OpenForum – a blog by the Health and Human Rights community

[Editor’s note: This is the second in a series of posts covering topics related to drug resistance, including causes, effects, what is being done to fight drug resistance, and what needs to be done to limit the harm caused by drug-resistant pathogens. The first post is available here.]

The failure of antiretroviral therapy and the appearance of drug-resistant HIV strains continue to hinder efforts to keep HIV-positive individuals healthy. Unfortunately, the tests needed for early detection of antiretroviral therapy failure and drug resistance are expensive and not widely available in many countries with a high HIV prevalence. But the provision of such tests may benefit from an unusual source: old shipping containers.

Immunological and viral load testing are necessary to slow the emergence and spread of drug-resistant HIV strains. A recent meta-analysis published in The Lancet Infectious Diseases revealed that patients whose viral loads were monitored frequently (at 3-month intervals) were less likely to harbor drug-resistant HIV viruses at the time of virological failure than patients who were monitored less frequently or not at all. (Virological failure occurs when drugs are no longer able to suppress HIV replication and viral loads increase. Patients with viral loads of 1000 viral RNA copies per milliliter of blood or higher are considered to have experienced virological failure.)

Numerous studies have shown that resistant HIV viruses can be transmitted, causing some newly infected individuals to harbor HIV viruses resistant to antiretrovirals even before beginning treatment. The possibility of transmission of resistant viruses makes the expansion of viral load testing even more important — monitoring the viral loads of patients on antiretroviral therapy (ART) not only protects the patient from the harmful effects of virological failure and the emergence of drug resistant strains but it also protects the patient’s sexual partners (and the partner’s partners, and so on) from drug-resistant HIV.

It is clear that viral load testing helps limit the emergence, and thus likely the spread, of drug-resistant HIV. The problem is now one of provision: How can we make sophisticated laboratory tests available to populations without access to modern laboratory facilities? One answer comes from the South African company Toga Labs, which turns old shipping containers into HIV testing labs. The use of these “container labs” has garnered some attention in the media over the past several years (recently, by Reuters and Health-e) and has been discussed in the academic press (see, for example, this Commentary piece in Nature Methods). The labs are equipped to provide the viral load testing necessary for early detection of virological failure. These labs can also do CD4 count testing, which is routinely used to determine when to start patients on ART. Therefore, these labs also could be used as part of a program to expand ART coverage.

Unfortunately, there seems to be little (publicly-available) analysis as to the cost-effectiveness of these container labs as compared to traditional labs in stationary buildings. However, even without a clear cost benefit, container labs are advantageous for two reasons. First, the labs are “built” using existing materials (i.e., the old shipping containers) and thus do not require the consumption of other resources. Second, the labs are somewhat portable, as they can be carried anywhere that a large truck can go. The ability to transport the lab to different areas would extend access to medical testing facilities more than constructing a stationary lab. Even if the container lab could not be transported into the villages that it is meant to serve, it could likely be brought close enough so that HIV patients would not have to travel far to get to the testing facility — walking two miles to a lab parked near a major highway is much more feasible than walking forty miles to the closest city with permanent lab facilities.

Of course, portable labs are not the only solution to the lack of adequate viral load testing services. The development of simple, inexpensive point-of-care tests could also dramatically expand access to viral load testing. Building or upgrading labs in stationary buildings is also a possibility. The point I am making here is not that container labs are the best way to expand access to viral load testing but rather that they could be part of the solution to this problem. Cost and feasibility will always be major barriers in the implementation of public health interventions. Because of this, as global health practitioners, we need to make sure that we identify and evaluate innovative solutions to these problems — like turning old shipping containers into medical testing labs.

More information:

American Journal of Epidemiology: Role of viral load in heterosexual transmission of human immunodeficiency virus type 1 by blood transfusion recipients

The New England Journal of Medicine: Viral load and heterosexual transmission of human immunodeficiency virus type 1

BMC Infectious Diseases: Risk factors for poor virological outcome at 12 months in a workplace-based antiretroviral therapy programme in South Africa: A cohort study

JAIDS: A population-based approach to determine the prevalence of transmitted drug-resistant HIV among recent versus established HIV infections: Results from the Canadian HIV strain and drug resistance surveillance program

The New England Journal of Medicine: Antiretroviral-drug resistance among patients recently infected with HIV