Doctors at a hospital in Aleppo, Syria, treat a boy injured in what the government said was a chemical weapons attack on March 19. Syria's government and rebels accused each other of firing a rocket loaded with chemical agents outside of Aleppo.
A baby receives a polio vaccine at the Medina Maternal Child Health center in Mogadishu, Somalia, on Wednesday. Somalia has one of the lowest immunization rates in the world.
A health worker collects pigeons from a trap at People's Square in Shanghai, China, earlier this month. So far, workers have tested more than 48,000 animals for the H7N9 flu virus.
A vendor weighs a live chicken at the Kowloon City Market in Hong Kong Friday. Health authorities there have stepped up the testing of live poultry from China to include a rapid test for the H7N9 bird virus.
Lam Yik Fei/Getty Images
Renande Raphael, aged 16 months, is measured to check whether she is growing normally. She's part of a trial in Haiti to see if an extra daily snack of enriched peanut butter prevents stunting and malnutrition.
Alex E. Proimos/via flickr