Antibiotic Regimens

Key points

  • Multiple antibiotic regimens have been used to eradicate carriage of group A Streptococcus (GAS) in previous outbreaks.
  • Regimen should be chosen on a case-by-case basis.
  • Some regimens require antibiotic susceptibility test results prior to their use.
A healthcare provider holds a pill bottle and two white pills.

Overview

Multiple antibiotic regimens have been recommended for GAS carriage eradication in either

  • 2002 U.S. guidelines for postpartum and post-surgical outbreaks1
  • Canada's guidelines for prevention and control of invasive GAS disease2

Several regimens have been used in previous outbreaks for GAS carriage eradication.

Download, print, and share‎

Get this information on antibiotic regimens and 3 scenarios in one print-ready PDF file.

Regimen choice

Which antibiotic regimen to use for GAS carriage eradication during an outbreak depends on multiple considerations. LTCF and public health staff should carefully consider the pros and cons of each regimen on a case-by-case basis. Key decision makers from the LTCF include the medical director and infection prevention and control personnel.

In addition to a first-line regimen, it's likely necessary to choose alternative regimens for those

  • With allergies to antibiotics
  • At risk for drug-drug interactions with antibiotic regimens

First-line regimens

GAS is universally susceptible to beta-lactam antibiotics, including penicillin and cephalosporins. LTCFs and public health don't need to consider antibiotic susceptibility when selecting one of these treatment regimens.

Universally susceptible antibiotic regimens, with dosages

Benzathine penicillin G plus rifampin134
  • BPG: 600,000 units for patients <27 kilograms (kg) or 1,200,000 units for patients ≥27 kg intramuscular (IM) in a single dose
  • Rifampin: 20 mg/kg/day (maximum daily dose 600 mg/day) oral in 2 divided doses for 4 days

1st generation cephalosporins234
  • Cephalexin: 25-50 mg/kg/day (maximum daily dose 1000 mg/day) in 2-4 divided doses for 10 days

Alternative regimens

LTCFs and public health should only consider clindamycin or macrolides if the outbreak strain is documented as susceptible to these antibiotics.

Clindamycin and macrolide (e.g., azithromycin) resistance have been commonly reported. Among invasive disease isolates in 2021, 35% of GAS isolates were macrolide resistant and 34% of isolates were clindamycin resistant5.

Antibiotic regimens, with dosages, that need susceptibility testing

Azithromycin16
  • 12 mg/kg/day (maximum daily dose 500 mg/day) in a single dose daily for 5 days
Clindamycin13
  • 20 mg/kg/day (maximum daily dose 900 mg/day) in 3 divided doses for 10 days
  1. CDC. Prevention of Invasive Group A Streptococcal Infections Workshop Participants. Prevention of invasive group A streptococcal disease among household contacts of case patients and among postpartum and postsurgical patients: Recommendations from the Centers for Disease Control and Prevention. Clin Infect Dis. 2002;35(8):950–9. Erratum in: Clin Infect Dis. 2003;36(2):243.
  2. Public Health Agency of Canada. Supplement—Guidelines for the prevention and control of invasive group A streptococcal disease. Can Commun Dis Rep. 2006;32S2(October 2006).
  3. Dooling KL, Crist MB, Nguyen DB, et al. Investigation of a prolonged group A streptococcal outbreak among residents of a skilled nursing facility, Georgia, 2009–2012. Clin Infect Dis. 2013;57(11):1562–7.
  4. Morita JY, Kahn E, Thompson T, et al. Impact of azithromycin on oropharyngeal carriage of group A Streptococcus and nasopharyngeal carriage of macrolide-resistant Streptococcus pneumoniae. Ped Infect Dis J. 2000;19(1):41–6.
  5. Centers for Disease Control and Prevention. Active Bacterial Core Surveillance, Bact Facts Interactive data dashboard, Emerging Infections Program Network, group A Streptococcus. Available at ABCs Bact Facts Interactive Data Dashboard.
  6. Nanduri SA, Metcalf BJ, Arwady MA, et al. Prolonged and large outbreak of invasive group A Streptococcus disease within a nursing home: Repeated intrafacility transmission of a single strain. Clin Microbiol Infect. 2019;25(2):248.e241–7.