Whenever an epidemic of any contagious or infectious disease exists or is threatened, or any special need arises for the protection of the public health, and in the judgment of the local board of health of any municipality the expenditure of a greater sum than that already appropriated to the local board for the current year is necessary, the local board shall so certify to the body having control of the finances of the municipality. Thereupon the body having control of the finances of such municipality may appropriate such sum as the local board may certify to be necessary. If the funds at the disposal of the governing body of the municipality are not sufficient for such purpose, it may borrow the sum on the credit of the municipality. In such event the governing body shall place an amount equal to the sum borrowed with interest in the next annual tax levy, and with the money so raised shall pay the debt incurred.