NEW YORK (Reuters Health) – Among children with sore throat, more than a third probably have group A streptococcal infection, a study shows. Furthermore, about one in every eight well children are carriers of the bacterium.

Those numbers come from a meta-analysis of 29 studies that contained data on the prevalence of group A Streptococcus (GAS) from pharyngeal specimens in children younger than 18 years.

Writing in the September issue of Pediatrics, Dr. Nader Shaikh of Children’s Hospital of Pittsburgh, Pennsylvania and colleagues say, “Prevalence estimates can help clinicians make informed decisions regarding diagnostic testing of children who present with symptoms of pharyngitis.”

The team’s findings indicate that the prevalence of GAS in children presenting with sore throat is 37%. In children younger than 5 years of age, it is 24%.

Among asymptomatic children of all ages over 5 years, the prevalence of GAS carriage is 12%. Other studies have found the prevalence of GAS in adults to be about 5% to 10%.

“The relatively high probability of GAS disease and acute rheumatic fever in school-aged children, as compared with adults and children who are younger than 5 years, suggests that testing of school-aged children who present with sore throat is beneficial,” Dr. Shaikh and colleagues advise.

Posttreatment cultures are unnecessary in the majority of patients with GAS pharyngitis, they suggest. However, “In selected children with recurrent pharyngitis, posttreatment testing may help to differentiate children with true recurrent GAS pharyngitis from carriers; children who are carriers are likely to have persistent GAS even after being treated with appropriate antimicrobial agents.”

Reference:

Prevalence of Streptococcal Pharyngitis and Streptococcal Carriage in Children: A Meta-analysis

Pediatrics 2010;126:e.