Monday, February 16, 2009

Bad Air

(Note: I'm working on my epic post about being out in the Maasai village. It'll be divided up into two parts. Until then, I wanted to write about a subject that has recently become near and dear to me. I hope you enjoy it and maybe even learn something from it. Don't worry, I'll have the travel post up in a few days; consider this the appetizer before the main course.)

What’s the deadliest creature on the planet? If you guessed hippos, sharks crossbred with rocket launchers, or Chuck Norris, you’d be wrong. The deadliest animal in the world, responsible for between 1 to 3 million deaths each year, is the humble Anopheles mosquito. The Anopheles mosquito is the vector for malaria. I didn’t fully appreciate how terrible and prevalent this disease is until I came here. We see it in the clinic every day. In fact, 90% of malaria related deaths occur in Sub-Saharan Africa.

There have been campaigns launched by The World Health Organization, The Bill and Melinda Gates Foundation (Bill Gates called malaria “the worst thing on the planet.”) and many others that rival the Normandy Beach landings in their scale and audacity that are attempting to slow malaria’s spread. But the scary thing is that malaria is quickly spreading. And with urban populations increasingly encroaching on wilderness combined with the unpredictable effects of climate change, malaria will only become more of a problem in the coming decades. The number of malaria-related deaths has more than doubled since the last generation.

Malaria’s impact on mankind can not be overstated. It has left an indelible mark on human history. Malaria has been around for as long as we have. Alexander the Great was not Great enough to overcome malaria. The lowly mosquito stopped the seemingly unstoppable hoards of both Attila the Hun and Genghis Khan. Abraham Lincoln, George Washington, and Ulysses S. Grant all suffered from malaria. It caused over one million Union casualties in the Civil War. More soldiers died from the disease in the Pacific Theater of WWII than from actual combat. Some scientists estimate that 1 out of 2 people that ever lived died of malaria.

Malaria gets its name from the Italian word for “bad air.” This is because the disease was thought to be caused by gas fumes from swamps near areas particularly affected by the disease. Of course, we now know that the disease is caused by mosquitoes which breed in swamps and other pools of water, but it’s easy to imagine how swamp gas could have been thought of as the cause of the disease in the days before modern medical science. The illness is caused by miniscule worm-like parasites called plasmodia. These parasites inhabit the salivary glands of female mosquitoes. Only female mosquitoes drink blood because they need blood proteins to feed their young. Feel free to insert the obligatory “all women are blood-suckers” joke here. When the mosquito feeds, it releases some of its saliva into our bloodstream to act as an anti-coagulant, similar to what leeches do when they feed. This is when the plasmodia enter our circulation. You can fit over 50000 plasmodia onto the period at the end of this sentence, but it takes just one parasite to kill someone.

The parasite finds its way into a liver cell, where it quickly replicates over the course of a week. The life cycle of the malaria-causing parasite is intimidating in its complexity, which is one of the reasons efforts to develop drugs against it are fraught with difficulty. For two weeks or so, the affected don’t realize they are harboring a deadly creature and feel nothing amiss. The first signs that the immune system has been triggered are headaches and muscle aches. Later, the body starts to violently shake and shiver – an attempt to generate body heat to kill off the invading organism. After that the victim spikes a fever, sometimes as high as 104 degrees Fahrenheit. Finally, a drenching sweat concludes the cycle. This classic cycle – shivering, fever, and sweating – repeats itself every three to four days, depending on the type of malaria. Other symptoms include nausea, anemia, seizures, and in severe cases, coma and death.

There are 4 distinct strains of malaria: Plasmodium vivax, P. ovale, P. malariae, and by far the deadliest, P. falciparum.

P. falciparum is the type of malaria we most commonly encounter in our clinic; falciparum is responsible for about half of all malaria infections but over 95% of its deaths. Falciparum is the only type capable of infecting the brain and has other unique features which makes it especially deadly. Sometimes patients develop disturbing-looking bodily contortions caused by the brainstem pushing out through the bottom of the scull, the end result of increased intracranial pressure. Seeing this posturing in a patient is a very ominous sign, and they will most likely end up dead.

The disease is diagnosed using symptoms and a blood smear called a Romanovski stain which looks for the parasite within blood cells. There are more sophisticated and accurate methods of detection, but they aren’t realistic options for the poor countries most affected by malaria. Malaria has devastating effects on economies. The disease can create mental changes and defects which can persist over a lifetime. As a result of the weakened economy, governments have trouble providing health care to its citizens, resulting in more malaria cases. It’s very much a “chicken or egg” type situation; are economies bad because of malaria, or are there so many cases of malaria because the economy is so bad? Stopping the vicious cycle is a seemingly impossible undertaking.

A multi-pronged approach is needed to slow the spread of malaria. Everything from low tech mosquito nets to cutting-edge multidrug cocktails are deployed in the battle against the disease. When it was introduced, the insecticide DDT was seen as a God-sent. It was cheaper, more effective, and longer lasting than its predecessors. Malaria cases plummeted with the start of its widespread use. Then Rachel Carson published Silent Spring, a book considered by many to be the start of the environmental movement. Her work showed how DDT weakened the egg shells of some animals. The problem wasn’t DDT’s use for malaria control, but rather its abuse by farmers; DDT was so cheap and effective, farmers practically drowned their plants in the stuff to keep insects away. From the farm soil, DDT drained into ground water and streams where it created its environmental effects. Silent Spring painted such a damaging picture of DDT that its agricultural use was practically banned, which in turn made it difficult to procure cheaply for malaria control. With this, malaria cases worldwide shot up. Rachel Carson is indirectly responsible for more deaths than Adolf Hitler.

The scariest thing about malaria is how quickly it develops drug resistance. Since it multiplies so quickly and in such great numbers, the malaria plasmodia can develop mutations which give it resistance to antimalarial drugs pretty quickly. We see resistance to chloroquine - the most common drug used to treat malaria – fairly often in our clinic. Stuff like this keeps me up at night. As I mentioned earlier, developing drugs against malaria is very difficult. Thus, there is an ever dwindling arsenal of effective drugs to fight against malaria, which is quickly becoming resistant to more and more types of drugs. There is currently no vaccine against malaria but scientists are frantically working to develop one. I’m lucky that I can afford doxycycline, an antibiotic that for some weird reason works against a parasite like malaria. I take one every night and it <*fingers crossed, knock on wood*> prevents me from getting malaria. There are other drug options available to prevent malaria transmission, but none of them are realistic options for poor countries, either because of high cost or distribution logistics. So the only real options for malaria control are prevention and quick treatment. Getting “quick treatment” isn’t always an option for many. Falciparum malaria moves fast; there are many stories of children laughing and playing soccer in the morning and dead by nighttime. The clinic I worked in when I was in Saiikiri was a closest one around for many people; the next closest one was 60 kilometers away. Most of our patients walked for hours and hours through the hot brushland to see us.

And that’s what it all comes down to. For all the thousands of scientists toiling away in labs around the world, for all the politicians diverting funding towards malaria eradication efforts, it’s the small and simple rural clinic that sees and treats malaria patients. I love being on the frontlines of medicine; it’s the reason I became a paramedic. And here I am in Kenya, on the frontlines, trying to stop malaria...One patient at a time.


1 comment:

  1. I have to say, your blog is truly amazing. I have been reading all your posts from Kenya in one go. It sounds like an horrific, yet amazing experience!

    I'll continue following your blog, looking forward to read about your visit to the Maasai Village.

    Say hi to Hanna for me, will you? I miss her back home, but admire your work!

    André

    ReplyDelete