guardian.co.uk,
Sarah Boseley, Health editor, Thursday 5 April 2012
Anti-malarial tactics, like bednets above, have helped stem epidemics, but now therapies sold over the counter and substandard pills threaten the success. Photograph: Paula Bronstein/Getty Images |
The global
fight against malaria is being threatened by growing resistance to powerful new
drugs which have become one of the most important weapons in the battle.
Experts say
that the medical effects of artemisinin-based compounds, being used to treat
people around the Burma/Thailand border, are weakening. Where there were once
apparently miraculous recoveries of children treated with
artemisinin-combination therapy (ACT) now the treatments take longer to be
effective.
Doctors
envisage a time, when, if nothing is done, the drugs will cease to work at all.
Malaria
parasite resistance to the drugs has been identified in western Cambodia but it
was hoped that tough controls would contain it. Now, however, scientists say
there are real problems in Burma – and they warn that resistance there must be
tackled if it is not to spread worldwide.
They warn
that history is repeating itself: resistance is appearing and artemisinin is
losing its potency just as happened with older drugs, like chloroquine, and it
is beginning in exactly the same places on the map.
The
discovery of resistance to drugs – which have, with insecticide-impregnated
bednets, altered the course of the malaria epidemic – "threatens worldwide
initiatives to control and eliminate malaria", reports a paper in the Lancet.
The paper
is one of two by teams of scientists who have studied the growth of resistance
on the Thai/Burmese border. "Resistance to the previous mainstays of
antimalarial treatment, namely, chloroquine and sulfadoxine-pyrimethamine, also
arose in western Cambodia and spread across South-east Asia into Africa,
resulting in the deaths of millions of children."
In another
paper, published by the journal Science, scientists in South-east Asia and the
US identify a major region of the malaria parasite genome associated with
artemisinin resistance. This link could allow researchers to map resistance and
help prevent its spread which, they write, "would be catastrophic for
malaria control".
Nick White,
chair of the Worldwide Antimalarial Resistance Network, and an author on each
of the papers, said there had been rumours that resistance might have spread to
Burma.
White, a
professor, who is also chair man of the Wellcome Trust's South-east Asia major
overseas programmes, added: "There is no doubt there has been quite
significant reduction in susceptibility to artemisinin. The problem is that
once it gets to Burma, that is the gateway to the west. Malaria control in
Burma is much weaker than in the rest of the region. It is going to be much
more difficult to contain it."
Because of
the political situation Burma did not get the same levels of funding for
malaria control as other countries. "Burma needs help," said White.
Misuse of
the drugs in Asia has allowed parasitic resistance to develop and the sale of
single artemisinin pills, which should be taken in combination with other
drugs, has been a disaster.
"It is
pretty clear that the widespread availability of substandard, counterfeit drugs
and monotherapies, is what has driven this," White said. "It has been
possible in parts of South-east Asia for more than 20 years to buy the pills
over the counter. Lots of them are substandard and people take one or two
pills, until they feel better."
More
information on the spread of resistance was vital. "We have not got enough
information. This is a war on malaria. It is remarkable how little investment
there is in intelligence gathering. People are not looking
properly."
If this
were a flu pandemic, the west would be mobilising all its forces, he said, but
too little was being done in spite of the consequences. "Chloroquine
resistance came from exactly the same place in Cambodia. That literally killed
millions of children in Africa. Here we have it again. Is the response
appropriate to the threat?" I don't think so. We really need to scale up.
It is going to require an international effort."
No comments:
Post a Comment