Big Leap Forward For Battle Against Malaria
October 4, 2002To some, mosquitoes are merely a nuisance as they buzz annoyingly and cause sleepless nights and tell-tale red bites.
But for millions of other people, the tiny bugs mean certain death.
Especially infants and children in sub-Saharan Africa are susceptible to death by malaria. Almost 90 percent of the between 1 million and 2.7 million deaths caused by malaria are found in Africa.
Malaria infects 300 million to 500 million people a year, an average of 2,700 children die of the disease every day.
Malaria resistant to drugs
So far three kinds of drugs have been used to treat malaria with varying degrees of success – chloroquines, quinine, which is based on the bark of Peru’s cinchona tree, and artemesinins, based on the 2,000-year-old Chinese remedy Qinghaosu.
For decades, the mainstay treatment for malaria has been chloroquine, a medicine costing about six U.S. cents for a course, which has saved millions of lives.
But with malaria in many areas proving resistant to chloroquines as well as more recently to the cheaper drug sulphadoxine-pyrimethamine, or Fansidar, and no immediate prospect of a vaccine on the horizon, the fight against malaria has been a sluggish one in past years.
Scientific breakthrough
An international team involving 150 scientists in nine countries have now achieved a revolutionary breakthrough in malaria research by mapping the genome of two bugs – the parasite that causes the disease and the mosquito that carries it.
It’s hoped that the scientific milestone will lead to the development of new drugs to fight the disease, vaccines to prevent it and pesticides to kill the mosquitoes.
"This is truly a landmark day celebrating a landmark accomplishment," said Dr Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, which helped fund the research at a news conference.
Earlier, Chris Newbold of Oxford University in England addressed a news conference in London. "This represents a quantum leap in our understanding of malaria," he said.
The breakthrough is the result of a six-year project by an international consortium of laboratories and funding agencies, in both the public and private sectors.
Mapping the genome
The main cause of malaria is a parasite called Plasmodium falciparum, which lives in the blood and liver.
Its main carrier is the Anopheles gambiae mosquito. With 14 chromosomes and 5,279 genes, the malaria genome is one of the smallest sequenced so far.
The threadlike Plasmodium falciparum parasite genome posed a major challenge to scientists because parts of its DNA are very unstable and broke apart as they were worked on.
"The amount of data involved was phenomenal. It was a bit like tearing up half a dozen bibles, scattering the pieces over a playing field and then trying to put them together again,", Dr Neil Hall of Britain’s Sanger institute, which collaborated on the 18.5 million pound ($ 29 million) parasite genome project, told a news conference.
Together with existing knowledge of the human genome sequence, the data should allow an unprecedented understanding of the life cycle of human host, parasite and mosquito.
The function of about 60 percent of the genes is unknown but the genome gives researchers an insight into the parasite’s metabolism, how drug resistance occurs and how to develop new weapons against malaria.
Some scientists sceptical
Despite the revolutionary breakthrough and hopes of being able to develop vaccines to eradicate malaria in the long-term and to engineer "malaria-proof" mosquitoes that are unable to carry the parasite, some voices in the scientific world are cautioning about being too euphoric of quick developments in the new post-genomic era.
They believe funds would be better spent on vaccines and drugs that are already being developed.
"If there were an extra 100 million pounds to spend on malaria-vaccine research, I would allocate very little of it to exploring the parasite genome," says Professor Adrian Hill of the University of Oxford in a news feature in the journal Nature.
His views are echoed by Chris Curtis, Professor of Medical Entomology at the London School of Hygiene and Tropical Medicine.
"I'm sceptical that the Anopheles mosquito genome will actually be useful in attempts to control malaria in very poor countries and I have a feeling that projects on the genome are done because molecular biologists think they can be done and are exciting to do so," he said.