Rukshona Saidova, 12, lives with both HIV and tuberculosis. She can't walk right now because the diseases have atrophied muscles in her legs. Jason Beaubien/NPR hide caption

itoggle caption Jason Beaubien/NPR

Nurse Tina Martin checks on Orion Qurbonaliev, 4, who has tuberculosis. Orion's grandmother, Kholbibi Abdulloeva, also has TB. Jason Beaubien/NPR hide caption

itoggle caption Jason Beaubien/NPR

Oxana and Pavel Rucsineanu walk to the tuberculosis hospital in Balti, Moldova. Oxana and their new baby live in an apartment, but Pavel still has to stay at the TB ward, fighting for his life. Jason Beaubien/NPR hide caption

itoggle caption Jason Beaubien/NPR

Michelle Williams (center) and two daughters visit the grave of her mother, Judy Williams, at Fairview Cemetery in Hyde Park, Mass., on May 11. Judy died in 2011. Ellen Webber for NPR hide caption

itoggle caption Ellen Webber for NPR

Chlorine can stop the Ebola virus. So medical workers disinfect their hands often at the Doctors Without Borders treatment center in Kailahun, Sierra Leone. Carl De Souza/AFP/Getty Images hide caption

itoggle caption Carl De Souza/AFP/Getty Images

The photographer Sebastiao Salgado, in New York City on Thursday, says we are at a "special moment" — our world now needs to be protected from climate change and other forces. Misha Friedman for NPR hide caption

itoggle caption Misha Friedman for NPR

President Obama meets with Emory University doctors and health care workers during his visit Tuesday to the Centers for Disease Control and Prevention in Atlanta. Mandel Ngan/AFP/Getty Images hide caption

itoggle caption Mandel Ngan/AFP/Getty Images

Dr. Kent Brantly was medical director at Monrovia's only Ebola treatment center when he fell ill with the disease in July. He survived after being evacuated and treated in the United States. Courtesy of Samaritan's Purse hide caption

itoggle caption Courtesy of Samaritan's Purse

Jung Ha-yoon, 2, and other children in Seoul, South Korea, enjoy playing around (and in) ceramic jars. The country's infant mortality rate dropped 91 percent between 1972 and 2012. Jacquelyn Martin/AP hide caption

itoggle caption Jacquelyn Martin/AP