Impacts of ambient temperature on the burden of bacillary dysentery in urban and rural Hefei, China

Bacillary dysentery continues to be a major health issue in developing countries and ambient temperature is a possible environmental determinant. However, evidence about the risk of bacillary dysentery attributable to ambient temperature under climate change scenarios is scarce. We examined the attributable fraction (AF) of temperature-related bacillary dysentery in urban and rural Hefei, China during 2006-2012 and projected its shifting pattern under climate change scenarios using a distributed lag non-linear model. The risk of bacillary dysentery increased with the temperature rise above a threshold (18.4 degrees C), and the temperature effects appeared to be acute. The proportion of bacillary dysentery attributable to hot temperatures was 18.74% (95 empirical confidence interval (eCI): 8.36-27.44%). Apparent difference of AF was observed between urban and rural areas, with AF varying from 26.87% (95% eCI 16.21-36.68%) in urban area to -1.90% (95 eCI -25.03 to 16.05%) in rural area. Under the climate change scenarios alone (1-4 degrees C rise), the AF from extreme hot temperatures (>31.2 degrees C) would rise greatly accompanied by the relatively stable AF from moderate hot temperatures (18.4-31.2 degrees C). If climate change proceeds, urban area may be more likely to suffer from rapidly increasing burden of disease from extreme hot temperatures in the absence of effective mitigation and adaptation strategies.