South Africa’s HIV/AIDS Crisis: why drug resistance matters
Following the introduction of three-drug antiretroviral (ARVs) regimens in 1996, HIV/AIDS morbidity and mortality were rapidly reduced in countries where these medications were made available for the public, particularly in North America and Brazil. HIV, however, naturally mutates and eventually develops resistance to ARVs, which are then rendered ineffective. Patients infected with drug resistant strains of HIV are therefore commonly moved to alternative (and significantly more expensive) regimens known as 2nd line drugs.
The average patient in the US today, for instance, typically initiate antiretroviral therapy on 3rd or 4th line drugs priced at an annual average of approximately R 299,000. This rising cost is because of the early introduction of AIDS treatment in that part of the world: the virus simply had ample time to develop resistance. In north-eastern Brazil, it was reported in 2011 that 19.1% of all new HIV infections were resistant to 1st line drugs. 10–15% of these strains were resistant to all available ARVs, so-called super HIV.
Meanwhile, in South Africa, the population has remained largely treatment naïve because AIDS treatment was not comprehensively introduced in the country until 2004. This means that South Africans initiating ART today are still mostly put on 1st line drugs at an annual cost of about R 7,700. South Africa is about eight years ‘behind’ other nations such as the US or Brazil, which is a good thing, resistance-wise.[quote float=right]South Africa is about eight years ‘behind’ other nations such as the US or Brazil, which is a good thing, resistance-wise.[/quote]
But will similar levels of drug resistance as those in the US or Brazil not eventually emerge in southern Africa? Say, perhaps in eight years’ time? If so, the consequence could be nothing short of a looming catastrophe of unprecedented proportions — the notion of South African health services sustaining public AIDS care worth more than an annual quarter of a million rand per patient is frankly absurd.
So what is the likelihood of this ever happening? Let us consider four essential variables: the future, viral mutation, adherence, and, perhaps most importantly, community viral loads.
With respect to the future, well who can tell? Pharmaceutical pricing and patents may change; new and better drugs may or may not be developed. However, global funding for HIV/AIDS research has been decreasing steadily in recent years and we should not anticipate any game-changing breakthroughs, at least not in our most immediate future. Talk of a cure is still premature.
Whereas natural viral mutation is inevitable, certain things, however, can be done to slow its progression. For instance, non-adherence to ARVs is a major cause of drug resistance. ‘Retention in care’ is a measure for the quantity of patients who remain in their AIDS programmes over time and take their pills regularly (i.e. adherence). Troublingly, retention in care remains poor in southern Africa. According to systematic reviews, as many as 35% abandon their treatment. Improving retention in care would therefore be one good place to start.
Another good place would be the ‘community viral load’. An individual suppressing HIV with ARVs has a low viral load and there is evidence that well-treated patients are much less likely to transmit the virus. As such, treatment is prevention. The higher the viral load in the community as a whole, the greater the likelihood of mutation and drug resistance, so it would seem logical to simply treat everyone as soon as they are diagnosed in order to keep the community viral load supressed.
Community viral loads remain high
Accordingly, in many developed countries, this is also the official recommendation. In the US, for instance, patients initiate ART regardless of their CD4 cell count, a measure used to gauge the detrimental effect of HIV on an individual’s immune system. So when the UNAIDS reports that we have now reached any level of treatment coverage in any given African country, the truth is that this number is based on how many people are ‘in-need’ of treatment, which again is determined by when they are deemed eligible for drug initiation. Throughout sub-Saharan Africa, such criteria, say CD4 <250, has traditionally been set low because of scarce resources. Patients are initiated earlier now, especially in South Africa, but not soon enough, meaning that community viral loads remain high.
‘Coverage’ is not the only concept sometimes used to obscure important epidemiological facts. Yes, it is true that South Africa’s ‘national prevalence rate’ is 19.2% in the reproductive age group (15–49), but this number disguises the fact that if we look separately at ethnic groups, we will find HIV prevalence to be highly disproportionate: 22.7% blacks, 0.6% whites, 4.6% coloureds (mixed race), and 1.0% Indians/Asians (reproductive age groups). Additional afflictions brought on by multi-resistant strains of HIV would therefore affect these groups differently and (very) unequally.[quote float=right]Many HIV-positive people might again one day find themselves back in the dark days before the dawn of the treatment era.[/quote]
While we cannot predict with any level of certainty how drug resistance will develop in South Africa, we can say that there is nothing much to suggest that its progression should occur any slower than in America. On the contrary, poor rates of adherence and relatively high community viral loads seem to hint that it might actually happen faster. If US or Brazilian levels of drug resistance are reached, there are grounds for serious concern about the continued affordability and sustainability of public AIDS care in South Africa.
Providing millions of ordinary people with ARVs, only to withhold them later when it becomes financially unmanageable to do so seems unimaginable, but following the line of thought presented here, it is one possible future. As such, many HIV-positive people might again one day find themselves back in the dark days before the dawn of the treatment era.
Dr Bent Steenberg Olsen, PhD, is based at the African Centre for Migration and Society (ACMS), Africa’s leading scholarly institution for research and teaching on human mobility at the University of the Witwatersrand.