There’s a new strand of the enterovirus that could be responsible for the paralysis of dozens of children, NBC News reported Monday. Enterovirus D68 (EV-D68) is a polio-like sickness that has affected more than 100 children. The children have suffered from a mystifying muscle weakness.

Twenty-five children with the virus are being studied, the journal Lancet Infectious Diseases reported Monday. Nine of them are from Colorado and 16 are from California, according to Dr. Charles Chiu of the University of California San Francisco.

"This is a virus that causes the common cold," Chiu told NBC News. "Parents don't bring their kids in until they are really sick. By that time, typically, the viral levels may be very, very low or undetectable."

The new strain of the virus, called B-1, was found in each of the children's cases, Chiu revealed. The B-1 strand has minor mutations similar to the ones seen in polio, but not everyone who has the new strand of the virus will develop paralysis, the New York Times added.

Researchers are working to discover the connection to paralysis. "We are planning to better understand the functional significance of this change," Chiu said.

Scientists have not been able to detect the B-1 strand in spinal fluid. "The lack of detectable virus in (cerebrospinal fluid) could also mean that the neurological symptoms are coming from an aberrant immune response to recent EV-D68 infection and not because the virus is directly invading neurons," Chiu said in a press release, The Denver Post noted.

With hope, answers will be discovered soon. Dr. Grace M. Aldrovandi, the chief of infectious diseases at Children’s Hospital Los Angeles, told the Times: “I can’t emphasize how scary this is. You have a normal child, and then all of sudden they are pretty incapacitated.”

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