Saturday, October 4, 2008

CIRCUMCISION AND HIV/AIDS AS A CURE OR PREVENTIVE?–CONT. PART 7

NO.CIRCUMCISION IS NOT THE ANSWER OR CURE FOR HIV/AIDS.

WHY? (3)-CONTINUED-Uncircumcised men are thought to be more susceptible to AIDS because the underside of the foreskin is rich in Langerhans’ cells, which attach easily to the virus. The foreskin may also suffer some small tears during intercourse, making it more susceptible to infection.

New factors to consider

Scientists Discover 'Natural Barrier' to HIV
E.J. Mundell of HealthDayNews reported that;

Researchers have discovered that cells in the mucosal lining of human genitalia produce a protein that "eats up" invading HIV -- possibly keeping the spread of the AIDS more contained than it might otherwise be.
Even more important, enhancing the activity of this protein-(Langerin) could be a potent new way to curtail the transmission of the virus that causes AIDS, the Dutch scientists added.

Langerin is produced by Langerhans cells, which form a web-like network in skin and mucosa. This network is one of the first structures HIV confronts as it attempts to infect its host.
However, "we observed that Langerin is able to scavenge viruses from the surrounding environment, thereby preventing infection," said lead researcher Teunis Geijtenbeek, an immunologist researcher at Vrije University Medical Center in Amsterdam.

And since generally all tissues on the outside of our bodies have Langerhans cells, we think that the human body is equipped with an antiviral defense mechanism, destroying incoming viruses," Geijtenbeek said.
The finding, reported some time ago in an online issue of Nature Medicine, "is very interesting and unexpected," said Dr. Jeffrey Laurence, director of the Laboratory for AIDS Virus Research at the Weill Cornell Medical College, in New York City. "It may explain part of the relative inefficiency of HIV in being transmitted."
Even though HIV has killed an estimated 22 million people since it was first recognized more than 25 years ago, it is actually not very good at infecting humans, relatively speaking.

For example, the human papillomavirus (HPV), which causes cervical cancer, is nearly 100 percent infectious, Laurence noted. That means that every encounter with the sexually transmitted virus will end in infection.
"On the other hand, during one episode of penile-vaginal intercourse with an HIV-infected partner, the chance that you are going to get HIV is somewhere between one in 100 and one in 200," Laurence said.

Experts have long puzzled why HIV is relatively tough to contract, compared to other pathogens. The Dutch study, conducted in the laboratory using Langerhans cells from 13 human donors, may explain why.
When HIV comes in contact with genital mucosa, its ultimate target -- the cells it seeks to hijack and destroy -- are immune system T-cells. But T-cells are relatively far away (in lymph tissues), so HIV uses nearby Langerhans cells as "vehicles" to migrate to T-cells.

For decades, the common wisdom was that HIV easily enters and infects Langerhans cells. Geijtenbeek's team has now cast doubt on that notion.
Looking closely at the interaction of HIV and Langerhans cells, they found that the cells "do not become infected by HIV-1, because the cells have the protein Langerin on their cell surface," Geijtenbeek said. "Langerin captures HIV-1 very efficiently, and this Langerin-bound HIV-1 is taken up (a bit like eating) by the Langerhans cells and destroyed."
In essence, Geijtenbeek said, "Langerhans cells act more like a virus vacuum cleaner."

Only in certain circumstances -- such as when levels of invading HIV are very high, or if Langerin activity is particularly weak -- are Langerhans cells overwhelmed by the virus and infected.

The finding is exciting for many reasons, not the least of which is its potential for HIV prevention, Geijtenbeek said.
"We are currently investigating whether we can enhance Langerin function by increasing the amount of Langerin on the cell surface of Langerhans cells," he said. "This might be a real possibility, but it will take time. I am also confident that other researchers will now also start exploring this possibility."

The discovery might also help explain differences in vulnerability to HIV infection among people.
"It is known that the Langerin gene is different in some individuals," Geijtenbeek noted. "These differences could affect the function of Langerin. Thus, Langerhans cells with a less functional Langerin might be more susceptible to HIV-1, and these individuals are more prone to infection. We are currently investigating this."
The finding should also impact the race to find topical microbicides that might protect women against HIV infection. Choosing compounds that allow Langerin to continue to work its magic will enhance any candidate microbicide's effectiveness, the Dutch researcher said.

Laurence did offer one note of caution, however.
"In the test tube, this is a very important finding," he said. "But there are many things in the test tube that don't occur when you get into an animal or a human. Having said that, this is a very intriguing finding, he said."

WHY?(4)-Other factors also to consider:

Kebaabetswe et al obviously believe the conventional wisdom that heterosexual sex is the major vector for the transmission/reception of HIV, and that male circumcision is an effective deterrent to infection. Based on that belief, they have constructed an elaborate and impressive study of the acceptability of circumcision as a prophylactic measure in Botswana. Furthermore, they argue for a programme of neonatal circumcision in Botswana in the hope of reducing the HIV infection rate 15 years later.

Discussion

It has been believed since about 1988 that heterosexual coitus accounts for 90% of the HIV infection in Africa.
Many studies do argue that circumcision can reduce the transmission of HIV through heterosexual coitus. The quality of these studies has been criticized for their methodological flaws, including their failure to control for numerous confounding factors.

Gray et al found that transmission by coitus ‘‘is unlikely to account for the explosive HIV-1 epidemic in sub-Saharan Africa.’’ It now appears that these studies have not accounted for the largest confounding factor of all—iatrogenic transmission of HIV. Sometimes back, the International Journal of STD & AIDS published a trilogy of articles.

These articles strongly argue that unsafe health care practices, especially non-sterile injections, not heterosexual intercourse, are the principal vectors by which HIV is transmitted. A program of mass circumcision would be ineffective against iatrogenic transmission of HIV through unsafe health care. Heterosexual transmission of HIV that one sees in Africa also cannot explain the incidence of HIV in children. Circumcision has some little known effects that may promote rather than deter HIV infection. The human foreskin has physiological functions designed to protect the human body from infection. The sub-preputial moisture contains lysozyme—an enzyme that attacks HIV. Circumcision destroys this natural protection.
Circumcision removes erogenous tissue, desensitizes the penis, changes sexual behavior, and makes males more likely to engage in unsafe sex practices. Circumcised males, therefore, are less willing to use additionally desensitizing condoms.

Male circumcision produces hardened scar tissue that encircles the shaft of the penis. The scar scrapes the inside of the partner’s vagina during coitus and, therefore, may enhance the transmission/reception of HIV. A program of mass circumcision would expose African males to unsafe genital cutting, would destroy the natural protection of the foreskin, would not be effective against iatrogenic unsafe health care, would divert scarce medical and social resources from measures of proved effectiveness, and, therefore, is likely to increase the transmission of HIV. The proportion of HIV infection attributable to heterosexual intercourse has been placed at 90%. Gissellquist and Potterat now estimate the proportion attributable to heterosexual intercourse at only about 30%—only a one third of the previous estimate.
Circumcision has not yet been shown to be an effective deterrent against HIV infection. The Council on Scientific Affairs of the American Medical Association says that ‘‘circumcision cannot be responsibly viewed as ‘protecting’ against such infections.’’ The Task Force on Circumcision of the American Academy of Pediatrics identifies behavioral factors, not lack of circumcision, as the major cause of HIV infection. The article by Kebaabetswe et al seems to show a strong cultural bias on the part of the authors in favor of circumcision. This may be due to their desire to preserve their culture of origin.

WHY?(5)-Bioethics and human rights-Finally, to address the legal and ethical issues. As noted above, male circumcision excises a large amount of functional healthy erogenous tissue from the penis. It is a clear violation of the basic human right to security of the person.

Several authorities report that circumcision degrades the erectile function of the penis. Circumcision, therefore, must be regarded as degrading treatment. Degrading treatment is an additional violation of human rights.
The leading international statement of medical ethics is the European Convention on Human Rights and Bioethics. Article 20(1) prohibits non-therapeutic tissue removal from those who do not have the capacity to consent. Children have a right to the protection of the security of their person and to protection from degrading treatment. Circumcision would violate those human rights. Doctors must respect patient human rights. Prophylactic circumcisions ethically may not be carried out on minors. Circumcisions, therefore, would have to be limited to adult males who legally may give informed consent.

WHY?(6)-Political factors

Ntozi warns-He says-It is important that, while circumcision interventions are being planned, several points must be considered carefully. If the experiment fails, the groups(Africans and others being used in these experiments) are likely to feel abused and exploited by scientists who recommended the circumcision policy. In a region highly sensitive to previous colonial exploitation and suspicious of the biological warfare origin of the virus, failure of circumcision is likely to be a big issue. Those recommending it should know how to handle the political implications.

Approval of circumcision by the surveyed Botswana people apparently is based on their belief that circumcision is efficacious in preventing the spread of HIV. If circumcision fails to control HIV, there would be disillusionment and anger. African and others- males would have sacrificed their erogenous tissue for a false hope of preventing HIV infection. There is no evidence that Kebaabetswe et al have considered the political issues that would arise if a circumcision experiment should fail.

Conclusion

Kebaabetswe et al propose the universal circumcision of male children in Botswana. They accept without question that HIV is primarily sexually transmitted in Africa and other areas by heterosexual coitus and that circumcision reduces or prevents the transmission of HIV; however, medical authorities do not accept the evidence of this. Kebaabetswe et al propose to provide in-hospital circumcision of male children in Botswana. However, there is already a substantial incidence of infection among children in South Africa as a result of iatrogenic infection from non-sterile injections, etc. They have not shown that safe, aseptic circumcisions can be delivered in Botswana. A program of mass circumcision would destroy the natural protections of the foreskin, further expose children to an apparently unsafe health care system, and would be more likely to increase than decrease infection.
Even if circumcision eventually should be shown to provide some protection against HIV infection, that protection could only work to reduce the 30% of infections that now are attributed to sexual activity. It would have no effect on the other 70%. Its effect, therefore, would be minimal at best and could not have an effect for the first 15 years during which time behavioral changes could be introduced into society through education, and a HIV vaccine could be developed to provide immunity.
Circumcision of male children with the intent of reducing an epidemic not of their making is unacceptable from medical, ethical, and legal perspectives. As a public health measure, male neonatal circumcision fails all tests.

1 comment:

specialaffinity said...

Quite interesting - thanks for giving us this side of the argument. The rush to perform mass circumcisions in Africa is suspicious to me.
Please keep up your efforts to educate and make the world community aware as to the opposing scientific opinions regarding this controversy.