§ 607-a. Performance of duty disability retirement. a. Any security hospital treatment assistant, as that term is defined in subdivision i of section eighty-nine of this chapter, who becomes physically or mentally incapacitated for the performance of duties as the natural and proximate result, of an injury, sustained in the performance or discharge of his or her duties by, or as the natural and proximate result of, an act of any person confined in an institution under the jurisdiction of the office of mental health, or by any person who has been committed to such institution by any court shall be paid a performance of duty disability retirement allowance equal to that which is provided in section sixty-three of this chapter, subject to the provisions of section sixty-four of this chapter.

b. Notwithstanding any provision of this chapter or of any general or special law to the contrary, a member covered by this section who contracts HIV (where there may have been an exposure to a bodily fluid of an incarcerated individual or a person described in subdivision a of this section as a natural and proximate result of an act of any incarcerated individual or person described in such subdivision a that may have involved transmission of a specified transmissible disease from an incarcerated individual or such person described in such subdivision a to the retirement system member), tuberculosis or hepatitis will be presumed to have contracted such disease in the performance or discharge of his or her duties, and will be presumed to be disabled from the performance of his or her duties, unless the contrary be proved by competent evidence.

c. Notwithstanding any provision of this chapter or of any general or special law to the contrary, any condition of impairment of health caused by diseases of the heart, resulting in disability or death to a member covered by this section, presently employed and who shall have sustained such disability while so employed, who successfully passed a physical examination on entry into service as a security hospital treatment assistant, which examination failed to disclose evidence of any disease or other impairment of the heart, shall be presumptive evidence that it was incurred in the performance and discharge of duty, unless the contrary be proved by competent evidence.