If your immune system is on the ropes — a very common scenario for tens of millions of sleep-deprived, stress-battered and nutrient-deficient Americans — just about any infection can trigger post-infectious chronic fatigue syndrome. And a new study has added another infection to the list: Giardia, a waterborne parasite that can cause severe GI upset called "Giardia gastroenteritis."
Researchers in Norway tracked 1,262 patients after a widespread outbreak of Giardia in the city of Bergen. They found that 58 of them (5%) developed CFS, with "long-lasting fatigue and abdominal symptoms" — an incidence of CFS 8 times higher than in the "general population."
"Our findings suggest that there may be a relationship between Giardia infection and CFS," concluded the researchers in BMC Gastroenterology.
Naess H, Nyland M, Hausken T, et al, "Chronic fatigue syndrome after Giardia enteritis: clinical characteristics, disability and long-term sickness absence." BMC Gastroenterol. 2012 Feb 8;12:13.