Testing for AIDS on samples of dried blood prepared on filter papers.

A substantial rise in the number of AIDS cases has been observed during the past year in many African countries, and HIV-2 indigenous transmission and increased disease have since gained importance in Senegal. Both for HIV-1 and HIV-2 diagnosis, ELISA positivity is followed by a Western blot test for specific antibodies. The serum samples are stored at sub-zero temperatures both during shipment and storage while awaiting serological testing. Attempts have been made to use dried blood on filter papers for AIDS diagnosis, in 35 samples from Africa and 10 from USA, along with corresponding serum samples. The concordance has been good with an almost invariable ELISA confirmation on Western blot, no selective loss in any of the bands in Western blot and the Pearson coefficient value for ELISA testing on serum and dried blood lots of 0.85. Based on the data obtained during the intentional exposure of blood-impregnated filter papers, from nine HIV-positive and one HIV-negative patient from the USA, to varying temperatures and humidity for different intervals, blood collection on filter paper would appear to have emerged as a satisfactory procedure for HIV seroepidemiological studies.