Under-five years old acute watery diarrhea (U5AWD) accounts for most diarrheal diseases' burden due to rotavirus infection. It is claimed that many climatic and socioeconomic factors are associated with U5AWD. However, little information is available about the occurrence of U5AWD in Iran and the adjusted effect of potential determinants.
We collected a dataset containing the seasonal numbers of U5AWD cases at the district level of Iran through MOHME. We calculated the district level Standardized Incidence Ratio and Moran's I values to detect the significant clusters of U5AWD over sixteen seasons from 2014 to 2018. In addition, we examined twelve Bayesian hierarchical models to recognize the strongest in predicting the seasonal number of incidents.
Iran has many hotspots of U5AWD, especially in southeast areas. An extended spatiotemporal model with seasonally varying coefficients and space-time interaction outperformed other models, becoming our proposal in modeling U5AWD. Temperature had a global positive relationship with seasonal U5AWD in districts (IRR: 1.0497, 95% CrI: 1.0254–1.0748), due to its varying effects in winter (IRR: 1.0877, 95% CrI: 1.0408–1.1375) and fall (IRR: 1.0866, 95% CrI: 1.0405–1.1357) seasons. Also, elevation (IRR: 0.9997, 95% CrI: 0.9996–0.9998), piped drinking water (IRR: 0.9948, 95% CrI: 0.9933–0.9964), public sewerage network (IRR: 0.9965, 95% CrI: 0.9938–0.9992), years of schooling (IRR: 0.9649, 95% CrI: 0.944–0.9862), Infrastructure-to-Household Size Ratio (IRR: 0.9903, 95% CrI: 0.986–0.9946), wealth index (IRR: 0.9502, 95% CrI: 0.9231–0.9781) and urbanization (IRR: 0.9919, 95% CrI: 0.9893–0.9944) of districts were negatively associated with seasonal U5AWD incidence.
The development of specific alert systems could be a strategy to predict high-risk areas of U5AWD using climatic inputs. Also, the study anticipates a higher incidence of U5AWD in districts with weaker hygiene and socioeconomic status. Therefore, policymakers should take appropriate preventive actions in such areas.