Efficacy of Strategies to Reduce Mother-to-Child HIV-1 Transmission in Argentina, 1993-2000

In Argentina, the National Program on Human Retrovirus of the Health Ministry reported 3,526 cases of AIDS in women older than 12 from 1988 to 2000. During that time, the male-to-female ratio of AIDS decreased from 20:1 in 1988 to 3:1 in 2000. During 2000, 166,133 pregnant women were tested for HIV; the prevalence of HIV infection was 0.60 percent. In addition, as of September 2000, 1,255 cases of AIDS in children due to mother-to-child transmission (MTCT) were reported, representing 7 percent of the total AIDS cases in Argentina.

The current study describes the trends in interventions to prevent MTCT in HIV-infected parents and their infants in Buenos Aires and surroundings, the area where most HIV-infected people are identified in Argentina. The authors used findings from 874 children under 12 months of age, born to HIV-infected mothers, and their parents. The families were referred from three hospitals in Buenos Aires to the National Reference Center for AIDS (CNRS) for diagnosis of pediatric HIV infection during 1993-2000. The average age of the mothers was 25.4 years; the fathers' average age was 29.5 years. Eighty-one percent of the infants were younger than 6 months at the first diagnostic visit. The remaining 19 percent were 7-12 months old.

Although zidovudine treatment had been offered to pregnant women in some Argentinean hospitals since 1995, it was not until 1997 that the Ministry of Health ruled that diagnosis and treatment of HIV infection for prevention of MTCT should be included in the national medical practice. Of the mothers referred to CNRS for HIV diagnosis for their infants before 1995, 72.4 percent were asymptomatic. The percentage significantly increased to 90.2 percent between 1995 and 2000. During the observation period (1993-2000) 20 of 874 infants, 22 of 636 mothers, and 14 of 341 fathers died of AIDS.

From 1993 to 2000, the proportion of HIV-infected mothers who received prenatal treatment for MTCT prevention increased from 3.2 percent to 73.1 percent. Researchers also found an increase in the use of cesarean section, up to 54.8 percent in 1999-2000, when elective cesarean delivery started to be routinely offered to HIV-infected mothers. MTCT decreased from 37.3 percent before 1995 to 10.7 percent in 1999-2000, and 6.5 percent up to September 2001.

The proportion of HIV-infected mothers who breast-fed remained steady throughout the study period. Although Argentine medical personnel do not recommend that HIV-infected women breast-feed, and formula feeding is offered free, limited access to information and health care probably accounts for this finding, the authors noted.

The most frequent risk factor for the 636 mothers was sexual contact (73 percent) followed by IDU (17 percent). For the 341 fathers, IDU was the most frequent risk factor (67 percent) followed by sexual contact (21 percent). Approximately 42 percent of the mothers studied from 1997 to 2000 knew their HIV status before pregnancy; 44.8 percent knew during pregnancy; and 12.3 percent knew after the birth of their child.

Data in this study suggest that MTCT of HIV is decreasing and a consequent decrease in pediatric AIDS cases should be expected in the future. However, the figures on incomplete treatment and diagnosis after birth indicate that many women are not completely aware of the importance of monitoring their infection status during their pregnancies. To improve the universal counseling and testing of pregnant women, there is an urgent need to stimulate the desire and facilitate medical monitoring during pregnancy, particularly among the lower socioeconomic classes.

The study also recommended the development of educational programs to improve the awareness of HIV risk among men with a history of IDU who are partners of pregnant women.

Back to other CDC news for December 10, 2002

Previous Updates