Kansas Department of Health and Environment spokeswoman Aimee Rosenow says none of the infants has died, but all have been hospitalized, reports CBS affiliate KCTV5 News.
The infections are caused by HPeV3, one of a group of viruses called human parechoviruses. Shawnee Mission Medical Center and Children's Mercy Hospital have both reported cases.
The Kansas City Star reports the first cases among local infants were discovered in June.
Rosenow says it's unclear if the infections are connected. Nine of the children are from Kansas and the rest are Missouri residents.
Rosenow says the department is working with the Missouri Health Department and the federal Centers for Disease Control and Prevention to determine if there have been other infections.
Children's Mercy released a newsletter about the virus back in 2010. It says the infections happen in babies less than 90 days old. Symptoms include fever, irritability and rash. Scientists isolated the first case of the virus 1999, after it sickened a 1-year-old child in Japan who presented with symptoms including fever, diarrhea and transient paralysis.
Experts also said it seems to be a summer-time disease, with peak months occurring in July through October.
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