Accuracy and costs of rapid human immunodeficiency virus testing technologies in rural hospitals in Zambia.

OBJECTIVE: To evaluate the accuracy and costs of newer rapid human immunodeficiency virus (HIV) antibody tests in primary health care settings in rural Zambia. METHODS: Three rural hospitals participated in this study. During a baseline assessment period, HIV testing practices were recorded on 250 consecutive clients at each hospital. Baseline evaluation was compared with 250 subsequent consecutive clients tested using a testing algorithm consisting of an initial screening HIV Dipstick test (McDonald Scientific [PVT] Limited, Harare, Zimbabwe) followed by confirmatory testing of all reactive specimens using the HIV Capillus test (Cambridge Diagnostics, Galway, Ireland), in conformity with World Health Organization HIV testing recommendations. Quality control was performed at a national university teaching hospital laboratory. RESULTS: A total of 1,500 clients was entered, with an HIV seropositivity rate of 53.2%. Most HIV testing was performed on patients with signs and symptoms suggestive of HIV infection. Same-day results were provided for only 16%. The HIV Dipstick testing algorithm sensitivity was 96.9%, and specificity was 98.0%. Counselor dissatisfaction was greater with the Dipstick algorithm as a result of 5.3% discordant results. Use of the HIV Dipstick testing algorithm cost between US $3.00 and US $3.80 per client tested. CONCLUSIONS: The accuracy of HIV testing in unsophisticated rural laboratories in Zambia is acceptable. Although HIV Dipstick testing algorithm costs were relatively high for a developing country, this HIV testing procedure is currently the most economical method available in Zambia. Accurate, less costly HIV testing algorithms are still needed.

PIP: The Program for Appropriate Technology in Health (PATH) HIV Dipstick antibody test was developed to make a low-cost tool available to primary health services, especially in rural areas where laboratory facilities are often inadequate. The accuracy and costs of this test were evaluated at three rural hospitals in Zambia in 1996. During a baseline assessment period, HIV testing practices were recorded for 250 consecutive patients at each hospital. The baseline evaluation was compared with 250 subsequent consecutive patients tested using an algorithm consisting of an initial screening HIV Dipstick test followed by confirmatory testing of all reactive specimens using the HIV Capillus test. The HIV seropositivity rate among the 1500 patients tested was 53.2%. The HIV Dipstick testing algorithm sensitivity was 96.9% and the specificity was 98.0%. Counselor dissatisfaction was greater with the Dipstick algorithm because of a 5.3% discordant result rate. The cost of the HIV Dipstick testing algorithm was US$3.00-3.80 per client tested. Despite this relatively high cost, the HIV Dipstick procedure is currently the most economical technology available in Zambia. Further study is needed to find more accurate, less costly HIV testing algorithms.

Rapid HIV testing and counseling for voluntary testing centers in Africa.

OBJECTIVE: Voluntary HIV testing and counseling (VTC) has been shown to reduce the incidence of HIV in cohabiting couples who now represent the majority of new infections in many African cities. Community and client perceptions of a 1-day voluntary testing and counseling program in Lusaka, Zambia, were assessed, and a rapid HIV-testing algorithm was evaluated for VTC centers. METHODS AND DESIGN: Between May 1995 and June 1996, outreach workers distributed written invitations door to door. The 1-day program was held 6 days/week including weekends. Transport, child care and lunch were provided. Community and client surveys followed in July 1996. RESULTS: Over 3500 couples married for a median of 4-5 years requested testing: 23% were HIV+/+, 57% were HIV-/- and 20% were discordant with one HIV+ and one HIV- partner. Sixty-eight per cent of couples surveyed had made the decision to be tested before attending the 1-day program and 80% had not previously known where to obtain HIV testing. Knowledge that couples could show discordant results rose from 29 before to 88% after pretest counseling. Clients reported high levels of satisfaction with the services and 90 out of 99 (92%) preferred to receive their results the same day. Clients at another center who waited 10 days for their results reported more fear, and 19 out of 31 (61%) would have preferred to get their results the same day. Over 99% of those who attended the program thought active promotion of voluntary HIV testing in the community was a positive thing, as did 90% of those who were invited but did not attend. Sensitivity and specificity of the rapid test algorithm were both 99.4% in this setting. CONCLUSIONS: Active promotion of voluntary HIV testing and counseling in couples is needed to reduce the spread of HIV in high-prevalence areas. The use of rapid, on-site HIV testing allows clients to receive result-specific counseling in a single visit. Ongoing quality control of a subset of samples at an outside laboratory is essential.

PIP: Voluntary, confidential HIV testing and counseling centers (VTCs) are becoming increasingly popular in African cities with high HIV prevalence. This strategy is especially effective among HIV-discordant couples. During a 12-month period during 1995-96, community outreach workers distributed written invitations to attend a VTC in Lusaka, Zambia, in which couples would receive testing and result-specific counseling in a single visit; transportation, child care, and lunch were offered. Over 3500 couples, one-third of those invited, responded to the invitation and underwent rapid HIV testing. The Dipstick HIV-1 + 2 rapid test was used for screening and the Capillus HIV-1/HIV-2 rapid test was employed for confirmation. Both partners were HIV-positive in 23% of cases and both were HIV-negative in 57%; in the remaining 20% of couples, 1 partner was HIV-positive and the other was uninfected. 68% of participating couples had decided to seek HIV testing before receiving notice of the VTC, but 80% of them did not know where to obtain such services. Couples who attended the VTC that offered same-day test results reported substantially less fear than those who had to wait 10 days for their results. 99% of those who participated in the program thought active community promotion of VTC was desirable, as did 90% of those who were invited but did not attend. The rapid test algorithm had both a sensitivity and specificity of 99.4%. Continued retesting of a subset of samples at an outside laboratory remains essential, however. This intervention is associated with an estimated cost of US $84 per HIV infection prevented.