Low Prevalence of Brucella agglutinins in Blood Donors in Central Province of Iran

Brucellosis is a zoonotic disease of worldwide distribution and has great economic importance. Despite its control in many countries, it remains endemic in Iran. Brucellosis was investigated in many high risk occupational groups; however, few studies on the prevalence of brucellosis among blood donors are available. To determine the seroprevalence of brucellosis antibodies in blood donors, a serological study was carried out in central province of Iran. A total of 897 healthy blood donors with mean age 37.23 ± 10.9 years were enrolled in the study. Laboratory tests including Standard Tube Agglutination Test (STA) and 2-mercaptoethanol (2ME) agglutination were checked in all samples. STA dilution ≥ 1:80, and in the presence of 2-mercaptoethanol (2ME) agglutination ≥ 20 was considered positive. Out of 897 cases, 11.9% were inhabitants of rural areas. 41.5% had history of consumption of unpasteurized dairy products and 9.3% had history of contact with domestic animals. A very low level of Brucella agglutinins was present in 3(0.33%) of the samples and only one sample (0.11%) was found to be truly positive for Brucella agglutinins. 2ME was negative in all samples. None of these 4 subjects showed signs and symptoms of brucellosis in 6 months follow-up. On the basis of our data, brucellosis has no epidemiological and clinical importance in our blood donors; therefore, it is not recommended to perform screening tests such as, STA and 2ME to identify brucellosis antibodies in the sera of blood donors.