Miniature anion-exchange/centrifugation technique for the diagnosis of microfilaraemia in the field

The miniature anion-exchange/centrifugation (AEC) technique, developed originally for the detection of low parasitaemias in laboratory rodents, was adapted to field use for the diagnosis of trypanosomiasis in man in Africa and was tested in The Gambia. During this field study it was found that microfilariae of Dipetalonema perstans could also pass through the anion exchange column and appear in the centrifugate as 'medusa heads'. One locality-group (Mansafa Bolon) showed a generally higher prevalence and prevalences in women over 40 years old were higher than in the corresponding male groups in every locality. The potential usefulness of this technique in epidemiological studies of filariasis and ways of improving the accuracy of numerical estimates are briefly discussed.