High rate of fatigue and abdominal symptoms 2 years after an outbreak of giardiasis

The aim of this study was to evaluate the prevalence of fatigue and abdominal symptoms 2 years after Giardia lamblia infection. All 1262 cases who had Giardia-positive stool samples during an outbreak in 2004 in Norway received a questionnaire in 2006 asking about fatigue and abdominal symptoms. Fatigue was reported by 41%, whereas 38% reported abdominal symptoms, and there was a highly significant association between these symptoms. Increasing age was a highly significant risk factor for fatigue. The symptoms were not due to chronic infection in this cohort. Our data warrant further investigations into the late effects of giardiasis.