Ebola: End of an Epidemic?

The Ebola outbreak in West Africa is over. The World Health Organization has announced that no new cases have developed in Liberia for 42 days. That time frame is key because it means that for two 21-day incubation cycles, the last known case tested negative for the disease. Mayo Clinic infectious disease specialist Dr. Pritish Tosh says, "While this is very good news, more work needs to be done to advance the public health infrastructure in developing nations.