Micro-counterimmunoelectrophoresis: a rapid screening technique for trypanosomiasis.

A rapid and economical micro-counterimmunoelectrophoresis (MCIE) test, for antibody to trypanosome antigens, has been developed which may prove useful in trypanosomiasis surveillance. MCIE was more sensitive and more rapid than immunodiffusion (ID). Serum samples from trypanosome-infected rabbits and cattle (Nigerian and Gambian), from Kuwaiti dogs and camels, from Ivory Coast sleeping sickness patients, from Brazilian patients with Chagas's disease, plus mouse-anti-malaria sera have been tested by MCIE with Trypanosoma brucei, T. vivax, T. congolense and T. cruzi antigens. A few of the rabbit and the mice sera were also tested against Trichomonas vaginalis, Entamoeba histolytica, Plasmodium berghei or P. chabaudi antigens. Whenever possible the MCIE results were compared with parasitological or other serological tests (ID; indirect fluorescent antibody test, IFAT; enzyme-linked immunosorbent assay, ELISA; complement fixation test, CFT or indirect haemagglutination test, IHAT). The MCIE test was not species specific but the homologous species reactions were more often positive than heterologous ones. Homologous species reactions, with rabbit sera, detected antibodies as early as 10 days after infection and developed more precipitin lines as the infection progressed. Trypanosomal antigens and antisera cross-reacted with those of other protozoa (E. histolytica, Tr. vaginalis, P. chabaudi, P. berghei, and Babesia sp. and Leishmania sp.) but such reactions required an antigen concentration 4 to 16 times greater than that required for homologous trypanosome reactions (a factor which might be exploited for identification of different species of trypanosome).(ABSTRACT TRUNCATED AT 250 WORDS)