Where: Brazil, Venezuela, Central America, sub-Saharan Africa
Why here? Great strides have been made worldwide in fighting malaria, but medical professionals say the effects of the disease are still deeply felt in Africa. The World Health Organization says that malaria was responsible for 438,000 deaths in 2015, more than two-thirds of which were young children. Zika is a growing and uncertain threat, particularly in the Americas. In Brazil, officials say the virus has affected an estimated 1.5 million people. The WHO recently declared Zika no longer a "health emergency," but stressed that it still poses a "significant and enduring threat," that requires a long-term approach to solutions.
About these groups: Save the Children, a UK-based NGO, is nearly a century old, started in the last days of World War I to fight starvation of German and Austrian children. The Against Malaria Foundation is the top-recommended charity three years running from GiveWell, which takes a data-driven, analytical approach to charity evaluation to determine in which areas a donation can go farthest.