HIV Drug-Resistant Strains

Researchers from the University of California Los Angeles predict that new strains of HIV/AIDS originated in the US threaten the World Health Organization's current efforts to prevent the spread of the disease in developing countries. The study, released in Scientific Magazine earlier this year, found that these strains began to emerge in San Francisco, New York, Chicago, London and other rich-resource cities. According the to World Health Organization, the drug resistant strains are being spread to resource-poor countries like South Africa, but exact figures of the new strain's prevalence in these countries are unknown due to a lack of reliable data. Currently, the World Health Organization (WHO) plans to provide large quantities of cheap antiretroviral drugs to the African continent. However, if used to treat drug-resistant strains, the implementation of this program may, in fact, enhance the spread of disease in Africa.

This study has raises serious concerns among those fighting to control the HIV/AIDS epidemic, because patients with the drug-resistant strain see little improvement in their health when provided antiretroviral drugs (or ARVs). ARV drugs are the standard treatment for people living with HIV/AIDS.

According to information compiled by The Microbicide Trials Network (a worldwide collaborative clinical trials network focused on preventing transmission of HIV) HIV develops resistance to ARV drugs because one of the virus' enzymes, "called reverse transcriptase, is prone to mistakes when copying the genetic blueprints (RNA and DNA) of the virus. Some of these mistakes, called mutations, can make HIV resistant to one or more ARV drug."

Sally Blower, a Professor of mathematical biology and one of the lead researchers in the study predicts that if the World Health Organization carries out it's current plans to test and treat people in developing nations without taking resistance into consideration, their efforts may halt, or even reverse, progress being made to control the spread HIV in those countries. In an interview with Bloomberg magazine, Blower stated, "Universal test and treat is just a recipe for disaster. Our modeling is saying the drug resistant strains that you will generate from this kind of strategy are ones that will be very strong, transmissible, and therefore you will get an awful lot of problems."

Drug resistance can be easily transmitted to uninfected persons if the new strain is not properly treated with alternative medications. The Microbicide Trails Network website explains, if ineffective ARV treatment is continued on a person with a drug-resistant strain, "the resistant virus can keep multiplying and eventually outnumber other viruses that are sensitive to or can be weakened by the ARV. This is why tests to detect drug-resistant virus should be performed regularly." Testing for drug-resistant strains is not yet a common practice in many HIV prevention programs.

Blower's study found that currently, 13% of HIV cases in San Francisco are of the drug-resistant variety. If these new strains are detected, infected patients should stop their current ARV treatments and begin a new combination of drugs. However, in countries where the majority of infected persons can only afford generic drugs, the alternative options to ARVs saving lives in San Francisco, where the strain originated, remain unavailable to the majority of citizens. Blower's study is an additional factor in the mounting critiques against the pharmaceutical companies ownership and over-pricing of drugs for profit.

Although the African continent is home to 22 million of the 33 million people living with HIV, the majority of its inhabitants are barely able to afford generic ARV drugs, let alone new treatments for new strains. The ARV drugs currently used by the majority of people in Africa are hardly prescribed in the US or Europe because they are inconvenient to take and can have serious side-effects. However, as an article from a December 2009 issue of Forbes Magazine reports, "they are cheap, costing under $100 per patient per year." The article's authors Megha Bahree and Matthew Herper continue, "By contrast, Truvada, the world's bestselling HIV pill, costs $12,000 annually in the U.S." The current practice of selling lower quality drugs to African nations does not bode well for attempts to HIV/AIDS epidemic in the face of a new strain that requires high-priced alternative treatment options to contain.

The UCLA study tested the three major classes of ARVs and found that "the greatest resistance was to NNRTIs" or non-nucleoside reverse-transcriptase inhibitors. This particular point of the study has serious implications for the World Health Organization's current approach to the AIDS epidemic in Africa. As James Kahn, an associate director of the HIV/AIDS Clinic at San Francisco General Hospital, told Bloomberg, "In Africa NNRTIs are the backbone of the treatment regimen." He continues, "Unlike San Francisco, where we have a lot of options to switch people to, they don't have that many options in Africa."

In 2009, it was reported that in the United States people living with HIV have a 69-year life expectancy. In parts of South Africa, such as the village of Khayelitsha, infected persons are dying after only 8 years of treatment. Commenting on this fact, Eric Goemaere the head physician at Medecins Sans Frontieres clinic in Khayelitsha states, "I don't accept the principle of double standards...If it is possible to get 69 years of life in the U.S., it should be possible to get something comparable in South Africa." A restructuring of current for-profit distribution system of HIV/AIDS treatments may be necessary to save lives and prevent the global spread of new drug-resistant strains of HIV/AIDS.

1.Simeon Bennett, "Wave of Mutant HIV May Undo Years of Drug Progress," Bloomberg, 5 Jan 2010

2. Robert J. Smith, Justin T. Okano, James S. Kahn, Erin N. Bodine, and Sally Blower, "Evolutionary Dynamics of Complex Networks of HIV Drug-Resistant Strains: The Case of San Francisco," Science Magazine, 5 February 2010

3. Microbicide Trials Network, "HIV Drug Resistance and ARV-Based Prevention," June 22, 2009, http://www.mtnstopshiv.org/node/876

4.Bennett

5. Ibd.

6. Microbicide Trials Network

7. Bennett

8. Megha Bahree and Matthew Herper, "The Next AIDS Crisis: Why don't the latest AIDS drugs get to dying patients in Africa? Arcane worries about intellectual property," Forbes Magazine, December 2009, 70.

9. Bahree and Herper, 71.

10. Smith, Okano, Kahn, Bodine and Blower

11. Bennett

12. Bahree and Herper, 71.

13. Ibd.