Friday, March 27, 2009

The Case for Thai MSM and MSW

The prevalence of HIV/AIDS in certain high risk groups is on the rise today as government funding for prevention campaigns nears an all-time low in Thailand, a country once touted the ‘poster-child’ for HIV/AIDS prevention efforts. Hello, I am Devynn Birx-Raybuck and this is The AIDS Pandemic, a podcast hosted by Dr. Dave Wessner, associate professor of biology, and his students at Davidson College.

Though Thailand’s initial response to the AIDS epidemic was weak in its early years, in 1991, the new Prime Minister made HIV prevention and treatment a national priority. However, the country’s grip on the disease seems to be slipping recently, as evidenced by decreased funding in important sectors, increases in infection rates among MSM (men who have sex with men) and injection drug users, inconsistent condom use by sex workers, and increasing risky sexual behavior, especially by young people.

Thailand is notorious for its sex industry. Brothels, go-go bars, massage parlors, and other venues cater to native Thais as well as Western tourists, who travel to the country on “sex tours.” Unfortunately, commercial sex is not only omnipresent; it is often backed and funded by corrupt government officials. Thankfully, with initiatives such as the 100% Condom Program and Mechai Viravaidya’s (a.k.a. Mr. Condom) tireless public outreach, HIV prevalence among female brothel-based sex workers decreased significantly after the early 1990’s, when as many as four out of five of prostitutes were infected. The 100% Condom Program began in 1991, along with a substantial public education campaign. The goal of the Program was to encourage and enforce constant condom use by female sex workers in commercial sex establishments. However, male sex workers have been neglected during such efforts to protect their female counterparts and clients.

A famous street in Pattaya where many commercial sex extablishments are located (left). Kathoeys (tansgender males) outside a go-go bar (right).

By the turn of the century, these enormous gaps in focus and funding were revealed. In a comprehensive review of the situation written in 2000, authors McCamish, Storer, and Carl, made a case for the inclusion of MSM in the country’s prevention efforts. Indeed, male sex workers (MSW) and MSM are at high risk for HIV infection, according to several studies which identified infection rates as high as 30% in these groups. Education and prevention programs aimed at MSW have been infrequent, limited to tourist areas, and generally unsuccessful in the past. The authors advocated for bar-based interventions and peer-support groups, which they believed would impact both the freelance and employed MSW.

Finally, in February 2006, “Sex Alert,” a safe-sex information campaign directed at MSM, was founded, with the hope of reaching this community that has been largely neglected by other efforts. According to the regional director, Dr. Somchai, the organization uses several media to advertise and educate, including the Internet and text messages. They also provide counseling, free condoms, and information regarding other health issues. This new outreach effort, along with others, will hopefully curb the rising rates of infection among MSM. However, programs such as these cannot act in isolation. They require the support of the Thai government, people, and most importantly, those affected most by the epidemic. Perhaps, despite recent concerns over rising HIV/AIDS infection rates and risky sexual behaviors, Thailand will prevail once again in the fight against the AIDS pandemic.

Free clininc in Bangkok that a sex worker might visit for counseling or treatment. This particular building is a collaborative center run by the Thai Red Cross and Armed Forces Research Institute of Medical Sciences.

On behalf of Dr. Wessner and his students, I thank you for listening.

For more information, please visit:
Thailand’s rising AIDS threat
UNAIDS Evaluation of 100% Condom Programme
Mr. Condom
Brothel-based sex workers

Wednesday, March 04, 2009

The Dissidents' Views of HIV Tests

Momentum for the alternate HIV/AIDS explanation started in 1987 when Dr. Peter Duesberg, a professor of Molecular and Cell Biology at the University of California at Berkeley and initial demonstrator that the influenza virus has a segmented genome, published a paper claiming that HIV cannot be the cause of AIDS. Four years later, a number of scientists formed “The Group for the Scientific Reappraisal of the HIV/AIDS Hypothesis” which later established itself as an official non-profit organization. Within another four years, 32 scientists with advanced medical degrees published a statement in Science asking for the reconsideration of the current HIV/AIDS theory. Since this publishing, over 2,100 people have signed this statement. Should institutions acknowledge any concerns from this small, not-too-silent minority or are their claims completely unsubstantiated? I’m Colby Uptegraft from Dr. Dave Wessner’s Biology of HIV/AIDS class at Davidson College, and while AIDS dissidents have many claims, I will present their arguments regarding HIV testing.

HIV critics rest a substantial amount of their theory on the problems with HIV tests. Currently, there are three main types of tests—antibody tests, antigen tests, and PCR tests. Dissidents primarily scrutinize the antibody tests.

HIV antibody tests begin with an enzyme-linked immunosorbent assay (ELISA). A second test confirms a positive ELISA. These secondary tests include Western blot assays, indirect immunoflorescence assays, line immunoassays, or a second ELISA. When used in combination, these tests are 99.9% accurate in detecting HIV antibodies.

According to Rebecca Culshaw, author of Science Sold Out: Does HIV Really Cause AIDS?, the flaws in antibody tests originate in the proteins initially used to define reactivity on ELISA and Western blots. Before HIV had been isolated, scientists stimulated cell cultures from AIDS patients with mitogens to produce more proteins. Researchers found 30 of these proteins to have densities characteristic of retroviruses and selected the 10 that most commonly reacted in blood from AIDS and pre-AIDS patients to be from HIV alone. Do you see the circular logic? Researchers assumed HIV caused AIDS and automatically attributed the 10 most common reactive proteins to HIV. Positive test results may have a high correlation to developing AIDS, but according to Culshaw, they do not mean HIV is the cause. HIV supporters ascribe her claims to outdated data.

Robert Geraldo, a medical doctor working at the Cornell University hospital, added suspicion to these tests when he discovered that everyone reacts positive on the ELISA test for HIV. Lab technicians typically use a 1:400 dilution of HIV-suspected serum samples for these tests. Many antibody tests for other viruses such as hepatitis A and B, rubella, and syphilis use undiluted samples, and the ones that use dilutions such as the Epstein-Barr virus, use dilutions an order of magnitude less. When Geraldo tested 100 undiluted samples, including his own blood, they all produced positive ELISA results. When diluted 1:400, all specimens produced negative results. He claims his results indicate that we all have antibodies to HIV or at least ones that will cross-react with ELISA tests. presents the counter argument. One cannot compare antibody tests for other viruses to the HIV test. All antibodies are unique and require different dilutions to eliminate false-positives resulting from non-specific binding.

The second HIV test detects antigens, substances that trigger generation of antibodies in organisms. The most common HIV antigen that provokes an immune response is the protein p24. According to Culshaw again, the dissidents assert that many AIDS patients do not have detectable levels of p24 and that many people without HIV infection produce positive p24 results. However, the HIV hypothesis acknowledges the disappearance of p24 in the bloodstream as AIDS progresses, and states lab technicians can use the p24 antigen test in conjunction with other antigen or antibody tests to increase its accuracy.

The third and final family of HIV tests uses PCR to amplify minute levels of RNA or DNA to quantities sufficient for detection. However, Kary Mullis, the inventor of PCR technology, proclaims, “Quantitative PCR is an oxymoron” and believes PCR is not applicable to HIV detection. PCR is too efficient in that it will amplify any DNA in a sample, whether it represents contamination or belongs to HIV. Therefore, scientists cannot use PCR to ascertain HIV infection status or viral load, the number of DNA or RNA copies per milliliter of blood. Even with these dissenting claims, the FDA approved these tests for monitoring the health of people with HIV and high statistical correlations exists between these tests and the onset and severity of AIDS.

While believing in Bigfoot or that the Holocaust never happened provides entertainment to some, the conspiracies cannot sustain actual scientific inquiry. The theory that HIV does not cause AIDS is not any different. AIDS dissidents cling to small individual details and pull them out of context with the vast majority of HIV evidence and research. In the case of HIV tests, critics ignore the use of multiple tests to predict HIV status and the combined accuracy of these tests in predicting the onset of AIDS and the causative nature of HIV. They instead focus upon the individual use of each test and make the illogical assertion that the unknowns in each are additive and cannot be used to support each other.

If you believe the United States never landed on the moon, then consider the arguments of the AIDS dissidents. If you like reality, then stick with the traditional explanation.