Application of a procedure starting with an HIV-I/HIV-2 mixed EIA

A procedure to diagnose the infections by the human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) was proposed. The specimens were first screened by a mixed enzyme immunoassay (EIA) for the presence of antibodies to HIV-1 as well as to HIV-2. Those screened positive were thereafter confirmed and differentiated their antibody reactivities toward the antigens of HIV-1 and HIV-2 by Western blot (WB). This procedure was found to be one hundred percent accurate to diagnose 66 coded specimens with well defined seroreactivities to HIV-1 from Centers for Disease Control (CDC). While its accuracy in HIV-2 antibody testing could not be evaluated in the present study owing to the lack of HIV-2 standard reference specimens. With this procedure, six out of each of two groups of 176 foreigners and 719 individuals who visited the Taipei Municipal Venereal Disease Control Institute (TMVDCI) were screened repeatedly reactive by the mixed EIA. By WB only four of the first six and two of the second six were confirmed HIV-1 positive. Their antibody reactivities toward HIV-2 antigens were either absent or significantly much lower than those toward HIV-1 antigens. Furthermore, none reacted to the env proteins gp160 and gp120 of HIV-2. We therefore concluded that out of the 895 test individuals, only six were confirmed infected with HIV-1. There were neither HIV-2 infections nor dual infections. The similar pathogenicity and trans mission of HIV-2 as of HIV-1 justify an equal appreciation for HIV-2 testing. The present study indicated that a procedure starting with a mixed EIA aimed to diagnose HIV-1 as well as HIV-2 did not have any adverse effects on HIV-1 testing.