VOA慢速英語:蚊子和蝙蝠都可能攜帶疾病

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Hello and welcome to another program designed to help you learn and improve your American English. I'm Jim Tedder in Washington. Today we are concerned with your health. We have information about a disease that seems to have spread from Africa and Asia into the Western Hemisphere. If you have mosquitoes near your home, you will need to listen carefully.

Then imagine you are sitting outside near the end of another day. Every now and then you see something fly above your house very quickly, and make sharp turns. No, it is not a bird. It is a bat, and it, too, may be a serious disease carrier.

What are these illnesses? And how can you protect yourself from them? We'll have the answers, next on As It Is.

A painful disease found mainly in Africa and Asia has been discovered in the Western Hemisphere. The World Health Organization reported last December that two cases of chikungunya were found in the French part of the Caribbean island of Saint Martin. Since then, the disease has been reported on other islands in the Caribbean.

Chikungunya results from a virus. It is passed to humans from the bite of an insect -- the mosquito. The disease can cause a higher than normal body temperature and pain in the head. It also causes pain in the joints, which can last for weeks. Chikunguya rarely kills people, but there is no treatment or vaccine for the disease.

The WHO says chikungunya infected many people in the African nation of Gabon, India and islands in the Indian Ocean about 10 years ago. It spread within Europe for the first time in 2007.

Peter Hotez is the head of the National School of Tropical Medicine at the Baylor College of Medicine in Texas. He says he soon expects to see reports of chikungunya in the southern United States.

"The mosquitoes are here. That's an important factor. Second, there may be some component of global warming."

He says insects carrying the disease are found in places where poverty and development are increasing, such as in the southern United States.

Straw-colored fruit bats are found across much of Africa. The bats carry two deadly viruses that could spread to people. While scientists have long known this, they did not know until recently how many of the animals were carriers.

A new study has found that one third of the fruit bats are infected with a virus similar to the one responsible for the viral disease rabies. And 42 percent carry henipaviruses, which can cause a deadly disease.

The new study was a project of researchers with the University of Cambridge and the Zoological Society of London. The researchers studied blood and tissue from more than 2,000 bats from 12 African countries. They found the animals were genetically similar -- meaning they travel and live together across the continent. James Wood of the University of Cambridge says this genetic similarity helps speed the spread of the viruses.

Fruit bats live in groups of more than 100,000. These groups often live near cities. In some areas, people hunt the animals for their meat. Eating bat meat can spread the viruses to humans. Henipaviruses can also be spread through contact with waste products from bats.

Neither disease has been reported in humans in Africa. But experts are warning that could change. Alison Peel helped to prepare a report on the study. She warns that trying to remove bats from cities could increase the risk of infection. In her words, "the most appropriate response is ongoing studies and public awareness to avoid handling bats, and to wash the wound thoroughly if you are bitten by a bat."

Straw-colored fruit bats rest together at Berlin’sZoological Garden.

The report appeared in the journal Nature Communications.

In December, China reported the death of a woman who it said was the first human to become infected with a new kind of avian influenza virus. Researchers are working to learn more about the H10N8 strain of the virus that killed her. The World Health Organization says the speed at which China reported the case shows the country is getting better at identifying deadly viruses. The 73-year old woman died late last year, just six days after visiting a poultry market in Jiangxi Province.

Bernhard Schwartlander is the WHO's representative in China. He says the quick identification of the bird flu that killed the woman shows the increased strength of China's surveillance system.

"The fact that Chinese authorities detected this case in a 73-year-old woman that had other medical conditions actually shows that the active surveillance system, the active alert system, is actually working quite well."

The woman often visited markets were live chickens and other poultry were sold.

She was taken to a hospital on November 30 and died December 6th. She had suffered from high blood pressure and heart disease, which may have kept her body from being able to fight the infection. Dr. Schwartlander says officials need to watch other people closely to see if the disease has spread.

"Of course, we are always concerned when we see that the virus has actually jumped from one species to another. And you have to be very careful watching this because every time this happens it has, of course in theory, the potential for a wider spread."

Last year, about 100 people were infected with the H7N9 strain of bird flu. Chinese officials reacted quickly with increased testing and reporting of similar cases.

The H10N8 virus had earlier been found in Guangdong Province and lived in poultry for many years. Dr. Schwartlander says the first human death from the virus is a worrisome development.

"This is the first case that we detected the virus in a human being."

In 2002 and 2003, some countries criticized China for being slow to release news about Severe Acute Respiratory Syndrome, also known as SARS. The disease killed more than 700 people. As health officials followed the disease, the government told reporters in China not to report on SARS. Government officials also did not tell WHO researchers much about the spread of the disease.

Since then, China's health systems have improved. But some experts say China must work harder to study laboratory-confirmed infections.

Chinese officials are also closely watching for cases of the H5N1 bird flu virus, which has killed more than 380 people since 2003. Scientists fear the virus could change and then spread quickly from one person to another.

When it comes to your health, it is always better to know than not to know. There are more Learning English programs coming your way next, and world news at the beginning of the hour on VOA. I'm Jim Tedder in Washington.