MSF research points to ways to expand viral load testing for HIV in developing countries
ATLANTA, MARCH 5, 2013—At the 20th Conference on Retroviruses and Opportunistic Infections (CROI) in Atlanta, the international medical humanitarian organization Doctors Without Borders/Médecins Sans Frontières (MSF) will present data today on strategies to reduce the costs and complexity of rolling out routine viral load monitoring in developing countries. Access to routine viral load monitoring will become increasingly important as WHO updates its HIV treatment guidelines and millions more people initiate earlier treatment.
“Viral load monitoring—a test that measures the amount of virus in a person’s blood and thus the effectiveness of antiretroviral treatment—is critical in allowing treatment failure to be detected earlier, and ensuring that people receive the support they need to adhere to treatment,” said Dr. Jennifer Cohn, medical coordinator for MSF’s Access Campaign. “It’s a standard part of HIV disease management in developed countries but due to high costs and the lack of suitable technology, this type of virological monitoring is almost non-existent in developing countries. We need to challenge this state of affairs by ensuring there is financial and political support for roll-out of viral load in remote settings as a routine part of decentralized care.”
Although the national guidelines in 15 out of the 16 countries where MSF has HIV projects recommend viral load monitoring, it is only widely available in two of these countries (Kenya and South Africa). The two main barriers to roll-out of viral load concern the cost of testing and the difficulties of sample collection and transport. In two studies to be presented at CROI from its projects in Thyolo, Malawi, MSF will show how viral load monitoring can be adapted for resource-limited settings by using novel technologies and strategies to address these barriers.
The first study looked at simplification. Instead of conducting a blood draw, which requires a nurse, MSF was able to acquire blood samples by performing a simple finger-prick in order to prepare dried blood spots, which were then transported to a laboratory with viral load testing capabilities. Because dried blood spots (DBS) are easy to prepare, extremely stable at room temperature, and can even be sent in the mail, the finger-prick method of collecting samples in conjunction with the practicality of using DBS helps to overcome the challenges of health worker shortages and lack of sophisticated sample transportation networks for blood-based samples. This makes access to viral load testing easier for patients in rural areas, who no longer need to travel long distances to reach facilities with testing capacity.
“We were able to use some very simple techniques to overcome staffing, cost, and logistical constraints to get people in very remote communities the gold standard for monitoring HIV therapy,” said Dr. Laura Triviño Duran, medical coordinator of MSF's project in Thyolo, Malawi. “We have to keep trying these field-adapted solutions to ensure that the benefits of viral load monitoring reach as many patients as possible.”
A second viral load study to be presented at CROI looked at overcoming cost barriers preventing routine viral load implementation. MSF evaluated the accuracy and cost-saving of pooling samples of dried blood spots compared to individual viral load testing in a rural district laboratory in Thyolo, Malawi. Pools of five patient samples were tested for viral load. If significant amounts of virus were detected in the pooled sample (either at a threshold of 1000 copies/mL or 5000 copies/mL), this meant there was replicating virus in at least one of the patients in the pooled sample, indicating treatment failure or non-adherence. Detectable virus in the pooled sample then triggered individual viral load testing for each of the patients in the pool.
Compared with individual testing, the pooling method means significantly fewer tests to screen. For the 220 study participants, pooling specimens instead of individual viral load testing could save between $2,023 to $4,011. When extrapolated to the viral load monitoring needs of the more than 30,000 people on antiretroviral treatment in Thyolo district, the savings are between $160,000 and $290,000 per year.
“Viral load monitoring is still one of the best tools we have to stay one step ahead of this virus,” said Sharonann Lynch, HIV policy advisor at MSF’s Access Campaign. “If we’re serious about reaching the enormous public health potential of expanded, earlier HIV treatment, viral load monitoring, along with enhanced adherence support, must become a standard part of treatment.”