BOSTON (AP) – Two children on Friday were added to the state’s list of suspected cases of severe acute respiratory syndrome, bringing the Massachusetts total to 13.

A 4-year-old Worcester County girl was listed after being exposed through close contact with another person suspected SARS case, according to the state Department of Public Health.

The girl is the first suspected case exposed through close contact. Every other person listed had possible exposure through travel to southeast Asia.

The only other Worcester County case is a boy, also 4, who re-entered the United States on April 1.

A public health spokeswoman did not immediately return a call to comment on their relationship.

The other new case is a 1-year-old Middlesex County boy who re-entered the United States from China on April 12.

Neither new suspected case required hospitalization, according to the DPH.

To protect identities, names and hometowns of suspected cases are withheld.

On Thursday, a Burlington daycare center closed temporarily after a 3-year-old boy who had recently returned from China showed symptoms of SARS.

SARS has killed more than 170 people worldwide – out of more than 3,000 infected – with six more deaths reported Friday in China’s Inner Mongolia, Hong Kong and Singapore.

There have been no deaths in the United States.

Symptoms of SARS include fever, shortness of breath, coughing, chills and body aches.