What caused the epidemic to spread so suddenly?

There are a number of factors that may have contributed to the sudden spread of HIV, most of which occurred in the latter half of the twentieth century.

Travel

Both national and international travel undoubtedly had a major role in the initial spread of HIV. In the US, international travel by young men making the most of the gay sexual revolution of the late 70s and early 80s would certainly have played a large part in taking the virus worldwide. In Africa, the virus would probably have been spread along truck routes and between towns and cities within the continent itself. However, it is quite conceivable that some of the early outbreaks in African nations were not started by Africans infected with the 'original' virus at all, but by people visiting from overseas where the epidemic had been growing too. The process of transmission in a global pandemic is simply too complex to blame on any one group or individual.

Much was made in the early years of the epidemic of a so-called 'Patient Zero' who was the basis of a complex "transmission scenario" compiled by Dr. William Darrow and colleagues at the Centre for Disease Control in the US. This epidemiological study showed how 'Patient O' (mistakenly identified in the press as 'Patient Zero') had given HIV to multiple partners, who then in turn transmitted it to others and rapidly spread the virus to locations all over the world. A journalist, Randy Shilts, subsequently wrote a book 23 based on Darrow's findings, which named Patient Zero as a gay Canadian flight attendant called Gaetan Dugas. For several years, Dugas was vilified as a 'mass spreader' of HIV and the original source of the HIV epidemic among gay men. However, four years after the publication of Shilts' article, Dr. Darrow repudiated his study, admitting its methods were flawed and that Shilts' had misrepresented its conclusions.

While Gaetan Dugas was a real person who did eventually die of AIDS, the Patient Zero story was not much more than myth and scaremongering. HIV in the US was to a large degree initially spread by gay men, but this occurred on a huge scale over many years, probably a long time before Dugas even began to travel.

The blood industry

As blood transfusions became a routine part of medical practice, an industry to meet this increased demand for blood began to develop rapidly. In some countries such as the USA, donors were paid to give blood, a policy that often attracted those most desperate for cash; among them intravenous drug users. In the early stages of the epidemic, doctors were unaware of how easily HIV could be spread and blood donations remained unscreened. This blood was then sent worldwide, and unfortunately most people who received infected donations went on to become HIV positive themselves.

In the late 1960's haemophiliacs also began to benefit from the blood clotting properties of a product called Factor VIII. However, to produce this coagulant, blood from hundreds of individual donors had to be pooled. This meant that a single donation of HIV+ blood could contaminate a huge batch of Factor VIII. This put thousands of haemophiliacs all over the world at risk of HIV, and many subsequently became infected with the virus.

Drug use

The 1970s saw an increase in the availability of heroin following the Vietnam War and other conflicts in the Middle East, which helped stimulate a growth in intravenous drug use. As a result of sharing unsterilised needles and syringes, HIV was passed on among injecting drug users (IDUs). Due to this repeated practice many IDUs continue to be infected with HIV.

Conclusions

It is likely that we will never know who the first person was to be infected with HIV, or exactly how it spread from that initial person. Scientists investigating the possibilities often become very attached to their individual 'pet' theories and insist that theirs is the only true answer, but the spread of AIDS could quite conceivably have been induced by a combination of many different events. Whether through injections, travel, wars, colonial practices or genetic engineering, the realities of the 20th century have undoubtedly had a major role to play. Nevertheless, perhaps a more pressing concern for scientists today should not be how the AIDS epidemic originated, but how those it affects can be treated, how the further spread of HIV can be prevented and how the world can change to ensure a similar pandemic never occurs again.

References

1. Worobey, M et. al (2010, 17th September) ' Island biogeography reveals the deep history of SIV' Science New York, N.Y, 329(5998)

2. Gao, F et al. (1999, 4th February) ' Origin of HIV-1 in the chimpanzee Pan troglodytes troglodytes', Nature 397(6718)

3. Bailes et al. (2003, 13th June) ' Hybrid Origin of SIV in Chimpanzees', Science 300(5626)

4. Wolfe, ND et al. (2004, 20th March) ' Naturally acquired simian retrovirus infections in Central African Hunters' The Lancet, 363(9413)

5. Edward Hooper (1999) 'The River', Little Brown and Company

6. Cohen, John (2000, October) ' The Hunt for the Origin of AIDS' The Atlantic

7. Blancou, P. et al. (2001, 26th April) ' Polio vaccine samples not linked to AIDS' Nature, 410

8. Berry, N. et al. (2001, 26th April) ' Vaccine safety: Analysis of oral polio vaccine CHAT stocks' Nature, 410

9. Chitnis, A et. al (2000, January) 'Origin of HIV Type 1 in Colonial French Equatorial Africa?' AIDS Research and Human Retroviruses, 16(1)

10. Fears, D. (2005, 25th January) ' Study: Many Blacks Cite AIDS Conspiracy', The Washington Post.

11. Zhu, T et. al (1998, 5th February) ' An African HIV-1 Sequence from 1959 and Implications for the Origin of the Epidemic' Nature, 391(6667)

12. Worobey, M et. al (2008, 2nd October) ' Direct Evidence of Extensive Diversity of HIV-1 in Kinshasa by 1960' Nature, 455(7213)

13. Kolata, G (1987, 28th October) ' Boy's 1969 death suggests AIDS invaded U.S. several times' New York Times

14. Frøland, SS et. al (1988, 11th June) ' HIV-1 infection in Norwegian family before 1970' The Lancet 331(8598)

15. Zhu, T et. al (1998, 5th February) ' An African HIV-1 Sequence from 1959 and Implications for the Origin of the Epidemic' Nature, 391(6668)

16. Korber, B et. al (2000, 9th June) ' Timing the Ancestor of the HIV-1 Pandemic Strains' Science, 288(5472)

17. Worobey, M (2008, 2nd October) ' Direct Evidence of Extensive Diversity of HIV-1 in Kinshasa by 1960' Nature, 455(7213)

18. Lemey, P et al. (2003, 27th May) ' Tracing the origin and history of the HIV-2 epidemic' PNAS, 100(11)

19. BBC.co.uk. (2006, 25th May) ' HIV origin 'found in wild chimps'

20. Farmer, P. (1992) ' AIDS and Accusation: Haiti and the Geography of Blame' University of California Press

21. Carter, M. (2007, 2nd March) ' CROI: Haiti is the source of HIV subtype B' Aidsmap.com

22. Chong, J-R (2007, 30th October) ' Analysis clarifies route of AIDS', LA Times

23. Shilts, R. (1987) ' And the Band Played on: Politics, People and the AIDS Epidemic', Penguin

20150520 http://scienceblogs.com/insolence/2009/09/15/pity-poor-peter-duesberg-even-medical-hy/

AnthonyL

August 3, 2011

Orac is an intelligent man, but he has made the mistake of assuming that an almost universally accepted paradigm is inevitably true, and its chief critic in peer reviewed journals is wrong. Unfortunately, this has led to a very noxious result. This article and most of its following comments are an example of the worst of the Web, where prejudice runs rampant and very few feel any sense of responsibility for checking their facts, even in science.

As a poster has pointed out, Orac shows no sign of familiarity with the basic papers in the issue of whether or not HIV is a valid candidate for causing AIDS, those in Cancer Research, Proceedings of the National Academy, Science, Indian Academy of Sciences, etc. Since none of these have been refuted, despite promises to do so in the same journals, or even answered in same, except for an exchange in Science where Duesberg’s science was left undisproved, this does not make them out of date, but the opposite: the latest valid work.

Unfortunately, a piece like this, if it is not withdrawn or ameliorated, just leaves Duesberg’s name covered with even more mud, without adding a single scientific reason for it. This has the very bad effect of disouraging those who have read these papers and kept up with the issue on an objective basis think it not worthwhile to illuminate it with corrective information.

So the swamp of misapprehension expands further, and the number of people who think that Duesberg is right and can tell you why and are willing to post here or anywhere else diminishes even further. Meanwhile people like Seth Kalichman who exploit the misapprehension and the prejudice against Duesberg post in comments and worsen the problem.

This is not what Orac imagines himself to be doing, and it is a pity that he does it. An intelligent peddler of peer reviewed information such as himself should actually enjoy reading the papers I refer to, since they are impeccably argued, written and evidenced to a level that is rarely seen nowadays.

Of course, he might if he paid close attention find them persuasive, but then he would be stuck in the unpleasant position of having to say so, and agree that they are not and never have been refuted, and that Duesberg is not a fool but a very fine scientist who is more thoughtful and cogent than those who attack him outside the peer reviewed journals where he has published these very excellent works.

Then he would be attacked in the same foolish and prejudiced manner that he has vilified a great scientist here in his blog.

Date: 2016-01-03; view: 1071