Health officials are alarmed with the rising cases of a rare condition that affects the body's nervous system causing paralysis.

The polio-like disease, called acute flaccid myelitis, is presently terrorizing people in the U.S., affecting mostly children. There are already 50 confirmed cases of acute flaccid myelitis in 24 different states as of August this year, and about 90 percent of the patients are children.

"The CDC is concerned about the increase in cases, so we're actively investigating the cases and working really closely with health departments on it," said Dr. Manisha Patel, a pediatrician at Centers for Disease Control and Prevention, in a report from CBS News. We're intensifying our efforts to find out what causes it - we don't know what causes it."

Acute flaccid myelitis can be caused by variety of germs including West Nile virus, enterovirus and adenovirus. CDC has no idea what caused the rising cases of the disease in the US. But they are looking into the possibility of environmental toxins, genetic disorders and Guillain-Barre syndrome.

The disease may have similar symptoms to polio, which attacks the spinal cord. However, unlike polio, acute flaccid myelitis has no available vaccine yet.

People inflicted with acute flaccid myelitis could experience sudden limb weakness. In some cases, people suffering from the disease may also experience difficulty in moving their eyes, difficulty swallowing, drooping of facial muscles and eyelids and slurred speech. Patients may also have difficulty in urinating.

Severe cases of acute flaccid myelitis may result to respiratory failure, especially if the muscles involve in breathing weaken. CDC is still worried about the number of acute flaccid myelitis this year, despite being low compared to the outbreak in 2014.

From August to December 2014, 120 confirmed cases of acute flaccid myelitis from 34 different states. The number of reported cases dropped to 21 in 16 states in 2015. However, the cases suddenly increased once again this year.