What is drug resistant malaria?
Think of drug resistance as an arms war between the parasites and whatever drugs we have available. This is not a new war – it's a decades long war. Every time scientists find a new drug to kill malaria parasites, those parasites become exposed to the drugs over time and eventually, at some point, they develop a genetic mutation that confers some advantage to them. It's widely acknowledged as a serious threat to global efforts to eliminate the disease.
The malaria-causing parasite that's resistant to the most effective medicine available, artemisinin, is a subset of populations of Plasmodium falciparum. The type of malaria that is drug resistant is known as "severe malaria." It kills more people around the world than any other.
When was drug resistant malaria discovered in Myanmar?
Drug resistant malaria was found during the last five years. That doesn't mean resistance here is new, but that we've only become aware of it recently. Pockets of resistance have been found along south-eastern Tanantharyi Region near the Thai-Myanmar border, neighbouring Kayin State and in the highlands of eastern Shan State. The reason why it's commonly found in border areas is because malaria is often transmitted by human movement. In the past, there were people moving from Myanmar to Thailand to the Cambodia border to work on gem mines and a lot of those people were Burmese. Then when they moved back, the parasites moved over the border. It's human migration that moves the parasites around – obviously mosquitoes themselves can only travel a few kilometres. So what we are trying to do is put a wall up to stop resistant forms from reaching India, Bangladesh – and eventually, Sub-Saharan Africa. We have to stop the westward spread.
What has PSI been doing to stop drug resistant malaria from spreading?
Well, the first thing is just to try to bring down malaria as a whole. That means preventative steps, such as sleeping under mosquito nets. But the most important thing is taking good quality medicine instead of medicines that can drive the problem up. So we've been working with our donor agencies to distribute a drug that's more effective, and importantly also, cheaper. Many people in rural communities buy medicines from the informal private sector – that is a kiosk style pharmacy – and most can only afford a partial dose of a mono-therapy drug, for about 500 kyat. From a curative standpoint, the mono-therapy drugs were effective. The problem is that they have one active ingredient. The way around this is to protect the miracle drug artemisen by combining it with another drug. The two anti-malaria drugs work in very different ways on the parasite, so the chances of a parasite developing a mutation are minimised, because the probability of two mutations is minuscule compared to having one active ingredient.
The really powerful part about this project is that we recognised that AA Medical in particular and another company dominate the anti-malarial market with about an 80% market share. So we persuaded them to work with us and we've had legally binding contracts in place for two years. Donor money subsidises the price of the more expensive combination therapies, which means we can outcompete them.
How do you measure tangible success?
A survey carried out by PSI in June 2013 at 3,500 outlets in the priority resistance containment region of eastern Myanmar found that the volumes of combination therapy being sold relative to monotherapy increased from 3 percent in mid 2012 to 73 percent in mid 2013. Our target had been ambitious at 50 percent, but we exceeded it. This was in just one year after we implemented it – it was a remarkable change.
We also have people coming in from the Chinese border and they are all saying the same thing – that they aren't seeing the "bad" medicine. I challenge anyone to find it in the market nowadays.
Has the government been cooperative?
Yes, the Ministry of Health has been very supportive and the minister himself takes a personal interest in it. The fact that the Food and Drug Administration banned the previous monotherapy medicines was very important to our success. A few years ago, things weren't so straightforward – it was much more difficult. There's been dramatic improvement over the last few years and decentralisation is more common, which means that township officials have more control over what is going on, which is helpful.
Does regional cooperation also exist?
It used to be fairly fragmented but in recent years there's been a tremendous push – and there's a global plan for fighting resistance malaria, along with a regional plan. Within the Greater Mekong Region there are country-specific plans, though each with a similar language, identifying consistent themes and approaches. In any given month I'll go to one or two donor coordination meetings. Could things be better though? Yes. There are different agendas for combating malaria. What I'd say is that there's always room for improvement, but there is an enormous effort on right now.
How is Myanmar succeeding as compared with other countries facing this threat?
In the past in Myanmar, we used to talk about drug resistance containment – but increasingly we don't use the word "containment." We talk about limitation. There's a big drive in the Asia-Pacific region as a whole to move to elimination, such as in Cambodia, Nepal and Laos.
Myanmar remains in the containment phase, that is, bringing down the transmission to a level where it's the pre-elimination stage. Pretty soon Myanmar will be recognised as being in the pre-elimination stage. That's the goal we're focused on for the next few years. But it's not straightforward – there are lots of technical, epidemiological challenges. But we need to move in that direction.
Is there a risk the parasites will eventually become resistant to these new drugs? What happens then?
It's increasingly recognised that the only long term solution isn't new drugs – it's wiping out the parasite population entirely (this is not to be confused with wiping out mosquitoes, which would be impractical). So while we've solved one particular piece of the puzzle, we are buying time until we have new alternatives. It's an arms war remember, so at some point, we will need to change medicines. In the past we had the luxury of having an alternative drug in the pipeline. The reason why everyone is so worried is because there isn't a new drug ready. It gets harder and harder to develop a new drug because it requires finding new compounds. That said, thanks to the Bill and Melinda Gates Foundation, there's more spending on scientific research than ever before. So we at least have potential options, but they aren't ready for deployment.
http://www.information.myanmaronlinecentre.com/public-enemy-number-one-drug-resistant-malaria/
No comments:
Post a Comment