title: An outbreak of pneumococcal pneumonia among military personnel at high risk: control by low-dose azithromycin postexposure chemoprophylaxis.
abstract: In the winter of 1998-1999 an outbreak of pneumococcal pneumonia occurred among Ranger students undergoing high-intensity training. Thirty pneumonia cases (attack rate = 12.6%) were identified among a group of 239 students. Eighteen students were hospitalized; Streptococcus pneumoniae-positive cultures were detected in 11 (61.1%) of these 18 hospitalized cases. Pneumococci were also identified in throat swabs of 30 (13.6%) of 221 nonhospitalized students surveyed. Serum antipneumolysin seroconversions were detected in 30 (18.3%) of 164 students tested. An association between development of serum antipneumolysin antibody and pneumococcal pharyngeal carriage/colonization was found. Of 30 seroconverters, eight (26.7%) had S. pneumoniae-positive cultures compared with only 17 (12.7%) of 134 nonseroconverters (relative risks = 2.02, 95% confidence interval = 1.02-4.02, p = 0.05). The outbreak was controlled by administrating lowdose, oral azithromycin prophylaxis (250 mg weekly for 2 weeks) and was associated with a 69% reduction in pneumococcal carriage and a 94% reduction in pneumonia rates.
authors.affiliation: Epidemiology Services, Directorate of Epidemiology and Disease Surveillance, U.S. Army Center for Health Promotion and Preventive Medicine, 5158 Blackhawk Road, Aberdeen Proving Ground, MD 21010-5403, USA. sanchez@namrid.sld.pe
authors.forename: Jose L
authors.initials: JL
authors.lastname: Sanchez
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Craig
authors.forename: Shellie
authors.initials: S
authors.lastname: Kolavic
authors.forename: Deborah
authors.initials: D
authors.lastname: Hastings
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Alsip
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Gray
authors.forename: Marie K
authors.initials: MK
authors.lastname: Hudspeth
authors.forename: Margaret A K
authors.initials: MA
authors.lastname: Ryan
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D019072:Antibiotic Prophylaxis; D017963:Azithromycin / Q000627:therapeutic use*; D004196:Disease Outbreaks / Q000517:prevention & control*; D006801:Humans; D015994:Incidence; D008297:Male; D008889:Military Personnel / Q000706:statistics & numerical data; D011018:Pneumonia, Pneumococcal / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D012306:Risk; D014481:United States / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin