David Livermore, the director of the Antibiotic Resistance Monitoring and Reference Laboratory in London, studies a new class of superbugs, called carbapenem-resistant Enterobacteriaceae, or CRE. Suzanne Plunkett/Reuters /Landov hide caption

itoggle caption Suzanne Plunkett/Reuters /Landov

A Cambodian boy gets tested for malaria at a clinic along the Thai-Cambodian border in 2010. Three strains of drug-resistant malaria have emerged from this region over the past 50 years. Paula Bronstein/Getty Images hide caption

itoggle caption Paula Bronstein/Getty Images

A public health poster from 1952 encourages Americans to get checked for sexually transmitted diseases. Gonorrhea is the second-most-common sexually transmitted disease in the U.S., with more than 300,000 cases reported in 2011. Images from the History of Medicine hide caption

itoggle caption Images from the History of Medicine

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

Dr. Aun Pyae Phyo examines a baby at the Whampa malaria clinic on the Thailand-Myanmar border. Ben de la Cruz/NPR hide caption

itoggle caption Ben de la Cruz/NPR

Health workers take a blood sample from an infant to test for the malaria at a clinic along the border between Thailand and Myanmar. Ben de la Cruz/NPR hide caption

itoggle caption Ben de la Cruz/NPR

This 5-year-old boy was carried to a Thai malaria clinic by his mother from deep inside Myanmar. If the mother had waited even a day longer, doctors say, the child probably would have died. Ben de la Cruz/NPR hide caption

itoggle caption Ben de la Cruz/NPR

Daw Khin Twon, an undocumented immigrant from Burma, rests at home after receiving malaria treatment at the Mae Tao Clinic in Mae Sot, Thailand. Ben de la Cruz/NPR hide caption

itoggle caption Ben de la Cruz/NPR

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 hide caption

itoggle caption Karin Schermbrucker /AP