Access to HIV viral load monitoring in resource poor settings has long felt a bit like the search for the Holy Grail—a seemingly hopeless, but essential quest. But at the recent ICASA conference, the corridors were buzzing with the possibility that routine use of this technology in sub Saharan Africa could soon become a reality.

Viral load has been the gold standard for monitoring the response to antiretroviral therapy in western settings for many years. WHO recommended it as the strategy of choice in their 2013 guidelines, but, mainly because of the complexities of sample transport, the technicalities of the test, and the costs, most countries still rely on clinical staging and CD4 counts to identify treatment failure. In places where access to treatment for opportunistic infections is extremely limited, waiting for a life threatening stage 4 event is highly risky. And without virological confirmation, current immunological criteria for failure would result in around two thirds of patients being switched unnecessarily to second line treatment. If we believe in investing money in a monitoring strategy it seems logical to invest in one that clearly identifies patients with true virological failure and before they present with a life threatening complication. So what is needed to make routine viral load monitoring a reality in resource poor settings?

Simplification of testing processes is key. Use of dried blood spot (DBS) rather than plasma samples removes many of the complexities of sample transport. Programmatic experience we presented at ICASA from Médecins Sans Frontières (MSF) programmes in Zimbabwe and Malawi demonstrated acceptable sensitivity and specificity with DBS samples. [1] In Zimbabwe, where use of DBS meant that samples could now be taken on any day of the week and easily transported, 83% coverage was achieved after 2 years – compared with 27% in Malawi, where plasma samples were used for a longer period of time. In addition to DBS, a rich pipeline of point-of-care (POC) viral load technologies may eventually enable viral load implementation in very remote sites or in clinics with lower throughputs. One such technology demonstrated at ICASA was the simple amplification-based assay (SAMBA), developed by the University of Cambridge, UK. This POC assay has been field tested successfully by MSF programmes in Malawi and Uganda where it was feasible for use in rural district hospital settings with good sensitivity and specificity achieved using plasma samples. [2]

While it is clear that the logistic and laboratory challenges are being faced head on, as a clinician, the main message I took home is that the viral load test alone is not enough. Unless there is serious investment by HIV programme managers to ensure that viral load monitoring is implemented effectively the potential gains will be lost. This point was demonstrated in a poster presentation of MSF data from South Africa where routine viral load monitoring has been utilized for several years. Of 7,094 patients on long term antiretroviral therapy (ART) only 4,041 (57%) had had at least one viral load measurement. Of these 4041, 37% had a most recent viral load result above 1000 copies/mL (the WHO threshold for concern) but no clear action to address this had been taken. After training and mentoring of clinic staff, the number of viral load tests increased from 357 in 2011 to 3,829 in 2012. [3]

Another programme management debate at ICASA centred on adherence counselling. What type and duration of intervention best promotes treatment adherence in patients with a high (>1000 copies/mL) viral load? Analysis of MSF programme data from Swaziland showed that attending three sessions of counselling, as advised by the programmatic algorithm, did not increase the likelihood of patients achieving viral re-suppression. Further investigation is undoubtedly needed. In some settings up to 60% of patients have been shown to resuppress after a counselling intervention, but considering the workload implications it is essential we develop effective and efficient approaches for management of patients with a high viral load. Perhaps just the knowledge of the viral load result is sometimes enough to motivate improvement in patients’ adherence.

If viral load monitoring is to be truly useful, patients themselves need to demand viral load testing and be able to understand their result. Investment is needed in educating patients to ensure that access to viral load strengthens patients’ empowerment and self-management of their chronic disease. Access to routine viral load testing could also enable programmes to comfortably reduce the number of clinic visits for patients with viral suppression while ensuring that patients with clinical needs are getting the additional input they require.

In summary, sorting out the technical issues seems, dare I say it, to be the easy part. It would be a huge mistake for the HIV world to financially invest at scale in a test that is not properly implemented. The aim should be to not just retain patients on ART but to retain them with an undetectable viral load. If the introduction of viral load monitoring is to be a success, laboratory and ART programme managers and patients need to work together to achieve this goal.

Helen Bygrave is a UK-trained General Practitioner. For the past 8 years she has worked for Médecins Sans Frontières (MSF) supporting HIV/TB programmes across Africa and Asia and currently works as one of MSF’s HIV/TB advisors in the Southern Africa Medical Unit. One of her major focuses has been supporting the implementation of a UNITAID-funded MSF viral load initiative aiming to influence the scale-up of viral load in resource-poor settings. In December 2013, Helen was at the ICASA conference in Cape Town. The International Conference on HIV/AIDS and Sexually Transmitted Infections in Africa (ICASA) is the principal forum on HIV/AIDS & STIs in Africa.

References:

[1] Bygrave H et al. Scaling up routine viral load monitoring in resource limited settings: field experience from antiretroviral therapy (ART) programmes in rural Zimbabwe and Malawi. 17th International Conference on AIDS and STIs in Africa, Cape Town, abstract ADS037, 2013.

[2] Satellite Number: SASS01. Implementing routine viral loading testing in Africa: No longer why but how?

[3] Shroufi A et al. The identification and management of widespread treatment failure: The benefits of routine viral load .17th International Conference on AIDS and STIs in Africa, Cape Town.