I have a confession to make: I am infatuated with Michelle Obama. I can’t think of any other celebrity that I have ever become so excited about. But I just love her – her smarts, her skills as an orator, a mother, and I must admit her style. I’ve worn pearls inspired by one of her outfits from last fall. Needless to say, I could not turn down picking up a copy of Vogue magazine this past week because she is on the cover. After skipping through about 200 pages of ads to get to the article, I was pleasantly surprised that the edition contained articles on a number of “first ladies”.
One of the articles was devoted to Melinda Gates, international champion for global health. It was one of the first such articles I have ever seen of this women, she tends to lead an exceptionally private life. To read more, click here.Share on Facebook
Once upon a time, long, long ago, high upon a hill in Montreal, I worked in a lab where I grew cells infected with HIV and spent a lot of time pipetting genetic material onto trays. Once upon a time I knew a lot about immunology, specifically, the immunology of HIV progression. Now I feel like I know next to nothing on the subject.
Last week, the annual CROI conference was held in Montreal. I have been getting updates here and there on some of the key papers presented at this conference and a few of them caught my eye, largely due to the policy implications of these studies. I will try to post on a few of these in the coming week.
The first report is based on the findings of two large cohort studies from Africa which suggests that the current treatment guidelines for ARVs are probably insufficient to make dramatic changes in mortality. The basic story goes something like this: HIV kills off your immune system, ARV allows your immune system cells to return, however, there appears to be some sort of damage that gets done when you have CD4 cells below a certain level for a certain amount of time. What ever the mechanism it means that when you treat people at low levels of CD4 levels they may not really lower their mortality rates as would be hoped. In developed countries, people generally start ARV treatments much earlier than they do in resources constrained environments.
So what does this all mean for the global HIV/AIDS response? First, it probably means that we have overestimated the impact of the rollout of ARV treatment programs and that resources could be more effective (potentially more cost-effective?) if they were directed at treating people earlier into their disease. Whether this is doable ethically, or in the context of countries with low testing rates (people generally present quite late) and lots of stigma and fear of the disease remains to be seen, but a shift in thinking of treating not just those who are most sick but also those who might benefit the most from treatment might have a larger impact in the long-run.
Second, it probably also means that we have greatly underestimated the costs of scaling up treatment programs in developing countries. I don’t know what the distribution of CD4 count levels in HIV infected individuals but would expect that the 350 cut point is much closer to whatever peak density there is in the distribution, meaning that a shift from 250 to 350 CD4 cells could mean a whole heck of a lot more people and hence cost a whole heck of a lot more money.
So more money and less impact that was estimated. Not a good combination.Share on Facebook
(photo from http://www.debswana.com/)
On my drive home the other night, I listed to a radio program that was interviewing an executive at Debswana, the partially government owned diamond company in Botswana. Diamond sales globally have been hit hard due to the global economic crisis and the company had thus decide to halt production at many of its mines. Thousands of workers have been laid off. I briefly wondered to myself, what impact would this have on HIV? Would the government need to scale back ARV treatment programs? Would there be fewer migrants from other countries? Would there be more or less new cases of the disease?
Today, a news article from Zambia made me think about this topic again. Copper has also seen significant declines in its prices and production has also been shuttered in many copper mines in Zambia. The news report suggested that it has led to an increase in sex work and thus in all likelihood an increase in incidence of HIV/AIDS in the region.
There is no doubt that economic activity and economic well-being are inextricably linked to the spread of HIV/AIDS but it is not at all clear to me what direction the effect of the current economic crisis will go. The diamond and copper mines have always been seen as part of the reason why southern African nations have had higher levels of HIV/AIDS prevalence. Will the laid off employees return to their homes and spouses (will this increase or decrease the spread)? Will they buy more or less sex from sex workers (presumably a normal good)? Will international trade of goods be reduced and lead to less spread of the disease?
Emily Oster believes that there is a direct causal relationship between economic activity and HIV incidence. She argues that the decline in incidence of HIV seen in Uganda, and which has been heralded as the text book example of how to make prevention work, may have been due to a decline in coffee exports rather than any major change in behavior. She focuses on coffee exports, which may involve different human patterns than mining so it is not clear how generalizable these results are to other countries. If only I had better data…Share on Facebook
There is great debate within the public health circles of whether the mantra that “a calorie, is a calorie, is a calorie” is in fact true when it comes to losing weight. The popularity of diets such as the Atkins diet suggests that certain combinations of calories, in this case low carbohydrate and high protein diets, may be superior to others with regards to weight loss. There are scientific studies (some supported by the Atkins Foundation) to support this claim. When I was a student at the Harvard School of Public Health, I attended the weekly nutrition seminar (they always had great lunches) and I remember great and heated debates about whether there was a violation of the laws of thermodynamics at play.
It has been speculated that part of the debate stemmed from the fact that many of the studies in question had very small samples of patients (some really small, like 20 or so), potentially unrepresentative populations, and that follow-up periods were very short. A recent study published this week in the NEJM tried to overcome these challenges by randomizing 800 patients to different diets and follow-up with the patients over 2 years. The study finds little difference between the diets in terms of short term weight loss, or long-term weight loss maintenance suggesting that the old adage is true.
While this clearly does not put the debate to rest once and for all, it does certainly suggest that much of what we have been led to believe of late is probably not true. The only real way to lose weight through diet is to reduce calorie intake. Darn.Share on Facebook
As I see it, there have been at least four major lines of research in the fight against malaria: new medicines, new vaccines, new methods of protecting people from mosquitoes, and new methods to eliminate mosquitoes from the environment. A whole new way of tackling the disease, however, has emerged. Scientists are also working on developing genetically modified versions of mosquitoes to prevent or reduce the transmission of the disease.
In the past few years, much progress has been made on this last line of research. Today a mutant strain Anopheles Gambiae has been developed that has been genetically modified to prevent the spread of malaria. The hope would be that this new strain could be introduced into the wild, would compete favorably with native mosquito populations and eventually reduce the transmission of disease.
To read more about these advance, see the following article recently published in PLoS Medicine.Share on Facebook
A recent NYTimes carried a gut wrenching story of women suffering from fistulas in Tanzania. The women in this story, fortunately, had some hope of recovering from these injuries thanks to the availability of expert foreign surgeons who had been flown in to provide assistance to these women.
Fistulas are common injuries suffered as a consequence of prolonged obstructed labor. A fistula is a general term given to a hole between organs that should not normally exist, in this particular case it usually means an abnormal opening between the bladder and the vagina, or between the rectum or vagina (other terrible combinations also exist). You can imagine the repercussions of such injuries. Women with fistulas are frequently outcasts in their communities due to the fact that they are unable to prevent themselves from uncontrollably releasing urine or feces.
Fistulas are relatively rare in developed countries since women who have prolonged childbirth generally quickly receive a caesarian section averting further complications. However, the incidence of these injuries is relatively high in developing countries. When births are prolonged the baby can push up against the mother’s insides causing tissue and nerve damage causing the tissues to die, leaving a fistula. In many ways, fistula prevalence is a good proxy for the availability of essential obstetric care.
It was nice to read that many of the women in this story eventually recovered from their injuries after undergoing reconstructive surgery, however, the vast majority of women never receive access to such services. Prevention should be the goal, but health systems in much of the world are so under resourced that such a goal is out of reach for the time being. Kudos to the NYTimes for covering this largely neglected global health issue.Share on Facebook
This morning’s NYTimes carried an article about one of the elements of the US government’s stimulus plan that may have a big impact on health. Buried within the massive stimulus plan is $1.1 billion dollars for “researchers to compare drugs, medical devices, surgery, and other ways of treating specific conditions”.
This may not seem like a very radical new program, but it is. While the US government and private companies spend literally billions of dollars every year on research on the effectiveness of new drugs and other health technologies, very little is spent in the US on what is known as “comparative effectiveness research”.
The big difference between this type of research and the current system is rather than leaving each individual developer in charge of studying the effectiveness of its own product relative to some standard treatment protocol (frequently nothing or a placebo), now research will be funded that can compare a whole set of treatment options and comment on the relative effectiveness of each approach. Many countries, in particular the United Kingdom (e.g. the NICE agency), do a lot of this type of research. However, the current structure of the US health care system means that each individual developer will not commit to doing such research because the costs would likely exceed its own benefit and because there is great risk you find out (and so does everyone else) that your product is relatively less effective than you hoped.
I loved this quote from the article:
“…Republican lawmakers and conservative commentators complained that the legislation would allow the federal government to intrude in a person’s health care by enforcing clinical guidelines and treatment protocols.”
What horror! When did clinical guidelines and treatment protocols become such a bad thing? Just because it is nice to think that I should have some choice in my treatment mean that I know best? I would rather walk into the office of a doctor who has some plan of action on how to treat me instead of having to rely upon some uninformed trial and error process. I get that people are worried that taking costs into consideration may mean that some treatments may become less available, but bear in mind that this process takes into consideration the effectiveness, so if the most expensive treatments also work the best, than they would likely be cost effective. At least I would now know what trade-offs are being made. After all, real life is always about trade-offs, in particular in the current economic crisis.Share on Facebook
When I say “neglected tropical disease“, I don’t mean the diseases that most people in the US have heard of or have even purchased a Starbucks coffee to help treat in Africa, I mean the real nasty ones like onchocerciasis, schistosomiasis, trachoma, lymphatic filariasis, and even a bunch that are so less well known that they often get grouped into catch-all categories like “soil transmitted helminths” – even by the experts who are crazy enough to devote their careers to tackling them. What these diseases have in common is that they actually affect a boatload of people and despite their massive burden of disease, relatively alarming outward manifestations (blindness, long-term educational problems, peeing blood on a regular basis), and even a well developed pharmacological war chest to treat them, they get little attention from donors, by countries, and even by people directly affected by the diseases themselves. How can anyone get excited about diseases that even people who regularly pee blood and suffer measurable learning problems won’t even pay $0.10 cents a year to avoid?
Over the past couple of years, there has been an incredibly hard working and dedicated group of parasitologists and entomologists-cum-global health advocates that have been trying to raise the profile of these neglected tropical diseases (aka the NTDs). Whether it is due to a lack of information, time-inconsistent preferences, short-term liquidity constraints, or some other behavioral model that we don’t fully understand, poor people in poor countries are not going to anytime soon take it upon themselves to protect themselves adequately from these diseases. Due to the massive positive spillovers that come from treating these diseases on interrupting transmission it also provides additional rationale for intervention. Unfortunately, NTDs are not sexy enough for us to care.
So how might we get more excited about these diseases? The strategy of these brilliant advocates thus far has been to make the case that treating NTDs is a great way to also help reduce the burden of diseases we do care about. In the latest iteration of this strategy, the worm guys have now made a clear case as to why NTD treatment could go a long way to improve the treatment of malaria. Their arguments?
First, there is evidence that the existing infrastructure for NTDs, such as the CDTI infrastructure tireless built up over 15 years by the APOC program (the most successful public health program you have never heard of) can instantly be used to further increase access to insecticide bed-nets and home-managmeent of malaria interventions. They even have a well controlled multi-country study evidence to support this claim.
Second, many of the helminthic infections discussed above lead to anaemia and anaemia makes malaria worse. So if we deworm with inexpensive drugs, we can reduce the burden or severity of malaria.
So for a few quick additional dollars, by thinking of NTD control as a means to achieve improved malaria outcomes, we might actually trick ourselves into wanting doing a whole heck of a lot of good. Hey if it works….Share on Facebook