Parallel Rapid HIV Antibody Testing during Pregnancy

Rolando Mario Viani, University of California, San Diego
Basic-Applied Clinical

This pilot study will evaluate the feasibility of using parallel rapid HIV testing on pregnant women without known HIV infection, who present to Tijuana General Hospital for prenatal care, or in active labor. In addition we will evaluate the performance of the parallel rapid HIV antibody testing strategy to confirm HIV infection when compared to the standard of care Western blot confirmatory test in pregnant women.

Over the past several years, the University of California San Diego Mother, Child and Adolescent HIV Program have had developed a research collaboration with pediatricians and obstetricians delivering HIV care in Baja California. AIDS is a major health crisis along the US- Mexico border. Mexico ranks third in the Americas for AIDS cases with 107,625 cases accumulated as of November 2006. According to CONASIDA, Baja California including Tijuana, has the second highest rates of AIDS in Mexico with 164 cases per 100,000 residents. The obstetric department at the Hospital General of Tijuana has an average of 389 deliveries per month, with only 26% having more than 2 prenatal visits. Most HIV infected pregnant women in Tijuana use hospitals for delivery, providing a crucial opportunity for systematic screening and intervention.

Written informed consent will be obtained from all women before any study-related procedures are performed. Eligible women will be offered counseling and parallel rapid HIV testing. A standardized form will be filled with demographic, risk behavior and clinical data for every pregnant woman. Blood will be drawn for parallel rapid HIV testing; Determine® HIV-1/2 and UniGold Recombigen┬« HIV test. Pregnant women with either one or both positive rapid test will have a real time confirmatory Western blot and will receive post-test counseling. Plasma samples from all women who tested negative for the rapid tests will be batched and tested with the standard HIV Western blot. Parallel rapid HIV test discordant results will be used to compare the sensitivity, specificity and predictive values of each rapid test with the gold standard Western blot. Our hypothesis is that by using two rapid HIV antibody tests in parallel, we may provide early confirmation if both tests are positive therefore replacing the confirmatory Western blot. An additional test, the Calypte┬« HIV-1 BED Incidence EIA will be performed in an attempt to differentiate women with early HIV infection from women with established HIV infection. Women found to be HIV infected will be offered combination antiretroviral therapy and follow-up care. Their exposed infants will receive preventive therapy and follow-up care. The estimated sample size will be 3,480 pregnant women and the duration of the study will be 12 months.

The findings of the research proposed in Tijuana will have important implications in providing an expeditious way to confirm HIV infection in pregnant women by parallel rapid HIV testing. This will enable us to intervene with antiretrovirals and reduce mother-to-child HIV transmission. This study is not only important for Baja California and throughout Mexico but for San Diego and California as a whole. Moreover, because 48% of pregnancies cared for at the UCSD Maternal HIV clinic are Hispanics (mostly Mexicans), and Latinos frequently cross the US-Mexico border, medical interventions in pregnant women in Tijuana are likely to have an important impact on Latino women in San Diego.