US Reports 5 Baby Deaths From Usually Mild Virus

CVB1 usually does not cause serious infections but can cause more severe and potentially life-threatening illness in newborns.

A virus that typically causes a mild infection killed at least five babies in the United States last year, the U.S. Centers for Disease Control and Prevention said on Thursday.

The virus was involved in an unusually high number of severe infections in newborns last year, but the CDC said it was not certain of the reason.

Coxsackievirus B1, or CVB1, is part of a group of viruses called enteroviruses. It usually does not cause serious infections but can cause more severe and potentially life-threatening illness in newborns.

The CDC's Steve Oberste, who headed a laboratory that helped track the infections, said tens of thousands of children are infected with this virus annually. He said people should probably not be very concerned about the virus and also said there is no sign it has mutated into a more dangerous form.

The virus killed two babies in California and one in Illinois, Colorado and New Mexico. There may have been more deaths that that the CDC did not know about, Oberste said.

All five newborns had symptoms of the virus within the first week of life, and in four of the cases, there was evidence of possible mother-to-infant transmission of the virus, the CDC said.

"CVB1-associated deaths are reported rarely, and had not been reported previously" to the formal enterovirus surveillance system in place since 1970, the agency said.

"The enteroviruses don't cause much disease. Probably less than 1 percent of all infections result in any illness at all. And an even smaller percentage are serious illness. They're mostly quite mild," Oberste said.

There is no specific treatment for this infection. Usual symptoms include fever, respiratory problems and sore throat. It can be spread in ways including sneezing or by touching contaminated fecal matter.

"Health-care providers and public health departments should be vigilant to the possibility of neonatal disease caused by CVB1," the CDC said.