Five children in California were found infected with a strange polio-like disease, leaving them paralyzed in the arms or legs.
All 5 cases were discovered over the last one year. Standford University researchers are currently conducting a study on the children to determine the cause of the disease and its consequences. Findings of the new study will be presented at the American Academy of Neurology's 66th Annual Meeting in Philadelphia, April 26 to May 3, 2014.
"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 in a press statement. "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."
The afflicted kids suffer severe weakness or paralysis, which strikes rapidly, sometimes after a mild respiratory illness. Scans of the patients' spinal cords showed patterns of damage similar to that found in polio sufferers. Two of the affected children tested positive for enterovirus-68, a virus that is usually associated with respiratory illness but which has been linked to polio-like illnesses too. The children were treated but their symptoms did not improve and they still had poor limb function after six months.
Three of the children had a respiratory illness before the symptoms began. All the children had been previously vaccinated against poliovirus. So researchers have ruled out the possibility of the virus being that of polio.
"We know definitively that it isn't polio," Dr. Carol Glaser, leader of a California Department of Public Health team, said to LA Times.
Polio is an acute viral infectious disease that spreads from person to person, primarily through the fecal-oral route.
"Our findings have important implications for disease surveillance, testing and treatment," said Van Haren. "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."
State health investigators have been tracking similar cases in California closely since a physician first requested polio testing for a child with severe paralytic illness in the fall of 2012. Ever since, researchers revealed that 20 similar cases have been reported. All children affected were about 12 years old. What's surprising is that none of the symptoms could be linked to known causes like West Nile virus or botulism. Glaser said that it was possible that children who tested negative for these viruses still may have contracted their illnesses from viruses that couldn't be detected because test samples were "not optimal."
"We want to hear from local public health jurisdictions and physicians who are seeing similar illnesses," she said.
Periodic polio epidemics occurred in the United States since the late 19th century and they increased in size and frequency in the late 1940s and early 1950s. An average of over 35,000 cases was reported during this time period. According to the CDC, the last cases of naturally occurring paralytic polio in the United States were in 1979, when an outbreak occurred among the Amish in several Midwestern states. From 1980 through 1999, there were 162 confirmed cases of paralytic polio cases reported.
The case report was supported by the McHugh/Sprague Award from the Lucile Packard Foundation.
