THE ANTIBODY-RESPONSE TO DRACUNCULUS-MEDINENSIS IN AN ENDEMIC HUMAN-POPULATION OF NORTHERN GHANA

The serum antibody response (total, and isotypes IgG1, IgG4, IgM, IgA and IgE) to Guinea worm infection was examined in humans from a highly endemic area of northern Ghana by ELISA and SDS-PAGE/Western blot tec hniques using an adult D. medinensis antigen. Sera were obtained early and late in the peak transmission period, from persons with patent an d postpatent infections, as well as from persons from the same endemic area who claimed never to have had Guinea worm infection. To observe for potential cross-reactions in the tests, sera were also obtained fr om areas with no transmission of Guinea worm from patients with hookwo rm, O. volvulus and W. bancrofti infections, and from noninfected cont rols. Sera from persons living in the Guinea worm endemic area reacted extensively with Guinea worm antigen in both tests, and large numbers of bands were produced in the Western blots (up to 35 identified for some sera). For most antibody isotypes, the ELISA absorbance values ob tained with sera from the same individuals varied between the two tran smission seasons, with the highest titres present towards the end of t he peak transmission period- The mean antibody titres for persons in t he patent and postpatent infection categories were not significantly d ifferent when sera were obtained at the same season of the year. Perso ns from the endemic area, who claimed never to experience patent infec tions, also had antibodies to Guinea worm, although at significantly l ower mean levels than for the patent and postpatent categories. The hi ghest specificity in the ELISA and the most homogenous Western blots w ere obtained when detecting for antibodies of the IgG4 isotype.