Schistosomiasis japonicum burden in adult villagers of Qingshan Island, China: a cross-sectional study on prevalence, intensity, knowledge and risk factors.

Schistosomiasis has been endemic in China for >1000 y. With decades of effort, significant progress has been achieved in its prevention and control. However, certain regions, like Qingshan Island, continue to pose challenges, representing a 'dark corner' in the final stages of elimination and hindering national eradication efforts. This cross-sectional research was conducted on Qingshan Island, China, to investigate the burden of schistosomiasis japonicum among villagers. A total of 133 residents were enrolled. Data were analysed using Pearson's χ2 test and odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess risk factors. The prevalence in males was 93.22% while that among females was 60.81%. The majority of participants (95.49%) were engaged in fishing and farming. These occupations were associated with a higher risk of schistosomiasis, with an OR of 3.233 (95% CI 0.602 to 16.867). Although all participants confirmed having received schistosomiasis-related education, only 18.80% indicated that they had adopted appropriate preventive measures. The primary source of income for local residents has shifted from fishing to cultivating traditional Chinese medicine plants. At present, Qingshan Island residents face persistent high schistosomiasis prevalence with past infections. Insufficient knowledge application of protection poses a reinfection risk. Balancing economic development with effective disease control is essential, especially in the context of the island's growing tourism industry, in achieving the final goal of schistosomiasis elimination.