Impact of climate warming on Oncomelania hupensis in China: multi-scale evidence

Abstract Background Climate warming is increasingly reshaping the population dynamics of Oncomelania hupensis , the sole intermediate host of Schistosoma japonicum in China. Investigating the response of O. hupensis to climate warming is crucial for guiding targeted and precise interventions against these snails , thereby advancing the progress towards schistosomiasis elimination and sustaining the achievement of elimination in China. This study aims to quantify the multi-scale responses of O. hupensis to climate warming. Method We conducted a 45-day temperature-controlled laboratory experiment with adult O. hupensis from Hubei Gongan County, China, exposing snails to the Low Temp group (5 ˚C), the Control group (25 ˚C), and the High Temp group (30 ˚C) to assess body-size-dependent survival. We then analyzed O. hupensis surveillance data from 1990 to 2022 across 12 provinces in China (34,554 villages), linked to climate data downloaded from ERA5-Land. We developed sliding-window models to examine climate exposure across life stages to assess population-level responses to climate warming, and used general linear mixed-effects models to explore the environmental factors influencing climate responses (geographic variables: latitude, longitude, altitude, land use, historical climate variability). Model performance was evaluated to identify the best predictive models, which were subsequently used to project future O. hupensis density under the SSP1-2.6, SSP2-4.5, and SSP5-8.5 scenarios. We further sampled 240 wild O. hupensis and measured their body sizes to validate the previous results inversely. Results At the individual level, we observed that larger snails had a higher survival rate at both the Low Temp group (91.6%, 95% CI 85.8–97.7%) and High Temp group (45.7%, 95% CI 31.9–65.6%) compared with the control group (76.5%, 95% CI 58.7–99.5%). At the population level, O. hupensis density closely tracks climate warming, with 92.0% of populations showing positive temperature sensitivity. Exposure during the coldest (January: 2.7 × 10 –2 , 95% CI 3 × 10 –3 –5.1 × 10 –2 ; February: 3.3 × 10 –2 , 95% CI 1.1 × 10 –2 –5.6 × 10 –2 ) and breeding seasons (April: 2.4 × 10 –2 , 95% CI 6 × 10 –3 –4.3 × 10 –2 ; September–October: 3.5 × 10 –2 , 95% CI 2 × 10 –3 –6.8 × 10 –2 ) had a greater influence on O. hupensis density under climate warming. O. hupensis in waterbody-dominated areas showed the largest density growth rates ( ß = 1.6 × 10 –1 , 95% CI 1.1 × 10 –1 –2.2 × 10 –1 ), whereas crop populations were the most sensitive to land cover, a 1% increase in crop cover was associated with a 0.2 increase in population density. At the ecosystem level, only 19.0–24.6% of populations were expected to benefit from climate change by 2100, and these benefiting populations were concentrated in regions where sampled wild snails had a mean body size of 8.2 mm. Cropland will account for 72.0% of populations benefiting from climate warming, compared with 17.2% in forests and 8.3% in impervious-dominated areas. Conclusion The O. hupensis populations grow under climate warming but are regulated by land-use types. To mitigate the impacts of climate warming and land-use on snails, surveillance and integrated interventions should be strengthened through multi-sector collaboration.