The CDC’s actions come in response to China's government-run media confirming that positivity rates of HMPV hare rising in children under the age of 14, despite respiratory illnesses being down overall since last year.

As cases of the HMPV virus continue to increase in the U.S. and in China, here's what you need to know about the virus.

There is no evidence yet that the outbreak is extraordinary yet and Chinese officials have pushed back against claims of yet another pandemic.