Ending the HIV epidemic faces daunting barriers, former WHO HIV chief warns

The difficulty of bringing the HIV epidemic “down to zero” should not be underestimated, Kevin de Cock, former director of HIV for the World Health Organization (WHO), warned earlier this month in a meeting of the European AIDS Clinical Society (EACS) in Brussels.

EACS called the meeting to formulate new Standards of Care for HIV in Europe. The meeting’s themes will be summarised in another report, but Dr de Cock, who, having directed the US Ebola programme in Liberia, now heads the US Centers for Disease Control’s HIV programme in Kenya, set the tone with a wide-ranging plenary presentation on the first evening. This brought in everything from climate change to the political future of Africa as issues that would influence and challenge future progress not only in HIV care, but global healthcare generally.

What does ‘Down to Zero’ mean?

Dr de Cock had some criticism of the ‘90-90-90’ target’s influence in how people viewed the possibility of ending the HIV epidemic. This target aims for a global achievement of 72% of all people with HIV on treatment and virally suppressed by 2020, and 86% by 2030.

“90/90/90 was developed as an advocacy tool,” he said, “and a yardstick with which to measure progress. However I am not sure how it slid into being a policy and a series of technical documents on how to get there.”

He warned against a too-literal interpretation of getting HIV infection “down to zero” by 2030. He said he preferred the definition offered by Hillary Clinton at the International AIDS Conference in Durban last July. This was that virtually no child should be born with HIV; that teenagers and young adults everywhere would be at “significantly lower risk” of becoming infected than they are today; and that all people with HIV should have access to treatment to prevent illness and onward transmission.

“Almost no deaths. That,” de Cock said, “is achievable by 2030.”

What we have achieved in global health

Dr De Cock put the struggle against HIV into the context of the much longer and broader struggle for global health generally. This had made remarkable progress. For instance, 12.7 million children under five died in 1990; in 2015 it was six million, despite population increases. Infant mortality had declined in Kenya from 7.4% a year to 3.9% during the same period. An even better method of direct improvements in healthcare was maternal mortality in childbirth: in Kenya, this had declined from 0.38 per 100 live births a year in 1990 to 0.21 now.

HIV acted as an amplifier of progress towards global health in many ways. Indeed, before 2000 “global health” was not commonly used as a term to describe an area of work – “tropical medicine” was still used before then, with its focus on specific treatment for specific maladies. It was the fight for antiretrovirals for Africa and the programmes set up to provide them, such as the US President's Emergency Plan for AIDS Relief (PEPFAR) programme and the Global Fund, that had helped to turn global medicine into a public heath endeavour.

However there were worrying indicators that progress not only against HIV but its associated diseases might face a more difficult path ahead. Tuberculosis, for instance, had not declined by as much as other diseases. In 2000, there had been 2.3 million deaths from TB, 25% of them in people with HIV; in 2015 this was 1.7 million (a 26% decline), 29% in people with HIV.

Barriers to 90-90-90: testing

Talking about the 90-90-90 target specifically, de Cock said that “It is proving frustratingly difficult to get to the first 90” – this being the target of having 90% of all people with HIV diagnosed.

In Kenya, between 2004 and 2015, there had been 6.5 million HIV tests in a country of 44 million people. Three per cent of people tested had HIV, which is half the 6% prevalence rate estimated by UNAIDS. And yet it is estimated that 28% of people with HIV are not in care, largely due to lack of diagnosis, and 48% in the highest-prevalence provinces of Kenya. Testing programmes in high-prevalence counties are not detecting a higher proportion of undiagnosed people than in low-prevalence ones; rather the reverse.

Testing programmes had to be redesigned to focus on testing the populations most likely to have HIV, de Cock said. In Kenya as elsewhere, the highest yield of positive tests was in people diagnosed with TB, where 18% turned out to have undiagnosed HIV; yet still only 60% of people diagnosed with TB get an HIV test worldwide, and in Europe only 50% of people diagnosed with TB get an HIV test.

Other than in people with TB, the highest detection rate of positive HIV results came from programmes that tested all people admitted as hospital inpatients: in PEPFAR countries, the HIV rate in this group was about 4.6%. In Africa, a similar rate was seen in men coming forward for voluntary medical male circumcision: this was important as men were harder to reach in testing programmes otherwise. In countries where there are sexual health clinics, testing in these clinics also yielded high positivity rates.

In contrast, outpatient, mobile and home testing programmes had lower rates (between 1.5 and 3% in PEPFAR countries). Outpatient testing was still by far the most common setting for testing so yielded the biggest absolute number of positive results. However de Cock argued that false-positive and false-negative tests may become an increasing problem in a situation where most of the people with chronic infection have already been diagnosed.

The only way to definitely establish HIV prevalence and its contribution to mortality was to test every single person, and this could only be done ethically by testing the deceased. De Cock gave some very interesting data from a study in which every cadaver arriving at two mortuaries in Nairobi was tested for HIV.

Although HIV prevalence in both Nairobi and Kenya generally is 6%, 20% of all the deceased tested HIV-positive, and 30% of females. A quarter of those aged 25 to 44 tested HIV-positive but even in those over 45, 15% were positive, and the proportion of deaths due to HIV was also 15%. This is despite the fact that an estimated 70% of all people with HIV in Nairobi are on antiretroviral therapy (ART). HIV is therefore still responsible for a disproportionate number of deaths, even in settings where ART coverage is good.

Barriers to 90-90-90: retention

Regarding the ‘second 90’, retention in care, this differs hugely between countries, from excellent in some places with ‘one-stop-shop’ HIV services to poor in countries where people may have to seek care for different conditions in different places or have some care needs unsupported.

Some studies such as the ANRS 12249 study show that testing people and then just expecting those who test positive to turn up at clinics for treatment does not always work. There was no doubt that same-day prescribing – letting people walk out of the clinic with their antiretrovirals the day they are diagnosed – encouraged better retention and adherence, as did single-pill regimens, de Cock said. Ensuring good retention did not have to mean offering more intensive support to all patients. However it did mean offering a stable programme, and a place to call if things went wrong.

Models of care in which newly-diagnosed patients and those starting ART receive monthly or even weekly appointments while people who have been on stable ART for more than two years received full checkups only every six months are already being adopted in Kenya and indeed high-income countries by default, but should be fitted into a differentiated care model, as advocated by WHO guidelines. This should not only consider the frequency of appointments but also Where people were seen (Hospital? Community clinic? Home?) by Whom (Doctor? Nurse? Pharmacist? Peer adherence support worker?) and with What (Psychosocial assessment? Peer adherence support? Drug level monitoring?).

Barriers to 90-90-90: viral load monitoring and consistency of guidelines

The mention of clinical monitoring brings us to the third 90 – viral suppression. Here there is one very clear barrier to overcome – the continued unavailability of regular viral load testing.

Even in Europe, Serbia is one example of a country that does not offer routine viral load testing – a situation that the EACS conference resolved to try to correct. Availability of viral load testing meant nothing if it was irregular, unrecorded, or led to no change in regimen in cases of virological failure, De Cock said. Kenya had relatively high rates of viral load testing for Africa but factors like the high cost of 2nd- and 3rd-line regimens conspired with the lack of clear clinical guidelines to perpetuate a situation in which people stayed on failing regimens for too long, resulting in widespread drug resistance.

People with HIV, he added, were still too often subjected to inconsistent, individualised treatment regimens, partly because of the range of antiretroviral drugs available.

“If you have TB, you will get the same drug regimens whether you are in Los Angeles or Malawi,” he said. “But physicians like to fiddle, and in HIV, people get dozens of different regimens. Such ‘centrifugal prescribing’ does not help to establish equity of treatment.”

He added that such variety often went in the face of clear scientific evidence. “I am disturbed,” he said, “that after the START study not all European countries immediately changed their guidelines to treating all patients on diagnosis.”

In a separate presentation, EACS president Manual Battegay showed that nine European countries, including some surprising ones like Ireland and Norway, still had guidelines saying that ART should only be started when the CD4 count had fallen below 350 cells/mm³.

“Even if treating all is not affordable,” de Cock said, “guidelines should say that universal treatment is the best clinical option and should be aimed for.”

The opportunities and challenges of the future

De Cock placed these challenges into a much broader context, both within Africa and globally. There were exciting opportunities for improved healthcare in low-income countries, he said, especially as they were the ones with highest economic growth – though economic growth brought with it the diseases of civilisation such as diabetes and hypertension.

Technologies such as cellphones in Africa have allowed Africans to ‘leapfrog’ whole generations of technology, he said. Antiretroviral therapy did that for healthcare, going straight from no healthcare to large public health programmes. Future developments such as point-of-care tests, improved diagnostics and eventually vaccines could continue that progress.

Against that, however, keeping the healthcare improvements of the last half-century going faced familiar and daunting barriers: conflict and security; migration; corruption; resource scarcity and environmental degradation; all these militated against improved health, and global warming threatened to introduce new emerging infections too.

The biggest challenge of all, he said, would be in providing healthcare to a global population which will swell from 7.3 billion (16% of them in Africa) in 2015 to 11.2 billion (40% of them in Africa) in 2100. By that time, Lagos and Kinshasa would be two of the world’s largest cities. Would HIV, at least, have been reduced to a rare infection in those conurbations of the future, or would it still be with us?