By Caty Weaver

This is Bill White with the VOA Special English DEVELOPMENT REPORT.

American scientists have created a genetic map of the bacterium that causes the deadly disease cholera. Scientists identified and placed in order all of the three-thousand-eight-hundred-eighty-five genes in the bacterium. Now scientists will be able to study all the genes.

The new research will help scientists develop an effective and safe vaccine medicine to prevent the disease. Vaccines use weakened or dead versions of disease organisms. The vaccine normally causes the body's defense system to create a permanent defense against the disease.

Cholera attacks the intestines and causes severe diarrhea and vomiting. People with the disease may die from a serious lack of water in their bodies. Medical treatments to replace this water can save the lives of cholera patients. However, people may not be able to get such treatments in developing countries.

Cholera also spreads more quickly in developing countries. People get the disease by drinking water or eating food that contains the bacteria. The disease is most often found in areas where there is unclean water and ineffective human waste removal systems.

The World Health Organization says more than two-hundred-fifty thousand cases of cholera were reported worldwide last year. More than eighty-percent of them were in Africa. The WHO says the disease killed at least nine-thousand people last year.

Researchers at the Institute for Genomic Research in Rockville, Maryland completed the cholera genetic mapping project. The findings were reported in the publication Nature. John Mekalanos (MEH-ku-LAHN-os) was a leading scientist on the project. He says the findings will help scientists learn which of the genes of the cholera bacterium are most powerful. He says they will be able to create a vaccine that is free of the most dangerous genes but still strong enough to prevent the disease.

Doctor Mekalanos says he used the genetic map to make a device that tests the activity level of the cholera genes. He says the device will help scientists know which genes are involved in the growth of the cholera bacterium in the human body. The scientist says this information may lead to new and better methods for fighting the disease.

This VOA Special English DEVELOPMENT REPORT was written by Caty Weaver. This is Bill White.

Voice of America Special English