Over the past 18 months, as many as 25 children in California have been stricken with a mysterious polio-like virus that has caused paralysis in five of the youngsters. The paralytic illness is caused by a virus in the same family as polio.
Polio has been eradicated from most of the globe, including the United States, following the development of a vaccine in the mid-1950’s. Outbreaks have been reported in countries that include Afghanistan, Pakistan and Nigeria.
Experts were surprised and extremely concerned when more than two dozen children in southern California and the San Francisco Bay area came down with a mysterious pathogen that, like polio, attacked the central nervous system, causing paralysis. So far, investigators say five children have permanently lost the use of one or more limbs.
Doctors suspect a virus is to blame, but have not confirmed its presence in all of the children. They have identified enterovirus-68 - in the same family as the polio virus - as the culprit in only two of the cases.
While there are more than 100 enteroviruses throughout the world, ENV-68 is rare, says Steven Tracy, a professor of pathology and microbiology at the University of Nebraska Medical Center in Omaha. Rarer still, he said, is the development of paralysis in children who become infected. “Enteroviruses are very common and cause a lot of minor diseases, colds and that sort of thing,” he explained.
Newly identified strains of enterovirus have been reported among children in Asia and Australia, causing polio-like syndromes.
The polio vaccine does not protect against ENV-68 because they are two different types of enterovirus. Tracy, however, said a preventive drug could be developed quickly using the polio vaccine as a model.
“It’s quite possible. We know how to develop enterovirus vaccines now from the yeoman work that went into developing the polio vaccines, both the injectable and the oral mouth ones,” said Tracy.
Because there are so few cases of ENV-68 infection, Tracy said drug companies are unlikely to begin work on a vaccine anytime soon.
Meanwhile, doctors and public health officials continue to stress that paralysis from ENV-68 is extremely rare; but, they say parents should rush their children to a doctor anytime they see signs of weakness appear suddenly.