Streptococcus pyogenes transmission among Air Force recruits: efficacy of surveillance and prophylaxis protocols

The prevalence of Streptococcus pyogenes in Air Force recruits (n = 10,634) completing basic training at Lackland Air Force Base between November 1, 1993, and March 1, 1994, was determined. Throat cultures were obtained on the second day and the last day of training, approximately 6 weeks later. Although the prevalence on the second day was nearly identical between males (1.99%) and females (1.98%), males with positive cultures increased to 4.30%, whereas females with positive cultures increased to 2.92% at the end of training. Within flights, an increase was noted in male flights when members sought care and subsequently were positive for S. pyogenes. Within these flights, S. pyogenes prevalence significantly increased from 2.79 to 7.20% (p < 0.001) despite antibiotic therapy and prophylaxis treatment measures. Within female flights, the increase was from 2.68 to 3.35%, which was not statistically significant (p < 0.19). A total of 161 trainees were treated for S. pyogenes as a result of positive cultures; remarkably, 27.3% of these were still culture-positive on the last day of training.