Section 43B. Whenever an officer or employee of a county has been elected or appointed to an office the term whereof exceeds one year, and has filed a fidelity bond covering his entire term of office, and subsequent to such filing he is required by law to file such a bond annually, the acceptance of such an annual bond shall preclude recovery, under any such bond previously filed and accepted, whether for the term of one year or for a longer term, for any default occurring during the term of any such bond subsequently filed and accepted.