Treating ourselves out of the HIV/Aids crisis -- hypothetically
The scenario: all South Africans are tested for HIV annually and every person who tests positive is immediately given antiretroviral therapy (ART).
According to a controversial mathematical formula known as the Granich model, more colloquially known as the “test and treat” strategy, this approach could lead to a 95% reduction in new HIV cases in South Africa within 10 years—and could see an end to the country’s Aids epidemic by 2050.
The hotly debated model was published in the prestigious British medical journal, The Lancet, earlier this year, using data from South Africa and Malawi to demonstrate its impact.
The “test and treat” approach is gaining support to such a great degree that the authoritative National Institutes of Health (NIH) in the United States has allocated funds and resources for in-depth studies into it; pilot studies are under way in New York’s Bronx district and in Washington DC.
According to Professor Gavin Churchyard, from the Johannesburg-based health research organisation the Aurum Institute, additional studies will be carried out in Vancouver in Canada and Hlabisa in KwaZulu-Natal.
“The question is: can we treat our way out of this epidemic?” asks Dr Guy de Bruyn, programme director of HIV prevention studies at the Perinatal HIV Research Unit at the University of the Witwatersrand. De Bruyn, who strongly supports the “test and treat” approach, says that current HIV prevention and treatment strategies will not make a positive impact in South Africa “if we don’t manage to decrease the number of new infections and deaths”.
Success with current methods is extremely limited, with 1500 new South African infections and 750 people dying every day from Aids-related complications.
Recently, the head of the US National Institute for Allergies and Infectious Diseases, Dr Anthony Fauci, affirmed in an NIH press release: “[The] test and treat [model] potentially could represent an important public health strategy for fighting HIV/Aids.”
Chief author of The Lancet study, World Health Organisation medical officer Dr Reuben Granich and his four co-writers base their predictions on scientific evidence that ART is remarkably effective at reducing the amount of virus in an HIV-infected person’s blood. This ensures the person is significantly less infectious—even if the person has unsafe sex. When placed on ART soon after infection, and if the individual takes his or her treatment correctly (even within multiple concurrent sexual relationships and without correct and consistent condom use), the chance of an HIV-positive person infecting his or her partner is often reduced to almost zero.
The researchers say that it’s been widely proved that people newly infected with HIV are most infectious and if those people, who mostly are unaware that they’re infected with the virus, receive HIV treatment, it could lead to a major reduction in infections.
Based on his experience of several HIV testing projects in Soweto, De Bruyn is convinced that it’s possible to get all South Africans to test for HIV through the mobilisation of community leaders, the use of mobile testing clinics and post-test support groups. “Creative strategies such as refusing to renew citizens’ driver’s licences without them first producing proof that they have gone for an HIV test, and testing people at fast-food stands can also be considered,” De Bruyn says.
But the contentious model presents many ethical as well as operational challenges, such as the cost of treatment and testing.
“Each HIV test costs about R96. To test everyone above 15 in South Africa will amount to R3,8-billion and almost 154 000 tests per day,” says Wits Clinical HIV Research Unit deputy director Dr Francesca Conradie.
“How do you get all adults in this country tested for the virus once a year if most of them have up until now been reluctant to or even refused to go for a test? If you force them to, you are infringing on their human rights. And, without test results, you can’t treat anyone,” Conradie says.
It is estimated that 700 000 South Africans are on ART. For the Granich model to be effective, 5,8-million (the estimated number of HIV-infected people in the country) would need to be on ART—more than eight times the current number. “South Africa simply has too many HIV-infected people for this strategy’s implementation to be practical. We’re not the US where the numbers are manageable,” Conradie says.
Granich and his colleagues point out that, although the model would require more money in the short term, the financial burden would be alleviated as the number of infections start to decline and fewer people would need treatment.
But, Conradie says: “We should rather put all our efforts into well-established prevention methods such as medical male circumcision, which reduces men’s risk to contract HIV by 60%.”