Prevalence of Anti-Borna Disease Virus Antibody in Horses and Their Caretakers in Bangladesh

To elucidate the spread of Borna disease virus (BDV) in Asian countries, we surveyed 48 normal horses in Bangladesh and their 26 caretakers for the BDV antibody by electrochemiluminescence immunoassay. Eleven horses (23%) were found positive. None of the 5 horses at the age of < 1 year was positive. Seven of 23 horses (30%) at the age of 1 year were positive, as well as 4 of 16 horses (25%) at the age of 3 years. The geometric average of the ECLIA titer of the antibody positive horses at the age of 1 year, 3041, was significantly lower than that found at the age of 3 years, 6887, by the Mann-Whitney test (P = 0.012). Sexual preference in the prevalence of anti-BDV was not evident. None of the 26 male horse caretakers between the ages of 12 to 54 years was positive, including those who were taking care of the antibody positive horses. Total RNA extracted from the peripheral blood nucleated cells was tested by polymerase chain reaction coupled with reverse transcription capable of detecting 200 molecules of BDV p40 RNA per reaction. None of the 11 seropositive horses and the 5 randomly selected seronegative horses was positive. The results showed that BDV is penetrating the Bangladeshi labor horse population with similar levels reported in Germany, Iran and Japan, although the viral genome in the blood was not detected.