title: Community-acquired pneumonia in a cohort of former injection drug users with and without human immunodeficiency virus infection: incidence, etiologies, and clinical aspects.
abstract: Although the association among bacterial pneumonia, human immunodeficiency virus (HIV) infection, and injection-drug use seems to have been well established, accurate estimates of the risk of community-acquired pneumonia among HIV-positive and HIV-negative injection-drug users (IDUs) are still needed. To estimate the incidence of pneumonia in a community of former IDUs, we followed 4,236 persons between 1991 and 1994; 1,114 (26.3%) were HIV-positive and 3,122 (73.7%) were HIV-negative. All patients were evaluated for pneumonia by standard criteria, a serum sample was obtained from each participant at least once a year, and laboratory values were monitored. Overall, 149 episodes of pneumonia occurred among HIV-positive patients and 61 among HIV-negative patients; incidence rates were 90.5 and 14.2 (per 1,000 person-years), respectively. The most common etiologic agents were Streptococcus pneumoniae, Chlamydia pneumoniae, and Haemophilus influenzae. Among the HIV-positive former IDUs, there was a 1.37-fold increase in the relative risk of pneumonia for every decrease of 100/mm3 in the CD4 cell count (95% confidence interval, 1.16-1.61). The incidence of community-acquired pneumonia was markedly higher among HIV-positive participants than among HIV-negative ones, a finding similar to that concerning the general population.
authors.affiliation: San Patrignano Centro Medico, Rimini, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Boschini
authors.forename: C
authors.initials: C
authors.lastname: Smacchia
authors.forename: M
authors.initials: M
authors.lastname: Di Fine
authors.forename: A
authors.initials: A
authors.lastname: Schiesari
authors.forename: P
authors.initials: P
authors.lastname: Ballarini
authors.forename: M
authors.initials: M
authors.lastname: Arlotti
authors.forename: C
authors.initials: C
authors.lastname: Gabrielli
authors.forename: G
authors.initials: G
authors.lastname: Castellani
authors.forename: M
authors.initials: M
authors.lastname: Genova
authors.forename: P
authors.initials: P
authors.lastname: Pantani
authors.forename: A C
authors.initials: AC
authors.lastname: Lepri
authors.forename: G
authors.initials: G
authors.lastname: Rezza
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000150:complications / Q000453:epidemiology* / Q000209:etiology; D000328:Adult; D018791:CD4 Lymphocyte Count; D002690:Chlamydia Infections / Q000150:complications / Q000453:epidemiology / Q000209:etiology; D016993:Chlamydophila pneumoniae; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000150:complications / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006192:Haemophilus Infections / Q000150:complications / Q000453:epidemiology / Q000209:etiology; D006193:Haemophilus influenzae; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D018410:Pneumonia, Bacterial / Q000150:complications / Q000453:epidemiology* / Q000209:etiology; D011018:Pneumonia, Pneumococcal / Q000150:complications / Q000453:epidemiology / Q000209:etiology; D012008:Recurrence; D012307:Risk Factors; D015819:Substance Abuse, Intravenous / Q000150:complications