Q fever in Greece: Findings of a 13 years surveillance study.

Q fever is an endemic disease in different parts of Greece. The current study aimed to investigate the prevalence of acute Q fever disease in Greece through the operation of the national reference centre for Q fever. A total of 5397 sera were received from febrile patients under the suspicion of Q fever infection during a 13 years period (2001-20013). A questionnaire was filled in by the clinicians containing certain clinical/epidemiological/demographic information. The diagnosis was based both on IFA (IgG and IgM phase II antibodies against Coxiella burnetii) and on molecular means. A total of 685 (12.7 %) samples were initially tested positive for acute Q fever. The mean (±SD) age of patients was 55.3 years (±18.7). Out of the 489 convalescent samples, 134 (27.4 %) samples indicated a minimum of a four-fold seroconversion and were considered as laboratory confirmed cases of acute Q fever. Pneumonia was the most frequently encountered clinical symptom with presence in 6.8 % of all positive samples. Forty six (46) patients were laboratory confirmed as chronic Q fever cases. Climate seemed to influence the distribution of Q fever cases throughout the years. The findings of the current study comply with past studies carried out elsewhere that had demonstrated a clear relation of the disease with temperature, south winds, etc. This study represents the first large scale attempt to gather a long period information on Q fever infection in Greece. The findings of the current study support the fact that Q fever is an important endemic zoonotic disease in Greece and needs increased awareness by clinical physicians and health care system.