Risk of infectious gastroenteritis and IBD relapse increases during heat wave periods

Swiss researchers report an increase risk of inflammatory bowel disease (IBD) relapse in patients during heat wave periods. The study published in The American Journal of Gastroenterology also found an increase of infectious gastroenteritis during heat waves, with the strongest impact following a 7 day lag time after the heat wave.

The authors noted, "There is evidence for an increase of IBD hospital admissions by 4-6 percent for each additional day within a heat wave period. Presence of a heat wave was estimated to increase the risk of infectious gastroenteritis by 4-7 percent for every additional day within a heat way period. In the control group there was no evidence for a heat wave effect."

Researchers from Zurich, Switzerland studied the data of 738 IBD and 786 IG patients admitted to the University Hospital of Zurich over a 5-year period (2001-2005) and compared data with other non-infectious chronic intestinal inflammations, as the control. The Swiss Federal Office for Meteorology and Climatology provided the climate data. A total of 17 heat waves were identified during that period.

"The evidence of patients with IBD having a significant increase risk of flare ups compared to the control group shows a cause and effect between the climate and the disease," said lead author Christine N. Manser, MD. "This study ties heat stress to digestive symptoms supporting the observed seasonal variation in the clinical course of inflammatory bowel disease and suggests that microbial infections of the gut might be additionally influenced by climate changes."

Some people with IBD may experience flare ups during significant weather changes. "Heat waves are known to cause physical stress as evident from increased frequencies of other stress dependent health events such as heart attacks. Physical as well as mental stress has been shown to cause flares of IBD, and may explain the increase in IBD hospital admissions during heat waves," commented Dr. Manser. "During a heat wave patients with IBD should be aware that there is an increased risk for a flare and contact their gastroenterologist in cases of an increase of stool frequency or abdominal pain. The public should know that a sudden onset of abdominal pain and diarrhea during or shortly after a heat wave might be symptoms of an infectious gastroenteritis."