(a) When used in the Public Health Law and in this Chapter, the term infectious, contagious or communicable disease, shall be held to include the following diseases and any other disease which the commissioner, in the reasonable exercise of his or her medical judgment, determines to be communicable, rapidly emergent or a significant threat to public health, provided that the disease which is added to this list solely by the commissioner's authority shall remain on the list only if confirmed by the Public Health and Health Planning Council at its next scheduled meeting:

(b) Upon receipt of a report made pursuant to section 2.10 of this Part, the city, county or district health officer shall retain a copy in his record of the reports of such communicable diseases as the State Commissioner of Health may direct, and shall retain these copies until their destruction is authorized by the State Commissioner of Health, and shall forward a copy of all reports immediately to the State Department of Health. In lieu of an individual report of each case, the city, county or district health officer may, with the written consent of the State Commissioner of Health, make such summarized reports as the commissioner may require.

(c) Any disease outbreak or unusual disease shall also be reported to the State Department of Health as provided in subdivision (b) of this section. Unusual disease is defined as a newly apparent or emerging disease or syndrome of uncertain etiology that a health care provider or the State Commissioner of Health has reason to believe could possibly be caused by a transmissible infectious agent or microbial toxin.