Day 265: Wasn’t this news released last December?

I am never opposed to more press coverage of HIV, but the big story today seems to be an old one. The CDC reports that instead of the approximately 40,000 new HIV infections in the U.S every year, in 2006 we actually had about 56,000 new infections. That’s a huge difference. They used a new surveillance method to come up with this number.

 

As you may note (as carried in this blog), the same data were released on World AIDS Day last year. The Wall Street Journal reported then that the U.S. incidence was about 60,000.  The CDC is saying this is a wake-up call—but the wake-up call should have been (at least) 8 months ago! Well, we’ve never done enough on HIV, and I don’t think the increased U.S. incidence estimates will do anything to change that. Should we start taking bets on whether HIV gets any debate time in the upcoming elections?

 

M. Linde

Day 143: Why is the FDA investigating these drugs?

Apparently, the FDA is investigating Bristol-Myers Squibb and GlaxoSmithKline for the drugs didanosine and abacavir, respectively. Data from The DAD Study Group published in the Lancet suggests that these drugs are associated with a higher risk of myocardial infarction. One can only assume that the FDA is under increased scrutiny for these types of events considering the recent history of Vioxx. 

While the findings of the DAD group were unexpected, I think an FDA investigation is utterly ridiculous. As I am sure you are well aware, HIV is a fatal disease when untreated. These drugs are truly life saving. I am not saying they don’t have some serious side effects, but increasing an already very low rate of MI among high risk patients should not be a primary barrier to prescribing these drugs. Conducting this investigation will only serve to scare patients away from these antiretrovirals (and maybe other antiretrovirals), which would not be a good thing. 

Now, having said that, I can’t help but find myself wondering whether the abacavir hypersensitivity reactions, slight increase in MIs, and recent troubles in ACTG 5202 (among which was an increase in general adverse events) have something in common. Could there be some inflammatory effect with abacavir? I don’t know and I probably shouldn’t even write this, as there’s no data to back it up. It would be interesting if there was a common etiology, though.

M. Linde

Day 124: Is this really a controversy?

There was a brief report in Nature Biotechnology that recently caught my eye.  The title wasn’t a big draw (“HIV Vaccine Controversy”), but I have to admit I was intrigued that it was in Nature Biotechnology. I thought it had the potential to discuss some real basic immunology. Of course, it turned out to be a news story and didn’t have any real science in it.

I’m glad I came across the article, though, because it’s an interesting story. Essentially, the International AIDS Vaccine Initiative (IAVI) conducted a vaccine trial among 30 participants in India despite the fact that the vaccine had been shown poor results in an earlier European trial. The IAVI claims that it did not act unethically, which I agree with. They argue that response to the vaccine could differ by host genotype, which presumably would be different between your average European and your average Indian. However, I found myself wondering why the IAVI didn’t try and enroll different ethnicities in the European trial—certainly they could have found 30 Indians living in Europe. I don’t know the details, but maybe the IAVI had a good reason for structuring this trial the way they did. 

Still, the whole thing sounded bad, so I am sure the IAVI will be a little more careful in the future. 

M. Linde

Day 67: Is it time to coformulate Viread with Viagra?

Ok, so I am sure the title of this entry will be the standard joke among HIV docs for a bit. Actually, it has probably been made far too many times already. The joke is based on recent data indicating that Viread (FTC/TDF) was shown to decrease the rate of vaginal infection among humanized mice. The mice essentially have human immune systems, which is why the can acquire HIV. Mice that received pre-exposure prophylaxis (PrEP) with Viread did not get infected when exposed vaginally, while 88% of the mice that did not receive PrEP acquired infection. The mice that received PrEP were given Viread 48 hrs and 24 hrs prior to HIV exposure and every 24 hrs for 5 days after exposure. The study was published by Denton and colleagues in PLoS Medicine this month. 

So, these data are kind of exciting. It’s humanized mice, so you can’t get too excited yet. I would assume a monkey study would be next and then a large-scale human trial. You have to take animal studies as they are—they don’t always translate to the same results in humans. But the data could be a boon for high-risk populations, especially women. One of issues with condoms is that it requires the cooperation of your partner. If there is an alternate method to block infection—one that does not require the partner’s cooperation—hopefully the transmission rate might be reduced. This could also be really helpful for serodiscordant couples who want to conceive. Granted, sperm-washing techniques (the process of eliminating virions from semen) are very successful, but this might be considerably less expensive and a lot easier. Viread PrEP could also be helpful for intravenous drug users, but it has yet to be established (as far as I know) if this method would protect against HIV acquired via needles.

Of course, there are also concerns. While I don’t think anyone would advocate using Viread PrEP instead of condoms (especially at this point), we have to establish whether Viread PrEP is as efficient in preventing infection as condom use. If PrEP with Viread is not as efficient as condom use for blocking infection, then you have to question the common utility of Viread PrEP. Additionally, condom use is one time and Viread PrEP might require a weeks worth of adherence, which might be difficult for some. Finally, Viread is not without side effects, although I doubt this would be a major concern considering Viread’s toxicity profile and the fact that the dosing would be intermittent instead of chronic. And cost is always an issue, especially in underdeveloped nations where HIV transmission is rampant. 

All in all, the study is good news. We desperately need more ways to prevent infection. A pill is a good start as it would help circumvent some of the social and political problems faced with condoms. We still need a barrier microbicide, but the data for PReP are encouraging. So, assuming this does work, does Viread go over the counter?

M. Linde

Day 47: Great news from D.C.!

The Associated Press reports that D.C will needle exchange programs. I wrote about the ban on needle exchanges in the city earlier on Day 21. It’s about time needle exchanges were rolled out in the District. Maybe D.C. wouldn’t have the highest HIV prevalence in the US if Congress and the White House had not blocked the District from using funds to provide these programs in the 90s. Hopefully we will learn from this experience.

M. Linde

Day 21 (World AIDS Day): A higher U.S. incidence

In honor of World AIDS Day, the CDC reports that the HIV incidence in the U.S. may be higher than previously reported. I have heard that the incidence was stable at about 40,000 new infections per year, for several years. I read in the Wall Street Journal today that the incidence may be as high as 60,000 new cases a year. This leads to the inevitable question: regardless of the actual number of new infections, why is the incidence not decreasing in the U.S.?

 

As I often say, the greatest tragedy about HIV is that it is an entirely preventable infection. If you take the proper precautions, the risk of infection should be minimal. So, why are so many people still getting infected? Certainly, there is a level of personal accountability for everyone, but as a society, we need to do everything we can to make to easier to prevent infection. My blood still boils when I think back to the moratorium on needle exchange programs from the late 90s. I was living in D.C. when there was a ballot measure on needle exchanges, but the results would not be tabulated because Congress would not fund the District if it enacted such a program. Is it a coincidence that D.C. now has the highest prevalence of HIV in the country, at a whopping 5%? Regardless of the moral implications, we need to make needles and condoms available to those who are at risk. Nobody deserves this disease because they made a bad decision or didn’t have access to preventative measures.

 

While I am on the topic of prevention, why can’t we have some more discussion on microbicides? A preventative vaccine is always the goal, but given the recent track record, can we spend a little more time and money looking into microbicides? Sure, the record with microbicide trials is about as bad as preventative vaccines—and the clinical trials are just as expensive and difficult as the vaccine trials—but as a former virologist and immunologist, I think we are going to have a lot more success at creating a microbicide than we are at making an effective preventative vaccine. There are conserved features of the virus that you can target with a microbicide that you cannot target with a vaccine. So, President Bush, can you talk about microbicides when you propose $30 billion for AIDS?

 

M. Linde

Day 14: CDC releases health disparities report

The Centers for Disease Control and Prevention released a report on health disparities in HIV/AIDS, viral hepatitis, TB and STDs this month. The report follows data from 2001 through 2004 in the US.

 

As we have been hearing for years, HIV rates among blacks and Hispanics are considerably higher than rates for other ethnicities. According to the report, HIV rates were 8.5 times higher for blacks than for whites (69.3 cases/100,000 vs. 8.2 cases/100,000). Notably, blacks accounted for 50% of new HIV cases.

 

The good news is that rates declined over this period for blacks, Hispanics, and in the Northeast. Levels were stable for other ethnicities and US regions. By region, the Northeast had the highest rate of infection (despite the decline), with 30.1 cases/100,000; comparatively, the South had rates of 23.5 cases/100,000. I have always heard that the rates of infection were increasing most rapidly in the South, but these data show that new cases were stable in this region for this period.

 

The report also broke down the new cases by age group. The highest rate of infection was among persons aged 35-39. I can only assume that this has to do with the latency period of HIV and that this age group reflects people who are getting infected in their 20s.

New infections were observed primarily in men, who accounted for 73% of new cases in 2004. Of these men, men who have sex with men accounted for 65% of cases.

 

The mode of transmission among males was predominantly reported as male-to-male sexual contact, with a slight upward tick in 2004. Infection due to injection drug use had a slight steady decrease over this period. For females, heterosexual contact was the main reported cause of infection, although this category decreased over the course of the study.

 

So, what does this study tell us? For many years, I have read and heard that the incidence of HIV was increasing the most among black and Hispanic women and in the South. It is important to note that the data in the CDC report are the number of new cases, which may differ slightly from the actual incidence. So, the face of HIV in the US may be changing compared to the early epidemic, but what we see in this study is a slightly different story. New cases of HIV are still dominated by men who have sex with men and the Northeast US appears to be the epicenter. Clearly, there is an issue when blacks have a considerably higher rate of new infections compared with whites. The reason for this difference is not clear, it could be due to prevention efforts, HIV education, access to treatment or care, or it could also be biological. Certainly, all of these issues need to be examined so we can reduce the incidence of HIV among all demographic groups.

 

M. Linde

Day 8: What we have here is a failure to communicate

Apparently many people don’t think AIDS is fatal. How one could think this with the estimated 20 million people dead from the disease is beyond me. I can only conclude that education efforts are (as usual) failing.

 

The data come from a survey of over 4,500 respondents conducted by the MAC AIDS Fund in the US, UK, India, Russia, France, China, Mexico, Brazil, and South Africa. Reuters reported that close to 60% of respondents in India believe a cure is available and that about 42% overall did not understand that HIV is fatal. Almost half of all polled believe that most people living with HIV are being treated. While I don’t expect most people to know the scope of the disease or even specific about the treatment, I do expect that we at least have education initiatives explaining that AIDS is fatal.

 

This brings me to what I believe is the saddest aspect of the epidemic: AIDS is an entirely preventable disease. We know how to reasonably protect ourselves from acquiring HIV. However, obviously we are doing a terrible job at this, as evidenced by the estimated 40 million people infected with the virus. Why is this not a top priority? Education and prevention measures are loaded issues, as they deal with sex and drugs, but why can’t we put aside our moral judgments and try to curb the spread of HIV? It’s a complete tragedy, because the epidemic never had to reach this level and I am sure it is destined to get worse.

 

M. Linde