Drugs May Offer AIDS Prevention

FlipFlopSnowMan writes "There is an interesting article on MSNBC about the possibility of preventing AIDS using the same pills that are currently used to fight the virus in affected individuals." From the article: "The drugs are tenofovir (Viread) and emtricitabine, or FTC (Emtriva), sold in combination as Truvada by Gilead Sciences Inc., a California company best known for inventing Tamiflu, a drug showing promise against bird flu. Unlike vaccines, which work through the immune system -- the very thing HIV destroys -- AIDS drugs simply keep the virus from reproducing. They already are used to prevent infection in health care workers accidentally exposed to HIV, and in babies whose pregnant mothers receive them."

Tamiflu the con

[scotbot]

Actually, I think you'll find Tamiflu is useless against bird flu [timesonline.co.uk]!

Save the melodramatic crap

[Fhqwhgadss]

What's with the qoute at the end: This is very promising. For us to be involved in a potential solution to the big HIV crisis and pandemic is very exciting.

Pandemic? Really? Tuberculosis affects far more people worldwide but doesn't have all the sensationalism that we see surrounding AIDS. I don't mean to imply that nothing is being done about TB, or that AIDS isn't a problem, but I'm tired of the media treating this disease like we're all living on the set of "Rent"

My father..AIDS! My sister...AIDS!
My uncle and my cousin and her best friend AIDS.
Gays, straights, whites and spades,
everyone has AIDS.
My grandma and my old dog Blue.
The Pope has got it and so do you.
Come on everybody we've got quiltin' to do.
Gonna break down these barricades everyone has AIDS,
AIDS, AIDS, AIDS...

But...

[Theatetus]

... what if one of the various "environmental factors" models is right rather than the "single pathogen" model? IE, retroviruses start multiplying in people whose immune systems are shot already -- it's the symptom; not the cause.

I know we like single-pathogen disease models but frankly those are pretty rare. Especially with autoimmune and immunodeficient disorders, it's not as easy as people think to even define the given disorder in the first place, let alone establish a pathogenic cause. Take lupus: the diagnostic criteria is a list of 11 symptoms of which the patient must present 4. AIDS *was* like that for a long time, now it's defined by presentation of a short list of symptoms and presence of HIV antibodies. But then again, any death in Africa by pneumonia is counted as an AIDS case; antibodies are not even tested for. At any rate, there are numerous [oikos.org] other [duesberg.com] that stress environmental factors. [mercola.com]

Single pathogens are sexy for epidemiologists. They let you focus funding on a single area and clean up a mess with some drugs (which, btw, makes lots of money for pharmaceudical companies, who fund a lot of the research in the first place). Environmental causes are less sexy. They are hard to identify. They are hard to correct. And correcting them can cost a lot of money to the people funding your research.

Re:Save the melodramatic crap

[will_die]

(statistics tend to prove this out- people like sex, seek it out, and are generally not monogamous)

Which surveys?
If anything surveys tend show that people are primarily mongamous and are happy in a with a relationship with a single person.
Look at something like the http://www.zogby.com/soundbites/ReadClips.dbm?ID=1 1954 [zogby.com] from late 2005. The survey was done online so you would expect that it to be a little high on the anything goes side.
Even there you get over 70% of the people in a monogamous relationship, the majority for over 5 years.
While they may seek it out people don't tend to pay, less then 15%. This number is about the same for various other surveys.
If you get thoses types of numbers in an survey where people had to activly seek out the survey the numbers are going to be a lot less if you did a truly random survey of the population.

Re:Save the melodramatic crap

[beheaderaswp]

Did you even READ the article?? "Just 39 percent of people who took the survey always ask whether a new partner is infected with HIV, the virus that causes AIDS, or other STDs. Nearly one-third said they never check on a prospective partner's sexual health status, and among those with less than a high school education, almost 50 percent never discuss the issue of STDs with a new partner -- troubling statistics given the deadliness of AIDS and rising rates of genital herpes and other diseases." This alone indicates the amount of risk people are willing to take is high!

Re:Ummm...

[scrub76]

The answer is, 'right now, not many'. But, and this is a huge but, generic drug manufacturers in places like India and Brazil have shown they can drive down the cost of 1st world med production time and time again. When generic HIV drugs were introduced in India in 2000, the cost was $778 per month. Now the drugs cost about $30 per month. If this approach works, there will be ways to reduce the cost and make it feasible for the populations that need it.

are you nuts!

[Anonymous Coward]

as an AIDS counsellor, I've worked with many people who are taking these drugs on a daily basis. While they are a brilliant development and have already saved millions of lives, they are EXTREMELY TOXIC; they are totally unsuitable for preventive purposes, apart from being very expensive, they require regular blood tests for specialised medical monitoring (to check your body's responses, get the doses correct, etc), and there are often really grim side effects (such as vomiting, diahoerrea, nausea, fatigue, depression, etc etc); I know many who have chosen to come off the drugs because the quality of their life had got so bad from the side effects that they would rather die with a bit of diginity.

They hammer your immune system; it's like taking poison every day, it's a bit like chemotherapy in ways.. in fact, that's not a bad analogy: why don't we all start on an ongoing course of chemotherapy as a preventive measure against getting cancer?

ps. I'm not an Anonymous Coward, I'm a *Lazy* Anonymous Coward from Ireland

Re:face the facts

[Theatetus]

The epidemiology of HIV has been studied extensively: the disease is clearly transmissible and no other factor than an existing HIV infection is associated with transmission.

Well, that's just not true, and the fact that people keep repeating it doesn't make it so.

• The presence of antibodies is not a determinant of virus load (and in the case of newborns of mothers with HIV, is not even an indication of the presence of the virus).
• Kashala, et al, published in the Journal of Infectious Diseases that the 'African' variety of AIDS (which as your sibling post points out is epidemiologically quite distinct from the North American / European disease, though labelling them by location is increasingly misleading as the clusters spread) can be linked more conclusively to leprosy and TB than to viral transmission.
• One cluster study (one!!!) has linked sexual contact to symptomatic disease transmission in one North American population -- with symptomatic presentations wildly different from those called AIDS in the developing world. No other studies along this line have been published that I can find.
• There are several different (and even conflicting) sets of criteria for the clinical diagnosis of AIDS: WHO, CDC, WHO-NEW, etc. not all of them require any test for HIV (as I mentioned, in most African clinics the simple presentation of pneumonia is sufficient to be diagnosed as AIDS). We don't even know if this is one disease.
• Lederman published a study showing a stronger link between Factor VII and VIII use in haemopheliacs and symptomatic presentation than between HIV antibody presence and symptomatic presentation -- and at any rate, haemopheliacs almost never developed the sarcoma associated with other AIDS populations.

That's just a few examples off the top of my head (with the help of Google for the study citations). IMO, we're in way over our heads here and are trying to fit a 21st-century peg into a 19th-century epidemiological hole. We've been pouring toxins into our environment and our bodies for decades; the days of single-pathogen well-defined epidimics may be passing, if not already past.

Re:This is tough to read over and over again

[geekyMD]

What a bunch of tripe. Michael Moore would be really proud of the first paper. (I didn't read the second one, sorry) I can excuse the writer if 1/2 of the inaccuracies are from an ignorance of the field, but it honestly seems like she's trying to dissuade. Virtually every 3rd paragraph contains and inaccuracy or inappropriate insinuation that is subtle enough to be missed by someone who isn't trained in these fields. The author focuses her arguments by looking at small segments of the literature and history and ignoring the broader sweeps. For example:

The paper's initial assertion is that AIDS was introduced as a polio virus. Simple logical disproof: 1) polio vaccine is given across social/habitual classes. 2) There has not been 1 case of AIDS where the person didn't have one of the following three risk factors: blood transfusion, risky sex*, IV drug use. 3) Not everyone in the US has previous three risk factors. 4) If 2 is true 1 or 3 must be false or at least excruciatingly improbable. 5) 3 is true, therefore 1 must be false. QED. (*risky sex = sexual activity where both partners are not exclusively monogamous to each other at any time during or prior to their relationship)

Several pages deal with the controversy surrounding the initial discovery of the HIV virus. There was also controversy surrounding the discovery of DNA, therefore we shouldn't believe DNA is the 'source code' of life?

She makes light of the microliter aliquots used in the CBC tests but fails to mention that all CBC tests (test which count the types and number of cells in your blood) uses these metrics. We shouldn't trust tests for hundreds of diseases including leukemia, polycythemia, or even iron deficiency based on this implication. (for example, look at the normals on this page: http://www.saintfranciscare.com/11377.cfm [saintfranciscare.com])

She also does not respect the validity of the HIV Load test, saying that since it uses PCR (a very common technique in medicine) it cannot be accurate. (no more genetic testing, goodbye cancer diagnosis, goodbye endocrinology) She also asserts that the HIV Load assay will give false-positives and is inaccurate if the procedures are not followed. Yes, it does give false positives, it is a HIGHLY sensitive test, with a low specificity. It is not a screening test, and it cannot be used for one because of its high false positive rate. Additionally, I challenge anyone to find a test in any field that is valid when its procedures are not followed. (magnetism doesn't attract wood, therefore magnetism is false)
http://www.labtestsonline.org/understanding/analyt es/viral_load/test.html [labtestsonline.org]

But the coup-de-gras for me was her statistics that showed how low CD4 counts don't correlate to AIDS. (AIDS is, incidentally, practically being defined by low CD4 count)

* "61% of people with CD4 count = 200 in 1997 were AIDS free"
* -response: Yes, CD4=200 is the upper limit at which you see AIDS symptoms, this is expected

* "190,000 Americans in 1993 with CD4 count=200 were AIDS free"
* -response: See above, plus in 1993 the AIDS definition was changing so you see changes in the statistics. Additionally, that number is far less than a quarter of the number of AIDS cases in the US that year. (http://wonder.cdc.gov/wonder/data/aidsPublic.html [cdc.gov])

* "No studies have been done to show removal of anti-retrovirals = disease"
* -response: No, but anti-retovirals have been tightly correlated to increased CD4 counts, and their withdrawal to lower CD4 counts. It has also been shown repeatedly (and even in this paper!) that low CD4 count correlates with disease.

The list goes on and on. I just pointed out a few of the most egregious and most easily refuted examples. It just goes to show that if someone really wants to believe someth

Re:Spreading fear

[lachlan76]

You can't be serious...lets have a comparison [womhealth.org.au]:

• The US. To my knowledge, there are quite a few places that take the abstinence-only route. You have a teenage birth rate of 51.1 babies per thousand females.
• Australia. No problems getting sex-ed through over here to my knowledge, and a teenage birth rate of 16.3 babies per thousand females.

While it is not the only factor involved, there is a very big difference.

Re:Stay with me

[geekyMD]

First off, I did not mean to make it personal. Just my own views. I can see how what I said could be insulting, and I really did not mean that. Science moves forward by challenging the establishment. 200 years ago if you told someone that the heard functions to pump blood they would have laughed at you. 50 years ago universal precautions were virtually unknown. Sometimes the 'crackpots' get it right, so its neccicary to regorously examine their claims. I'm sorry you've been insulted for your views, I hope not to do that, but only to engage in debate. I really wish we could sit down over coffee with a couple of text books and journals and really talk about this stuff. Lets move on...

The reason I didn't tackle some of the other issues (and not necciarly the primary 4 you referred to) was that I don't have it. It would require a paper of triple the lenght of the original to compose a fully cited and complete rebuttle. Many of the 'harder issues' I referred to require background that is not easy to impart quickly and briefly. For example, I have no clue how the math works behind the Riemann Zeta equation, and I doubt anything less than months if not years of intense study would bring me up to speed. http://science.slashdot.org/article.pl?sid=06/03/2 7/1315212 [slashdot.org] The issues at hand are definately not that erudite, but I hope you get my meaning. My point for some my contentions was that the author of the article was making fun of simple ideas like "lightbulbs make light", and so she earned some easy crackpot points for belittling fundamental ideas. (overt anti-establishment thought process to the point of scientific disregard)

To answer your 4 questions:
1) Yes, I will admit that the mechanism has not been elucidated. However, the word idiopathic peppers medical literature, it is not uncommon to not know the exact mechanism, but to know generally whats happening. For example, digoxin (aka. digitalis) has been around since 1756, but the exact mechanism of how it effects cardiomyocytes is still under investigation. There are several theories, some very good, but none have been proven conclusively. A lot of pharmacology is that way. But I digress. What has been shown is that if you take blood from someone with aids, and inject into another person, you get aids in that person too. Furthermore, if you isolate HIV from the blood of an infected person you can induce CD4 cell destruction and AIDS like symptoms in model organisms. Lets hope someone has not tried this on humans. Of course, this explaination will not hold water for you if you do not believe HIV can be isolated, so lets move on to #2.

2) The initial research was flawed, granted. However, their research has been followed by others who have not been as fraudulent. I offer this instead:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd= Retrieve&db=pubmed&dopt=Abstract&list_uids=1656345 8&query_hl=2&itool=pubmed_docsum [nih.gov]

Plus, there are more ways than antibodies to detect HIV. HIV is a dsDNA virus with many unique proteins in its repitoire. Yes, there are other retroviruses out there, and some have embedded themselves in our DNA. However, they do not have the same genetic sequence of HIV. HIV like any unique organism has a unique genetic code. It has been sequenced, and is in fact regularly sequenced to determine which drugs the patients are treated with. The correlation is emperical - different HIV sequences have been shown to correlate 100% with resistance or succeptability to certain drugs. There are many sequences due to the innacuracies of reverse transcriptase, and not all of these changes result in a functional modification.

You cannot isolate the HIV DNA sequence from someone not infect

Re:Stay with me

[geekyMD]

Whoops! Strike that, forgot to proofread. HIV is a positive sense ssRNA virus, not a dsDNA virus. Told ya I didn't proofread. Doh! Please substitute RNA for DNA where I'm talking about the virus particle. The discussion of HIV DNA not being found in human genomic segments is still accurate.