Cameroon And The Origin Of HIV

By Alan Thevenet N. Tita, MD, Ph.D and Denis M. Tebit, Ph.D

Widespread international press reports of a recent study published in a prestigious medical journal (Science) attributing the origin of the human immunodeficiency virus (HIV), the virus that causes AIDS, to chimpanzees in Cameroon generated uproar within the Cameroonian community.

Many raised concerns about an agenda to label Africa as the origin of everything bad and emphasised alternative theories for the advent of HIV, including conspiracies.

One vital ingredient of scientific critique is to go beyond press reports and conduct direct reviews of the actual research publication. To inform and educate those who like ourselves are interested in this controversy, we prepared a summary of the published article with an accompanying commentary.

Summary Of Research

Background: Molecular studies indicate that HIV-1 is a descendant of the simian immunodeficiency virus (SIV) found in certain captive chimpanzees, suggesting chimpanzees as an animal origin for HIV. For this reason, HIV has been classified as a zoonotic infection (transmitted from animals to humans).

However, to be tenable, the virus must also be found in non-captive (wild-living) chimpanzees in their natural habitat. The purpose of the reported study was, therefore, to examine whether wild living chimpanzees identical to the captive ones, also harbor SIV.

Methods

The chimpanzee sub-species that carry the HIV-1 ancestor virus (SIV) are known to be wild-living in South Cameroon, Gabon and Congo with extensions into Equatorial Guinea and Central African Republic.

The study was set in Cameroon (possibly for logistic reasons) and 10 forest sites were covered. Chimpanzees being reclusive were not directly accessible for specimen collection.

Therefore, researchers utilised serologic, molecular, genetic and epidemiologic methods to a) identify the HIV-1 ancestor virus from fecal specimens collected from the surface of the soil in forest habitats, b) confirm that these fecal specimens were from the specific type of chimpanzee in question, c) identify fecal specimens that came from each individual chimpanzee, and d) determine the gender of each chimpanzee.

Results

423 (70.6 percent) out of 599 fecal samples were from the chimpanzee type known to harbour HIV-1 ancestor virus (the remaining samples were either from a different type of chimpanzee or from gorillas, or were too degraded to yield reliable results).

These 423 fecal samples were from a total of 108 individual chimpanzees. 34 of those fecal samples (8%) tested positive for the HIV-1 ancestor virus (SIV), representing 16 individual chimpanzees (14.8 percent) including 7 males and 9 females.

Infected fecal samples, (and therefore infected individual chimpanzees), where found in only 5 of the 10 forest sites and the sero-positive rate in chimpanzees in these sites ranged from 4.4 percent to 35.3 percent.

Additional studies to determine if HIV-1 could have evolved from the 16 identified ancestor viruses were all positive for 2 of 3 HIV-1 subgroups (M and N) but not for subgroup O (which is traced primarily to Cameroon but is also prevalent in Gabon and Equatorial Guinea).

Viruses from forest sites deep to the southeast of Cameroon were most closely related to HIV-1 subgroup M, while viruses from a more central site were related to subgroup N.
As expected, none of the fecal samples from gorillas or from other chimpanzee types were positive for the HIV-1 ancestor virus.

Conclusion: Chimpanzees found in the south of Cameroon are natural reservoirs for the HIV-1 ancestor virus (SIV).

Commentary

Investing in deciphering the origin of HIV/AIDS is certainly a worthwhile effort. This can help tailor effective preventive interventions (especially a vaccine), and optimize therapy against the current epidemic. It can also help forestall the emergence of a similar epidemic from another virus. Unfortunately, there is the unproductive risk of attributing blame.

There is evidence and consensus among experts that a chimpanzee species (captive or habituated) from Central Africa harbour an HIV-1 ancestor virus. Recent disagreement has centered on the mechanism of transmission between humans and chimpanzees.

One theory is the natural transmission theory, which proposes that the ancestor virus was transmitted to humans through the hunting and handling of chimpanzees. Certainly, alternative theories abound including conspiracies and medical accidents.

Prominent among these is the theory that human infection originated from widespread testing between 1957-1960 of an oral polio vaccine in Africa [Democratic Republic of Congo (DRC), Rwanda and Burundi] by a U.S. researcher.

Supporters believe that the vaccine was contaminated with the HIV-precursor through a production process that involved chimpanzees. However, the lead researcher and other collaborators in the polio study have maintained that chimpanzees were not used in the production process.

This polio vaccine theory has been brought into further disrepute by several studies on old samples of the vaccine, which yielded neither chimpanzee DNA, nor HIV or its precursor. Furthermore, genetic evolutionary studies of HIV suggest the transmission to man might have occurred earlier than 1950s when the polio vaccine trial took place.

The researchers in the current study reviewed here, support the predominant natural transmission theory, which is further strengthened by their unquestionable finding that the HIV-1 precursor has a natural habitat in wild living chimpanzees in southern Cameroon.

However, contrary to some press reports, it is our estimation that the finding is not the "smoking gun" evidence supporting the natural transmission theory. It firmly establishes that chimpanzees were involved in the origination of the HIV/AIDS pandemic but it does not dispel reasonable doubts about the veracity of the natural transmission theory. Less compelling is any suggestion that findings establish an exclusive geographic origin of HIV/AIDS.

It is not proven that these chimpanzee reservoirs are exclusive to Cameroon. In fact, the same chimpanzee species are found in Gabon and Congo as well as Equatorial Guinea and Central African Republic. One would expect chimpanzees in the other countries to also harbor the HIV-1 precursor, seriously confounding any speculation about HIV/AIDS originating in Cameroon.

Additionally, the findings do not completely exclude the likelihood that chimpanzees may not be the original or only host of the HIV-1 precursor. Thus, press declarations that "the jump between chimps and humans occurred in southeastern Cameroon" should be prefaced as speculation, albeit informed.

1Center for Research in Women's Health, Division of Maternal-Fetal Medicine, Dep't of Obstetrics and Gynecology, University of Alabama at Birmingham. 2Division of Infectious Diseases, Case Western Reserve University Cleveland, Ohio

Comments

[LILIAN]

Let's say it originated from the chimpanzees in Cameroon, how long had the chimpanzees carried the virus? How did it affect Cameroonians before being discovered in the U. S. A.?

[medical accidents]

Medical accidents which are due to a medical practitioner demonstrating a lack of skill – or failure to apply it – may include:-

The failure to diagnose (or misdiagnose) a disease or medical condition
The failure to provide appropriate treatment for a disease or medical condition
The failure to provide adequate treatment of the disease or medical condition within a reasonable period of time

[medical accidents]

Research is good but please provide some more information about results.

[John Dinga]

Seething with anger at the constant provocation and the allegation that Africans originally brought human immunodeficiency virus into the world XYZ conceded that his country men interacted with monkeys - spoke with them, lived with them, ate with them and generally shared the tropical forest with them. Like ABC, he went on to put the finishing touch by describing how that simple coexistence had been completely upset by Americans who came to his country, went into the very forest and went as far as making love to those very monkeys and chimpanzees, thereby contracting the terrible AIDS virus and passing it on to the rest of humanity. Who could beat that? XYZ had developed a real art of self defense and was using it with relish. He justified some of his excesses by saying that he liked to give his white friends just what they loved to hear and in the process he would add spicing here and there to make it really good. It made him feel good too. As a member of the local tourism board he said he would escort visitors to many sites, help them with local lore and, as always, give himself the liberty of putting finishing touches where appropriate. He would narrate gleefully and with a weird sense of humor about life back in his village pointing to where, according to him, his ancestors had cooked and eaten the ancestors of his visitors!
Did XYZ and ABC cross the line? Not quite. As little children growing up in their home communities, of course they did notice things even if they could not explain. Human interaction with chimpanzees is a heavy topic, encompassing sociology, anthropology, paleontology, law, folk tales, religion, evolution, development, international relations and more. Just as incarcerated prisoners in South Africa and mine workers separated from spouses turned to homosexuality to assuage an urgent biological need, so also do animals in the wild or in captivity turn to other species to remedy powerful biological needs. Intriguing experiments have been designed and carried out all over the world in an effort to probe into man’s presumed proximity to the apes. Blood collected in the field have been brought into laboratories and mixed up with all sorts of antibodies to see how surface antigens bring cells together or repel them. Research has sequenced chimpanzee genome to provide a window and new insights into the difference between humans and primates - our closest cousins - to confirm or dispel the myth that human and chimpanzees differ by a mere 1%. It is quite intriguing to explore why and how human beings and chimpanzees have 99% internal similarity (genes, proteins, sperms) yet, paradoxically they look and behave so differently from the outside. Unless and until human beings get close enough to these wild cousins of ours, there is no other way to carry out such findings.
Certain facts can be gleaned right by sight but others require profound investigations in the field and in the laboratory in Europe, Russia, US, Cuba, Kenya, Nepal, Indonesia and other places. Even though they diverged from a common evolutionary ancestor over 25 million years ago, monkeys have tails but not the apes (chimpanzees, humans, gorillas, bonobos, gibbons, orangutans). Human beings who denigrate others by calling them monkeys are only showing their own dose of ignorance. All human beings, unlike chimpanzees, possess a big brain, the ability to assume a supine posture, the characteristic of a long opposable thumb that can rotate toward the palm allowing for many skills and feet with shorter and more rigid digits that enable our bipedal upright walk.
Animals captured and reared in captivity have tremendously enriched human knowledge. The work done may be perverted and unethical sometimes. In nature a horse can mate with a donkey and produce a mule, the most popular type of hybrid species known to man. What is less common is a male lion mating with a tigress to produce a product called a liger. The only setback is that like the mule, the liger is a dead end because it is infertile, cannot produce sperms and therefore cannot bring forth young ones! The defect seems to lie with some chromosomal aberration. Portmanteau is the conventional custom by which such hybrids are named, first with the father species, followed by the mother. Thus liger is derived from lion and tiger. Other hybrids are zorses, zonkeys, tigons, beefalos, pumapards, and humanzees or chimans. TIGERS (The Institute for Greatly endangered and Rare Species) situated in Myrtle Beach, South Carolina is a place worth visiting.
Mention of humanzee (chimpanzee –human hybrid) brings to mind the name of late Russian scientist, Illya Ivanovich Ivanov whose work in Pasteur Institute in France and Guinea Conakry raised goose flesh and repulsion in many circles as it involved human beings and chimpanzees. Breeding such a hybrid was expected to put an end to the speculation in evolution circles that we all have a common ancestor. Where else but the American Association for the Advancement of Atheism could the scientist turn to assistance with such a project? There were Darwinian proselytes of evolution as well as opponents belonging to Creationism, for radically different reasons. Inseminating female chimpanzees with human sperm was the plan in the Canary Island, in Cuba’s Quinta Palatino, in New Guinea or Guinea Conakry, especially if it could be done behind flummoxed assisting African staff. Inseminating hospitalized ignorant African women with sperm obtained from chimpanzees – the notion of informed consent being moot - was also in the works. The belief in some circles that orangutans were more closely related to the “yellow races,” gorillas to the blacks and chimpanzees to whites made the pairing of apes with their proper human race for reproductive purposes a desirable objective. Slices of chimpanzee scrotums were grafted on to human scrotums, a procedure known as vasoligation. At the last minute a local governor in Guinea Conakry refused to go along with Ivanov’s quixotic quest, following which the man turned to his home, Soviet Union to seek permission to inseminate women there with ape sperm. This time he went for volunteers and actually got one but unfortunately Tarzan, the orangutan died of brain hemorrhage before sperm could be obtained from it. The scientist was arrested, imprisoned in Kazakhstan from where he died, putting an end to his quest. There is no doubt that others are following in his footsteps to attain the goal of ensuring the perpetuation of endangered species some where in the world.
But human-animal interactions in tropical forests were not all weird or perverted. Indeed much good came of the studies of committed scientists all over the world as they put in painstaking effort to study our hairy cousins in their natural habitats in Franceville, Gabon, Kisangani in DRC, Brazzaville Congo, Equatorial Guinea, Yaounde, Cameroon, Kinyara, Uganda, Kenya, Tanzania and other places. Plenty of PhD theses came from studies in those natural habitats and thanks to the many explorations out there, the world knows quite a lot about polioviruses, Ebola virus, simian immunodeficiency virus (SIV), human immunodeficiency virus (HIV). Natives as well as curious visitors entered those rich forests to pry into their secrets, hunt and butcher animals for food or capture them for pets or simply study their make-up to find out what could help unravel the new epidemics wreaking havoc on human populations all over the world. Chimpanzees prey on Cercopithecus monkeys for food and are in turn bush meat for human consumption. After close contact with those cousins in the wild, human beings eventually moved to the metropolis, carrying along the germs that they had shared in relative tranquility and symbiosis over the years. In the urban areas there is sex and there are needles. Sudden exposure to thousands of new hosts led to new challenges and adaptations, some with catastrophic results. The first study materials were feces and urine tossed at new comers intruders by apprehensive and suspicious chimpanzees. As confidence grew it became possible to obtain blood, saliva and other body fluids and tissues by more invasive methods to study diseases and gain more insights into how the animals coped with the diseases. HIV infects humans and specifically targets a population of white cells called CD4, destroying them and by so doing, weakening human response to attack by common germs. AIDS is simply the disease inflicted on human beings as a result of this depletion of CD4 below a count of 200 per micro liter of blood.

Extracts from my upcoming "America's Irresistible Attraction" Trafford Publishers

[medical malpractice]

Thanks for providing this knowledge. Nice post.