MEDICINE / POLIO : Western Hemisphere Free of Crippler Disease for Year

No cases of polio have been reported in the Western Hemisphere for more than a year, an important milestone in the campaign to eradicate the feared crippler of children throughout the world, federal health officials reported Thursday.

The last case of polio in the Americas was reported in August, 1991, in Peru. The World Health Organization has set a goal of eliminating polio worldwide by the year 2000.

“We consider it an important achievement in medicine,” said spokesman Dan Epstein of the Pan American Health Organization, which began its polio eradication and monitoring campaign in 1985.

In making the announcement, the Centers for Disease Control in Atlanta said: “The apparent elimination of (polio) in the Americas underscores the feasibility of achieving a similar goal in other regions.”

The Pan American Health Organization will now begin a process to certify that the disease has been eliminated. Three years must pass without a single case before the eradication of polio can be declared, officials said.

The success was attributed to a combination of mass vaccination programs for young children, intensive surveillance of potential cases, and house-to-house immunization efforts to reach children in high-risk areas.

There were 11 confirmed polio cases in the Americas in 1990 and nine in 1991. This compares to 1,000 cases reported in 1986.

Around the world, there were 16,400 official reports of polio cases in 1990, a number that substantially underestimates the actual number of infections. Three-quarters of the reported cases were from India and China, according to the World Health Organization.

Polio is caused by a virus that can be transmitted easily through food and water contaminated with human feces, as well as by close person-to-person contact. By the time a single case of polio paralysis is recognized, many people in a community have likely been infected.

Most of those infected with the polio virus will have only minor or inapparent illnesses, not the severe paralysis that is the hallmark of the disease.

Because of the danger of importing the polio virus into countries in which the disease has previously been eradicated, health officials say that no country is totally safe from outbreaks until the virus is eradicated throughout the world.

So far, the only human germ to be eradicated throughout the world is smallpox. The last naturally transmitted case occurred in Africa in 1977.