Upper respiratory symptoms more common in children with pharyngitis identified as GAS carriers

Upper respiratory (UR) and atypical symptoms are more likely to occur in children with symptomatic pharyngitis and group A Streptococcus (GAS) on throat culture identified as carrier than those who are acutely infected, according to a study.

Two separate longitudinal studies of children with symptomatic pharyngitis associated with a positive GAS throat culture (illness culture) were examined. Cohort 1 included children who presented to a clinician with pharyngitis symptoms and had follow-up cultures at regular intervals. In cohort 2, throat cultures were carried out at regular intervals and with pharyngitis symptoms.

Based on follow-up culture results, illness cultures were classified as either carrier or acute infection. In cohort 2, carriers were further categorized as follows: (1) a GAS carrier with a new emm-type or (2) a GAS carrier with a previous emm-type based on typing data from prior culture results. The investigators compared symptoms for each cohort at the time of illness culture between carriers and those with acute infection.

Of the children in cohort 1 (n=75 illness cultures), 87 percent were categorized as having acute infection compared with 13 percent carriers. The latter were more likely to have UR symptoms (odds ratio [OR], 5.5, 95 percent confidence interval [CI], 1.4–22.1), headache (OR, 6.0, 95 percent CI, 1.2–40.5) or vomiting (OR, 5.5, 95 percent CI, 1.2–24.5).

In cohort 2 (n=122 illness cultures), 79 percent were acutely infected and 21 percent were carriers. Children identified as carriers with a previously detected emm-type were more likely to have UR symptoms than those who acquired a new emm-type.

“Among children with pharyngitis who test positive for GAS, 10–25 percent are GAS carriers,” the investigators noted.