This is SCIENCE IN THE NEWS in VOA Special English. I’m Barbara Klein.
And I’m Steve Ember. On our program this week, we tell about the disease tuberculosis. It is one of the world's leading infectious diseases. We also tell about efforts to fight tuberculosis in several countries.
The World Health Organization says one-third of the world’s population is infected with the bacteria that cause tuberculosis. That is about two billion people. One in ten people infected with the TB bacteria will become sick with tuberculosis at some time during their life. The WHO says almost nine million people became sick with the disease in two thousand five. About one million six hundred thousand people died of the disease that year. However, the WHO also says almost sixty percent of TB cases around the world are discovered. A large majority of them are cured.
Most people infected with the bacteria never develop active TB. However, people with weak body defense systems often develop the disease. TB can damage a person’s lungs or other parts of the body and cause serious sickness.
The disease is spread by people who have active, untreated TB bacteria in their throat or lungs. The bacteria are spread into the air when infected people talk or expel air suddenly.
Most TB cases can be cured with medicines. Successful treatment of TB requires close cooperation among patients, doctors and other health care workers. The World Health Organization has a five-step program to guarantee that TB patients take their medicine correctly. The program is called Directly Observed Treatment, Short-course, or DOTS. Directly observed means that patients must go to local health centers every day or several times a week to take their medicines. Health care workers watch to make sure patients take their medicine every day. Full treatment usually lasts from six to nine months to destroy all signs of the bacteria.
It is very important for patients to be educated about the disease and its treatment. Sometimes patients fail to finish taking the medicine ordered by their doctors. Experts say this is because some patients feel better after only two to four weeks of treatment and stop taking their medicine. This can lead to the TB bacteria becoming stronger, resistant to drugs, and more difficult to treat.
This kind of TB is called multi-drug resistant tuberculosis or MDR-TB. The World Health Organization says MDR-TB is one hundred times more costly to treat than the other form of the disease.
The World Health Organization says most deaths from tuberculosis are in developing countries. More than half of all deaths from TB are in Asia. And half of all new cases are in six Asian countries. They are Bangladesh, China, India, Indonesia, Pakistan and the Philippines.
More than twenty-five percent of the world's multi-drug resistant tuberculosis cases are in Asia. Patients with MDR-TB must take more powerful and costly drugs for more than two years. Some patients experience side effects from the drugs.
Experts say the fight against TB and drug resistance has been successful in Hong Kong. In the past fifty years, Hong Kong has reduced cases of TB by almost ninety-eight percent. In the nineteen fifties, the British colonial government built TB hospitals and began giving vaccines to children. The government also replaced poor, unclean housing with modern public housing.
Today, the Chinese government gives anti-TB drugs free of cost in public health centers. Health workers visit patients who fail to go to health centers to get their medicines. So Hong Kong has very low levels of drug-resistant TB.
The World Health Organization is improving its efforts against TB in China. Almost one million four hundred thousand people there develop active TB each year. Almost twenty-five percent of the world's multi-drug resistant cases are in China. The WHO says the situation is now improving. It says half of China's provinces have put the DOTS treatment method into effect. This has resulted in about a fifty percent reduction in deaths from TB.
The WHO has also set a goal for nations in the Western Pacific area. They are being urged to cut by half infection rates and deaths from TB within three years. Doctors say this goal may not be possible because the disease AIDS is a serious problem in the Western Pacific. Other problems are poverty and lack of money for public health.
In Africa, more than three million people are living with TB. Five hundred thousand people there die each year from the disease. The number of TB victims is rising quickly in Africa. This is mainly because of the virus that causes AIDS. The virus weakens the body's ability to fight disease.
Drug-resistant TB is a serious problem in South Africa. Sizwe Hospital in the city of Johannesburg treats only people with MDR-TB. Three thousand new cases of MDR-TB were identified in Johannesburg alone last year. People with this kind of TB have only a fifty percent chance of being cured. Patients must take one painful injection of medicine and as many as twenty-four pills each day. Treatment can take up to two years. The drugs have serious side effects.
Few people survive a new kind of TB, called Extreme Drug-Resistant TB. This disease is resistant to just about every drug known to science.
The National Health Laboratory in Johannesburg tests for drug-resistant TB. Its workers test five hundred samples from patients from all over southern Africa every day. The testing often last several weeks because each bacterium must be tested in several ways. Almost one-fourth of the bacteria tested are found to be drug-resistant. These have to be tested again to show which drugs they resist.
During this time, the patient may be infecting other people. So it is important to find ways to test for the disease more quickly. The laboratory is now carrying out experiments with tests that identify drug-resistant bacteria within two days. This helps health workers quickly identify an infected person and begin treatment.
Patients being treated for MDR-TB are separated from their families, sometimes for years. This causes economic and social problems for patients and family members. The head doctor at Sizwe Hospital says most patients accept treatment and separation. Health workers believe patients with drug-resistant TB should be separated to protect their communities. But human rights activists say this would be a violation of their rights.
Tuberculosis is a health emergency in Russia. In February, the Russian parliament approved almost three billion dollars to fight infectious diseases such as TB.
Russian studies show that eighty-three of every one hundred thousand people in Russia are infected with TB. Thirty thousand people die of the disease every year. However, the number of people infected is not fully known because officials say not all cases are reported. The WHO official for TB control in Central Asia says education about tuberculosis is lacking. The population does not know much about the disease or how it is treated.
The United Nations says the highest rates of reported infection in Russia are among men between thirty-five and sixty-four years of age. Many of these men are unemployed and drink too much alcohol. Many are former prisoners who are also homeless. So treating these men is difficult. Health experts say tuberculosis spreads easily in prisons. The infection rate in prisons is about twenty times higher than the general population. Drug-resistant TB is also a problem there.
World Health Organization officials say fighting TB in Russia is not just a medical problem but also one of economics and organization. They say government money is now available for health care workers to visit treatment centers to study the care and progress of the disease. There is also more money to train workers and provide equipment for laboratories. Health officials say there is now hope in the fight against TB.
This SCIENCE IN THE NEWS program was written by Shelley Gollust. Brianna Blake was our producer. I’m Barbara Klein.
And I’m Steve Ember. Join us again next week for more news about science in Special English on the Voice of America.