditions. The purpose of our study was to investigate the epidemiology of PC in non-AIDS patients, and to determine predictors of outcome among these patients.