Basics
The Polio Vaccine Is Causing Polio. Oops?
Published August 16, 2009 @ 09:25AM PT
(Nigerian kids. Photo credit: OziAfricana)
124 children in Nigeria have been paralyzed by a type of polio that was actually caused by the polio vaccine. It's the result of using a cheaper, more effective type of polio vaccine. This could be bad news for that vaccine - if it's causing that much polio, we may have to stop using it.
Developing countries use a type of polio vaccine - a live, oral vaccine - that causes a very mild form of the virus, and therefore the infection. The mild form triggers an immune response which protects from the serious, wild form of the virus. The mild virus also spreads from child to child and provides some protection to kids who've never gotten the vaccine. It's used in developing countries because it can be given by mouth, it's cheaper than the vaccine made with an inactivated (as opposed to live) virus, and because of that protection it provides to unvaccinated children.
Everything, of course, has a catch. In the case of the live oral vaccine, the catch is that every once in a while, it causes a more severe form of polio. Not often - it's usually about 1 case of polio-paralysis in every 2.5 million doses of vaccine, which makes the odds worthwhile from both an individual and a population perspective. And the more severe form happens in children who have not actually been vaccinated. Sometimes the vaccine virus can mutate in its host, and then cause a more severe form of polio in the child who catches it. If you can vaccinate almost all kids, then there is an even tinier risk of vaccine-related polio paralysis.
42 million children have been vaccinated for polio in Nigeria. This year, there have 124 cases of polio caused by the vaccine. That is double what we saw last year. Experts are blaming low vaccination rates for the spread, and they are right - to a point. If more children were vaccinated, then this wouldn't be happening. But accepted wisdom has always been that vaccine-caused polio virus didn't spread the way wild polio does. The Nigerian outbreaks cast some doubt on that.
If the oral polio vaccination is only effective when given to nearly 100% of the population, then it changes the whole cost-benefit discussion. It starts to look like there's no real point to using the oral vaccine except to save money. That makes cases of vaccine-induced polio paralysis a lot harder to accept.
Friday Futures: Food
Published August 08, 2009 @ 12:44PM PT
(No, not this kind of wheat rust. Photo credit: dave_7)
So far we're still defeating Malthus. We've managed to keep increasing food production enough to keep up with population growth and even make much of the globe fat. I think we'll keep outrunning him in terms of calories. We'll continue to grow enough food in aggregate to support the weight of the world's population. In terms of the variety of our food, however, we're on the verge of a major contraction. Variety will shrink, and prices of food will go up enough that the even the middle class will see their food options substantially limited by price.
We're eating pretty much all the fish in the ocean. There will be many fewer kinds of fish available to consume, and they will be extremely expensive. Eating fish will be something you and I tell our grandchildren about. Only the rich will have any kind of access to seafood.
We're losing a lot of crop variety because of the industrialization of agriculture. Bananas are down to about two strains already, and other fruit will suffer similar genetic diminishment. Rare grains will get rarer. Vegetables that don't travel well are already on the verge of vanishing; that's not going to change. Non-GMO crops will be hard to get unless you grow them yourself. Fruits and vegetables will also get less nutritious over time, as they are developed to be attractive, travel well, and resistant to pesticides and pests, not to be packed with nutrition. GMO crops will keep us all eating, but not eating well.
Most non-rich people on the planet will have a choice of no more than 50 different foods in their diet, and not much more. I don't think most people will mind. Humans don't seem to be designed to desire much food variety.
Being dependent on this narrow range of crops will, however, put us at risk for losing food sources to new diseases. Wheat stem rust is already putting much of the world's food supply at risk. Another crop disease could happen just as easily, especially since diseases - even plant diseases - can now travel so fast around the globe.
Maternal Mortality - The Medical Basics
Published July 31, 2009 @ 05:55AM PT
(Memorial Quilt. Photo credit: net_efekt)
The primary medical conditions that cause maternal mortality are severe bleeding, infections, hypertensive (blood pressure) disorders, obstructed labor, and medical consequences from unsafe abortions. They cause 80% of maternal deaths.Other medical causes of maternal mortality include malaria and HIV complications, and kidney and heart failure. Access to medical care can prevent death from all of the five major causes.
Severe Bleeding
Severe bleeding, also known as maternal hemorrhage, is blood loss before, during, and after childbirth. Bleeding may be external, out through the vagina, or internal, into the abdomen. When a woman loses too much blood, she dies. It can happen for a number of physiological reasons; anemia in particular can lead to hemorrhage. However, if proper medical care is available, maternal hemorrhage is almost never fatal. That is one reason there are so few maternal deaths in the developed world.
There are some basic technologies that can be used to reduce the impact and likelihood of maternal hemorrhage. Using a drape under the mother that collects lost blood helps health care providers estimate the severity of blood loss and know when to being treatment. Managing the delivery of the placenta after the baby is born, often by giving a hormone called oxytocin, can reduce the risk of hemorrhage.
Infections
Infections, also known as sepsis, usually develop after delivery, when the mother at home. It causes 15% of all maternal mortality, and is a major cause of infertility among women.It's more common after home births than after births that take place in a hospital. It's more common among poor women. Anemia, poor nutrition, and prolonged labor are also factors.
The most important issue with regard to infection, though, seems to be Caesarian section - it is the biggest risk factor for maternal infections. This is a reminder that that women need access not only to medical care, but to good quality medical care. A C-section is a life-saving intervention, but it's not a surgery without risk. It should only be done if there are no other options.
Hypertensive Disorders
Hypertensive disorders, primarily eclampsia and pre-eclampsia, make up 25% of maternal mortality in the developing world.High blood pressure can lead to vascular problems, bleeding and organ failure. Pre-eclampsia is a specific kind of high blood pressure that damages the mother's kidney, liver, and blood vessels. Pre-eclampsia can develop into eclampsia which causes severe convulsions and will kill the mother and fetus if the child is not immediately delivered. These are some of the most difficult maternal deaths to prevent. Hypertensive disorders have a range of different causes, and we don't know a lot about effectively preventing them.
Obstructed Labor
Obstructed labor occurs when a woman in labor is unable to actually push the baby out. That usual happens because of cephalo-pelvic disproportion - the baby's head is too large to get through the mother's pelvic bones. It can also be caused by the fetus being positioned awkwardly in the uterus, or by malformation or trauma in the mother's pelvis. Obstructed labor can be resolved with a Caesarian section, but as discussed above, c-sections carry their own risks.
Effects of Unsafe Abortion
A safe, medical abortion has fewer risks than carrying a child to term. An abortion performed at home, by an unqualified provider, or in an unsterile environment carries serious dangers. They include serious bleeding, infection, and tearing or puncturing of the uterus. 1/3 of all abortions take place in unsafe conditions, and 500 women die every day from unsafe abortion.
How Does the Money Move?
Published July 20, 2009 @ 08:01AM PT
The next thing to look for in health care financing is how the money moves. There are a lot of different ways a health care provider can be paid. A hospital can be paid by how many patients it sees, by the diagnosis of each of those patients, or for each individual service it provides to each patient. A physician can be paid an annual salary regardless of how much care she provides, she can be paid a flat annual sum for every patient she takes responsibility for, or she can be paid for each individual service she provides.
As a rule, paying providers, whether hospitals or individuals, for each service provided tends to lead to over-medicalization and unnecessary health care provision. Surgery and diagnostic tests in particular are over-used. Paying providers a flat salary prevents that, but removes a certain amount of profit motive from becoming a health care provider, and could conceivably decrease the supply of providers. Onehospital equivalent of a flat salary is to pay by catchment area; a hospital receives a fixed sum of money every year based on the number of patients it's responsible for. That's known as per capita reimbursement. (You can, of course, also pay the individual provider this way.) You can also pay by diagnosis. For example, a hospital or individual would be reimbursed according to how many AIDS patients it saw, how many people with pneumonia, or lung cancer, and so on. None of this is simple. Every case of pneumonia is not the same. Every patient is not the same; women, children, and the elderly require more care than men in their 20s. You need to adjust your rates to allow for this.
These different financing systems can be used in a single-payer system or a multi-payer system. It's much more complex in a multi-payer system, but it's possible. (That might be one good rule of thumb in thinking about health financing - multi-payer systems are far more complex. If you're American, you have a multi-payer system. Explains a lot, doesn't it?)
Who Pays for Health Care?
Published July 20, 2009 @ 05:24AM PT
Health care financing isn't a topic that most people get excited about, but they should. The way that money moves for health care shapes the kind of care that people receive. Health is not driven by people's health needs. You'd expect that, but it's not. People don't know enough about medicine to demand care in specific ways. Instead, health care providers decide what kind of care that patients need. And what they decide is driven by what gets paid for; we've got studies to prove it. If specialist care is the most reimbursed, people get specialist care. If primary health care is reimbursed, they get that.
One thing to look at in health financing is who pays. You can have a single payer system, where a single entity (generally a government body, though I suppose it could be a foundation or private sector fund) pays health care providers and facilities. Or you can have a multi-payer system, where people pay out of pocket, insurance companies, and others pay for health care.
In a single payer system, the single payer has a lot of control over how health care is provided. Reimbursement for providers can be standardized, for example, and dangerous or unproven treatments can be ineligible for reimbursement. In a multi-payer system, different providers will be willing to pay different rates, and reimburse for different kinds of care. It means more options, and less quality control. The American system is a multi-payer system; the Canadian system is single-payer. Personally, I believe that the evidence supports single-payer systems as providing better, cheaper health care. Either system can be used to provide universal health care.
Polio and Health Systems
Published July 15, 2009 @ 06:22AM PT
(Boy in an iron lung, a treatment for polio paralysis, in 1955. Photo credit: otisarchives4)
The fact that polio still exists is a testament to just how hard it is to successfully vaccinate children. We've had effective vaccines since 1955, but there were still 1,652 cases of polio in 2008. Under two thousand cases doesn't sound like that many, but polio is highly contagious. Outbreaks spread fast. And the 2008 number was actually higher than the 2007 number - we only saw 1,315 cases of polio in 2007.
So, why haven't we eradicated polio yet? Part of it is about polio's specific characteristics as a virus. Multiple vaccinations are needed for full protection from the polio viruses.
The largest part of the challenge, however, is just the challenge of childhood vaccinations. It takes a lot of health system effort to provide childhood vaccinations, both in terms of cost and in terms of time and capacity.
In order to immunize a population, you need health care providers who know how to provide vaccinations. You need a sufficient supply of vaccines, syringes, and a distribution system to get them to the providers. You need a way to keep the vaccines cold, and therefore effective, until they are given. You need access to children - either by going to them, or having them come to a health facility. You also need parental permission for the vaccination.
All of those health system factors tie into larger structural concerns. Parental permission is dependent on faith in the health system, which depends on faith in government. A cold chain requires safe and reliable travel. Health care providers need to get paid. That's a lot of points for failure.
It's those points of failure that have kept us from eradicating polio.
Bridge Blogs
Published July 14, 2009 @ 12:35AM PT
One thing I talk about a lot is the importance of cultural understanding in global health. Without knowing context, your work is remarkably useless. But we can't all spend years in a place learning society and culture before we start a program, though I wish we could. Instead, we research as best we can. I like to do a lot of reading on the history and sociology of where I work. I also read local media (in English if that is all I can do) and novels set in that location.
Lastly, I like bridge blogs - blogs which serve to help outsiders understand a culture. Some are written by insiders for an international audience, others by outsiders sharing their own leaning process. Either way, they are an easy, bite-size way to learn a new place.
Some of my favorite bridge blogs:
Window on Eurasia - Russia, Central Asia, and the Caucasus - This blog features commentary and translations of regional news media, bringing ideas and perspectives I haven't found anywhere else.
Marc Lynch at Foreign Policy - The Middle East - Informed insight into the politics of the Middle East. I am especially impressed by his analysis of Muslim Brotherhood internal dynamics.
Aimee Barnes on China - China (obviously) - Written by an American specialist on business and China, the blog has a specific goal of explaining China to outsiders.
Gori Wife Life - Pakistan - This is a change of pace from the others. It's a blog written by an American woman who married a Pakistani, and it focuses on Pakistani culture and domestic life. She's not aiming to look at anything larger, but she's very observant and her insight casts light on a bigger picture.
Scarlett Lion - Liberia - American journalist Glenna Gordon is based in Liberia and writes about politics and daily life.
I notice, listing them out, that all these blogs are written by outsiders. I wonder if being in the middle of a culture you take so much for granted that you have trouble being accessible to outsiders? Or maybe I am lazy?
For more blogs that bridge cultures, I strongly recommend Global Voices. In their own words: "Global Voices is a community of more than 200 bloggers around the world who work together to bring you translations and reports from blogs and citizen media everywhere, with emphasis on voices that are not ordinarily heard in international mainstream media."
Do you have favorite bridge blogs? Suggest them in the comments.
