A doctor examines chest X-rays at a tuberculosis clinic in Gugulethu, Cape Town, South Africa in late 2007. The number of TB cases that don't respond to both first- and second-line medications is rising worldwide.
Karin Schermbrucker /AP
Families wait for hours to register at the Yida refugee camp in South Sudan along the northern border in early July. Within a few weeks, the population of the camp more than doubled, leading to shortages of food, water and medicine.
Paula Bronstein/Getty Images
Childhood obesity is on the rise in many countries and overuse of antibiotics is now on the radar as a possible factor in the epidemic. Here 18-month-old twins are weighed in a nutritionist's office in Colombia.
Raul Arboleda/AFP/Getty Images
Thousands of doses of cholera vaccine sit in a refrigerated trailer in a United Nations compound in Saint-Marc, Haiti, in March. After some delays, a vaccination project proved successful.
A man smokes a bidi on "No Tobacco Day," May 31, in Allahabad, India. These small, hand-rolled cigarettes are popular in India and Bangladesh because they are far cheaper than regular cigarettes.
Bill Gates, co-founder of the the Bill & Melinda Gates Foundation, checks out a toilet demo at the Reinvent the Toilet Fair in Seattle, Wash. The festival featured prototypes of high-tech toilets developed by researchers around the world.
Bill & Melinda Gates Foundation
Care managers tend elderly people in March 2012 in Minamisoma, Japan. The home's residents were evacuated eight days after the Fukushima Dai-ichi nuclear power station was crippled by the March 11, 2011 tsunami.