25 April marks World Malaria Day 2012, which aims to raise awareness of malaria control around the world. In the previous decade, deaths caused by malaria have been successfully reduced by a third in Africa, and up to 50% in 35 out of the 53 countries which are affected by malaria.
Malaria is caused by a parasite called Plasmodium, which is transmitted via the bites of infected mosquitoes. In the human body, the parasites multiply in the liver, and then infect red blood cells.
The key to successful intervention in order to control malaria, according to the WHO, requires a prompt and effective treatment with an artemisinin-based treatment, the use of insecticidal nets, and indoor sprays to kill mosquitos. Artemisinin, isolated from a plant called Sweet Wormwood, and its derivatives are the basis for all current treatments that destroy Plasmodium.
The New Scientist reported on a study published in April in The Lancet, which has discovered that Plasmodium parasites in Thailand and Cambodia are becoming increasingly resistant to artemisinins. The study looked at the time it took for the number of Plasmodium in a person’s blood to halve, which should take around two hours for artemisinin-based treatments. However in Cambodia, it now takes around 5.5 hours.
In Thailand, the length of time taken to half Plasmodium has risen from 2.6 hours in 2001 to 3.7 hours in 2010, and the percentage of slow clearing infections (which is classed as any length of time over 6.2 hours taken for Plasmodium levels to half) has risen from 0.6% in 2001 to 20% in 2010.
The biggest worry is that the resistant strains of malaria could reach Africa, where 90% of total malaria deaths occur.
The authors of the study, ‘Emergence of artemisinin-resistant malaria on the western border of Thailand: a longitudinal study’ say that the factors affecting the increased resistance could be several fold. One reason could be due to increased sales of diluted artemisinin treatments, or that Plasmodium in Cambodia could have enhanced genetic resistance to the treatments.
We at Aurora are interested to see how World Malaria Day will affect conversations about malaria in social media and will be running a short listening exercise. We will be sure to update you with any findings!