Artemisinin: the miracle drug against malaria and how we may be losing it
Image credit: Centre for Disease Control
Today we would like to announce the publication of an elective report from New York by Gus Gasteratos, a medical student at the Aristotle University of Thessaloniki, Greece. Read it here.
Meanwhile, this month, the 25th April celebrates World Malaria Day 2010. With this in mind, Inderjeet Sahota, M.Sc. student at Simon Fraser University, Canada, discusses the recent reports of artemisinin resistance in Cambodia, and how important this is for anti-malarial work around the world.
Artemisinin is effective, has few side effects and stays in the blood for a relatively short time, thereby helping decrease its chances of bacteria becoming resistant to it.
Malaria is an enormous global health problem that causes approximately 1-3 million deaths per year (1). Malaria is caused by a group of parasitic protists called Plasmodium. The Plasmodium species responsible for the vast majority of malaria cases across the world is Plasmodium falciparum which accounts for roughly 90% of all cases.
Steps to prevent malaria by providing mosquito nets and removing or destroying mosquito breeding grounds have increased over much of the globe while research has also continued to try and find better and safer anti-malarial treatments. However, the underlying problem with most anti-malarial treatments is that as the cause of the disease is a bacterium they may become ineffective with time as these organisms become resistant to them; eventually to the point where they are no longer useful as a treatment option. This becomes a major problem in anti-malarial strategies and one that requires constant development of new and improved anti-malarial medications.
In this blog I’ll review current effective anti-malarial treatments and a recent report that suggests this gold-standard of treatment may be at risk.
Many anti-malarial drugs exist, each of which have varying degrees of effectiveness. Some examples of anti-malarial drugs include quinine, mefloquine and artemisinin. Drugs such as chloroquine, which were commonly used in the past, have almost become obsolete as malarial parasites have become resistant to them. Currently, the best anti-malarial treatment is a combination of various drugs of which artemisinin is the core.
Artemisinin is a drug derived from a herb used in Chinese traditional medicine that, when combined with other treatments to form artemisinin-based combination therapy (ACT), is highly effective at killing the parasites responsible for malaria (2). Artemisinin is effective, has few side effects and stays in the blood for a relatively short time, thereby helping decrease its chances of bacteria becoming resistant to it. Artemisinin is currently the gold-standard for pharmacological combat against malaria and forms a key part of anti-malarial strategies across the globe.
However, in early 2009 reports in Cambodia surfaced stating that the protist responsible for malaria may be developing resistance to artemisinin (3,4). As ACT’s are currently the most effective treatments with a success rate of almost 95%, losing these as weapons in the fight against malaria could be devastating and may severely hinder progress made in much of the world. In March 2010 the World Health Organization (WHO), in response to this threat, released new malaria guidelines for the treatment and procurement of medicines involved in malaria where they emphasized the importance of using artemisinin as combination therapies and not as monotherapies to help prevent bacterial resistance to the drug (5).
A BBC World Service Health Check podcast released on March 7, 2010 (6) outlined some of the more recent developments in artemisinin resistance in Cambodia. Since last year when these reports surfaced, authorities in the area have taken aggressive steps to contain and treat the malaria in hopes that this resistant-strain will be eradicated and will not spread to other parts of the world. Greater communication between villages with malarial outbreaks across the region, increased use of bed nets and more stringent use of anti-malarial drugs are but some of the measures that have been taken and so far these efforts seem to have been successful. However, not all people believe these efforts will be enough.
Many experts believe that resistance to artemisinin is inevitable and, unfortunately, history has been on their side. In only recent times two anti-malarial drugs have become obsolete as bacteria became resistant to their effects and spread over much of the world. These people believe that the best case scenario is to delay and hinder this resistance as much as possible until new and improved treatments can be developed. In this sense, the battle against malaria will be a continuous and ever-changing one and one that may never be ‘won’ in the traditional sense.
However the problem of anti-malarial resistance is viewed, the fact of the matter is should we lose ACT’s as an effective treatment today the world will be left with no viable alternative; and this is something health professionals should be very concerned about.
REFERENCES
1. Snow RW, Guerra CA, Noor AM, Myint HY, Hay SI (2005). “The global distribution of clinical episodes of Plasmodium falciparum malaria”. Nature 434 (7030): 214–217.
2. What is Artemisinin? Scientific American. Available online: [http://www.scientificamerican.com/article.cfm?id=artemisinin-coartem-malaria-novartis].
3. Malaria parasites ‘resist drugs’. BBC News. Available online: [http://news.bbc.co.uk/2/hi/asia-pacific/8073118.stm]
4. Fears for new malaria drug resistance. BBC News. Available online: [http://news.bbc.co.uk/2/hi/asia-pacific/8072742.stm]
5. WHO releases new malaria guidelines for treatment and procurement of medicines. World Health Organization. Available online: [http://www.who.int/mediacentre/news/releases/2010/malaria_20100308/en/index.html]
6. BBC World Service: Health Check [podcast]. Mar 7, 2010.