Nigeria's HIV epidemic reassessed

Two years ago the Naked Scientists were joined by Sani Aliyu, an infectious disease consultant from Addenbrooke’s Hospital, who was about to embark on a secondment to Nigeria - a country with one of the world’s highest populations and also one of the world’s highest burdens of HIV infection. In his role as Director General of the National Agency for the Control of AIDS in Nigeria, Sani set up and ran their largest HIV survey ever conducted. He’s now returned and has come in to report to Chris Smith and Adam Murphy on what his survey showed...

Sani - Well it's important because HIV, as we know, is an epidemic. You need to know the numbers in order to know how much resources you need to put in. You also need to know the numbers in order to define where the location is, what the population risks are, et cetera. In other words, for you to have impact - both in terms of testing, and putting people on treatment - you need to have an idea of the data. Data is what drives programming. And that's why it's so critical to have a survey that's accurate, that's good, and that can allow us to invest money properly.

Adam - Now surely this study didn't cost nothing, so wouldn't it have been better to buy, say, anti-HIV medication with that instead of this?

Sani - Well in the first instance, you need to identify people living with HIV first before you buy the HIV drugs and put them on treatment. And the only way you can do that is knowing where to target. In other words, hotspots. And what surveys do is they allow us to identify the main risk factors within a population - what we call a population-location approach - so the population that's most likely to have HIV; and then allows us to know exactly where to put our resources in. So in other words you'll be throwing good money after bad money if you don't know what you're targeting. In fact the Nigeria programme was a typical example. The US government have spent more than 4.5 billion US dollars on HIV in Nigeria over the last 15 years, global fund more than 1.5 billion. But despite that we're still pretty far off from identifying people living with HIV.

Chris - Sani, it’s soon going to be 40 years since we first discovered the virus that causes HIV/AIDS. Why is it only now you're collecting this sort of data in Nigeria? And why just focus on Nigeria? Why not the whole world?

Sani - So as you said earlier on, Nigeria has a very large population: about 200 million people. And before we did our survey, the estimates in terms of HIV burden was about 3... we estimated about 3.2 to 3.4 million people were living with HIV, which made Nigeria have the second largest HIV burden in the world.

Chris - I mean that's 1 in 10 of the world's HIV patients, isn’t it.

Sani - Exactly. So if you're really talking about epidemic control, you cannot have epidemic control without getting on top of the HIV problem in Nigeria. This is the first time that money has been invested properly in a survey to define the problem, because I think our own partners realise that they can continue chasing cases, testing thousands, hundreds of thousands of people to get a few positives. We need to be able to test a few hundreds in order to get positives so that we can put money, we can have the greatest impact when it comes to our investment.

Adam - So what did this study actually find then out the other end?

Sani - In summary we had three or four findings. First of all the burden of HIV, the prevalence of HIV turned out to be half of what was initially expected. So we estimate about 1.9 million people are living with HIV in Nigeria now instead of the 3.2-3.4 million initially. So the prevalence went down from 2.8% to 1.4% for ages 15 to 49. So that's huge. Secondly we realised that there were a lot more women having HIV than men - although globally that's the case. But what was even more significant was that young women were at least three times more likely to have HIV than young men of the same age group.

Chris - Does this mean you can strategically target better? If you know that now, you can go in and target certain demographics, certain groups, certain geographies much more specifically than we could before. So before it's just a blanket bomb approach, we've got a problem with HIV in Nigeria and countries like it. Now you've got this data you can be much more strategic.

Sani - Absolutely. So I'll give you an example: in the North West of Nigeria, the HIV prevalence was 0.6%. In the South South it was 3.1%. Fivefold. So really where we should be investing, where we should be putting money, is where we have the problem. So in the past we've been putting money mostly in the North Central and we've saturated the North Central, as was seen by the population-level biological suppression rates, which were pretty good, they were more than 60% in the North Central. But in other parts of the country, particularly the South South, the numbers were so low in terms of the number of people on treatment and biologically suppressed. And if you're biologically suppressed you do not transmit the virus. That's the best way to cut the epidemic really. So in a way this has allowed us to identify the areas, the location identified, the people that are most at risk, and put more resources in. In fact the US government in March, we had a meeting in Johannesburg, and they have put forward the money to put half a million Nigerians on treatment between now and the end of December 2020. So if that trend continues, as a public health threat, HIV will cease to be a public health threat in Nigeria. And it's simply because of the value of the survey we've had.

Chris - But just very briefly, 30 seconds: why should someone who doesn't live in Nigeria care about what you found? Why is this important?

Sani - From a human angle, it's important that we make sure that those that do not have the money to be able to have treatment are provided with that opportunity. The only reason why we still have, we have about 1.1 million Nigerians on treatment, is because they have been on treatment for a while. If today that treatment is taken away most of them will be dead within five years. In fact we looked at the burden of the HIV epidemic in Nigeria: without an HIV program in Nigeria we would have had at least 1.5 million more people dead, and we would have had at least 5 million Nigerians infected with the virus by now.