This week, as scientists and public health partners meet at the International AIDS Society (AIDS 2012) meeting in Washington, D.C., one of the key challenges for the U.S. President’s Emergency Plan for AIDS Relief (PEPFAR) is to continue to increase the numbers of individuals on antiretroviral therapy (ART) while making sure that those who are currently on ART get quality care.
Increasing access to improved clinical management in resource-limited settings and identifying persons on ART whose treatment is beginning to fail is a key area where CDC, one of the key U.S. agencies implementing PEPFAR, brings its public health research and evaluation expertise to the table. Through research supported by PEPFAR, CDC in partnership with the Kenya Medical Research Institute (KEMRI) and the Kenya Ministry of Health and Sanitation will present at AIDS 2012 the results of three studies on viral load (VL) testing and illustrate how treatment access and outcomes can be improved.
Viral load testing helps to determine if a person on ART is no longer responding to the particular drug regimen they are on (i.e., virologic failure), putting them at risk for illness and also making it more likely they may transmit HIV to partners or to unborn children. When someone begins to fail to respond to their treatment, they are moved to second line drugs, which may be more expensive or difficult to manage. It is important to determine when failure begins to maximize prevention and treatment goals while ensuring those taking ART can stay on first line drugs as long as possible. However, use of virologic measurement to monitor response to ART is not routinely provided in Kenya due to cost and accessibility.
Confirming Treatment Failure in Children – In Kenya, about 9% of those on ART are children less than 15 years old. CDC and partners did a comparison study of the current Kenya national clinical and immunologic criteria for treatment failure in children (see text box) and compared it with criteria for virologic failure as detected by VL testing. Eighty-five percent of those pediatric patients with signs of treatment failure by current Kenya criteria were confirmed to have virologic failure. Immunologic or clinical criteria alone were less predictive of virologic failure but, when both criteria were met, they predicted virologic failure 96% of the time. The study showed that using clinical and immunologic criteria together is a close predictor of virologic failure and helps correctly identify patients who need a change in their drug regimen.
Optimizing Clinical Management to Reduce Risk of HIV Transmission From Mother to Child – For HIV-infected women, using ART during pregnancy and breastfeeding reduces the risk of HIV transmission to their child. Maternal viral load is an important predictor of transmission risk, and VL monitoring during pregnancy can optimize clinical management.
To determine the proportion of pregnant HIV-infected women who had detectable viral loads (>400 copies) indicating treatment and prophylaxis goals were not being met, CDC and partners conducted a study across 66 clinical sites in Kenya’s Nyanza Province. Of the pregnant women with HIV without signs of clinical or immunologic failure, almost one in four (24%) had a detectable viral load. Those with a baseline CD4 count of <200 were more likely to have a detectable viral load. Recommendations based on this research are to provide enhanced ART adherence counseling and clinical monitoring of pregnant women and suggests routine VL monitoring of pregnant women can identify those that need additional intervention to maximize treatment and prevention outcomes.
Making Improved Clinical Management of HIV More Accessible – One of the challenges of using VL monitoring in resource-limited settings is that it typically requires use of blood plasma, which can be difficult to collect and requires special handling to transport. CDC and KEMRI conducted research to evaluate whether dried blood spots (DBS) could be used effectively in viral load testing. Unlike plasma, DBS samples can be taken with a finger or heel stick, present a low biohazard risk, and can be transported without special temperature controls. Researchers compared results of VL testing using paired DBS and blood plasma specimens and found close agreement in the results from both samples.
Research on alternatives in clinical and laboratory practices is one way that CDC and partners identify best practices and cost-efficient alternatives for resource limited settings, helping PEPFAR-supported countries in reaching HIV treatment and prevention goals.
To learn more about CDC’s efforts in Kenya, visit the CDC Kenya website.