Randomized, Placebo‐Controlled Clinical Trial of Oral Azithromycin Prophylaxis against Respiratory Infections in a High‐Risk, Young Adult Population

Abstract

Military Special Forces trainees undergo intense psychological and physical stressors that often lead to respiratory infection. During 1998-2000, 477 Navy Special Forces trainees were enrolled in a double-blind trial of oral azithromycin (1 g given weekly) plus a placebo injection, compared with benzathine penicillin G (1.2 million U) plus azithromycin placebo tablets. Among the 464 subjects with complete data, 44 developed acute respiratory infection (20 with pneumonia) during the 2 weeks of most intense training; of these subjects, 12 (27.3%) had evidence of Chlamydia pneumoniae infection and 7 (15.9%) had evidence of Mycoplasma pneumoniae infection. Trainees who received azithromycin were less likely than were trainees who received benzathine penicillin G to develop acute respiratory infection (risk ratio, 0.50; 95% confidence interval [CI], 0.28-0.92) and less likely at the end of training to report episodes of breathing difficulty (odds ratio [OR], 0.59; 95% CI, 0.34-1.01) or sore throat (OR, 0.66; 95% CI, 0.41-1.05). Compared with benzathine penicillin G prophylaxis, weekly oral azithromycin was superior in preventing respiratory infection in this population at transient high risk.

Two Regimens of Azithromycin Prophylaxis against Community‐Acquired Respiratory and Skin/Soft‐Tissue Infections among Military Trainees

“…This antibiotic has been used to successfully control the spread of M. pneumoniae in high-risk civilian groups [15]. Good prophylaxis results have also been previously been documented among US military forces [4]. It is interesting that in this US study, azithromycin-resistant S. pneumoniae isolates were similarly detected after receipt of treatment.…”

“…Although some vaccines are available to prevent such respiratory infections (e.g., influenza and Streptococcus pneumoniae infection), no available vaccines exist for a number of important respiratory pathogens [4].…”

“…Numerous antimicrobial prophylaxis treatments have been evaluated [1,4,7,[9][10][11], and the most promising has been a weekly dose of azithromycin [9,10,12]. At the same time, increased use of antibiotics is associated with the selection of resistant microorganisms and their spread in populations.…”

Once weekly azithromycin in secondary prevention of rheumatic fever

“…But there are reports of the successful use of once weekly AZT in preventing colonisation and recurrences of streptococcal throat infections. 11,12 Gray et al 12 reported superiority of weekly oral AZT in the prevention of upper respiratory infection over penicillin when used as prophylaxis in 1016 US marine trainees at highrisk of respiratory disease. Azithromycin group reported less side-effects, respiratory symptoms and serological evidence for sterptococcal, mycoplasmal, and chamydial infections.…”

“…[11][12][13] It has a long half-life and hence can be given once a week. The effectiveness of once weekly oral AZT in preventing group A beta haemolytic streptococcal throat colonisation, infection, and acute rheumatic fever was evaluated against oral penicillin in this study.…”