Thursday, April 5, 2012

HIV Drugs Necessary But Nowhere Near Sufficient for Treatment or Prevention

Under new US guidelines for HIV antiretroviral treatment, it is now recommended that all HIV positive people receive the drugs, regardless of what stage of disease progression they have reached. Draft UK guidelines, on the other hand, recommend treatment where CD4 cell count, a measure of immune function, falls below 350, though treatment may be started earlier under certain circumstances.

But, as an article on the UK guidelines points out, patients should "be told that the evidence of a lower risk of transmission on treatment mainly relates to vaginal sex, not anal sex, and that use of condoms will continue to protect against sexually transmitted infections as well as lowering any residual risk of HIV transmission." This is important because in UK and US contexts, most HIV transmission occurs among men who have sex with men and intravenous drug users.

Reminiscent of mass male circumcision campaigns and the insistence that injectable Depo Provera hormonal contraceptive is safe in African countries, we are told that condoms also need to be used even when on antiretrovirals. In other words, under ideal conditions greater access to antiretroviral drugs should reduce HIV transmission; but a lot of transmission, perhaps most, occurs where ideal conditions do not prevail.

But the caution seems justified by the finding that HIV transmission continues to occur among men who have sex with men who are receiving treatment. One of the reasons may be that a substantial number of men with an undetectable viral load in their blood have a detectable viral load in their semen. As for the effect of widespread antiretroviral use on behavior, this is not so clear. Will one of the results be 'disinhibition', the adoption of unsafe behaviors because HIV is no longer seen as such a threat?

Things are quite different in African countries, many of which have far higher HIV prevalence figures than found anywhere else. It's not just that epidemics are far more severe but the virus is not confined to identifiable risk factors. Men who have sex with men, intravenous drug users and probably even sex workers contribute a relatively small fraction to overall country epidemics. In stark contrast with non-African countries, most transmission appears to occur among people who face very low sexual risk.

It is possible that 25% or more HIV positive people in African countries know their status; some countries claim 30 or 40% do, though such claims are hard to verify. But it seems unlikely that enough money will ever be forthcoming to treat even those who know they are positive, let alone all HIV positive people. Estimates of how much it would cost seem to concentrate on figures that are not so difficult to guess at, such as costs of commodities like drugs. But the overall cost of treatment, which includes a lot more than just drugs, is so difficult to guess at, most don't bother trying.

A few years ago, someone came up with a suggestion that everyone at any risk at all of being infected with HIV should be tested, perhaps every year or more, and everyone found to be infected should be given antiretroviral drugs. But even the logistical difficulties involved in testing so many people once may prove insurmountable; they are certainly inscrutible. Even the much vaunted mass male circumcision program has been shown to be a lot more expensive when you include the overall costs, which likely double the $60 figure that is often bandied about.

Indeed, drug supply chains are not an easy matter for any country, but especially for a country like Tanzania, where health services have been decimated by structural adjustment policies and torn apart by various vertical health programs, especially HIV related programs. A recent article finds that many millions of dollars worth of drugs have been lost because they expired before being used. Some may have been 'donated' shortly before expiration or even after; others may not be of any use in Tanzania. But it's a huge loss for this health service, albeit one that is virtually inaccessible to many Tanzanians.

The new guidelines on antiretroviral drug use may be, in part, a reaction to research data. But it's hard not to wonder if it is also a reaction to substantial lobbying by pharmaceutical manufacturers and others who profit from ever increasing use of these very expensive drugs. The US guidelines, in particular, will be very good news for Big Pharma. It's hard to know how good the news will be for those with HIV or those who are at risk of being infected. I have been sent a link to a list of those who write these guidelines and their financial disclosures. That's very Big Pharma indeed!

[For more about non-sexual HIV transmission and how to avoid it, see the Don't Get Stuck With HIV site.]


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