Prevalence of cytomegalovirus in Thai blood donors by monoclonal staining of blood leukocytes.

Four hundred and forty-one blood and serum samples were collected during August to October 1998 from the blood donors at the blood bank of Rajvithi Hospital, Bangkok, Thailand. Their ages were varied between 18-55 years. All specimens were tested by immunostaining and ELISA methods. Forty-seven specimens (10.66%) gave positive results by immunostaining. Among these, 20 cases were seropositive and 27 cases were seronegative. The age group between 41-50 years had a high percentage of CMV infection as judged by the immunostaining method, more than the other age groups. By ELISA, 231 cases (52.38%) had positive IgG antibody to CMV, 42 cases (9.52%) were IgM antibody positive and 39 cases (8.84%) were positive for both IgG and IgM antibodies. The age groups between 36-40 years had a higher percentage of IgM antibody positives than the other age groups. Since the immunostaining method can detect early CMV infection, screening for the presence of antibodies alone is not enough to rule out CMV infection. Immunostaining along with ELISA detection of antibodies was useful for determining a decrease in CMV infection.