Background: In 2024, mainland China witnessed a significant upsurge in Hand, Foot, and Mouth Disease (HFMD) cases. Coxsackievirus A16 (CVA16) is one of the primary causative agents of HFMD. Long-term monitoring of theCVA16 infection rate and genotype changes is crucial for the prevention and control of HFMD. Methods: A total of 40,673 clinical specimens were collected from suspected HFMD cases in Guangdong province from 2018 to 2024, including rectal swabs (n = 27,954), throat swabs (n = 6791), stool (n = 5923), cerebrospinal fluid (n = 3), and herpes fluid (n = 2). A total of 24,410 samples were detected as EV-positive and further typed by RT-PCR. A total of 872 CVA16-positive samples were isolated and further sequenced to obtain the full-length VP1 sequence. Phylogenetic analysis was performed based on viral protein 1 gene (VP1). Results: In the first 25 weeks of 2024, reported cases of HFMD were 1.36 times higher than the mean rates of 2023. In 2024, CVA16 predominated at 75.42%, contrasting with the past etiological pattern in which the CVA6 was predominant with the detection rate ranging from 32.85 to 77.61% from 2019 to 2023. Phylogenetic analysis based on the VP1 gene revealed that the B1a and B1b subtypes co-circulated in Guangdong from 2018 to 2022. The B1c outbreak clade, detected in Guangdong in 2023, constituted 68.24% of the 148 strains of CVA16 collected in 2024, suggesting a subtype shift in the CVA16 virus. There were three specific amino acid variations (P3S, I235V, and T240A) in the VP1 sequence of B1c. Conclusions: The new emergence of the CVA16 B1c outbreak clade in Guangdong during 2023–2024 highlights the necessity for the enhanced surveillance of the virus evolution epidemiological dynamic in this region. Furthermore, it is imperative to closely monitor the etiological pattern changes in Hand, Foot, and Mouth Disease (HFMD) in other regions as well. Such vigilance will be instrumental in guiding future vaccination strategies for HFMD.

Following the normalization of the COVID-19 pandemic, the focus of wastewater-based epidemiology (WBE) must be broadened from SARS-CoV-2 to encompass surveillance of other major infectious diseases, particularly for pathogens where conventional clinical monitoring systems exhibit inherent surveillance gaps. In this study, we conducted a continuous two-year WBE study (January 2023 to December 2024) across three high-population-density cities in Guangdong, China to establish epidemiological baselines for enteric diarrheal viruses. We analyzed monthly raw wastewater samples from major treatment plants using advanced molecular methods, including digital PCR (ddPCR) for viral load quantification and targeted high-throughput sequencing (tNGS) for genotypic analysis. Our findings revealed diverse circulation patterns among the monitored enteric viruses. Astrovirus (AstV) had the highest detection rate (100%), reflecting its broad endemic distribution, while Norovirus genogroup II (NoV GII) exhibited relatively high viral loads (median 4 × 10⁴ copies/mL) and presented explosive seasonal peaks (significant upward trend in spring.), highlighting its epidemic potential. Furthermore, distinct spatiotemporal patterns were observed, with Sapovirus showing a significant summer peak in Foshan city, contrasting with the winter/spring peaks in the other cities. The tNGS results demonstrated similar sensitivity to RT-PCR in virus detection, and sequencing analyses uncovered the co-circulation and periodic shifts in dominant viral genotypes, such as the emergence of multiple NoV and AstV lineages. This longitudinal WBE surveillance successfully established critical baseline data and demonstrated significant regional heterogeneity in viral circulation, providing essential, complementary data to inform public health strategies for preventing diarrheal outbreaks in urban settings.

Heatstroke causes numerous pathophysiological changes and can lead to death. Extreme heat events have been increasing in frequency, duration, and intensity worldwide in recent decades and are causing growing public health concern. However, epidemiological studies of heatstroke are limited in number and scope, and have had relatively small sample sizes. To better understand the epidemiological characteristics of heatstroke and advance evidence-based prevention and control strategies, we conducted an observational study of reported heatstroke cases in China. Cases included in this study were patients clinically diagnosed with heatstroke during the study period of 2010–2023, reported through a dedicated heatstroke surveillance system established by China CDC. We used descriptive statistical methods to determine the epidemiological characteristics of heatstroke in China. There were 86,406 heatstroke cases reported during the study period, with an increasing reporting trend (Spearman correlation coefficient r = 0·79). Annual incidence (Spearman r = 0·77) and proportion of severe cases (Pearson r = 0·67) were positively correlated with the number of nationwide average annual high-temperature days. The overall incidence was 44·83 per 10 million person-years, and the mortality rate was 0·89 per 10 million person-years; 32·02% of cases were severe; the overall case fatality rate (CFR) was 1·98%, and the CFR for severe cases was 6·19%. Most cases and deaths were reported in summer, with peaks in late July. The peaks of incidence, duration, and severity varied by region. The mean age was (50·46 ± 18·73) years, with male cases younger than female cases (49·21 ± 17·41 vs 53·60 ± 21·36; t = −28·73, p < 0·0001). For every five-year increase in age, the risks of severe heatstroke and death increased by 14·64% (95% CI: 1·1415–1·1513) and 25·76% (CI: 1·2400–1·2755), respectively. The male:female ratio was 2·49:1; males exhibited a higher risk of suffering from heatstroke and having greater disease severity than females. Our study provides a clear profile of heatstroke cases, and highlights differences by population, region, and time of year. Results inform formulation of evidence-based strategies for enhanced heatstroke preparedness and response, such as enhancing public health early warning systems, prioritizing protection for vulnerable groups, and advancing localized interventions for risk communication and clinical management. Public Health Talent Program of China’s National Disease Control and Prevention Administration.