Chronic fatigue syndrome after Giardia enteritis: clinical characteristics, disability and long-term sickness absence.
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 employmentloss 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, 1262 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.


CONCLUSIONS
After giardiasis enteritis at least 5% developed clinical characteristics and functional impairment comparable to previously described post-infectious fatigue syndrome.
Institute of Clinical Medicine, Department of Neurology, and Unit for Gastroenterology, Department for Medicine, Haukeland University Hospital, Bergen, Norway. halvor.naess@haukeland.no
Halvor
H
Naess
Morten
M
Nyland
Trygve
T
Hausken
Inghild
I
Follestad
Harald I
HI
Nyland
D000041:Absenteeism; D000328:Adult; D001007:Anxiety / Q000453:epidemiology / Q000523:psychology; D003863:Depression / Q000453:epidemiology / Q000523:psychology; D004185:Disability Evaluation; D004751:Enteritis / Q000150:complications* / Q000469:parasitology*; D015673:Fatigue Syndrome, Chronic / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D005872:Giardia / Q000302:isolation & purification*; D005873:Giardiasis / Q000150:complications*; D006801:Humans; D015994:Incidence; D008297:Male; D009664:Norway; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors