By Stephen Leahy
BROOKLIN, Canada, Oct 4 2002 (IPS)

The fight against malaria, a plague that kills at least one person every 30 seconds in sub-Saharan Africa, was boosted this week by news that scientists have decoded the genetic blueprint of the malaria parasite and the mosquito that spreads it.

The discovery, reported this week in the journals Nature and Science, lays the foundation for a major new scientific assault on malaria and other mosquito-borne diseases.

By understanding the parasite’s genome, researchers will be better able to select new targets for drugs, and discover how the microbe has built resistance to the two principal anti-malaria drugs, chloroquine and Fansidar.

Scientists have also been able to create a genetically engineered mosquito that resists the malaria parasite.

But the announcements will fade into obscurity if more money is not spent on controlling malaria, says renowned economist Jeffrey Sachs, a special adviser to United Nations Secretary General Kofi Annan.

The research, by a global team of 160 scientists from 10 countries, found that the ‘malaria’ mosquito also has developed immunity to pesticides including DDT and, in some places, is growing immune to bed netting treated with pyrethroid, a cheap and effective way to control malaria that is heavily promoted by a new global programme, Roll Back Malaria.

Identifying the genes that play a critical role in the mosquito’s ability to see, taste, touch and smell will go a long way to knowing why the insect feeds only on humans and how it hunts people down.

”If we can identify the receptors that mosquitoes use to smell humans, we should be able to design novel repellents and attractants that can substantially reduce the incidence of malaria,” says Laurence Zwiebel of Vanderbilt University in Tennessee state.

Experts caution that any new anti-malaria weapons that will grow out of the DNA information are at least a decade away. But other genetically based tools could be closer.

This week’s Science notes that molecular scientists, who have dominated mosquito research for the past 15 years, have created a transgenic or genetically engineered (GE) mosquito. The World Health Organization (WHO) has also made GE mosquitoes that resist the malaria parasite one of its top priorities in fighting malaria.

The first GE mosquito was created earlier this year at Case Western Reserve University in Cleveland, Ohio. An extra gene was added to a cousin of the malaria mosquito, which made it resistant to infection from the malaria parasite and incapable of transmitting the disease.

Researchers are now trying to duplicate the feat in the malaria mosquito, whose scientific name is An. gambiae. If a laboratory version could be engineered to out compete the natural An. Gambiae, eventually the number of disease-carrying, non-resistant mosquitoes would be reduced to a level that would significantly curtail human infection.

But not everyone is impressed by the genetic research.

”It’s pie in the sky,” says Yale medical entomologist Durland Fish. So little is known about mosquito ecology that it is impossible to know if the GE insects would actually do anything to control malaria, he says.

Thomas Scott, a medical entomologist at the University of California, Davis, also has many questions. For instance, will the GE mosquitoes survive in the wild? Can they find mates, have viable offspring and will their parasite-resistance genes spread through non-GE mosquito populations.

”Before this approach will be considered safe and effective we need to have a much better understanding of mosquito ecology,” he writes. The field studies required to address some of those ecological issues will last a decade or more, adds Scott.

Even if the GE mosquito could do its job, it may not solve the problem.

Research indicates that the severity of malaria, which affects half the world’s population, may actually increase when the overall number of human infections decreases, because transmission slows down and more people are infected for the first time as adults. For malaria and dengue, first infections in adults cause more severe illnesses than in children, says Scott.

Sachs says high-tech solutions are no replacement for the international will and money to combat the disease. Twenty years ago the world lost interest in the problem when it realised that eradication of malaria was impossible, he says.

That coincided with a general downturn in foreign aid and Africa fell into a significant debt crisis from which it has not yet recovered, adds Sachs.

He says intensive control measures combined with better treatment of infected individuals can bring transmission down sharply in Africa as it did in the sub-tropics. ”Substantial malaria control is possible by extending the coverage of existing technologies to impoverished households and communities.”

New drugs and vaccines based on the genetic discoveries will also play a role. But worldwide public and private annual spending on malaria drug and vaccine research is less than 100 million dollars. That is less than one-seventh of one percent of the 70 billion dollars, or more, spent on biomedical research and development worldwide each year, Sachs says.

International efforts to control the disease have been renewed recently with the creation of Roll Back Malaria in 1998, the Global Fund to Fight AIDS, TB, and Malaria, launched in January 2002, and other programmes.

”All remain woefully under funded, and an effective international effort has not yet begun,” Sachs writes. Current worldwide donor spending on prevention and treatment is 100 million to 200 million dollars a year, while actual needs exceed two billion dollars, he says.

In addition to its enormous human cost, malaria carries a large economic price tag. Sachs estimates the disease has imposed a $100 billion penalty on Africa in the last 30 years.

Excerpt:

By Stephen Leahy
BROOKLIN, Canada, Oct 4 2002 (IPS)

The fight against malaria, a plague that kills at least one person every 30 seconds in sub-Saharan Africa, was boosted this week by news that scientists have decoded the genetic blueprint of the malaria parasite and the mosquito that spreads it.

The discovery, reported this week in the journals Nature and Science, lays the foundation for a major new scientific assault on malaria and other mosquito-borne diseases.

By understanding the parasite’s genome, researchers will be better able to select new targets for drugs, and discover how the microbe has built resistance to the two principal anti-malaria drugs, chloroquine and Fansidar.

Scientists have also been able to create a genetically engineered mosquito that resists the malaria parasite.

But the announcements will fade into obscurity if more money is not spent on controlling malaria, says renowned economist Jeffrey Sachs, a special adviser to United Nations Secretary General Kofi Annan.

The research, by a global team of 160 scientists from 10 countries, found that the ‘malaria’ mosquito also has developed immunity to pesticides including DDT and, in some places, is growing immune to bed netting treated with pyrethroid, a cheap and effective way to control malaria that is heavily promoted by a new global programme, Roll Back Malaria.

Identifying the genes that play a critical role in the mosquito’s ability to see, taste, touch and smell will go a long way to knowing why the insect feeds only on humans and how it hunts people down.

“If we can identify the receptors that mosquitoes use to smell humans, we should be able to design novel repellents and attractants that can substantially reduce the incidence of malaria,” says Laurence Zwiebel of Vanderbilt University in Tennessee state.

Experts caution that any new anti-malaria weapons that will grow out of the DNA information are at least a decade away. But other genetically based tools could be closer.

This week’s Science notes that molecular scientists, who have dominated mosquito research for the past 15 years, have created a transgenic or genetically engineered (GE) mosquito. The World Health Organization (WHO) has also made GE mosquitoes that resist the malaria parasite one of its top priorities in fighting malaria.

The first GE mosquito was created earlier this year at Case Western Reserve University in Cleveland, Ohio. An extra gene was added to a cousin of the malaria mosquito, which made it resistant to infection from the malaria parasite and incapable of transmitting the disease.

Researchers are now trying to duplicate the feat in the malaria mosquito, whose scientific name is An. gambiae. If a laboratory version could be engineered to out compete the natural An. Gambiae, eventually the number of disease-carrying, non-resistant mosquitoes would be reduced to a level that would significantly curtail human infection.

But not everyone is impressed by the genetic research.

“It’s pie in the sky,” says Yale medical entomologist Durland Fish. So little is known about mosquito ecology that it is impossible to know if the GE insects would actually do anything to control malaria, he says.

Thomas Scott, a medical entomologist at the University of California, Davis, also has many questions. For instance, will the GE mosquitoes survive in the wild? Can they find mates, have viable offspring and will their parasite-resistance genes spread through non-GE mosquito populations.

“Before this approach will be considered safe and effective we need to have a much better understanding of mosquito ecology,” he writes. The field studies required to address some of those ecological issues will last a decade or more, adds Scott.

Even if the GE mosquito could do its job, it may not solve the problem.

Research indicates that the severity of malaria, which affects half the world’s population, may actually increase when the overall number of human infections decreases, because transmission slows down and more people are infected for the first time as adults. For malaria and dengue, first infections in adults cause more severe illnesses than in children, says Scott.

Sachs says high-tech solutions are no replacement for the international will and money to combat the disease. Twenty years ago the world lost interest in the problem when it realised that eradication of malaria was impossible, he says.

That coincided with a general downturn in foreign aid and Africa fell into a significant debt crisis from which it has not yet recovered, adds Sachs.

He says intensive control measures combined with better treatment of infected individuals can bring transmission down sharply in Africa as it did in the sub-tropics. “Substantial malaria control is possible by extending the coverage of existing technologies to impoverished households and communities.”

New drugs and vaccines based on the genetic discoveries will also play a role. But worldwide public and private annual spending on malaria drug and vaccine research is less than 100 million dollars. That is less than one-seventh of one percent of the 70 billion dollars, or more, spent on biomedical research and development worldwide each year, Sachs says.

International efforts to control the disease have been renewed recently with the creation of Roll Back Malaria in 1998, the Global Fund to Fight AIDS, TB, and Malaria, launched in January 2002, and other programmes.

“All remain woefully under funded, and an effective international effort has not yet begun,” Sachs writes. Current worldwide donor spending on prevention and treatment is 100 million to 200 million dollars a year, while actual needs exceed two billion dollars, he says.

In addition to its enormous human cost, malaria carries a large economic price tag. Sachs estimates the disease has imposed a $100 billion penalty on Africa in the last 30 years.

Excerpt: