Unless the poliovirus is totally eradicated, there still remains a global threat of new outbreaks
A LARGE segment of the population would only have read about the death and mayhem arising from the 1954 poliomyelitis outbreak in Jamaica. About 750 cases of the infectious and disabling disease were reported; 94 of the affected persons died and many more lost the use of their limbs.
Similarly, the summer months of the 1940s and 50s were characterised by panics linked to large polio epidemics in industrialised countries -- the United States and Western Europe.
Effective immunisation strategies saw Jamaica reporting the last case of polio in 1982 and the declaration of the region of the Americas as polio-free in 1994. But Jamaica and the rest of the world are still not out of the woods when it comes to polio. The threat still exists.
An emergency meeting of Health Ministers from the six remaining countries where the infectious disease, poliomyelitis, is still endemic, will be held later this week in Europe. This meeting of the Global Polio Eradication Initiative has become urgent as the World Health Organisation (WHO) intensifies efforts to stop the spread of the poliovirus throughout the world by year end.
Up to the end of last year, according to the Global Polio Eradication Initiative, wild poliovirus transmission was still evident in six countries -- Afghanistan, Egypt, India, Niger, Nigeria, Pakistan -- and three of these countries, India, Nigeria and Pakistan, accounted for 99 per cent of the cases.
The effort to eradicate poliomyelitis becomes more urgent as two new cases
of poliovirus were confirmed last week in Benin and Cameroon, where the disease had previously been eradicated. Health officials are seeing a potential global risk of new polio outbreaks unless a final thrust is made to
eradicate the illness in the few remaining countries.
This is not the first scare in recent times, indicating the potential for this infectious condition to make a comeback. In 2000 neighbouring Dominican Republic and Haiti saw a resurgence of polio cases. At that time, the health experts at the Pan American Health Organisation (PAHO) said that the outbreak raised serious concerns not only because the Western Hemisphere has been free of the wild poliovirus circulation since 1991, but because the virus identified in infected persons is an unusual derivative of the Sabin type 1 oral poliovirus vaccine (OPV).
Although Jamaica's immunisation coverage of the target population has grown over the last 20 years, the United Nations Report on the State of the World's Vaccines and Immunisation points out that in 2000 coverage for tuberculosis, diphtheria, tetanus, pertussis (whooping cough), measles and poliomyelitis, were just over 80 per cent -- still leaving a reserve of the target population at possible risk if exposed to the poliovirus.
There are three serotypes of human poliovirus. The virus usually attacks the gastrointestinal tract and nasopharynx and is often asymptomatic. The WHO indicates however, that in some cases the central nervous system, primarily the spinal cord, is affected, leading to rapidly progressive paralysis. The virus is spread through person-to-person contact as well as faecal-oral contact; children living under condition where hygiene and sanitation are poor, are reportedly at the greatest risk. The Global Polio Eradication Initiative also indicates that polio can be spread when food or drink is contaminated by faeces and there is evidence that flies can transfer poliovirus from faeces to food.
