HIGH SEROPREVALENCE OF COXIELLA-BURNETII INFECTION IN EASTERN CANTABRIA (SPAIN)

Background Coxiella burnetii is the causative agent of Q fever, a worl dwide zoonosis which shows a wide diversity of clinical manifestations . The objective of this seroepidemiological study was to estimate the prevalence of antibodies to C. burnetii in a representative population of the Eastern area of the Cantabrian Community (Northern Spain). Met hods A cross-sectional study was conducted in 595 subjects from Easter n Cantabria. Four different zones (one urban and three rural zones) we re defined according to the geographical characteristics of the area a nd the economic activities of the population. The population sample fo r this study was collected between December 1994 and March 1995, and w as stratified by age, sex and municipality of residence. IgG and IgM a ntibodies against C. burnetii were assayed by an indirect immunofluore scence technique. Results The prevalence of anti-phase II Coxiella IgG (titre greater than or equal to 1:16) was 48.6% (95% confidence inter val: 44.6-52.6%), with 81.3% having a titre of greater than or equal t o 1:64. The prevalence of IgG increased with age, ranging from 12.0% i n people <15 years to 70.3% in those >65 years (P < 0.001). The antibo dy detection rate was higher in males (53.6%) than in females (43.3%) (P < 0.01). The prevalence of anti-phase II Coxiella IgG was less amon g subjects living in the urban zone (32.8%) than in those living in th e other three rural zones: the two situated on the coast (54.0% and 54 .9% respectively) and the inner mountainous zone (82.3%) (P < 0.001). Conclusions The prevalence of C. burnetii infection observed in this s tudy is one of the highest reported in Europe. The eastern area of Can tabria is a hyperendemic area for Q fever.