PHOENIX -- A new test available at Banner Good Samaritan Medical Center will allow women who were not previously tested for human immunodeficiency virus (HIV) during pregnancy to be tested for the virus.
The OraQuick Rapid HIV-1 Antibody Test allows physicians and nursing staff to learn the results within a few minutes and, if the mother is HIV-infected, to administer antiretroviral therapy immediately to prevent perinatal transmission to an unborn child.
Although many women are screened for HIV during their pregnancy, an estimated 10 percent to 15 percent of HIV-infected mothers do not receive care before labor and delivery (L&D), said Cathleen Harris, MD, a perinatalogist practicing at Banner Good Samaritan and other Banner Health hospitals.
"Rapid HIV testing in obstetric units can help the labor and delivery staff to identify and offer treatment to HIV-infected women in time to reduce HIV transmission to their child," Harris said.
A pregnant woman with an HIV infection has a 25 percent to 30 percent chance of passing the infection to her baby with no treatment. In the past, pregnant women would only receive AZT during pregnancy and labor, and the baby would get AZT for the first six weeks after delivery. Using that approach, the transmission rates declined to between five percent and eight percent.
For women receiving antiretroviral medications whose levels of the HIV virus are less than 1000 copies/ml at delivery, the risk of transmission to the baby is as low as one percent to three percent. An elective cesarean section delivery at about 38 weeks can reduce the transmission rates also, to about one percent to two percent.
"Even if a woman only gets medicines for a short time in late pregnancy or during labor only, the risk of HIV passage to the baby is greatly reduced," Harris said. "Most studies estimate a 10 percent risk of transmitting the virus if a short course of AZT is given in late pregnancy or only during labor. Even though giving short courses of treatment is not the optimal way to reduce transmission, it is still quite beneficial and we shouldn't miss any opportunities to give it."
In 2000, the U.S. Centers for Disease Control and Prevention (CDC) developed the Mother-Infant Rapid Intervention at Delivery (MIRIAD) study. MIRIAD allowed health-care workers to determine the feasibility of rapid HIV testing in L&D units of women with undocumented HIV status, provide timely therapy to reduce perinatal transmission, and facilitate follow-up care for HIV-infected mothers and their infants. The MIRIAD guidelines included women who were 34 weeks or later in their pregnancy and had no documented HIV results available to the L&D staff when asked for consent to be tested.
In Chicago, the MIRIAD study took place at the four hospitals with the city's highest HIV-1 prevalence among childbearing-aged women. Between November 2001 and July 2002, 6,262 women were admitted and 610 were eligible for rapid testing. Of these, 453 consented to participate and were tested with OraQuick. The median turn-around time in the three Chicago hospitals where nurses, midwives or physicians performed the rapid test was 45 minutes.
Three previously undetected HIV-infected women were identified and started on antiretroviral prophylaxis (none of the infants was HIV-infected).
"Because of the very favorable experience with the approach, the CDC recommended that rapid HIV testing on L&D be considered as a strategy for all pregnant women not previously tested during prenatal care," Harris said. "The CDC now recommends that all women be offered an HIV test as a routine part of prenatal care in an 'opt-out' approach, where HIV testing is considered a routine prenatal laboratory test unless a patient chooses to 'opt out.'
"In addition, if a woman tested preliminary positive, we would advise her not to breastfeed her baby, as that can transmit the virus. Also, we would be able to do a complete medical evaluation to confirm that an HIV infection is present and get that woman the services she needs," she added.
Harris was trained by the CDC in administration of the OraQuick test and recently began the Banner Good Samaritan program to encourage mothers entering labor to consent to rapid HIV screening test prior to birth of their babies.
"We are implementing the program here at Banner Good Samaritan in an effort to offer all women the opportunity for HIV screening prior to delivery," Harris said. "This program brings the very important subject of HIV/AIDS to the attention of our physicians, our staff, and our patients. We hope it will help promote healthy behaviors, while reducing the misconceptions and stigma of HIV."
Banner Good Samaritan has the first L&D unit in Arizona to offer rapid HIV testing. "We want to be the leaders of our community for health care among pregnant women, and we want to do all we can to ensure that mothers and babies can lead healthy lives," Harris said. "Even if we prevent only one case of pediatric AIDS, this program will have been extremely worthwhile."
Banner Good Samaritan Medical Center is Arizona's largest and busiest medical center. Located in downtown Phoenix, Banner Good Samaritan has been providing medical care since 1911. Today, nearly 1,700 physicians representing more than 50 specialties work with Banner Good Samaritan staff to provide care to more than 36,000 inpatients a year.
Source: Banner Health System