The correlation between rainfall and the prevalence of trematode metacercaria in freshwater fish in Thailand.

The author performed a retrospective study on 5 complete reports with geographical data and the prevalence of metacercariae in Thailand. The relation between rainfall (derived from the geographical data) and the prevalence of metacercariae in freshwater fish (derived from the overall infection rate of metacercaria) was investigated. The least- square equation plot rainfall (y) versus prevalence (x) is y = 12.4x + 43.8 (r = 0.858; p < 0.05). A significant correlation was discerned between rainfall and the prevalence of freshwater fish infection. According to these previous studies, the prevalence of freshwater fish infection may depend on rainfall. Predicted prevalence of freshwater fish infection as a GIS figure was also presented.