The number of confirmed cases of an uncommon respiratory illness has increased to 277 in 40 states and the District of Columbia, affecting mostly children, according to the Centers for Disease Control and Prevention.

First identified 50 years ago, Enterovirus 68 or EV-D68 was rarely tested for and only began getting attention last month as hundreds of cases were linked to the virus.

"The severity is what triggered our concern," said Mark Pallansch, director of the CDC's Division of Viral Diseases.

The mild symptoms are similar to the common cold, but can progress into wheezing, problems breathing and paralysis.

The CDC is investigating whether nine cases in Colorado of children with muscle weakness or paralysis are linked to the virus. The nine children had respiratory illness about two weeks before they experienced varying degrees of limb weakness, the Associated Press reports.

The CDC says lab results for EV-D68, not to be confused with the Ebola virus, do not indicate how widespread the cases are in each state. The health agency and a handful of state public health are working through a backlog of "multiple hundreds" of specimens, with more coming in, Pallansch said.

So far, about half of the specimens the labs have tested have come back positive for EV-D68 and the number of confirmed cases is likely to grow nationwide as the testing continues, according to the CDC.

Last year, there were no more than a dozen confirmed cases of the virus, but mainly because not as many cases were tested, Pallansch said.

"These increases will not necessarily reflect changes in real time, or mean that the situation is getting worse," according to the CDC.

Infants, children and teens are most at risk to get sick, especially children with asthma and the reason for the current outbreak is not completely understood, Pallansch said. Currently, there is no vaccine, he added.

The treatment is focused on improving the patients' "ability to uptake oxygen," but there is no antiviral for people with EV-D68, he said.

"A lot of this is still under investigation, and these investigations can take weeks," Pallansch said.

How widespread Is EV-D68?

The CDC was first notified Aug. 19 of 19 patients in Kansas City, Mo., and a few days later of 11 patients in Chicago. Since then, reported cases have not been confined to the Midwest.

• In the nine cases in Colorado of muscle weakness or paralysis, the virus was detected in four out of eight sick children who had a specific medical test. The status of the ninth test unclear, the Associated Press reports. All nine are being treated at Children's Hospital Colorado in Aurora.

That hospital has treated more than 2,500 children for severe respiratory illnesses from mid-August to mid-September, with nearly 10% admitted for hospital stays, said Ann-Christine Nyquist, medical director of infection prevention and control at the hospital, in an interview with the American Academy of Family Physicians.

The CDC confirmed 19 of 25 specimens from the hospital tested positive for EV-D68, as of Sept. 15, Nyquist told AAFP.

• In Texas, 10 cases have been confirmed in Dallas County and one in Denton County, reports WFAA-TV.

"It is taking us three-to-four times longer to break the wheezing," said Jim Allard, director of pediatric services at Medical City Children's Hospital in Dallas, in an interview with the station.

• In New Jersey, about 30 children have been hospitalized at Jersey Shore University Medical Center in Neptune since mid-September, reports The Asbury Park Press.

But many improved "dramatically within several days," said Steven Kairys, chairman of pediatrics at the medical center. As of Thursday, the CDC had confirmed one case of the virus but is testing dozens more in the state, the Asbury Park Press reports.

Last week, a 4-year-old boy in Hamilton, N.J., died of an unidentified respiratory illness, but it's unclear yet if EV-D68 can be blamed for the death, reports The Times of Trenton. (Source: USA Today)

Story Date: September 30, 2014