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
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
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
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