mutation

[tommy246]

How long on average does it take for hiv to mutate causing people to change meds.

[Inchlingblue]

Since HIV is a retrovirus the reverse "copying" process (from RNA to DNA) is quite imprecise and so it is constantly making "mistakes," i.e. mutations.

Having said that, if a person is on an appropriate cocktail of drugs that their particular strain of HIV has no resistance to, and that person is adherent in taking their medications, then there is no reason to believe that the mutations will be enough to actually create resistance to the meds.

There are people who have lasted on the same combo for many years with no resistances, theoretically it could last indefinitely as long as there is the right level of adherence.

There's a very recent study that looked into this matter at length. They concluded, among other things, that the longer a person's virus is suppressed, the better the chances that it will remain suppressed.

Adherence is especially important during the first year of treatment, during which time it should be 95% or above. The study found that "the level of adherence necessary to maintain viral suppression appeared to decline with time."

Viral rebound was less likely to occur among those with long duration of suppression This translates in an odds of viral rebound decrease of 8% per each month of continuous viral suppression across all adherence levels. Individuals with high levels of adherence (≥95%), the probability of failure was 0.12 (IQR: 0.08-0.45) after being suppressed for 12 months and 0.04 (IQR 0.03-0.07) after being suppressed for 72 months". Sustained & near perfect adherence increases probability of long-term viral suppression, this is particularly critical at the earliest stages after starting HAART. From Jules: High levels (95%) of adherence required during first year on HART to achieve best chances for long-term viral suppression.


LINK:

Duration of Viral Suppression Strongly Modifies the Adherence-Viral Rebound Relationship

http://www.natap.org/2009/IAS/IAS_92.htm

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[newt]

If you are adherent and have no prior mutations (which means no prior mutations not no detected prior mutations) -- an indefinite time

According to the literature, for the UK, on an intent to treat basis, it's 3.5 years, but that includes non-adherent people and people who went on combo half-hearted like, and people who never went on treatment at all, and people who done loads of treatment before.

So I would pay attention to the first bit of this post.

- matt

[physicsguy]

Ignore the average.  As newt pointed out, it's heavily skewed downward by people who start treatment and put zero effort into it.

Take your meds correctly and there's no reason to think resistance will ever be an issue.

[Rev. Moon]

Please pardon my ignorance, can mutations occur if there is "some" resistance or the "potential" for resistance in the near future?  On day one, when this was explained to me by the doctor I was out to lunch in another planet and didn't get a real grasp of the concept of mutation (too much info to process at once).  Also, does the virus show mutations at the time of the initial infection?  I believe to have read something in that regard within these forums (i.e. that two people infected with the same strain could present different mutations or so) .

Again, I'm sorry if I sound dumb about something that may be simple HIV 101, but sometimes it is all Greek to a non-science guy like me...

[Inchlingblue]

The link below has some excellent basic info, such as:

WHAT IS RESISTANCE?

HIV is "resistant" to a drug if it keeps multiplying rapidly while you are taking the drug. Changes (mutations) in the virus cause resistance. HIV mutates almost every time a new copy is made. Not every mutation causes resistance. The "wild type" virus is the most common form of HIV. Anything different from the wild type is considered a mutation.

An antiretroviral drug (ARV) won't control a virus that is resistant to it. It can "escape" from the drug. If you keep taking the drug, the resistant virus will multiply the fastest. This is called "selective pressure."

If you stop taking medications, there is no selective pressure. The wild type virus will multiply the fastest. Although tests may not detect any drug resistance, it might come back if you re-start the same drugs.

Resistance testing helps health care providers make better treatment decisions for their patients.

LINK:

http://www.aids.org/factSheets/126-HIV-Resistance-Testing.html

  Also, does the virus show mutations at the time of the initial infection?  I believe to have read something in that regard within these forums (i.e. that two people infected with the same strain could present different mutations or so) .
 

Soon after HIV enters the body, the virus begins reproducing at a rapid rate (approximately 10 billion new viruses every day). In the process, HIV produces both perfect copies of itself (wild-type virus) and copies containing errors (mutated virus). In other words, there is no single virus in the body but, instead, a large population of mixed viruses called quasi-species.

Continued....

LINK:

http://www.thebody.com/content/art14466.html