February 5, 2008
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There's nothing like hearing the results of studies directly from those who actually conducted the research. It is these women and men who are transforming HIV treatment and care. In this interview, you'll meet one of these impressive HIV researchers and read an explanation of the study she is presenting at CROI 2008. Accompanying me on this interview is Gerald Pierone, M.D., an HIV clinician/researcher and the founder and executive director of the AIDS Research and Treatment Center of the Treasure Coast in Fort Pierce, Fla.
Sandra McCoy, Ph.D.
Acute HIV is a public health opportunity to interrupt transmission during a time when people have very heightened infectiousness.1 We test for acute HIV in people who seek testing at all publicly funded clinics in the state. We've done the program for five years, and during that time we've identified 89 people with acute HIV infection. This represents 3.3% of all of our total [HIV-infected people] in the state.
Then we do partner counseling and referral services [PCRS] for people with acute HIV infection. We have a group of people called disease investigation specialists [DIS]; they go out and find people with acute HIV infection within 72 hours of the initial report, and they find all of their partners within the last eight weeks.
Bonnie Goldman: How do they do this?
Sandra McCoy: They interview the acute patient at the same time that they're doing confirmatory testing. They'll interview the acute patient, and if they agree, the acute patient will tell them the partners that they've had in the last eight weeks.
Bonnie Goldman: Meaning names, addresses and phone numbers?
Sandra McCoy: Whatever they have, yes. Overall, about 40% of the partners that they report are anonymous partners, meaning we can't further try to find those partners. Of the remaining partners, the disease investigation specialists will go and attempt to locate those partners and offer them testing.
On the poster, we have a breakdown of our 89 patients with acute HIV infection. You can see that about half of them were men who have sex with men; a little over half were of black race; and about half were under 25 years old. It's a young population, and every year we've noticed it's been progressively younger. Ninety-two percent of those with acute HIV were found and accepted partner counseling and referral services. That's very high; our program is doing quite well.
In the past eight weeks [dating from their interview], our acute HIV patients report a mean of three partners: two partners who are named and can be attempted to be located; and one partner who is anonymous.
There were 148 partners who were named, and of those, 80% were found by the disease investigation specialists. Of this group, 31% were already positive -- they knew they were infected at that time.
Half of them were of unknown status and were tested by the DIS officers. We identified an additional 11 infections, which is 16% of those who were tested. We identified three new acute HIV cases, and eight new cases of established infection that were unknown to the partner. The majority of [partners] were negative.
This compares to data on PCRS for people with established infection. In North Carolina, about 20% of the partners of people with established infection are [also] positive. Here [in this study] we have 16%, so it's somewhat comparable.
We also looked at a phylogenetic analysis of three partnerships. We looked at three acute HIV cases and their partner with established infection. Based on a sequence analysis we found that [the HIV samples from each pair] were very closely connected genetically -- they had 97% sequence identity, showing that there was a transmission pair likely here. Of these positive partners, two of them were brand-new identified partners in this group.
The last thing we looked at was transmitted drug resistance. We found 13 people with any transmitted drug resistance among our acute population. Sixty-five percent of them actually had a partner with established infection. We expected to see a lot more acute-to-acute transmission in our population, but it looks like a lot of our transmissions are from people with established infection to our acutes.
Bonnie Goldman: Do they know that their partner is positive?
Sandra McCoy: A lot of them do. Certainly some don't, but a lot of them do.
That's our results. Some of our conclusions are that, in the acute HIV setting, PCRS works well. Ninety-two percent of people were located and utilized PCRS services. We also were surprised to find that half of people reported a partner with known infection. Forty-one percent were anonymous partners, which makes us think about new strategies to identify and find anonymous partners -- maybe using the Internet or e-mail, things we don't routinely use for partner notification.
We'd like to continue doing our phylogenetic analysis, because this does tell us a little bit about transmission in our state. If you have strict procedures to keep things confidential, it can tell you some interesting things about transmission from acutes to other acutes, or from chronics to other acutes.
Bonnie Goldman: But you were surprised that more infections weren't from acute to acute?
Sandra McCoy: We were surprised. We thought we'd find more acutes, because you're so infectious when you have acute HIV that we thought you'd find a lot more partners who are also acute, who'd just been transmitted to.
Bonnie Goldman: Did you get the partners' viral loads, by any chance?
Sandra McCoy: For these people we actually did, because they're part of our acute HIV program.
Bonnie Goldman: Because if they're still highly infectious, they might have uncontrolled viral load.
Sandra McCoy: Right. And in these cases, we don't know which way the transmission went [i.e., from whom to whom]. That's part of what the phylogenetic analysis might be able to help us with.
Also, we were surprised to see the number of people with transmitted drug resistance who had partners with established infections. Our next step will be to look at how many of them were in care and how many of them were on medications, to learn more about transmission dynamics in North Carolina.
Bonnie Goldman: The majority of the transmitted drug resistance was NNRTI, which is common?
Sandra McCoy: Yes.
Gerald Pierone: Can you talk a little more about the algorithm you used to identify newly infected patients?
Sandra McCoy: Sure. In North Carolina, all people who present for testing at publicly funded clinics are tested for HIV with a standard antibody test. If the antibody test is negative, they're automatically included in a pooling algorithm to test for HIV RNA. Also, people who were antibody positive and have a Western Blot indeterminate test are tested for RNA automatically.
Gerald Pierone: When you look at the description of your acute HIV cases -- the gender and risk behavior -- it's about 50% men who have sex with men. When you looked at the actual transmission of disease, were there differences between men who have sex with men and men who have sex with women?
Sandra McCoy: That's a good question. That's something we haven't looked at.
Gerald Pierone: It also seems that when you look at some studies like this -- for example, if you did this study in an urban gay population where there's a lot of methamphetamine use -- you might see mean sexual partners much higher than you're seeing in North Carolina. Perhaps that may account for why that acute infection rate is a bit lower than other cohorts.
Sandra McCoy: North Carolina, like the rest of the South, has a unique epidemic. We have a lot of heterosexual involvement, a lot of transmission to women, and we don't have much injection drug use in our population. Certainly, this is unique to our population; you'd see something very different, probably, in San Francisco.
Bonnie Goldman: I see it was 89 acute HIV cases from 2002 to 2007. Is that considered a lot or a little?
Sandra McCoy: We're doing this on a statewide basis. We have a lot compared to other studies, because we've been doing it for so long.
Bonnie Goldman: But it's still not that many.
Sandra McCoy: It's 3% of our total positives, so yes, it's not that many. We detect one acute person for about every 7,000 tests we perform in the state. We perform about 150,000 tests annually through our publicly funded testing system, and we find about 20 acutes [per year].
Gerald Pierone: Are other states or other regions taking your lead in using this algorithm to identify acute infections?
Sandra McCoy: I don't believe there are any other states doing it on a statewide level, but there's certainly Los Angeles, Seattle, San Francisco, New York -- areas are doing different combinations of this. Some of them are targeting to specific populations.
For example, King County in Seattle does acute HIV testing for their men who have sex with men.2 I just talked to someone from New York who said that New York City is doing acute HIV testing in their STD clinics. We identify about half of our acute cases from STD clinics, so that's a population you could certainly restrict your testing to.
The idea has caught on. Not everyone does pooling, necessarily, but some people do pooling. It is something people are moving towards.
Sandra McCoy: Yes. North Carolina is starting to do an emergency room testing program. It hasn't got off the ground quite yet, but we're moving in that direction.
Bonnie Goldman: That's surprising, that you're advanced in this way, but still ...
Sandra McCoy: [Laughs.] Yes. Actually, one way we're looking at our data is a way we can perhaps target it to counties that have high prevalence or to specific clinics, so we wouldn't have to do the program at a state level. There are some counties and clinics where we've never found a case of acute HIV, so it might not be necessary to continue doing that there.
Bonnie Goldman: Thank you very much.
This transcript has been lightly edited for clarity.
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