Aetiology of cavitary lung lesions in patients with HIV infection

Although many studies have been carried out on pulmonary diseases in HIV-infected patients, studies specifically investigating the aetiologies of cavitary lung lesions are rare.

HIV-infected patients enrolled in a cohort study who presented with cavitary lung lesions by radiography were identified between June 1994 and March 2008. Medical records and radiological and microbiological data for these patients were retrospectively reviewed using a standardized case collection form.

During the 14-year study period, 73 episodes of cavitary lung lesions were diagnosed in 66 of 1790 (3.7%) HIV-infected patients. At the diagnosis of cavitary lung lesions, the median CD4 count was 25 cells/microL (range 1-575 cells/microL). Eighty-one pathogens were considered causative, with fungi being the most common aetiology (42.0%), followed by bacteria (29.6%) and mycobacteria (25.9%). Of the fungal pneumonias, 19 (55.9%) were caused by Penicillium marneffei, 11 (32.4%) by Cryptococcus neoformans, two (5.9%) by Pneumocystis jirovecii, and two (5.9%) by Aspergillus species. During the study period, 11 of 205 patients (5.4%) who were diagnosed as having tuberculosis presented with cavitary lung lesions, compared with 19 of 36 patients (52.8%) with penicilliosis and 11 of 64 patients (17.2%) with cryptococcosis (P<0.0001). The median CD4 count of patients with cavitary lung lesions resulting from tuberculosis (115 cells/microL) was significantly higher than that of patients with cavitary lung lesions resulting from penicilliosis (4 cells/microL) and cryptococcosis (29.5 cells/microL).

Our findings suggest that invasive infections attributable to endemic fungi were the leading cause of cavitary lung lesions among patients in the late stage of HIV infection, and were more common than infections attributable to bacteria and mycobacteria.