Estimated burden of group a streptococcal pharyngitis among children in Beijing, China

BACKGROUND: Burden of Group A streptococcus (GAS) pharyngitis is scarce in developing countries, still unknown in China. The objective of this study was to determine the incidence of clinical cases of pharyngitis and GAS culture-positive pharyngitis, and their outpatient visits among children aged 0–14 years in Beijing, the capital of China. METHODS: Multiplier model was used to estimate the numbers of pharyngitis cases, based on reported numbers of clinical cases and GAS culture-positive rates from GAS surveillances in Beijing, consultation rate, population coverage of GAS surveillances, sampling success rate, and test sensitivity of GAS culture from previous studies, surveys and surveillances. RESULTS: An average of 29804.6 (95 % CI: 28333.2–31276.0) clinical cases of pharyngitis per 100,000 person-years occurred among children aged 0–14 years, resulting in correspondingly 19519.0 (95 % CI: 18516.7–20521.2) outpatient visits per 100,000 person-years from 2012 to 2014 in Beijing. On average, there were 2685.1 (95 % CI: 2039.6–3330.6) GAS culture-positive cases of pharyngitis and 1652.7 (95 % CI: 1256.5–2049.0) outpatient visits per 100,000 person-years during the same period. The estimated burden of GAS pharyngitis was significantly higher than that of scarlet fever. Children aged 5–14 years had a higher burden of GAS pharyngitis than those aged 0–4 years. CONCLUSIONS: The present data suggests that GAS pharyngitis is very common in children in China. Further studies and surveillances are needed to monitor trends and the effectiveness of control measures.