There's a lot going on with the little blue pill called Truvada made by Gilead Sciences of Forest City, Calif. Paul Sakuma/AP hide caption

itoggle caption Paul Sakuma/AP

A man helps his dengue fever-stricken daughter in Tegucigalpa, Honduras. In June, Honduran authorities declared a state of emergency due to the high rate of dengue cases reported around the country. Orlando Sierra/AFP hide caption

itoggle caption Orlando Sierra/AFP

Tests of cholera samples from Haiti suggest the strain behind the outbreak came from South Asia. Lawrence Livermore National Laboratory hide caption

itoggle caption Lawrence Livermore National Laboratory

Two trucks crashed on a road toward Saint-Marc in Haiti. One truck was carrying Coke bottles, the other was full of people. The head-on collision knocked the bed off the back of one truck, killing several and injuring many more. Christopher Joyce/NPR hide caption

itoggle caption Christopher Joyce/NPR

Sick cholera victims and families wait at St. Nicolas Hospital in Saint-Marc, north of Port-au-Prince. Saint-Marc residents burned down nearby tents Wednesday that were supposed to relieve pressure on the hospital. Thony Belizaire/AFP/Getty Images hide caption

itoggle caption Thony Belizaire/AFP/Getty Images