Symptoms of infection and altitude illness among hikers in the Mount Everest region of Nepal.

Symptoms of acute mountain sickness (AMS) and infection were recorded daily in 283 hikers walking the Mount Everest base camp trek in the Nepal Himalaya. Some 57% of subjects developed AMS, and 87% experienced at least one symptom of infection during the study period. Coryza (75%), cough (42%), sore throat (39%), and diarrhea (36%) were especially prevalent. All symptoms of infection were more prevalent among those with AMS. The incidence of AMS was greater among those with more symptoms of infection (p = 0.00004), and the number of symptoms of infection experienced with positively correlated with AMS score (rs = 0.43, 95% CI = 0.33 to 0.52). These results suggest that symptoms of infection are common at high altitude and are associated with a higher incidence of AMS. People with infections should ascend at a slower rate at high altitude.