Epidemiological characteristics of brucellosis in sheep and goats in Bulgaria: 2005-2008.

AIM: To analyse and present the epidemiological and epizootological situation of brucellosis in humans, sheep and goats caused by Brucella melitensis. METHODS: The veterinary health services analyzsd epidemiological reports, as well as other official documents, in relation to the epidemiology and the measures undertaken for control of brucellosis in Bulgaria, 2005-08. RESULTS: In Bulgaria animal infections caused by Brucella melitensis have been eradicated since 1941. In 2005 several Bulgarian citizens with Brucella infection were diagnosed in the National Reference Laboratory. All the cases were imported, mostly by employees on sheep and goat farms in Greece. For a period of four years, the number of infected humans was 120 and distributed in 12 districts. Epidemiological investigations suggested that 45 persons (37.5%) were infected in Greece and 4 in Cyprus, Turkey, Italy and Tanzania respectively. All other patients were considered to be infected in Bulgaria. They were owners of infected sheep and goats or consumers of contaminated dairy products with Brucella melitensis. In June 2006, the first outbreaks of brucellosis in sheep and goat farms were recorded in the Smolyan district. By the end of 2008, the infection was registered in 16 villages of 4 districts. The average prevalence rate in the infected herds was 12.2% in goats and 1.8% in sheep. In order to achieve eradication 496 goats and 117 sheep were slaughtered. CONCLUSION: A farm where goats from Greece were introduced illegally in 2005 was identified as the primary source of the infection. the negative epidemiological aspects of free movement of goods and persons in the European Union are considered.

Evaluation of three methods to measure anti-Brucella IgM antibodies and interference of IgA in the interpretation of mercaptan-based tests.

The results of a dipstick assay for the detection of immunoglobulin M (IgM) to Brucella smooth lipopolysaccharide (S-LPS) correlated with those of an enzyme-linked immunosorbent assay (ELISA) for IgM and of the serum agglutination test (SAT) performed with and without dithiothreitol. Two sera which were dithiothreitol-sensitive and were dipstick negative were shown to contain specific IgA. The dipstick assay is recommended as a simple method for detecting specific IgM antibodies in acute-phase brucellosis patients.