Workers spray to kill fleas in a public school in Antananarivo, Madagascar's capital. A bite from an infected flea can spread the plague, which has stricken 157 people in the island nation since August.
Anadolu Agency/Getty Images
A member of the Syrian government forces watches during an evacuation of Syrian rebel fighters and civilians from a opposition-held area of Aleppo on Friday.
George Ourfalia/AFP/Getty Images
One of these candidates will be the next head of WHO. Top row from left: Tedros Adhanom Ghebreyesus, Flavia Bustreo, David Nabarro. Bottom row from left: Miklós Szócska, Sania Nishtar, Philippe Douste-Blazy.
Getty Images, AP and WHO
A government worker sprays mosquito insecticide fog in Kuala Lumpur, Malaysia, earlier this month to block the spread of Zika. The U.S. CDC advises pregnant women to reconsider plans to travel to Malaysia and 10 other countries because of the virus.