Mass. Gen. Laws ch. 111 § 94B
If any active tuberculosis patient in a municipal, county, state or private sanatorium or hospital indicates his desire to leave the institution against the medical advice of the superintendent or manager of the institution in accord with the accepted medical policy of the institution, and the superintendent or manager determines that to allow his release would be a serious danger to the public health, he may detain the patient, or, if he fears the patient may try to leave the hospital, he may request the local police department to transport the patient immediately to the tuberculosis treatment center established under section ninety-four D.
If the superintendent or manager detains the patient at his own institution, he shall immediately file a petition in the district court under section ninety-four C for the prolonged hospitalization of the patient. The patient may be detained at the institution pending disposition of the petition.
If the patient is transported to the tuberculosis treatment center he shall be detained there no longer than fifteen days, and upon the expiration of that time he shall be released, unless a petition for the prolonged hospitalization of such patient is filed by the superintendent thereof in the district court under section ninety-four C.
Mass. Gen. Laws ch. 111, § 94B