Background:
Q fever is a common and acute but rare chronic zoonosis caused by Coxiella burnetii. Its acute form manifests as atypical pneumonia, flu-like syndrome, or hepatitis. Some authors observed symptoms of chronic fatigue in a small number of patients after the acute phase of Q fever; in many cases serological assay confirmed the activity of Coxiella burnetii infection. The effect of antibiotic therapy on post-Q-fever fatigue syndrome has not been studied in south-east Europe thus far.
Case Reports:
Three patients are presented with post-Q-fever fatigue syndrome. All fulfilled the CDC criteria for chronic fatigue syndrome. IgA antibodies to phase I of the growth cycle of Coxiella burnetii were positive in two patients and negative in one. Two patients were treated with doxycycline for two weeks in the acute phase of illness and one with a combination of erythromycin and gentamycin. After 4–12 months they developed post-Q-fever fatigue syndrome and were treated with intracellular active antibiotics (fluoroquinolones and tetracycline) for 3–12 months. Efficacy of the treatment was observed in two patients, but in one patient the results were not encouraging.
Conclusions:
These results suggest the possibility of the involvement of Coxiella burnetii infection in the evolution of chronic fatigue syndrome. This is the first report on post-Q-fever fatigue syndrome in Mediterranean countries. Evidence of IgA antibodies to phase I of the growth cycle of Coxiella burnetii is not a prerequisite for establishing a diagnosis of CFS. The recommendation of antibiotic treatment in post-Q-fever fatigue syndrome requires further investigation.

Keywords: Anti-Infective Agents - pharmacology, Coxiella burnetii - metabolism, Croatia, Enzyme-Linked Immunosorbent Assay, Fatigue Syndrome, Chronic - etiology, Follow-Up Studies, HLA-DR Antigens - metabolism, Immunoglobulin A - chemistry, Q Fever - complications