Pneumococcal Disease during HIV Infection: Epidemiologic, Clinical, and Immunologic Perspectives

Abstract

OBJECTIVE: To characterize the epidemiology, clinical manifestations, and immunologic risk factors for infections with Streptococcus pneumoniae among persons infected with human immunodeficiency virus (HIV); and to delineate a practical approach for diagnosis, treatment, and prevention of these infections. DATA SOURCES: English-language articles from Index Medicus and their references as well as abstracts from conference proceedings that compared rates as well as clinical and microbiologic features of S. pneumoniae infections in HIV-infected patients. STUDY SELECTION: All human studies that included denominators, appropriate control groups, or sufficient clinical descriptions and animal studies with key immunologic observations were cited. DATA EXTRACTION: We compared epidemiologic and clinical responses to pneumococcal disease in HIV-infected patients and control subjects and correlated clinical and experimental data on immunologic defects associated with HIV infection with those on regulation of pneumococcal infections. DATA SYNTHESIS: Among patients with HIV infection, the incidence of invasive pneumococcal disease is high, bacteremia is a common complication of pneumonia, and relapses occur frequently. However, the clinical presentation, response to therapy, and serotypes isolated are similar to those in persons without HIV infection, and mortality is similar or lower. Specific local and systemic defects in host defense, particularly humoral immunity, may contribute to the high incidence of invasive pneumococcal disease. CONCLUSIONS: Streptococcus pneumoniae is the leading cause of invasive bacterial respiratory disease in adults and children with HIV infection. Prompt diagnosis and antimicrobial therapy are associated with a favorable clinical outcome. Characterizing the specific immunologic defects associated with invasive pneumococcal disease in HIV-infected patients may facilitate development of successful, cost-effective strategies for prophylaxis.