ENZYME IMMUNOASSAYS (EIAS) FOR THE DETECTION OF ANTI-HAEMOPHILUS DUCREYI SERUM IGA, IGG, AND IGM ANTIBODIES

Background and Objectives: Chancroid is a risk factor for heterosexual ly acquiring HIV. Controlling its spread may reduce HIV transmission. Coal of the Study: To develop EIAs for assessing antibody levels and f or seroepidemiologic studies. Study Design: Anti-Haemophilus ducreyi I gA, IgG and IgM EIAs were standardized using a crude cocktail antigen. Evaluation was on sera from Kenya, Rwanda, Thailand and The Gambia. T he two-tailed student's t test was used to compare results. Results: T he specificity of IgA was 97% (95% confidence interval (CI):95-99%), o f IgG was 92% (95%CI:89-95%), and of IgM was 93% (95%CI:98-100%). The sensitivity of IgA was 88% (95%CI:83-93%), of lgG was 93% (95%CI:89-97 %), and of IgM was 78% (95%CI:71-85%) in patients having an ulceration for more than eight days. Thus, 95% (95%CI:92-98%) of the chancroid p atients were seropositive for at least one antibody type. The IgG and IgA EIAs were more sensitive in patients older than 24 years of age. H igher IgG rates were found in HIV infected chancroid patients. Conclus ion: The EIAs should be useful for studying the kinetics of antibody L evels and the epidemiology of H. ducreyi infection.