It is estimated that every three seconds, a child death is prevented thanks to care provided by a frontline health worker. But many don't have all the support and supplies they need to do their jobs well, and hundreds of thousands more are needed to end preventable deaths.

He doesn't run a large company, lead a government agency or record the music he so loves on a major label. But 8-year-old J.D. Malkin has quite a voice.

Frontline health workers are really the backbone of effective health systems in developing countries. These workers are members of the community who live in the communities they serve and understand the needs as well as the barriers to achieving optimal health.

What sets Florence Nightingale, Dr. Quinn, Medicine Woman, and Heathcliff Huxtable apart from other famous health workers like Dr. House or Doogie Howser, M.D.? Tied to this answer is the key to addressing some of the world's greatest health challenges.