TCS Daily


South Africa's Good News on AIDS

By Roger Bate - December 20, 2005 12:00 AM

JOHANNESBURG, South Africa -- Bad policy contributing to rampant AIDS has become the master narrative of much western reporting on South Africa. But the tide has turned and there is progress to report.

Science Breakthroughs

South African researchers have developed a cheap CD4 test for HIV patients, which is particularly vital in rural areas where testing costs can be high. The team is led by Dr. Debbie Glencross from the Medical School of the University of Witwatersrand (Wits) in Johannesburg. The test reduces costs by over 75 percent and allows for greater rural access to testing -- a major advance in the treatment of the poorest in Africa.

With at least 5 million HIV-positive South Africans alongside 20 million more infected Africans, it is important that as many people as possible receive sustainable treatment. But it is impossible to provide appropriate treatment for HIV-positive patients without measuring the CD4 count in white blood cells. (The CD4 count helps physicians determine how far the disease has advanced and how strong a person's immune system is at the time.)

Where counts drop below a certain level (clinical policy can change but it is currently a CD4 reading of below 200 in South Africa), treatment with anti-retroviral drugs becomes vital. Otherwise the patient may -- and eventually will -- contract opportunistic infections and develop full-blown AIDS. The availability of cheap tests is vital because CD4 counts have to be monitored continually during the life of the patient. That way, drug regimens can be altered in response to CD4 changes over time.

The novelty of the Glencross/Wits test is that it utilizes the white cell count as a reference point. Traditionally, CD4 cells are referenced to total lymphocytes, a sub-population of white cells. Measuring the total lymphocytes is a less reliable indicator, but easier to use and hence formed the basis of previous tests.

To ensure accuracy, other additional measures of lymphocyte concentration through flow cytometry are often undertaken, which increases costs. By simplifying the strategy and referencing the test to all white blood cells, the need for extra steps disappears. Not only is this approach cost-effective, it also has an additional benefit: unlike the traditional tests which require testing within 24 hours, samples can be tested even up to five days after blood is collected.

Some African locations are very remote. Given their distance from the few existing HIV clinics, this new test brings hope. By lowering the cost of testing and providing an extra five-day window, many more South Africans will be tested and properly treated. Given that about 27 percent of the sexually active population (at least 5 million people) is probably HIV-positive, more action is required.

Herpes and HIV...Together Forever?

Interesting work is also being done on Herpes Simplex Virus and HIV. HSV is one of the most prevalent sexually transmitted infections in the world. According to figures from Wits University, 22% of Americans have the disease (which is apparently dormant for most of one's life), and an astonishing 70% of South African women have it.

Although HIV and HSV act in entirely different ways, there are some unfortunate synergistic effects. Critically, a HSV-infected cell makes it easier for HIV to take hold. Due to the ulcers that HSV causes, there is an estimated three-fold increase in the risk of contracting HIV from those who are infected with both HSV and HIV than those who only have the latter.

This observation is relevant because there is a cheap prophylactic anti-viral drug called "acyclovir" that can prevent Herpes. If it is given to HIV-negative people with HIV-positive partners, it can lower the chances of transmission considerably. Teams at Wits Medical School and Chris Hani Baragwanath Hospital in Soweto are currently undertaking a Gates Foundation-sponsored clinical trial. The trial focuses on discordant couples (i.e. one with both HSV and HIV and the other with neither disease) and it is designed to show whether acyclovir can lower rates of uptake of both diseases in the negative partner, but especially prevent the uptake of the more virulent HSV. The trial is ongoing, but physicians are optimistic that there will be a lowering of transmission of HSV, and hence HIV.

A related group is also testing microbicides to prevent HIV infection. These compounds are a useful prophylactic that can be controlled by women, whereas condom use is nearly always determined by the man. South Africa publicly distributed over 300 million male condoms last year, but consistent use is low.

757 HIV-negative women in Soweto are participating in a trial funded by the UK Department for International Development. As with the HSV trial, the researchers expect tests to show a substantial reduction in uptake of HIV. Microbicides can be applied as a gel but also as a sponge which gradually releases the active ingredient. A few of the women have had vaginal irritation resulting from the gel use, but there have been no major side-effects. The microbicides are anticipated to be on the market as of 2008, and many are hopeful that such measures will make a big difference in empowering women to protect themselves.

Roger Bate is a Resident Fellow of the American Enterprise Institute.
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