Re: Strep A: GPs are put on alert as cases and deaths rise

Dear Editor

English guidance changed in 2008, recommending the use of chemoprophylaxis (giving antibiotics to contacts of cases to prevent disease) when cases of invasive group A streptococcal disease (iGAS) were identified.[1]

While there does appear to be an increased risk of iGAS in household members following a case of scarlet fever,[2] I am not clear that there is compelling evidence that chemoprophylaxis significantly modifies this risk. It also seems illogical, if we do not provide chemoprophylaxis following cases of non invasive GAS disease – I am not aware of any evidence that the bacteria causing iGAS are any different.

Indeed, the documents relating to the guidance (in place since 2008) suggest “that over 2,000 contacts would need to receive antibiotic prophylaxis to prevent a subsequent case of invasive group A streptococcal disease.”[1]

When such large numbers of healthy individuals are given antibiotics, not only does this drive antimicrobial resistance (although it is true that GAS is sensitive to penicillin, so perhaps this will cause little additional harm); but adverse drug reactions will arise. The additional workload, in an already overstressed health service, may also mean that other important work is not done, other problems are missed, and the opportunity costs will cause harms.

I am not sure that there is convincing evidence that the health gain from preventing deaths and cases of iGAS by giving chemoprophylaxis to huge numbers of healthy individuals is greater than the harms done, especially when indirect harms are factored in.

References

1. Health Protection Agency Group A Streptococcus Working Group. One- page summary of interim UK guidelines for management of close community contacts of invasive group A streptococcal disease (iGAS): Health Protection Agency Group, 2008 (19 March); (https://www.gov.uk/government/publications/invasive-group-a-streptococca…).
2. Vicky W, Sooria B, Colin SB, Suzanna M, Rachel M, Derren R, et al. Increased Risk for Invasive Group A Streptococcus Disease for Household Contacts of Scarlet Fever Cases, England, 2011–2016. Emerging Infectious Disease journal 2019;25(3):529. (http://wwwnc.cdc.gov/eid/article/25/3/18-1518).