Gene Map of Malaria / Concerns About Genetic Engineering / AIDS Warning for Five Countries
This is Bob Doughty. And this is Steve Ember with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science. Today, we tell about a major new discovery about the organisms that cause and spread the disease malaria. We tell about some concerns about genetic engineering. And we tell about a serious increase in the disease AIDS in five countries.
Two international teams of scientists have completed a map of the genetic material of the main organism that causes malaria. They also have mapped the genes of the mosquito insect that spreads the disease to people. Experts say this genetic information will speed the development of new drugs to treat or prevent the deadly disease.
Malaria infects about five-hundred-million people each year. Ninety percent of them are in southern Africa. The disease kills more than two-and-one-half-million people a year. Most of the victims are children. Doctors say new drugs and chemicals against malaria are urgently needed. All of the major chemicals and drugs in use are old and their effectiveness is decreasing.
The latest research appeared in the British publication Nature and the American publication Science. The results also were announced at news conferences in London and Washington, D.C. More than one-hundred-sixty scientists from ten countries identified the genetic maps. A number of public and private organizations paid for the research.
American and British scientists led the effort to complete the genetic map of the Anopheles gambiae (an-OFF-oh-leez GAM-bee) mosquito. This insect is sometimes called a "malaria machine." The female mosquito spreads the most severe kind of malaria. The insect breaks through human skin with its long, tube-like feeding device. The female mosquito bites people and drinks their blood.
When it bites a person with malaria, the mosquito gets the organism that causes the disease. This organism is a parasite called Plasmodium falciparum (plas-MO-dee-um fall-SIP-ah-rum). The parasite invades the mosquito's stomach and reproduces. The mosquito then bites other people and spreads the malaria parasite to them.
The scientists collected genetic material from seven-hundred-sixty mosquitoes. A computer program showed that the mosquito has about fourteen-thousand genes. The researchers found seventy-nine genes that are probably involved in the mosquito's sense of smell. They also found seventy-two genes probably involved in its sense of taste. This information could lead to better chemicals to protect people from mosquito bites.
The researchers also identified which mosquito genes act after the mosquito drinks human blood. Some of these genes protect the insect. They remove poisons from iron in the blood. The mosquitoes would die if this process could be blocked.
The researchers also identified the genes in the Plasmodium falciparum parasite. They found that the parasite has about five-thousand-three-hundred genes. About two-thirds of these genes are not similar to any human genes. This suggests that chemicals developed to attack the parasite might not harm humans. One such drug has been proven effective in animals.
The scientists also found the genes the parasite uses to invade red blood cells in humans. Malaria infection might be prevented if the action of those genes could be blocked. The parasite appears to have more than two-hundred genes that help it defeat the human body's defense system against disease.
Anthony Fauci (FOW-chee) directs the National Institute of Allergy and Infectious Diseases near Washington, D-C. Doctor Fauci praised the research. He noted that scientists now have identified the genes of the three organisms involved in malaria – the parasite, the mosquito and the human victim.
A scientist with the World Health Organization said the research is an important development in the history of science. He said the powers of modern technology are being used against an ancient disease.
A new report released by the National Academy of Sciences concerns genetically engineered plants and animals. The report says the greatest concern is that they may become mixed with wild animal and plant populations. A committee of the National Research Council wrote the report.
The United States Food and Drug Administration requested the report. That agency is preparing to rule on the safety of animal and plant products that are developed through genetic engineering.
The report says that genetically changed animals or plants may escape into the wild. Some kinds of animals like fish, birds and insects can move very quickly. They could easily spread and reproduce faster than wild animals. This means that wild animals might not be able to compete with genetically engineered ones for food and mates.
The study also says that there are unknown dangers from the substances produced by genetically engineered animals. Genetically changed animals might produce proteins that cause serious health reactions in some people. These reactions are called allergies. A large percentage of people might react severely to some protein produced through an unknown side-effect of genetic change.
Another issue of concern is the use of products that come from animals genetically engineered to produce non-food products. For example, a cow that is genetically changed for the qualities of its skin, or leather, should not be used for food. The committee says it is important to make sure that no food products come from such animals. This will require official action and new laws.
The committee said the well-being of genetically changed animals is also a major issue. It found that there are several effects that scientists should investigate more carefully. For example, studies have found that genetically changed cows and sheep give birth to baby animals that are much larger than normal. This has caused an increase in births that require operations instead of natural births.
Genetic engineering sometimes causes major genetic mistakes. The results of these genetic mistakes are animals with abnormal body parts or changed chemical qualities. The way animals act also can be changed genetically.
Currently, there are few laws governing how to deal with genetically engineered animals and plants. The Food and Drug Administration has asked the owners of several hundred genetically copied cows to avoid selling them or permitting them to reproduce. The F-D-A has not yet decided if the cows or their products can safely be sold or used.
A new American report warns that rates of infection from the AIDS virus will rise sharply by the year two-thousand-ten. The National Intelligence Council prepared the report for the United States Central Intelligence Agency. It says the increase will result mainly from the spread of AIDS in five countries. They are China, India, Ethiopia, Nigeria and Russia.
The report estimates that the number of people infected in those countries could increase to between fifty-million and seventy-five-million. That is three times the number currently estimated. It also is far more than the number of AIDS cases expected in central and southern Africa. That number is expected to increase to as many as thirty-five-million people.
China, India, Ethiopia, Nigeria and Russia have more than forty percent of the world's population. Officials warn that the increase of AIDS could harm the economic, social, political and military systems in these countries.
The report estimates that India might have as many as twenty-five-million AIDS victims by two-thousand-ten. That is the highest estimate of any country.
The report says the AIDS virus is spreading at different rates in the five countries. It says that risky sexual activity is increasing infection rates in all five. The problem is reported to be most severe in Nigeria and Ethiopia.
This SCIENCE IN THE NEWS program was written by Jerilyn Watson, Mario Ritter and George Grow. It was produced by George Grow. This is Bob Doughty. And this is Steve Ember. Join us again next week for more news about