February 24, 2014
Nearly 20 California Children Diagnosed With Polio-Like Paralysis
Lawrence LeBlond for redOrbit.com - Your Universe Online
While polio was eradicated from the United States in the 1950s after a vaccine was developed to stop the disease dead in its tracks, researchers have pointed out that a mysterious polio-like illness has been discovered in a cluster of children in California.
In a case report that is scheduled to be presented at the 66th Annual Meeting of the American Academy of Neurology (AAN) in Philadelphia later this spring, a team of researchers has identified the syndrome over a one-year period in as many as 20 children.
Researchers confirmed the illness after several children had developed paralysis in all four limbs and did not improve with treatment.
"Although poliovirus has been eradicated from most of the globe, other viruses can also injure the spine, leading to a polio-like syndrome," said case report author Keith Van Haren, MD, with Stanford University in Palo Alto, Calif., and a member of the AAN.
"In the past decade, newly identified strains of enterovirus have been linked to polio-like outbreaks among children in Asia and Australia. These five new cases highlight the possibility of an emerging infectious polio-like syndrome in California," he added.
Emanuelle Waubant, MD, of the University of California, San Francisco, is a colleague of Van Haren’s. The two doctors noted that several cases of the mysterious paralysis were evident at their medical centers and after an analysis of other medical facilities throughout California, the team turned up evidence of several more cases, mostly in children.
They discovered the new evidence while reviewing polio-like cases among children who had samples referred to California’s Neurologic and Surveillance Testing program from August 2012 to July 2013. All cases that involved paralysis in one or more limbs along with abnormal MRI scans that explained the paralysis were included in the analysis. However, the team did not include children who met the criteria for Guillain-Barre syndrome and botulism, which is known to cause similar symptoms.
The five original children experienced paralysis in one or more limbs that came on suddenly and reached the height of severity within two days of onset. Three of the children also had a respiratory illness before symptoms began. All five children had been previously vaccinated against poliovirus.
After six months of treatment, all the children still had poor limb function and no visible signs of improvement. Two of the children tested positive for enterovirus-68 (HEV68), which is a rare virus previously associated with polio-like symptoms. No official diagnosis was made in the other three children.
"Our findings have important implications for disease surveillance, testing and treatment," said Van Haren in a statement. "We would like to stress that this syndrome appears to be very, very rare. Any time a parent sees symptoms of paralysis in a child, the child should be seen by a doctor right away."
The researchers maintained that the infection remains rare and see no signs of an epidemic in the making.
"There has been no obvious increase in the pace of new cases so we don't think we're about to experience an epidemic, that's the good news,” Dr Waubant told the BBC’s James Gallagher. "But it's bad news for individuals unlucky enough to develop symptoms which tend to be moderate to severe and don't appear to improve too much despite reasonably aggressive treatment."
California Department of Public Health’s Dr Carol Glaser, who led the team investigating the illnesses, said state health investigators have been tracking new cases since a physician first requested polio testing for a child with severe paralytic illness in the fall of 2012. She said the request was “concerning,” because polio was eradicated and the child had not traveled outside the country.
Glaser told Eryn Brown of The Los Angeles Times that the health department continued to hear about additional cases of children suffering from paralysis that could not be linked to West Nile virus or botulism. Glaser did not disclose the total number of illnesses, but Van Haren estimated the number to be around 20.
The team said the cases have been spread out over a 100-mile radius so it is unlikely that the virus represents a single cluster or outbreak. However, many people could have been infected but had not developed serious symptoms, they noted.
A CDC Morbidity and Mortality Weekly Report published on September 30, 2011 reported on several clusters of HEV68 from Asia, Europe and the United States from 2008 to 2010. The disease was first isolated in California in 1962 from four children who had bronchiolitis and pneumonia.