Around 20 California children have been stricken with what doctors are calling a "polio-like illness" in which they suffer a treatment-resistant paralysis of one or more limbs. All of the affected children have been received the vaccine against polio. CNN.com has more:
Neurologists have identified five patients who developed paralysis in one or more of their limbs between August 2012 and July 2013. All five children had been vaccinated against the poliovirus. Treatment did not seem to help the children regain their motor function.
Samples from two of the children tested positive for enterovirus 68, a rare virus that has been linked to severe respiratory illness in the past. Samples from the other three children were not collected or tested soon enough to yield conclusive results, said Dr. Emmanuelle Waubant, a neurologist at the University of California, San Francisco.
Waubant and her colleagues will present a case report about these patients' illnesses at the American Academy of Neurology's annual meeting in late April. They are asking health care providers to be on the lookout for similar cases and send in samples from any patient exhibiting these symptoms.
Dr. Carol Glaser, chief of the Encephalitis and Special Investigation Section at the California Department of Public Health, said the state is aware of the paralysis cases but believes the risk to families is very low.
"We are evaluating cases as they are reported to us," Glaser said in an e-mail to CNN. "We have not found anything at this point that raises any public health concerns."
"Enteroviruses are among the most common viruses causing respiratory tract illnesses in children," said Dr. Al DeMaria, state epidemiologist at the Massachusetts Department of Public Health.
Various strains can cause coughing, sore throats and sneezing and can also infect the gastrointestinal tract leading to diarrhea and vomiting. Far less commonly, this virus could, like polio, invade the bloodstream and attack nerve cells in the spine sometimes causing irreversible paralysis in the arms and legs.
"With polio, 1 in every 1,000 children who were infected developed paralysis," DeMaria said, "and at its height, polio caused 20,000 to 30,000 cases of paralysis per year." No one knows how common paralysis is with rare enterovirus-68 infections, but it's likely far less common than with polio—perhaps between 1 in 10,000 to 1 in 100,000 infections, DeMaria estimated.
"It's something we need to keep an eye on," he said.