Resistant strains of the malaria turning up in Asia

The most effective drugs against malaria have been derived from the Chinese plant, Artemisia annua, also known as sweet wormwood.

Efforts to contain malaria now 'seriously compromised'

4/8/2012

Catholic Online (www.catholic.org)

Scientists have confirmed that resistant strains of the malaria parasite have been discovered on the border between Thailand and Burma, 500 miles away from previous sites. This comes as especially dire news, as resistance to front-line treatments for malaria are now increasing, and the effort to eliminate malaria is "seriously compromised."

LOS ANGELES, CA (Catholic Online) - As published in The Lancet medical journal, the most effective drugs against malaria have been derived from the Chinese plant, Artemisia annua, also known as sweet wormwood.

Researchers found in 2009 that the most deadly species of malaria parasites, spread by mosquitoes, have become resistant to these drugs in parts of western Cambodia.

The new data confirms that these Plasmodium falciparum parasites, which are infecting patients more than 500 miles away on the border between Thailand and Burma, are growing steadily more resistant.

The Shoklo Malaria Research Unit measured the time it took the artemisinin drugs to clear parasites from the bloodstreams of more than 3,000 patients. Over the nine years between 2001 and 2010, doctors found that drugs became less effective and the number of patients showing resistance rose to 20 percent.

Professor Francois Nosten, part of the research team that has carried out the latest work, says the development is very serious. "It would certainly compromise the idea of eliminating malaria that's for sure and will probably translate into a resurgence of malaria in many places," he said.

Dr. Standwell Nkhoma from the Texas Biomedical Research Institute, another scientist involved with the study says that the "spread of drug-resistant malaria parasites within South East Asia and overspill into sub-Saharan Africa, where most malaria deaths occur, would be a public health disaster resulting in millions of deaths."

Scientists still can't tell if the resistance has moved because mosquitoes carrying the resistant parasites have moved to the Burmese border or if it has arisen spontaneously among the population there. The researchers involved say this raises the ghastly specter of untreatable malaria.

"Either the resistance has moved and will continue to move and will eventually reach Africa. Or if it has emerged, now that artemisinin is the standard therapy worldwide then it means it could emerge anywhere," Nosten told British television journalists.

"If we were to lose artemisinin then we don't have any new drugs in the pipeline to replace them. We could be going back 15 years to where cases were very difficult to treat because of the lack of an efficacious drug."

Artemisinin is seldom used by itself, usually being combined with older drugs to help fight the rise of resistance. These artemisinin based combination therapies are now recommended by the World Health Organization as the first-line treatment and have contributed substantially to the recent decline in malaria cases in many regions.

Nosten says the current spread of resistance could be similar to what happened in the Seventies with chloroquine, a drug that was once a front-line treatment against the disease.

"When chloroquine resistance reached Africa in the middle of the 1970s it translated into a large increase in the number of cases and the number of children who died increased dramatically."