Poliomyelitis: Background information when reading Warm Springs

Poliomyelitis

This article relates to Warm Springs

Poliomyelitis, more commonly known as Polio, is a viral disease that has plagued humans since ancient times. It is transmitted primarily through direct fecal-oral contact. However, it can also be transmitted by indirect contact with infectious saliva or feces or by contaminated sewage or water.

In over 90% of cases there are no symptoms but in those who show symptoms the illness takes three forms: Abortive polio in which people experience mild flu-like symptoms; a more serious form called nonparalytic polio in which a person experiences sensitivity to light and neck stiffness; and then there is the severe, debilitating form known as paralytic polio in which the virus leaves the intestinal tract and enters the bloodstream, attacking the nerves and causing muscle paralysis.

Although the acute illness usually lasts less than 2 weeks, damage to the nerves can last a lifetime. Even those who apparently recover may go on to develop post-polio syndrome (PPS) as many as 30 to 40 years after contracting polio.

The most extensive known outbreak of the disease occurred during the 1950s. In 1952, at the height of the outbreak, there were 60,000 cases in the USA alone resulting in 3,000 deaths. Thanks to the vaccination created by Jonas Salk in 1955, polio was eliminated from the USA in 1979, and was thought to have been eliminated from the Western hemisphere in 1991, but in 2000 there was an outbreak of paralytic polio in the Dominican Republican and Haiti.

The World Health Organization (WHO) with the support of organizations such as Rotary, UNICEF and theGates Foundation are working towards eradicating polio worldwide. In 1988, 355,000 cases of polio were reported in 125 countries; by the end of 2004 there were just 1,255 cases.


Should you still vaccinate & is vaccination safe?
According to the Center for Disease Control (CDC), yes and yes!

There are two types of vaccination for polio - OPV and IPV. OPV is the vaccination that most of us received in the form of oral drops (served, at least in the UK, on sugar lumps!). OPV is better than IPV at keeping the disease from spreading to other people, but in very rare cases (1:2.4 million) it can cause polio. IPV, on the other hand, cannot cause polio. Because the risk of getting polio in the US is now so low, the IPV vaccine, given by injection, has replaced OPV as the usual vaccination of choice (IPV is also administered in the UK and probably elsewhere).

There is no cure for polio, so even though the risk of contracting polio in most countries is very low, vaccination is still strongly recommended as the virus is still active in at least six countries (Afghanistan, Egypt, India, Niger, Nigeria, and Pakistan). Until the disease is entirely eradicated, all it would take is for one infected person to import the virus into a country where not enough people are immune and a polio outbreak could occur.


Related Links:
The goal of theGlobal Polio Eradication Initiative is to ensure that no child will ever again know the crippling effects of polio. It is the largest public health initiative the world has ever known.

Filed under Medicine, Science and Tech

This "beyond the book article" relates to Warm Springs. It originally ran in July 2007 and has been updated for the June 2008 paperback edition. Go to magazine.