The mysterious respiratory illness entero-virus has spread to more than half the United States — with symptoms ranging from mild colds to serious breathing problems, health officials said.

Since mid-August, 175 people across 27 states have been diagnosed with the sickness caused by the entero-virus D68, the US Centers for Disease Control and Prevention said.

The entero-virus, a more virulent strain of the virus that causes the common cold, can lead to fever, sneezing and coughing in mild cases.

Hospitalization for breathing difficulties and wheezing is required in more severe cases.

The most recent diagnosis of the virus was Tuesday in Massachusetts, where an 8-year-old girl with a history of asthma was infected, according to CBS Boston.

The girl was treated at Boston Children’s Hospital and released.

“We treated her in our unit as she was relatively ill at the time, but has done terrifically well and is home,” said Dr. Michael Agus. “I just spoke with her mother and she’s doing terrifically well at home.”

Last week, two youngsters — one from the city and another from Long Island — were diagnosed with the mysterious disease.

A 6-year-old girl in Connecticut was also infected and one case in New Jersey was confirmed.

The state department in North Carolina also confirmed the virus, with six children age 10 and under having tested positive. It added that the illness has spread to at least 28 states.

Confirmed cases of the virus are expected to pop up in more states in the coming weeks as testing to confirm the illness is completed, the CDC said.

The agency said the virus is more common in the US during the summer and fall.

There are no specific treatments for the entero-virus, but public health officials said washing your hands regularly can prevent spreading it.

Infants, children and teens are at the highest risk of infection.

By Lia Eustachewich.