The spread of polio to countries previously considered free of the crippling disease is a global health emergency, the World Health Organization said, as the virus once driven to the brink of extinction mounts a comeback.

Pakistan, Cameroon and Syria pose the greatest risk of exporting the virus to other countries, and should ensure that residents have been vaccinated before they travel, the Geneva-based WHO said in a statement today after a meeting of its emergency committee. It’s only the second time the United Nations agency has declared a public health emergency of international concern, after the 2009 influenza pandemic.

Polio has resurged as military conflicts from Sudan to Pakistan disrupt vaccination campaigns, giving the virus a toehold. The number of cases reached a record low of 223 globally in 2012 and jumped to 417 last year, according to the WHO. There have been 74 cases this year, including 59 in Pakistan, during what is usually polio’s “low season,” the WHO said.

The disease’s spread, if unchecked, “could result in failure to eradicate globally one of the world’s most serious, vaccine-preventable diseases,” Bruce Aylward, the WHO’s assistant director general for polio, emergencies and country collaboration, told reporters in Geneva today. “The consequences of further international spread are particularly acute today given the large number of polio-free but conflict-torn and fragile states which have severely compromised routine immunization services.”

“Conflict makes it very difficult for the vaccinators to get to the children who need vaccine,” David Heymann, a professor of infectious diseases at the London School of Hygiene and Tropical Medicine, said in an interview before the WHO’s announcement. “It’s been more difficult to finish than had been hoped.”

The polio virus, which is spread through feces, attacks the nervous system and can cause paralysis within hours, and death in as many as 10 percent of its victims. There is no cure. The disease can be prevented by vaccines…

The resurgence of the virus “reminds us that, until it’s eradicated, it’s going to spread internationally and it’s going to find and paralyze susceptible kids,” Aylward said.

Resurgence, as well, of the question: what holds back progress for most of the people living on this planet? Is it stupidity or ignorance? My answer changes from week to week.

It takes a special kind of stupidity after all to make uninformed and ignorant decisions. Whether the ignorance is religion-based, hatred of furriners, paranoid rejection of science and info from educated folks who obviously don’t live in your own neighborhood/state/region/country/continent – doesn’t matter a whole boatload. Killing your kin and letting your children die sounds mostly stupid to me.