title: Efficacy of antibiotic prophylaxis for intrafamilial transmission of group A beta-hemolytic streptococci.
abstract: BACKGROUND
  The role of chemoprophylaxis for household contacts of patients with acute streptococcal disease is uncertain.
  
  
  METHODS
  The subjects were 1440 sibling contacts of 1181 index patients with group A beta-hemolytic streptococcal (GABHS) pharyngitis. Instances of subsequent GABHS pharyngitis in sibling contacts who received chemoprophylaxis and in a control group without prophylaxis were compared.
  
  
  RESULTS
  Of the 948 siblings in the prophylaxis group, 507 were treated with cephalosporins and 441 were treated with penicillins for 3 to 5 days. Subsequent GABHS pharyngitis occurred within 30 days in 28 (3.0%) of the 948 siblings in the prophylaxis group and in 26 (5.3%) of the 492 siblings in the control group. Among siblings in the prophylaxis group, subsequent GABHS pharyngitis occurred in 9 (1.8%) of the 507 siblings in the cephalosporin prophylaxis group and in 19 (4.3%) of the 441 siblings in the penicillin prophylaxis group. When these data were each compared with that in the control group (5.3%), a significant statistical difference was seen in the cephalosporin prophylaxis group (P = 0.003) but not in the penicillin prophylaxis group (P = 0.542). Only 5-day cephalosporin prophylaxis showed significant reduction in the rate of subsequent GABHS pharyngitis compared with that in the control group (P = 0.002).
  
  
  CONCLUSIONS
  In view of the low incidence of subsequent GABHS pharyngitis in the nonprophylaxis group, the usual self-limited nature of GABHS pharyngitis, the cost of prophylaxis and the risk for selecting resistant flora, routine chemoprophylaxis against GABHS pharyngitis for sibling contacts is not recommended.
authors.affiliation: Pediatric Clinic, Touei Hospital, Sapporo, Japan. hide-ki@touei.or.jp
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kikuta
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Shibata
authors.forename: Shuji
authors.initials: S
authors.lastname: Nakata
authors.forename: Tatsuru
authors.initials: T
authors.lastname: Yamanaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakata
authors.forename: Kozo
authors.initials: K
authors.lastname: Fujita
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Kobayashi
mesh_terms: D000293:Adolescent; D019072:Antibiotic Prophylaxis; D002511:Cephalosporins / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D018562:Disease Transmission, Infectious / Q000517:prevention & control; D005192:Family Health; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010406:Penicillins / Q000627:therapeutic use; D010612:Pharyngitis / Q000382:microbiology / Q000517:prevention & control*; D013223:Statistics as Topic; D013290:Streptococcal Infections / Q000382:microbiology / Q000517:prevention & control* / Q000635:transmission*; D013297:Streptococcus pyogenes / Q000187:drug effects*
chemical_list: D002511:Cephalosporins; D010406:Penicillins