[Note: the free full text of this article is available as a PDF HERE. Giardiasis is an intestinal infection resulting from infestation with Giardia - a parasite commonly found worldwide and generally transmitted via human, animal or bird feces-contaminated water, food, or hands. Infection usually lasts a few weeks, but in some individuals may enter a prolonged phase. In this case, one to three years after a major community outbreak, 5% of those who'd tested positive for giardiasis presented with long-lasting symptoms consistent with a diagnosis of ME/CFS. The authors note that this more than 8 times the normal ME/CFS rates of 0.23% to 0.56% in different populations.]
Background: A waterborne outbreak of Giardia lamblia gastroenteritis led to a high prevalance of long-lasting fatigue and abdominal symptoms. The aim was to describe the clinical characteristics, disability and employment loss in a case series of patients with Chronic Fatigue Syndrome (CFS) after the infection.
Methods: Patients who reported persistent fatigue, lowered functional capacity and sickness leave or delayed education after a large community outbreak of giardiasis enteritis in the city of Bergen, Norway were evaluated with the established Centers for Disease Control and Prevention criteria for CFS.
Fatigue was self-rated by the Fatigue Severity Scale (FSS). Physical and mental health status and functional impairment was measured by the Medical Outcome Severity Scale-short Form-36 (SF-36). The Hospital Anxiety and Depression Scale (HADS) was used to measure co-morbid anxiety and depression. Inability to work or study because of fatigue was determined by sickness absence certified by a doctor.
Results: A total of 58 (60%) out of 96 patients with long-lasting post-infectious fatigue after laboratory confirmed giardiasis were diagnosed with CFS.
In all, 1,262 patients had laboratory confirmed giardiasis. At the time of referral (mean illness duration 2.7 years) 16% reported improvement, 28% reported no change, and 57% reported progressive course with gradual worsening. Mean FSS score was 6.6. A distinctive pattern of impairment was documented with the SF-36. The physical functioning, vitality (energy/fatigue) and social functioning were especially reduced. Long-term sickness absence from studies and work was noted in all patients.
Conclusion: After giardiasis enteritis at least 5% developed clinical characteristics and functional impairment comparable to previously described post-infectious fatigue syndrome.
Source: BMC Gastroenterology, Feb 8, 2012. Naess H, Nyland M, Hausken t, Follestad I, Nyland HI. Institute of Clinical Medicine, Department of Neurology, and Unit for Gastroenterology, Department for Medicine, Haukeland University Hospital, Bergen, Norway.