Antibiotic sensitivity

When prescribing oral antibiotics for possible group A streptococcus (1)

• phenoxymethylpenicillin remains first line due to its high effectiveness, no reported resistance, and narrow spectrum of activity. In the event of non-availability, amoxicillin, macrolides and cefalexin are alternative agents in decreasing preference
• in non severe-penicillin allergy, macrolides are the option of choice, with cefalexin as an alternative
• in severe penicillin allergy, macrolides remain the option of choice. Co-trimoxazole is an option in the event of macrolide non-availability and penicillin anaphylaxis. A severe penicillin allergy is when there is a history of allergy to penicillin with effects that are clearly likely to be allergic in nature such as anaphylaxis, respiratory distress, angioedema or urticaria
• both cefalexin and co-trimoxazole are broad-spectrum agents that may promote the development of antimicrobial resistance. Resistance to macrolides and co-trimoxazole is currently 7% and 10% respectively
• antibiotic treatment length for sore throat
  • for phenoxymethylpenicillin:
    • five days of phenoxymethylpenicillin may be enough for symptomatic cure, but a 10-day course may increase the chance of microbiological cure

Management of contacts of GAS (1)

• contacts will be identified by HPTs (Health Protection Teams)
  • HPTs will advise on who requires prophylaxis. For information, the following individuals who are close contacts of cases are recommended for antibiotic prophylaxis due to higher risk of severe outcomes:
    • pregnant women from >= 37 weeks gestation
    • neonates and women within the first 28 days of delivery
    • older household contacts (>=75 years)
    • individuals who develop chickenpox with active lesions either seven days prior to onset in the iGAS case or within 48 hours after the iGAS case commences antibiotics, if exposure is ongoing
  • close contact is defined as:
    • prolonged contact with the case in a household-type setting during the 7 days before onset of symptoms and up to 24 hours after initiation of appropriate antimicrobial therapy in the index case

Reference:

• NHS England. Group A streptococcus communications to clinicians (December 2022).