NEW YORK – As public health officials struggle to track and contain a respiratory virus that has hospitalized hundreds of children across the U.S., there are now concerns that the illness may also cause paralysis in some cases.
In Missouri, doctors are investigating whether Enterovirus D68 caused three children to develop paralysis in their limbs this month, Mary Anne Jackson, director of the division of infectious disease at Children’s Mercy Kansas City, said in a telephone interview. In Colorado, officials are examining nine similar cases of severe muscle weakness and limb paralysis, according to the Centers for Disease Control and Prevention.
While the virus has been confirmed in all but 10 states, with 277 cases, the actual number is likely much higher, health authorities said. Testing facilities have been overwhelmed with samples and only the sickest are being tested.
“We don’t even have our finger on the pulse of how extensive this is, we have a guess,” said Jackson, whose hospital has treated more than 700 suspected cases and was among the first to report an outbreak of the virus. “We are in a very dynamic period right now.”
The enterovirus is related to the common cold, and this strain has hit children hardest. Most only experience symptoms such as a runny nose, though a small percentage develop trouble breathing and have to be admitted to the intensive care unit.
The possibility of paralysis adds another layer to the mystery around the virus as it has swept the nation, and why it has caused such severe illness in so many children.
The Colorado and Missouri patients showed similar symptoms to other enterovirus patients before developing their paralysis. In Colorado, at least four of the paralyzed children tested positive for EV-D68 through nasal swabs. In Missouri, doctors haven’t been able to confirm the diagnosis with lab testing, and are still testing to find out whether the patients had this strain of enterovirus or another infection, Jackson said.
None of the patients has seen an improvement in their paralysis, which causes extremely weak limbs that couldn’t function normally, she said.
The CDC said that no patients tested positive for the virus in their spinal fluid. The patients also tested negative for polio and West Nile virus.
This isn’t the first time the virus has been linked to paralysis. Until now, though, such cases have been extremely rare, Jackson said. In April, researchers at the University of California at San Francisco reported that the virus was detected in at least two children who suddenly lost the function in an arm or leg.
Despite such reports, paralysis still isn’t a confirmed symptom, said Rafal Tokarz, a researcher at Columbia University who has studied enterovirus. He said further testing is needed to know for sure whether the virus is the cause of the paralysis cases seen in Colorado.
Enterovirus D68 was first seen in 1962. There is no vaccine, and no specific medicine approved to treat it. The latest outbreak began in the Midwest, with clusters of cases in Kansas City and Chicago.
Health officials are encouraging the standard approach to good hygiene to reduce the risk of spreading the virus, including regular hand washing, limiting time with ill people and staying home when sick. Parents should watch for signs their children are having trouble breathing or wheezing, which may be a warning.