HIV-associated opportunistic pneumonias

Abstract

Among the HIV-associated pulmonary complications, opportunistic pneumonias are major causes of morbidity and mortality. The spectrum of HIV-associated opportunistic pneumonias is broad and includes bacterial, mycobacterial, fungal, viral and parasitic pneumonias. Bacterial pneumonia is the most frequent opportunistic pneumonia in the United States and Western Europe while tuberculosis is the dominant pathogen in sub-Saharan Africa. With the use of combination antiretroviral therapy and prophylaxis, the incidence of Pneumocystis pneumonia (PCP) has declined. Nevertheless, PCP continues to occur in persons who are unaware of their HIV infection, those who fail to access medical care, and those who fail to adhere to antiretroviral therapy or prophylaxis. Although pneumonias due to Cryptococcus neoformans, Histoplasma capsulatum, Coccidioides immitis, cytomegalovirus and Toxoplasma gondii are less frequent, their presence in the lung is often indicative of disseminated disease and is associated with significant mortality.

Figure 1

Diagnostic assessment for an HIV-infected patient with respiratory symptoms and CD4 cell count >200 cells/μl. AFB, acid-fast bacilli; BP, bacterial pneumonia; CT, chest computed tomography; HRCT, chest high-resolution computed tomography; PCP, Pneumocystis pneumonia; PFTs, pulmonary function tests; TB, tuberculosis; URI, upper respiratory tract infection. Adapted from: Huang, L. Respiratory Disease. In Dolin, R, Masur, H, and Saag, M, eds. AIDS Therapy. Third edition. Philadelphia: Churchill Livingstone Elsevier, Inc., 2007. pp. 1225-1252.

Figure 2

Diagnostic assessment for an HIV-infected patient with respiratory symptoms and CD4 cell count of <200 cells/μl. *Some of the diagnoses occur when the CD4 cell count is ≤100 cells/μl or even ≤50 cells/μl. AFB, acid-fast bacilli; BP, bacterial pneumonia; CMV, Cytomegalovirus; CRAG, cryptococcal antigen; HRCT, chest high-resolution computed tomography; KS, Kaposi sarcoma; NHL, non-Hodgkin lymphoma; PCP, Pneumocystis pneumonia; PFTs, pulmonary function tests; TB, tuberculosis; URI, upper respiratory tract infection. Adapted from: Huang, L. Respiratory Disease. In Dolin, R, Masur, H, and Saag, M, eds. AIDS Therapy. Third edition. Philadelphia: Churchill Livingstone Elsevier, Inc., 2007. pp. 1225-1252.