Enterovirus D68 (EV-D68) has struck New York City and New Jersey, health officials announced Wednesday afternoon. The respiratory virus has spread rapidly across the United States this year, with cases confirmed in 13 states and tests underway to determine whether it has hit in other states.

Twelve cases of EV-D68 had already been identified in the state of New York, but the Wednesday announcement by the U.S. Centers for Disease Control and Prevention confirmed for the first time that one or more of the victims was in New York City, according to NBC New York. A child whose condition has improved and who has since been discharged from a Philadelphia hospital was confirmed Wednesday as New Jersey's first EV-D68 case, the station added.

First identified in California in 1962, EV-D68 is one of more than 100 known enteroviruses, but it did not begin to spread quickly across the U.S. until this year. Most infections of the virus cause little more than mild symptoms like sneezing, coughing and runny nose, but in some instances it can require hospitalization to deal with “severe illness requiring intensive care and mechanical ventilation,” the CDC has said. Children and infants are at greatest risk of contracting EV-D68, for which there is currently no treatment or vaccine.

Since mid-August, 130 patients have been stricken ill with confirmed cases of EV-D68 in 12 states: Alabama, Colorado, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Missouri, New York, Oklahoma and Pennsylvania, according to the CDC. New Jersey was added to the list Wednesday, and patients are being tested for the virus in states including Michigan, Georgia, Ohio and Utah, according to CNN.