Resistance to anti-malarial drug artemisinin in western
Thailand is sending alarm bells ringing among global experts involved
in controlling and eliminating the scrouge worldwide, a new study says.
Another
study, also by Texas Biomedical Research Institute and their Thai
collaborators has indentified a major region of the malaria parasite
genome tied to artemisinin resistance, raising hope that there may soon
be effective molecular markers for monitoring the spread of resistance.
Malaria
killed 655,000 people or over one per minute in 2010. Malaria deaths
have declined by 30 per cent over the past decade, because of effective
control using treatment with combination therapies containing
artemisinin, a plant-derived antimalarial drug developed in China, the
journal Lancet reported.
Patients infected with
malaria parasites who respond poorly to treatment have been observed in
Cambodia, bringing forth a coordinated World Health Organization effort
to eliminate the disease in this region, said a university statement.
From
2001 until 2010, the Texas Biomed team and collaborators studied 3,202
patients in clinics in Northwestern Thailand, 500 miles from the
Cambodian focus, according to the journal Lancet.
Researchers
observed a dramatic decline in the drug potency over that period.
Further, by measuring drug potency in patients infected with genetically
identical malaria parasites, they were able to show that the decline in
potency results from the spread of resistance genes.
“Spread
of drug resistant malaria parasites within Southeast Asia and overspill
into sub-Saharan Africa, where most malaria deaths occur, would be a
public health disaster resulting in millions of deaths,” said Texas
Biomed’s Standwell Nkhoma, who led the study.
“The
problem we have is that treatment with artemisinin-based drugs will
promote spread of resistance, but there are no viable alternative
treatment options in Southeast Asia,” said Nkhoma.
“Our
group wanted to understand what genetic changes have occurred in these
parasites,” said Texas Biomed’s Ian Cheeseman, who led the companion
study, the journal Science reported.
“This study
narrows the search to a region of the parasite genome containing around
10 genes. We haven’t yet found the precise changes involved, but we are
getting close,” said Cheeseman.
Source: The Hindu
