Viral shedding and clinical differences in hand, foot and mouth disease associated with coxsackievirus A16 and coxsackievirus A10

Background Hand, foot, and mouth disease (HFMD) remains a major and persistent public health challenge in China and across many parts of Asia. Following widespread implementation of enterovirus A71 vaccination in China, coxsackievirus A10 (CVA10) and coxsackievirus A16 (CVA16) have emerged as the dominant serotypes associated with outbreaks in children. Objective To investigate the viral shedding duration and clinical differences of CVA10 and CVA16 in HFMD outbreaks in Jiangsu Province, and to generate evidence for optimizing case management and outbreak control. Methods In 2024, a total of 63 HFMD cases were prospectively followed daily to monitor symptom progression. Pharyngeal swabs were collected once at symptom onset and on days 3, 7, 10, and 14 post-onset from cases and close contacts. All specimens were tested by RT-PCR for nucleic acid detection and serotype identification. Results CVA10-infected children had a significantly longer duration (9.5 days) than those with CVA16 (8.0 days, P = 0.012). CVA16 infection correlated with more symptomatic cases, especially higher rash incidence, and increased healthcare-seeking behavior. Viral load dropped sharply from days 1–4, and symptom duration was positively correlated with viral shedding duration in symptomatic children (r = 0.33); 91.7% of children tested negative within 5 days after symptom resolution. Conclusions This study suggests that symptom resolution may provide a potential reference for evaluating isolation strategies, early monitoring is critical due to rapid viral load decline, and symptom duration may serve as an indicator of viral RNA shedding duration. Given CVA10’s prolonged viral shedding and CVA16’s symptom-driven transmission, serotype-specific and tailored management strategies may be valuable for HFMD control. However, infectivity was not directly assessed, and these findings should be further validated using viral culture.