The HIV viral load blog

World AIDS Day 2008 – Economic crisis raises significance of this year’s event

December 1st is World AIDS Day. This year it's more important than ever. It was instituted in 1988 to spread awareness of the severity of the HIV pandemic and how much work needs to be done to stem the tide. Local governments and organisations around the world answered the call and have been doing their part to fulfil the promise of the event each year since. But this year we face a big distraction – the economy.

All around the world, organisations are slashing their budgets and consumers like you and me are looking for ways to cut back. Where will these organisations and individuals look to cut? I guess I’d be naïve not to assume that funding of HIV treatment initiatives would escape their fiscal fitness program.

If you’re in a position to provide assistance or funding to HIV-related programs (and that’s all of us), I’d ask you to consider the cost of cutting back now.

Over the past 20 years, the global HIV community has made astounding advances in battling the pandemic. Back in 1988, the percentage of people receiving treatment who needed it was negligible. Today, millions have access to ARVs, including those in developing countries. Prevention and education campaigns are reaching new audiences all the time. Real strides have also been made in developing the medication and diagnostics required for proper treatment. The investment of time and money since 1988 is paying dividends today in terms of both hampering the spread of the disease and treating those already infected.

Unfortunately, HIV doesn’t slow down during a recession. It is always striving to move forward and will take swift advantage of any weakening of resolve. If treatment is interrupted for those already on ART, their health will be compromised and an increase in drug resistance is certain. If we don’t keep the number of people on treatment rising, AIDS deaths will jump even higher than the millions it already claims annually. And if we don’t keep prevention campaigns going strong, the virus will spread even faster.

This isn’t only a humanitarian concern, but an economic one as well. These negative consequences will result in enormous financial strain on the battle against HIV in the long run. This economic crisis is not just in Africa, but in everyone’s backyard. We need to keep in mind that life will go on during, and after, the recession, and we don’t want to undermine all the work we’ve done up to this point by not looking ahead.

HIV affects everyone and has the potential to be an even greater problem than it already is, on both our health and our economy. So do your part to spread awareness on this World AIDS Day. Here are 5 things you can do to keep the fight against HIV moving in the right direction.

1.    Write a blog post about World AIDS Day, or use other social media to spread the word
2.    Write a letter to the editor or an opinion column for your newspaper
3.    Call or write your local government official and tell them you believe that fighting HIV is still a priority
4.    Get involved in local World AIDS Day events, or create one if nothing is planned in your community
5.    Wear a red ribbon and encourage others to do so

If you have any ideas of your own, please share them in the comments section.

The HIV Subtype Picture

If you live in the West, you might be a little surprised by the subhead on this map. In Western countries, we’re used to it being a given that subtype B is the most prevalent strain of HIV. This map is a great visualization of where the HIV epidemic actually stands in terms of subtype distribution and concentration.

It also makes it clear why there is such a great need for a subtype-independent viral load monitoring assay like our ExaVir Load. It’s not only because the traditional assays were developed for measuring subtype-B and are of limited use outside the Western world, but because the spread of that huge prevalence of other subtypes Westward is only a matter of time.

 

As far as our ExaVir Load’s performance goes, that whole map might as well be the same color. But with the diagnostics most prevalently in use today, we’re facing a problem in providing accurate disease monitoring. And the problem will only get bigger as subtypes continue to migrate and mix. 

This is why we’re continually developing diagnostics that are subtype-independent and why we believe it’s so important. We have every opportunity to be ready for when the need for such diagnostics can no longer be ignored, so let’s stay a step ahead this time. 

What Sudden Spikes in HIV Viral Load Really Mean

The following was written by Professor John Mills, Monash University, Australia, who I have had the pleasure to work with for a number of years. John is an authority in the HIV field, having extensive experience both in research and in practice, including measuring viral load with our ExaVir Load assay. I’m posting this piece because it does a great job of explaining what HIV viral load blips are, when you should be worried and when it’s a false alarm.

An elevated HIV viral load on therapy: is it a "blip" or a "bust"?

 Although measurements of HIV viral load are useful for assessing the prognosis and need for treatment of patients not on anti-retroviral therapy (ART), they are absolutely critical for monitoring the efficacy of therapy. 

When treatment naïve patients are started on combination ART, the HIV viral load should fall very quickly. Usually within 2-3 months, and certainly by 3-6 months, the viral load should be "undetectable". 

What constitutes an "undetectable" viral load depends on the assay system used. It varies from less than 400 copies/ml to less than 40 copies/ml. Although it might seem that <40 is better than <400, to date the evidence suggests they are equivalent. Clearly, however, viral loads at or above 400 are a real cause for worry (Pilcher et al, 1999). 

Once a patient on ART achieves an "undetectable" viral load, it should remain undetectable indefinitely if they continue to take their ART as directed, and do not develop an unusual circumstance that would interfere with drug efficacy (e.g. drug interactions or a gastrointestinal condition interfering with drug absorption or metabolism). 

Surprisingly, a number of studies, including ones in which viral loads were measured daily (Nettles et al, 2005) – as well as substantial clinical experience – have shown that many patients will have transient elevations of viral load known as "blips." Blips are defined as transient, low-level increases in viral load. Specifically, they are a single detectable HIV viral load measurement of less than 1000 (although rare blips may be slightly higher than that), which is immediately preceded and followed by an undetectable viral load (Gallant 2007).

Argument continues as to whether blips are a laboratory artifact or represent true HIV viremia. I think the weight of evidence is that they do represent short-term viremia. 

In an individual patient, the frequency of blips seem to be related to less than perfect adherence to the treatment regimen – patients who have missed ART doses in the week prior to the blip are more likely to have them than patients who are highly adherent (Podsadecki et al, 2007). Curiously, however, blips do not seem to predict subsequent development of an HIV strain resistant to ART ("virologic failure" of the ART regimen). 

How can you tell if a patient who previously has had an undetectable viral load has just a "blip", or whether it is a "bust" – an elevated viral load likely indicating that the ART regimen is failing (due to resistance, poor adherence, poor absorption or drug interactions)? 

If the renegade viral load is well above 1000, it is almost certainly a "bust." But the only way to definitively answer the "Blip or Bust" question is to perform another viral load assay, ideally 3-8 weeks later than the first. Even if the first value is well above 1000, it could still represent a lab error and should be repeated (you wouldn't want to switch a patient to a second line regimen on the basis of an erroneous viral load!). 

If the first viral load value is >1000, and the second value is also >1000, and especially if it is higher than the first, it is almost certainly a "bust", and the patient should be investigated for ART regimen failure. 

If the first value is <1000, and the second value is back to undetectable, you can relax as you're seeing a blip.  However, since blips are related to episodic lapses of adherence, it is definitely worth reminding the patient that the best results from ART are achieved if 100% of doses are taken. 

References

Gallant JE (2007).  Making sense of blips.  J Infect Dis, 196:1729-31

Nettles RE, Kieffer TL, Kwon P, et al. (2005). Intermittent HIV-1 viremia (blips) and drug resistance in patients receiving HAART.  JAMA 293: 817-829.

Pilcher CD, Miller WC, Beatty ZA, Eron JJ. (1999).  Detectable HIV-1 RNA at levels below auntifiable limits by Amplicor HIV Monitor is associated with virologic relapse on antiretroviral therapy.  AIDS 13:1337-42.

Podsadecki TJ, Vrijens BC, Tousset EP et al. (2007). Decreased adherence to antiretroviral therapy observed prior to transient human immunodeficiency virus type 1 viremia.  J Infect Dis 196:1773-8.