The Secretary or his delegate may, pursuant to section 214(d) of the Public Health Service Act, 42 U.S.C. 215(d), and with the consent of the officer or employee concerned, arrange, through agreements or otherwise, for a civilian officer or employee of the Public Health Service to be placed on leave without pay for the period of a detail to a State, a subdivision thereof, or a private non-profit institution and be paid by the non-Federal organization. Such an arrangement may be for a period of not to exceed 2 years, but may be extended for additional periods of not to exceed 2 years each.