An adult with tuberculosis spent time in a Manchester daycare center while infectious.
State health officials said there have been no other confirmed cases related to this one.
Families have been notified of the potential exposure, which occurred from March 1 to August 6, and the individual is no longer in the daycare center.
Healthcare providers have also been notified, said the Department of Health and Human Services.
“DHHS has informed healthcare providers of patient monitoring and treatment protocols to ensure proper care of any child who may have been exposed,” a health department spokesperson said in an email.
The state says it's working with Manchester's health department to identify anyone else who may have had prolonged exposure to the adult.
Tuberculosis is rare in the U.S., with New Hampshire generally seeing less than 20 cases a year. Many of those cases come from outside the US, according to the state’s health department.
But, tuberculosis is the deadliest infectious disease worldwide. Children under five are especially at risk for the disease.