The role of antibody in natural resistance to African trypanosomiasis.

The nature and usefulness of trypanoresistance in West African Baoule cattle was studied by exposing animals in areas of high Glossina density. Under such conditions, Zebu and some Baoule died soon with high parasitaemia while resistant Baoule showed little patent parasitemia, almost no anaemia and thrived. Subsequently the role that specific antibody may play in such trypanoresistance was analyzed. In the first instance we examined protective antibody titres during T. congolense infection of inbred mice strains, comparing results obtained in trypanosome-mouse combinations where the host controls parasitemia and survives with those obtained when the host fails to control parasitemia and dies. We then attempted to extend these observations to cattle by following the disease course and appearance of neutralizing antibodies in animals of known sensitivity to natural Glossina challenges, following artificial challenge with T. congolense infected Glossina.