Climatic predictors of molecular haemoparasite test positivity among hospitalised goats during the monsoon transition period in tropical India.

Vector-borne hemoparasitic diseases pose a significant threat to the health and productivity of small ruminants, particularly in tropical regions characterized by high humidity and elevated temperatures. This study aimed to investigate the dynamic association between climatic indices and the molecular test positivity rates of hemoparasitism in clinically symptomatic goats during the monsoon transition period in the tropical monsoon zone of India. A total of 102 goats hospitalized with non-specific clinical signs from November 2024 to May 2025 were randomly screened for the presence of five major hemoparasite genera, Theileria, Babesia, Anaplasma/Ehrlichia, hemotropic Mycoplasma, and Trypanosoma spp., using both blood smear examination and polymerase chain reaction (PCR). The climatic indices, including average daily temperature (°F), maximum daily temperature (Tmax), minimum daily temperature (Tmin), daily variation in temperature (Tdelta), average relative humidity (%), maximum daily relative humidity (RHmax), minimum daily relative humidity (RHmin), daily variation in relative humidity (RHdelta), temperature-humidity index (THI) and sunshine duration were recorded on each sampling day. Spearman's rank correlation coefficient was applied to assess the association of these climatic variables on the molecular test positivity of hemoparasites. Theileria and Anaplasma/Ehrlichia spp. emerged as the predominant pathogens, with positivity rates of 58.82% and 43.13%, respectively. Among all pathogens, the apicomplexan piroplasms (Theileria and Babesia spp.) demonstrated statistically significant correlations with climatic indices, whereas hemotropic bacteria (Mycoplasma spp.) and Trypanosoma spp. showed no significant associations. Theileria and Anaplasma/Ehrlichia test positivity rates showed similar trends with RH during the monsoon transition period. Concurrent infections were frequently observed in goats positive for Anaplasma/Ehrlichia spp., followed by co-occurrence with Theileria and Babesia spp. This is the first study to quantitatively link climatic indices with PCR-confirmed hemoparasitism in goats during the monsoon transition in tropical India. The findings provide preliminary insights into climate-associated patterns of molecular haemoparasite positivity among hospital-presented goats and may inform future climate-based surveillance and vector-control studies. Validation in community-based goat populations is required before these associations can be used as generalized predictive or early-warning indicators.