February 13, 2004

HIV Infection Higher Than Expected Among Pregnant Tijuana Women

UCSD Study Includes Counseling & Rapid HIV Testing

HIV infection among pregnant women in labor at Tijuana General Hospital in Mexico is 14 times higher than previously reported by CONASIDA, the Mexican organization that tracks AIDS cases, according to a study conducted by physicians at the University of California, San Diego (UCSD) School of Medicine.

Presented at the 11th Conference on Retroviruses and Opportunistic Infections Feb. 10, 2004 in San Francisco, California, the study found a 1.26 percent HIV infection rate among 947 women in labor tested during June through September 2003. CONASIDA had estimated the prevalence of HIV infection at only 0.09 percent among pregnant Mexican women.

“The key to preventing HIV infection in children is the identification and treatment of pregnant women who are HIV positive,” said Rolando Viani, M.D., UCSD assistant professor of pediatrics, who presented the findings at the conference. “Unfortunately, HIV testing during pregnancy is not routinely done at Tijuana General Hospital.”

The researchers found that the vast majority of women in labor (96.7 percent of those asked) were willing to undergo HIV counseling and rapid-result testing. When a woman in active labor was found to be HIV positive, she was given the drug zidovudine (ZDV, AZT) intravenously, and was advised to refrain from breast feeding, which is a means of transmitting the disease to her infant. Within the first week of life, the newborn was tested for HIV, with repeat tests at four weeks, two months and four months. The child also received zidovudine orally for six weeks. In addition to the test in labor and delivery, the women were given follow-up tests to confirm the diagnosis after delivery.

The problem of HIV/AIDS in Tijuana doesn’t stop at the border, added Stephen Spector, M.D., chair of the executive committee of the National Pediatric AIDS Clinical Trial Group, chief of the UCSD Division of Pediatric Infectious Diseases, and director of UCSD’s Mother, Child & Adolescent HIV Program, which oversaw the UCSD study at Tijuana General Hospital.

The Tijuana/San Diego border crossing is the busiest land port of entry in the world with more than 131,000 legal border crossings daily. Because so many people cross the border on a daily basis, and since Mexicans frequently seek medical care and consultation in the United States, San Diego is impacted by the rate of HIV infection in Tijuana, Spector noted.

“Our maternal-child HIV clinic at UCSD is about 50 percent Latinas,” Viani said. “Of these women, 95 percent are of Mexican descent. This points to the problem that spills over on both sides of the border.”

Mexico ranks 3rd in the Americas for AIDS cases with 29.9 cases per 100,000 residents. According to CONASIDA, the highest rates of AIDS are in Baja California with 62 cases per 100,000 residents. Although the rates of HIV infection are unknown, they are likely to be more than 10-fold greater than the reported number of AIDS cases.

In 2002, the California Department of Health Services released a study among high-risk men who have sex with men in Tijuana and San Diego. The two-year study revealed that 43 percent of Tijuana men reported unprotected heterosexual intercourse and 25 percent reported sharing needles in the previous four months. Furthermore, 39 percent of men reported having sexual partners from across the border in their lifetime.

“We can’t solve the problem of HIV/AIDS in San Diego unless we work with the problem in Tijuana,” Spector said. He added that “the false perception is that compared to HIV/AIDS in Africa, there isn’t a problem in Mexico.”

Fortunately, several Tijuana physicians recognized the need to stop HIV transmission in their border communities, and began meeting with Spector and Viani in a bi-national effort to develop programs for HIV positive mothers and children. The program in Tijuana became an extension of the successful 15-year-old UCSD Mother, Child and Adolescent HIV Program that has provided comprehensive HIV care to pregnant women, children and teens. As a result of the UCSD program, there have been no transmissions of HIV from mother to child in women followed by the UCSD program in the last nine years. However, some pregnant women, even in San Diego, who have gone undiagnosed, have still given birth to HIV-infected infants during this period.

For the past five years, the UCSD team has followed pediatric HIV patients at Tijuana General Hospital and last March began HIV testing for women attending the hospital’s prenatal clinic. However, since 40 percent of women who deliver at the hospital have never had prenatal care, in June the UCSD and Tijuana General Hospital physicians expanded the testing to all women in active labor who arrive at the hospital.

The prenatal counseling and testing at Tijuana General Hospital was first funded by the National Institutes of Health (NIH) and the Center for AIDS Research (CFAR) at the UCSD School of Medicine. Current funding comes from CFAR and the University of California’s Universitywide AIDS Research Program, which funded the study presented at the Retroviral Conference.

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