Continued investment is needed if rates of mother-to-child transmission of HIV in the US are to remain low, investigators write in the online edition of the Journal of Acquired Immune Deficiency Syndromes.
They calculated that HIV-positive women gave birth to 8,700 infants in 2006 – a 30% increase in the number of births compared to 2000.
“That the number of infants exposed to HIV has risen by approximately 30% since 2000 has important implications for perinatal prevention programs and highlights the need to reinforce and expand critical resources for all HIV-infected women,” comment the authors.
Surveillance data from 2005 showed that the rate of mother-to-child transmission was approximately 2.5%, well above the rate that can be achieved with appropriate treatment and care.
“Further reduction in the number of infected infants will depend upon extension of these known effective interventions to…women who do not access them,” write the investigators.
With the right treatment and care, the risk of mother-to-child transmission of HIV can be reduced to below 1%.
An accurate understanding of the extent of the epidemic in women of childbearing age is needed so that prevention services can be planned and properly financed. However, there is no single source of data from which to estimate the number of HIV-exposed infants in the US.
A total of 34 states and territories do, however, report on HIV-exposed infants, and other surveillance data can be used to estimate the total number of HIV-infected women and categories them according to the stage of their infection.
In addition, it is possible to gain an idea of pregnancy rates among women with HIV by looking at the result of observational cohorts.
Using these data investigators calculated the total number of HIV-infected women of childbearing age (15-44) living in the US and its dependent territories in 2006. They also estimated the number of HIV-exposed infants born in that year.
The total number of HIV-infected women of childbearing living in the US in 2006 was estimated to be 171,400. This figure included 37,000 undiagnosed individuals.
It was calculated that 115,200 women had a CD4 cell count of 200 cells/mm3 or above, and that the remaining women had a CD4 cell count below this figure.
The overall pregnancy rate in 2006 was 6 per 100 person years. Based on this rate, the investigators calculated that HIV-positive mothers gave birth to a total of 8,700 infants in that year.
Analysis of the results of cohort studies shoed that overall pregnancy rates did not change between 2001 and 2006.
However, the total number of births was 30% higher in 2006 compared to 2000. This was explained by an increase in HIV prevalence.
“Our analyses indicate that the number of HIV-infected women giving birth increased in the United States from 2000 to 2006,” write the authors, “the estimated number of births in 2006 to all women living with HIV disease was…approximately 30% higher the estimated number of births reported…in 2002.”
The rate of mother-to-child transmission can be reduced to very low levels, emphasise the investigators. Indeed, they comment on the “remarkable” success of services. But investigators fear that the apparent success of prevention interventions will mean that they are targeted for cuts.
However, the authors emphasise that the transmission rate if still well above target, and that the complex problems of many HIV-positive women mean that some do not access services. This means that efforts to prevent transmissions are still vital, especially as HIV prevalence is increasing in women of childbearing age, and this increase has been accompanied by a steep rise in the number of HIV-exposed infants since 2000.
The investigators therefore conclude, “the increased number of perinatal HIV exposures estimated in the present study, in combination with the well-documented efficacy of available interventions, and the continuing health disparity implications of the status quo, combine to produce a powerful argument that [prevention] programs should be strengthened rather than reduced.”
Whitmore SK et al. Estimated number of infants born to HIV-infected women in the United States and five dependent areas. J Acquir Immune Defic Syndr, (online edition) doi: 10.1097/QAI.0b013e3182167dec, 2011 (click here for the free abstract).