THE THOMAS FRANCIS, JR. MEDAL IN GLOBAL PUBLIC HEALTH

Polio Still Stalks the Third World

Thomas Francis and Jonas Salk won a huge battle 50 years ago, but the war against polio rages on.

The crippling, sometimes lethal, polio virus continues to infect people in more than a dozen countries of north Africa, the Middle East, and southern Asia. In a few countries that seemed to have locally eliminated transmission of the virus, it appears to be making a comeback.

Although paralysis is the most visible sign of polio infection, it occurs in fewer than 1% of polio infections. Most cases, maybe 200 times as many, don’t show and aren’t diagnosed.

And polio works slowly, only causing paralysis more than a month after infection.

“One of the challenges for this particular disease is that the symptoms we recognize appear well after transmission has occurred,” said Mark Wilson, director of the Global Health Program in the U-M School of Public Health. “It’s also very unlike smallpox, where virtually every person infected shows signs.”

Though it recorded just 1,200 confirmed cases last year, the World Health Organization (WHO) considers poliovirus widespread in six countries: Nigeria, India, Pakistan, Niger, Afghanistan, and Egypt. It has reemerged recently in Ethiopia, Eritrea, Kenya, and Sudan in the east of the African continent and the Democratic Republic of Congo, and Cote d’Ivoire in the west.

Nigeria has gone from 28 confirmed cases in 2000 to nearly 800 last year. If the confirmed cases represent just 1 in 200 infections, that means 16,000 people carry polio there.

View MAP of new polio cases worldwide >>>

Given its slow and largely invisible spread, public health officials are especially concerned about the sudden reappearance of the virus in Saudia Arabia in January of this year. Two cases were identified just before the hajj, or holy pilgrimage to Mecca, by more than 2 million Muslims from all over the world. The pilgrims have since returned to their homes, but it may be months before anyone knows if there was an outbreak of polio at the hajj.

Polio virus is transmitted through feces, via poor sanitation or fecal-oral contact from poor hygiene.

The initial symptoms of polio aren’t particularly distinctive: fever, fatigue, headache, vomiting, stiffness in the neck, and pain in the limbs. Most people experience no symptoms, and don’t even know that they were infected and possibly transmitting the virus to others. But one in 200 infections leads to irreversible paralysis, usually in the legs. Of the paralyzed patients, 5 to 10 percent die when their breathing muscles are immobilized. More than half of the cases are in children under three years old.

“As soon as health officials see a case of ‘flaccid paralysis‘ suggestive of polio, they can undertake a massive immunization of the population around the patient, but the paralyzed patient is only the tip of the infection,” Wilson said. Others in the population will be infected but without symptoms.

“And the places where this occurs usually don’t have the public health infrastructure you’d need to identify and rapidly respond,” Wilson noted.

An organization called the Global Polio Eradication Initiative (GPEI) was launched in 1988 by WHO, Rotary International, the US Centers for Disease Control and Prevention, and UNICEF to immunize more people in the underdeveloped world. More than 20 million people have been immunized by the program so far, at a cost of more than $3 billion.

Visit the GPEI website >>>

This year, WHO has plans to try to reach 100 million children across northern Africa with vaccine, an effort that will require at least $75 million in additional funding by July 2005. Immunizations in 2006 will cost about $200 million, according to WHO. Since 1985, the members of Rotary International have contributed countless volunteer hours and more than $500 million to the polio eradication effort.

“There has to be a serious commitment on the part of developed countries to put resources into that part of the world,” Wilson said. The dollar figures involved are miniscule compared to some of our other spending priorities, and “it’s in our interest, for global political stability. These bugs don’t respect borders.”