Science Interviews


Sun, 25th Nov 2007

HIV and AIDS in South Africa

Prof. Helen Rees, Dr Francois Venter & Dr Jocelyn Moyes, Witswatersrand University

Listen Now    Download as mp3 from the show Highlights from South Africa

The conditions we saw in Soweto were a breeding ground for infectious diseases. Things like HIV and TB are no exception. This week the UN reduced its estimates for how many people are actually infected and affected by HIV. They also announced that South Africa is officially the country with the world’s highest prevalence (in other words cases of the disease) anywhere.

There is one benefit to being a country with the most HIV and AIDS and also being relatively connected to the First World and that is that the scientists and doctors working there have some of the best statistics on disease that the world has to offer. I met up with some of those scientists working to try and understand this condition and to try and break the back of this epidemic.

Helen - My name is Helen Reese. I’m the executive director of the Reproductive Health and HIV Research Unit at the University of Witwatersrand, based in Johannesburg. The scale of the HIV epidemic is something that hasn’t been known in the world ever before. We can say that 5 million people out of the 41 million people in South Africa are infected. What that really means is that 1 in 8 of every adult in this country are infected with HIV. It means that when we see pregnant women in clinics, between 1 in 3 and up to 1 in 2 are infected with HIV with a very high risk that they’ll transmit the virus to their infant. In young girls aged between 15 and 24 about 1 in 4 of those young women are infected with HIV. If these were the statistics that we saw in a developing country a state of emergency would be declared.

Stylized rendering of a cross-section of the Human Immunodeficiency VirusChris - If you look at who those people are, is there any particular group- a subset of the population who are affected or is this everybody?

Helen - HIV can affect everybody and if you look in South Africa, indeed it affects all various groups. It affects rich and poor. However, if you look at the way that the epidemic is now spreading it is disproportionately affecting black South Africans and we do think that it’s affecting young people much more than older people.

Chris - Do you have any ideas as to why it’s affecting the people that it’s affecting? Is it an educational thing? Is there something else going on?

Helen - I think there’s a lot of something else that goes on. There’s a whole mixture of issues here. There is the issue of poverty that as a background affects all infectious diseases. There is a historical issue that apartheid created the migrant labour system that’s both destroyed the social structure of families but has also pulled men from their families and made them single male individuals living in urban settings where they take often second partners. There are other things as well. There are issues about other sexually transmitted infections and possibly just the virus that you’ve got and possibly receptivity of the population. It could be right down to basic science as an influencing factor as well and why we have such a bad epidemic.

If, indeed, there is some sort of scientific and basic biological explanation to this then we need to understand that if we’re going to stand a change to make a vaccine.

Chris - Francois Venter – you work with Helen. What have we learned so far about how people actually pass this on and when they’re most infectious and when, therefore, most of the transmissions occur?

Francois - It’s only in the first few months that people harbour infections. They’re still infectious after that but the scale of infectiousness is so much greater during those first few months. It’s starting to explain some of the frustration as to why large scale provincial programmes in our country in particular but throughout southern Africa have not had the impact we’d hoped they would. Condom provision, for instance, in this country’s actually very, very good. Education processes – if you measure it against people’s understandings of HIV and the spellings of most, people understand what’s going on. It hasn’t changed the dynamics of the epidemic on the face of it.

Chris - Why are they still getting it then if they know all that?

Francois - I think what we haven’t understood is when transmission actually occurs. It seems to be very concentrated in the first few months, immediately after infection. If you do not intervene in those first few months you actually lose the overall public health benefit of dealing with transmission.

Chris - So what you’re saying is if everyone stopped having sex for three months, which is when you’re most infectious when you first catch it then potentially, you could stop it in its tracks because people’s infectivity falls so much after that period?

Francois - I guess you could probably break the back of the entire epidemic if you could just alter sexual behaviours for a very brief period of time.

Chris - What about drugs? That’s the thing at the moment. It’s the mainstay of how we’re trying to deal with HIV. There’s no vaccine so we’ve got to treat people that have got it rather than trying to prevent people getting it in the first place because, as we’ve shown it’s part of the argument but not the whole solution. How do the drugs work and have you got access to them here in South Africa?

Francois - The drugs are very, very effective. They essentially switch off the manufacture of the virus and allow the body’s immune system to regenerate. They are available in South Africa and have been relatively freely for the last 3 - 3½ years. In the rest of southern Africa it varies from country to country. Even in our own country from region to region. In some rural areas people battle to get access to these drugs. In urban areas access is relatively free and available.

Chris - We’ve heard about drugs and other behavioural education to try and cut this down. Jocelyn Moyes, you’re working on another way to try and deal with this problem.

Jocelyn - It’s an area that we’re doing quite a lot of work in is vaginal microbicides. The two present products that are about to come the end of clinical trials will lock HIV from attaching to the body cells. They’re a very large molecule which will sit on the HIV receptor of the cell and form almost like a key into the keyhole. When HIV comes along it can’t get through the keyhole into the body’s cells. The present microbicides we are testing come in a gel formulation which is applied vaginally to prevent HIV either attaching to the cells or replicating.

Chris - Just for women or can men get some benefit from this?

Jocelyn - Well, it’s topically applied and controlled by a woman but there is a chance that there will be protection for the male partner as well.

Chris - Have you any feel for how effective this is? It’s a lot to put your faith in. How do you know that you’re going to get complete coverage or how do you know that you’re going to get enough concentration to do away with the virus?

Jocelyn - We’ve got two candidates in phase 3 testing which is the efficacy testing – does it work or doesn’t it work? We’ll have one set of results early in next year and the other results probably early in 2010. So then I think we will have some proof of concept. Will it work or can’t it work?

At the moment our basis is that these compounds are active against HIV in the lab. They’ve been active at preventing infection in animal models and they are safe to use in humans. That’s our assumption to this point. Our efficacy in humans will be proved early next year and then again in 2010.

Chris - Just returning to you, briefly Helen. A lot of people are probably thinking, why should the rest of the world worry about what’s happening in one other country? There are lots of problems in the world. Why should HIV in South Africa be such a big international issue?

Helen - It’s not just HIV in South Africa. HIV globally is not going away. In fact in many countries it’s re-emerging as a problem. The other thing that we know is with a disease that’s as devastating as this that seeing life expectancy drop by ten year aliquots, almost year-on-year, that’s going to have a profound impact on the social fabric in many African countries and on many other countries in the Far East that are affected. You must then think what that will do to the economies of those countries or what it will do to political stability and once again we are a global family. If we have instability and poverty and growing problems in one part of the world inevitably they will relate to what happens in other parts of the world. That’s one argument. The other basic argument is the argument that I hope we never lose touch with is that we are one common human family and we cannot ever look at the level of suffering that we’re seeing as an epidemic in this part of the world and just turn our back on it because it’s not directly affecting us.

Chris - Pretty scary, aren’t they, those statistics? One person in two who’s pregnant, turning up at antenatal clinics and they’re HIV positive. South Africa, the country as the UN’s put it, ‘with the world’s worst prevalence of HIV.’


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