제주도 주민에서 브루셀라 감염에 관한 혈청역학적 조사

Abstract

Background : Brucellosis is a zoonosis caused by the gram-negative coccobacilli Brucella. Humans are infected by ingestion of unpasteurized milk or dairy products from or by direct contact with infected animals. Although human brucellosis is known to be rare, there has been an increase in bovine brucellosis in Cheju island since the 1980s. The purpose of this study was to investigate the prevalence of anti-Brucella antibody in people from endemic areas. Methods : Sera obtained from 2,372 residents in Cheju island were screened for anti-Brucella antibody by slide agglutination test and confirmed by duplicated tube agglutination test. Sera with titers equal to or above 1 :80 were considered positive. Results : Fourteen of 2,372 sera were positive(0.59%). Positive rate was 0.34% in males and 0.82% in females. There was no significant difference in the positive rates between males and females. Seropositive rate was slightly higher in persons at 40 years or older. Seropositive rates in different areas of Cheju island were as follows : South Cheju-gun 0.97%, North Cheju-gun 0.64%, Cheju city 0.46%, and Sogwipo city 0.0%. The antibody titers of positive sera were determined: 7 sera were positive at 1:80, 4 at 1:160, and 3 were positive at 1 :320. Occupations of seropositive persons were as follows : 7 farmers; 3 stockbreeders; 1 engaged in service trade; 1 engaged in food processing; 1 working at a stable; one unknown. Seropositive rates among people at a relatively high risk were 0.94%. Seropositive rate of people who were proven to be not at risk for Brucella infection was 0.51%. There was no significant difference in the seropositive rates between the two groups(P>0.05). Conclusion : These findings confirmed the occurrence of human Brucella infection in Cheju island and suggest the need for surveillance in other part of the country as well.