Contemporary State of the Problem Q Fever in Bulgaria

ABSTRACT

Q fever is a leading in presence and importance rickettsial zoonosis in Bulgaria. The purpose of this study is to reveal the contemporary state of the disease on the basis of vast etiological, clinical and epidemiological investigations. Serologically by complement fixation test (CFT) and microimmunofluorescence test were examined a total of 319993 sera from domestic and wild mammals and birds, and 19 794 patients. The seroepizootiology of Q fever in three comparative periods (1950-1976, 1977–1988, 1989–2006) reflects three different stages in the organizational structure of the Bulgarian stock-breeding. During 2002–2006 the average seropositivity for C. burnetii was 10.18% (13.69% in goats, 11.5% in sheep, 8.53% in cattle). Seropositive buffalos, horses, swine, geese, ducks were also established. Positive data for the significant spread of C. burnetii among 15 species of wild mammals and birds exists too. Clinical and pathologicalgical materials were tested by culture, and in general 88 isolates were obtained. Serologically 3087 (15.78%) from the tested 19560 patients with atypical pneumoniae were positive. Convincing serological data for C. burnetii was obtained in human vascular diseases (34.61% from the tested 234 with Burger's disease and thrombosis of thigh artery).

The C. burnetii isolates showed differences in pathogenicity for guinea pigs and mice following inoculations by various routes. Experimentally produced Q fever with respiratory manifestations in lambs and a sheep has been described. By means of immunofluorescent haemocytic test were established that 16.84% ixodic ticks out of 1769 tested were infected with C. burnetii. Three hundred ninety three agricultural foci (AF) of Q fever among cattle, sheep and goats have been revealed. Presented is the autonomous circle of C. burnetii in AF and its interrelations with the nature foci of the infection.