What you need to know about the new direct marketing guidance note
Nadine Mather and Chloë Loubser
Gene clues point to Cambodia for resistant malaria
PARIS, FRANCE: Gene analysis of malaria parasites has pinpointed western Cambodia as the hotspot of strains that are dangerously resistant to artemisinin, the frontline drug against the disease, scientists said on Sunday, 28 April 2013.
Image courtesy of SweetCrisis / FreeDigitalPhotos.net
An international consortium of researchers unravelled the genetic code of 825 samples of the Plasmodium falciparum parasite from Burkina Faso, Gambia, Ghana, Mali, Thailand, Vietnam and from northeastern and western Cambodia.
The 166 samples from western Cambodia stood out, the team reported in the journal Nature Genetics.
Included in them were three sub-populations of parasites whose genetic mutations made them resistant to artemisinin.
These strains appear to be the wellspring for malarial resistance that is spreading to other countries.
"Clinical resistance to artemisinin and its derivatives is now well established in the P. falciparum population of western Cambodia and appears to be emerging in neighbouring regions," said the paper.
"These recent developments have grave implications for public health, as artemisinin derivatives are the mainstay of malaria treatment worldwide." Western Cambodia has unleashed "successive global waves" of antimalarial drug resistance, the investigators said.
Resistance to chloroquine drugs was observed there in the late 1950s before it spread around the world, and the most common forms of resistance to pyrimethamine and sulfadoxine drugs are also thought to have originated there.
The study offers several reasons why such a relatively small geographical area should be so unusual.
Parasites are transmitted to humans by Anopheles mosquitoes, and a crucial step in the process is the way in which the parasites swap genes within mosquito.
In the case of Cambodia, parasites experienced inbreeding that created lineages with drug-resistant mutations, the study found. Such inbreeding typically comes from isolation.
One scenario is that a group of parasites became isolated in a remote area of jungle.
Another is that the 1979-1998 period of Khmer Rouge resistance in western Cambodia restricted human movement.
As the parasite could not move easily out of the area through infected humans, this provided excellent conditions for inbreeding.
Malaria causes around 650,000 deaths each year, mostly African children under five, according to the UN's World Health Organisation (WHO).
Artemisinin-resistant parasites emerged on the Thai-Cambodian border around nine years ago and were later discovered in western Thailand, Myanmar and Vietnam.
Source: AFP
Source: I-Net Bridge
For more than two decades, I-Net Bridge has been one of South Africa’s preferred electronic providers of innovative solutions, data of the highest calibre, reliable platforms and excellent supporting systems. Our products include workstations, web applications and data feeds packaged with in-depth news and powerful analytical tools empowering clients to make meaningful decisions.
We pride ourselves on our wide variety of in-house skills, encompassing multiple platforms and applications. These skills enable us to not only function as a first class facility, but also design, implement and support all our client needs at a level that confirms I-Net Bridge a leader in its field.
Go to: http://www.inet.co.za
Related
