Ask the Doc: Testing Sex Partners, and New Drugs for Resistant Virus
This week, we take a look at using rapid home test kits to screen sex partners for HIV, and new drugs for people with resistant virus, with EDGE's resident HIV expert, Dr. Joel Gallant.
Is the Rapid HIV Test Substitute for Condoms?
Q: I'm HIV-negative, and I prefer to have sex without condoms. I heard about the new home test kit, and wondered whether I could use it to test my partners before sex (if they agreed, of course), so we could bareback.
A: You're referring to the new rapid test using an oral swab (no blood required). It gives you results in about 20 minutes. This approach has actually been studied, and the results were presented at the International AIDS Conference in Washington this summer. Gay men were given a supply of test kits to test their potential sex partners. An advantage of the strategy was that study participants tended to see refusal of testing as a "red flag," which often caused them to use condoms. I'll bet the 20-minute waiting period wasn't a bad thing either: it probably allowed them time to learn each other's names and favorite colors, and who knows -- maybe to even talk about safe sex and HIV prevention.
There are important limitations to this approach. First, the test isn't cheap -- much more expensive than a condom. Second, it can be wrong in both directions: Not only are there false positives -- a problem with all rapid tests -- but there are also false negatives, which is a problem if you're trying to figure out whether you can dispense with condoms. Finally, the rapid test can be negative in people who were very recently infected. These acutely infected people tend to have extremely high viral loads, making them highly infectious.
For all these reasons, it's best not to rely on rapid tests as your only means of HIV prevention. Condoms and/or PrEP (which I discussed here) are your best bets.
Is There Drug Development for Those on Salvage Regimens?
Q: I've got a lot of drug resistance and am on what they call a "salvage" regimen: Prezista, Norvir, Isentress and Intelence. My doctor says I have to make this last, because there's nothing left if it fails. I'm doing fine; I take my meds, I don't have side effects, and my viral load is always undetectable. But it's scary to think I've got no other options. Why aren't drug companies developing new drugs the way they used to?
A: Drug companies aren't developing new "salvage drugs" exactly because of people like you: people who once had untreatable virus but are now "doing fine." There's just not a big need for drugs that treat highly resistant virus right now. When I ask my colleagues at other institutions how many patients they have whose virus can't be treated, the answer is usually either "zero" or "one." That makes this a hard group to study in clinical trials. It also means that drug companies don't see this as a big enough market to justify the enormous expense of drug development.
Your doctor is right about making this last, but that shouldn't be a problem if you're not missing doses. Drugs that suppress your viral load tend to keep on suppressing it as long as you're good about taking your meds. It's also not true that there are no options in development. For example, the integrase inhibitor dolutegravir has activity against virus that's resistant to raltegravir (Isentress), and there are new entry inhibitors being developed. I don't know whether you've ever had a tropism test, but if your virus is R5-tropic, maraviroc (Selzentry) or one of the other CCR5-antagonists in development could be options for you in the future, if you ever need them.
My guess is that you'll never need them. You're aware of the consequences of failure, so you'll probably never fail.