A meta-analysis of infection rates of Schistosoma japonicum in sentinel mice associated with infectious waters in mainland China over last 40 years

• Published in: PLoS neglected tropical diseases 2019-06, Vol.13 (6), p.e0007475
• Main Authors: Qiu, Chen, Zou, Hui-Ying, Deng, Yao, Liang, You-Sheng, Lu, Da-Bing
• Format: Article
• Language: English
• Subjects: Analysis; Animals; Biology and Life Sciences; Care and treatment; China - epidemiology; Confidence intervals; Dams; Deployment; Detection; Diagnosis; Disease control; Disease prevention; Disease transmission; Eggs; Epidemiology; Estimates; Family planning; Gastropoda; Geriatrics; Heterogeneity; Humans; Infection; Infections; Laboratories; Livestock; Medical research; Medicine; Medicine and Health Sciences; Meta-analysis; Mice; Mollusks; Parasites; Parasitic diseases; Parasitology; Parasitoses; People and Places; Physical Sciences; Public health; Regions; Research and Analysis Methods; Risk factors; Rivers; Schistosoma japonicum - growth & development; Schistosoma japonicum - isolation & purification; Schistosomiasis; Schistosomiasis japonica - epidemiology; Sentinel Surveillance; Serological tests; Snails; Subgroups; Surveys; Transmission; Tropical diseases; Water - parasitology; Wildlife; Worms; Zoonoses
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0007475

Schistosomiasis japonica is a zoonotic parasitic disease. After nearly 70 years of control efforts in China, Schistosomiasis transmission has been reduced to a much lower level. The absence or near absence of infections in humans or livestock, based on traditional fecal and serological tests, has made the targets and priorities of future control efforts difficult to determine. However, detection of schistosome cercariae in waters using sentinel mice could be an alternative way of identifying remaining foci of infection, or even serve as a tool for evaluation of control efficacy. This method has been employed in China over last forty years. We therefore performed a meta-analysis of the relevant research to investigate if infections in sentinel mice mirror the ongoing trend of schistosomiasis transmission in China. We conducted a meta-analysis of studies reporting infection rates of S. japonicum in sentinel mice in China before Sep 1, 2018 in accordance with the PRISMA guidelines. We retrieved all relative studies based on five databases (CNKI, WanFang, VIP, PubMed and Web of Science) and the reference lists of resulting articles. For each individual study, the infection rate in sentinel mice is presented together with its 95% confidence interval (CI). Point estimates of the overall infection rates and their 95% CIs were calculated. Subgroup analyses were performed according to study periods, seasons or regions. We identified 90 articles, including 290 studies covering eight endemic provinces. The overall rate in sentinel mice was 12.31% (95% CI: 10.14-14.65%) from 1980 to 2018. The value of 3.66% (95% CI: 2.62-4.85%) estimated in 2004 to 2018 was significantly lower than in 1980 to 2003 (22.96%, 95% CI: 19.25-26.89%). The estimate was significantly higher in the middle and lower reaches than in the upper reaches of the Yangtze River. The highest estimates were obtained in Hunan (30.11%, 95% CI: 25.64-34.77%) followed by Anhui (26.34%, 95% CI: 12.88-42.44%) and then Jiangxi (13.73%, 95% CI: 6.71-22.56%). Unlike the other provinces in the middle and lower reaches, no significant reduction was seen in Hubei after 2003. Even in Hubei two studies carried out after 2014 reported infections in sentinel mice, although no infected snails were reported across the province. Infections were most found in April (17.40%, 95% CI: 1.13-45.49%), July (24.98%, 95% CI: 15.64-35.62%) and October (17.08%, 95% CI 5.94-32.05%). High degrees of heterogeneity were observed. This me