Mandatory 21-day quarantines on health care workers returning from Ebola-ravaged West Africa, like those put in place by three states, can have the unintended consequence of discouraging them from volunteering, a top federal health official said Sunday.

While Manhattan is confronting its first Ebola infection, a Liberian community on Staten Island has been following the devastating toll of the epidemic in West Africa. Hari Sreenivasan reports from “Little Liberia,” where he talks to people who have been…