title: HIV-1 and bacterial pneumonia in the era of antiretroviral therapy.
abstract: Community-acquired pneumonia affects approximately 4 million people in the United States, with 40,000 deaths per year. The incidence is increased about 35-fold in HIV-infected individuals, and this rate has decreased since the antiretroviral era has begun. Bacterial pneumonia has decreased from 5 to 20 cases per 100 person-years to less than 1 to 5 cases per 100 person-years in the era of antiretroviral therapy. HIV-1 infection impairs the function of neutrophils in the lung and infects CD4⁺ cells and alveolar macrophages. Opportunistic infections dramatically increase local HIV replication in the lung cells, especially alveolar macrophages and CD4⁺ cells. This enhanced replication increases viral mutations and provides opportunities for viral escape from latent reservoirs. Mortality is increased with more comorbidities in this highly susceptible population. Immunization with vaccines is recommended, especially pneumococcal vaccines, although the vaccine itself may stimulate viral replication. Recent studies show that the lower respiratory tract is a microbial reservoir in HIV-infected individuals rather than being a sterile environment, as originally thought. This may provide new opportunities for preventing opportunistic infections in HIV-infected subjects. Bacterial pneumonia presents an ongoing challenge in these high-risk individuals, particularly in studying the functions of the innate and acquired immune response.
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, New York University School of Medicine, New York, New York 10016, USA. Leopoldo.Segal@nyumc.org
authors.forename: Leopoldo N
authors.initials: LN
authors.lastname: Segal
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Methé
authors.forename: Anna
authors.initials: A
authors.lastname: Nolan
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Hoshino
authors.forename: William N
authors.initials: WN
authors.lastname: Rom
authors.forename: Rod
authors.initials: R
authors.lastname: Dawson
authors.forename: Eric
authors.initials: E
authors.lastname: Bateman
authors.forename: Michael D
authors.initials: MD
authors.lastname: Weiden
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D001419:Bacteria / Q000235:genetics; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D018791:CD4 Lymphocyte Count; D017714:Community-Acquired Infections / Q000453:epidemiology; D004275:DNA, Ribosomal / Q000032:analysis; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology*; D015497:HIV-1; D006801:Humans; D008168:Lung / Q000382:microbiology / Q000473:pathology; D009504:Neutrophils / Q000378:metabolism; D018410:Pneumonia, Bacterial / Q000453:epidemiology*; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D044966:Anti-Retroviral Agents; D004275:DNA, Ribosomal