The Straits Times (Singapore)

Friday, August 22, 1997

  • Polio on the way out if present efforts cotinue
By R. Senthilnathan in Geneva

IF COUNTRIES maintain their present level of commitment and programmes, the chances that polio will be eradicated from the world by the turn of the century are good, a senior UN official has said.

Mr Harry Hull, a medical officer at the Expanded Immunisation Programme of the Geneva-based World Health Organisation (WHO), said great progress had been made in the global fight against the disease in recent years.

"If we have not eradicated by year 2000, then we will be pretty close to it," he said.

He added that about half a billion people, mostly children, would be immunised against polio this year.

This will be a 25-per-cent increase over the numbers immunised last year as part of the ongoing campaign against polio, an infectious disease caused by a virus.

According to the WHO, the demand for the polio vaccine last year was so great that it exceeded the capacities of the major producers.

The WHO launched a global polio-eradication programme along with Unicef, Rotary international and the US Centres for Disease Control and Prevention in 1988. It aims to eradicate the disease from the world by the end of this century. As a result of the four-pronged programme, the number of polio incidences has been reduced by 90 per cent over the past nine years, from 350,000 in 1988 to around 40,000 last year.

Polio strikes at any age, but between 50 and 70 per cent of all victims are children under the age of three.

There are three types of virus -- polio virus Type One, Type Two and Type Three -- and they enter the human body through the mouth and then multiply in the throat and intestines. The incubation period is usually between four and 35 days and once established, the virus enters the blood stream and affects the central nervous system.

Usually leg muscles are more affected than the arm muscles, but in more extensive cases, the trunk and muscles of the abdomen could also be affected, leading to quadriplegia.

The most severe form, however, is when the virus reduces the breathing capacity and causes difficulty in swallowing and speaking. This is called bulbar polio, which could lead to death by asphyxiation.

At present, there are two forms of immunisation: the injectible polio vaccine and the more widely used oral vaccine.

One crucial part of the campaign against the disease is the so-called national immunisation days carried out by countries. The WHO estimates that once polio is eradicated from the world, an estimated US$1.5 billion (S$2.28 billion) would be saved annually.