|In a large, observational study, hospitalizations for inflammatory bowel disease and infectious gastroenteritis increased with heat-wave durations.|
|Heat waves are associated with increases in mortality, commonly reported in patients who are sick or elderly. To examine the effect of heat waves on inflammatory bowel disease (IBD) and infectious gastroenteritis (IG), investigators conducted a retrospective, observational study involving 2030 patients admitted to the University Hospital of Zurich with IBD (738 patients), IG (786 patients), or non-IBD, noninfectious intestinal inflammation (NII; 506 controls). The study period was from 2001 through 2005, during which there were 17 heat waves, defined as ≥6 consecutive days with temperatures ≥9 degrees Fahrenheit above the average daily maximum.
Admissions for IBD rose 34.4% overall during heat-wave periods and 4.6% for each additional day of a heat wave. Admissions for IG, which was not distinguished as bacterial or viral, rose 34.8% overall during heat-wave periods and 4.7% for each additional day of a heat wave; however, the maximum increase in admissions per day was estimated at 7.2% when a 7-day lag in the development of IG was considered. No such lag effect was observed with IBD. NII controls experienced no increase in hospital admissions during the heat waves.
Presumably, the increases in hospitalizations for infectious gastroenteritis are related to greater environmental growth of pathogens with higher temperatures. The cause of the increase in inflammatory bowel disease hospitalizations is uncertain, and could reflect increased physical stress associated with heat, changes in growth rates of infectious pathogens, or other factors.