Malaria becomes Drug Resistant

"Ring forms" of the Plasmodium falciparum (malaria) parasite, inside red blood cells. Microscope image using 100x oil-immersion lens. From a blood smear, stained with hematoxylin. (Photo credit: Wikipedia)

 

Malarial Parasites have become drug resistant, team of Researchers in Thailand report.

The reason attributed is over usage of the Drug which has made the parasite immune to the medication.

Frequent and over usage of Antibiotics and drugs of any nature spoils one’s health and the bacteria/virus becomes drug resistant.

Allow the body immune system reasonable time to take action by itself.

Refers to:

There are fears the disease could be spreading after a strain of Plasmodium falciparum has been discovered on the border of Thailand and Burma – 500 miles away from western Cambodia, where the first cases of the parasite were reported in 2009.

Tests by a team of British and Thai scientists over a 10-year period have found the most dangerous species of malaria parasites, spread by mosquitoes, are becoming more resistant to the most effective treatments containing artemisinin, a drug derived from the sweet wormwood shrub.

Report in Lancet.

“

Background

Artemisinin-resistant falciparum malaria has arisen in western Cambodia. A concerted international effort is underway to contain artemisinin-resistant Plasmodium falciparum, but containment strategies are dependent on whether resistance has emerged elsewhere. We aimed to establish whether artemisinin resistance has spread or emerged on the Thailand—Myanmar (Burma) border.

Methods

In malaria clinics located along the northwestern border of Thailand, we measured six hourly parasite counts in patients with uncomplicated hyperparasitaemic falciparum malaria (≥4% infected red blood cells) who had been given various oral artesunate-containing regimens since 2001. Parasite clearance half-lives were estimated and parasites were genotyped for 93 single nucleotide polymorphisms.

Findings

3202 patients were studied between 2001 and 2010. Parasite clearance half-lives lengthened from a geometric mean of 2·6 h (95% CI 2·5—2·7) in 2001, to 3·7 h (3·6—3·8) in 2010, compared with a mean of 5·5 h (5·2—5·9) in 119 patients in western Cambodia measured between 2007 and 2010. The proportion of slow-clearing infections (half-life ≥6·2 h) increased from 0·6% in 2001, to 20% in 2010, compared with 42% in western Cambodia between 2007 and 2010. Of 1583 infections genotyped, 148 multilocus parasite genotypes were identified, each of which infected between two and 13 patients. The proportion of variation in parasite clearance attributable to parasite genetics increased from 30% between 2001 and 2004, to 66% between 2007 and 2010.

Interpretation

Genetically determined artemisinin resistance in P falciparum emerged along the Thailand—Myanmar border at least 8 years ago and has since increased substantially. At this rate of increase, resistance will reach rates reported in western Cambodia in 2—6 years.

Funding

The Wellcome Trust and National Institutes of Health.

http://www.thelancet.com/journals/laneur/article/PIIS0140-6736(12)60484-X/fulltext

1. “Study leader Professor Francois Nosten, director of the Shoklo Malaria Research Unit in Thailand, warned of a “race against time” to halt the spread of the potentially untreatable malaria.

He told Sky News: “If the situation continues to deteriorate then it could mean that the newest drugs that we have to treat malaria now which are the derivatives of artemisinin, will be progressively inefficient, ineffective.

“We know what the consequences of this will be because we have seen it in the past… it results in increasing number of cases of malaria and therefore more deaths, and so we are very concerned.”

“It is not a new strain. It is the same species of parasite, but it is evolving rapidly.

“The reason why it has evolved resistance to new treatments is probably because we have been using them a lot over the last 20 years. They were the only treatments that could effectively cure the disease.

“We can still treat the patient with these drugs and they get better and they get cured, it just takes longer for them to clear the disease.

“We don’t know yet whether this is a spreading phenomenon – whether this resistance has spread from Cambodia to the Thai-Burma border, or whether it is emerging spontaneously.”

He said: “We have now seen the emergence of malaria resistant to our best drugs, and these resistant parasites are not confined to western Cambodia.

“This is very worrying indeed and suggests that we are in a race against time to control malaria in these regions before drug resistance worsens and develops and spreads further. The effect of that happening could be devastating.

http://news.sky.com/home/world-news/article/16203828