A strange and possibly deadly form of paralysis with symptoms similar to polio is affecting hundreds of children in the United States and other countries.
Health officials said the mysterious disease might be caused by a virus from 55 years ago that have mutated to become more dangerous.
The increasing number of acute flaccid myelitis (AFM) cases is found related to the spike of respiratory illnesses caused by EV-D68 in the recent years. EV-D68 belongs to a large family of enteroviruses that mainly affects the central nervous system.
In 2008, a 5-year-old boy from New Hampshire died after showing neck tenderness, fever, weakened arms, and deadened legs. A medical report attributed the patient's death to his history of EV-D68.
The first major surge of AFM began in 2014, when 120 cases were confirmed mostly in California and Colorado. The disease has shown an odd-year and even-year pattern. Twenty-two cases were reported in 2015, 149 in 2016, and 35 in 2017.
Last year, the confirmed AFM cases reached 228. Experts believe this number may still increase as they investigate other illnesses. Britain, Canada, France, and Norway also reported incidents of AFM.
Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, said AFM is unlikely to affect populations as bad as polio. However, the number of affected individuals will likely exceed the number trend.
"The trajectory of AFM over the past 5 years suggests that the problem is getting worse, and so it is critical that we galvanize our efforts to learn more about, and respond adequately to, this ubiquitous, often crippling, continually reemerging group of viruses," Fauci and his colleagues reported.
The most recent study on AFM was published in the journal mBio.
AFM is a rare and sometimes fatal disease that appears to strike more children every other year. It starts with cold-like symptoms and fever, which progresses to inability to move certain body parts and then paralysis.
Four-year-old Joey Wilcox from Herndon, Virginia, acquired AFM and is now unable to move his legs, arms, or even sit up. Doctors said he might eventually lose his ability to breathe on his own.
Wilcox is one of the 228 confirmed cases of AFM in the United States last year. The illness affects both children and adults. More than 90 percent of them are children from ages four to six. The oldest patient was 32 years old.
"AFM affects the nervous system, specifically the spinal cord, which can cause the muscles and reflexes in the body not to work normally," the U.S. Centers for Disease Control and Prevention said on its website.
Experts warn parents to seek immediate medical attention if their children experience symptoms such as weakness or loss of muscle tone and facial droop. They may also have difficulty with eye movement, problems with swallowing, and slurred speech.
Dr. Benjamin Greenberg, an AFM expert from UT Southwestern Medical Center in Dallas, said kids can recover slowly every year. Their improvement depends largely on how much therapy they receive.