This is Phoebe Zimmerman. And this is Bob Doughty with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science.
Today, we tell about the deadly disease polio and efforts to end it around the world.
People do not usually celebrate a disease. But recently, in the northern Nigerian village of Rogo, men and women gathered for a special ceremony. The celebration launched National Immunization Days in Nigeria. This is a government-organized campaign to give polio vaccine medicine to more than forty-million Nigerian children under age five. The message of the men and women singing at the event is simple: Parents, give your children the polio vaccine medicine. If you do not, you hurt yourselves and them.
Efforts to end polio around the world started in nineteen-eighty-eight. At that time, four international aid groups launched a campaign to end polio by two-thousand-five. The groups are the World Health Organization, the United Nations Children's Fund, the private group Rotary International and the United States Centers for Disease Control and Prevention. The campaign is called the Global Polio Eradication Initiative.
It has been very successful. Over the past fourteen years, the number of new polio infections around the world has dropped by more than ninety-nine percent.
When the campaign first started, more than three-hundred-fifty-thousand new cases of polio were reported. In two-thousand-one, however, there were just four-hundred-eighty-three new cases. The disease used to infect people in one-hundred-twenty-five countries. Now it is found in fewer than ten countries. Most of these remaining cases are in parts of the world where getting the polio vaccine to children has been difficult.
India, Pakistan and Nigeria currently have the most new cases of polio. These nations share conditions that support the spread of the disease. They include low rates of vaccination, unclean living conditions, weak public health systems, and large crowded populations. Nigeria, for example, has the largest population in Africa – more than one-hundred-twenty-million people.
This is why the Nigerian government holds National Immunization Days several times a year. During these special campaigns, trained health workers bring the polio vaccine to children in every house in every village throughout the country.
In some countries, medical teams find it difficult to vaccinate children against polio. This is because communities are far from cities, or in areas where travel is difficult. Conflicts are also a problem in some countries. Sometimes travel is not permitted or areas are too dangerous to enter. These workers in Nigeria, however, were lucky. They were able to bring the polio vaccine to all the country's villages.
Polio is an infectious disease caused by a virus. It can affect people at any age. However, it usually affects children under age three. The virus enters through the mouth and then grows inside the throat and intestines.
It can spread quickly through communities in drinking water infected with human waste. It can also be passed through human touch, such as kissing an infected person.
Signs of polio include a high temperature, stomach sickness, and pain in the head and neck. Once the poliovirus becomes established in the intestines, it can spread to the blood and nervous system. When this happens, victims can become paralyzed. They lose the ability to move. This paralysis is almost always permanent. In very serious cases, the paralysis can lead to death because victims are not able to breathe.
Stephen Cochi (CO-chee) heads international vaccination efforts at the Centers for Disease Control and Prevention in the United States. He says that one in two-hundred polio-infected children in high-risk populations will become permanently paralyzed. The other children will become carriers of the virus and may spread the disease to other people.
There is no cure for polio, so the best treatment is prevention. A few drops of a powerful vaccine medicine will protect a child for life. The vaccine must be given four times over several years to be fully effective.
The effects of polio can revisit some victims later in life. This is called post-polio syndrome, or P-P-S. This condition affects polio survivors about thirty-five years after their first polio attack. Currently, there are about twenty-million polio survivors around the world. Signs of the condition include muscle weakness, pain in the head, neck and back, tiredness, and trouble sleeping, breathing and swallowing. There is no cure for P-P-S. However, rest and less physical activity can help treat the condition.
During the nineteen-fifties, American scientists Jonas Salk and Albert Sabin developed medicines that prevented polio. Before these first vaccines were discovered, thousands of children got the disease every year. Today, however, vaccine medicine has made polio rare. In the United States, the vaccine is injected into the body. However, in developing countries, the vaccine is usually given by drops in the mouth. This method is more effective for developing countries because so many children need to be treated. Some young people, like this one in Nigeria, do not like taking the medicine.
((SOUNDS: CHILD CRYING))
Health officials hope to halt the spread of polio in Nigeria. The World Health Organization will declare the country polio-free after three years of no new cases. This depends on the success of the government's vaccination campaign. Over the past four years, more than two-hundred-thousand people have taken part in National Immunization Days in Nigeria. These trained health workers usually work in teams of two people.
The teams bring the vaccine to children in villages. They also look for signs of possible new cases. This kind of work permits medical experts to study the virus and its development. Any information about new polio cases is sent to an important health laboratory in Africa. It is part of a special system of more than one-hundred similar laboratories around the world.
This system of laboratories is the most complete for any disease. Health officials use the system to examine the genetic form of the polio virus and study how it spreads through populations. This information helps health workers give polio vaccines to children who live in the exact area where the disease started.
Officials say the campaign to end polio by two-thousand-five has been very successful. However, some problems have developed. One problem is finding well-trained people to give the vaccines and investigate individual polio cases as they develop. The international laboratory system has eased this problem. Officials say it has helped build closer ties between public officials and health workers around the world.
Since the polio campaign began fourteen years ago, two-thousand-million children in ninety-four countries have been vaccinated. In two-thousand-one alone, the vaccine was given to five-hundred-seventy-five-million children. The World Health Organization estimates the international polio campaign will cost about three-thousand-million dollars during the next three years. Currently, plans to gain about two-hundred-seventy-five-million dollars of that amount are moving forward. Support has come from governments, international agencies and many private aid groups, such as Rotary International. This organization has given more money than any other private group.
Rotary International has given almost five-hundred-million dollars. It has promised to raise about eighty-million dollars by the end of this year. This is a lot of money. However, Rotary International says that no price is too high to pay to end polio on Earth.
This SCIENCE IN THE NEWS program was written by Jill Moss. It was produced by George Grow. This is Bob Doughty. And this is Phoebe Zimmerman. Join us again next week for more news about science in Special English on the Voice of America.