A boy with symptoms of cholera waits for treatment at the St. Catherine hospital in Cite Soleil in Port-au-Prince on Nov. 10, 2010. Cholera has sickened more than 91,000 Haitians and killed more than 2,000. Ramon Espinosa/AP hide caption

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In Oxford, England, people are 16 times more likely to get a particular kind of hip replacement than residents of London. Wikimedia Commons hide caption

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Two sisters rest under a mosquito net during a July monsoon rain in Prey Mong kol village in Cambodia's Pailin province. Paula Bronstein/Getty Images AsiaPac hide caption

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A 10-year-old Somali boy being treated for meningitis in May 2009 at a makeshift clinic in Mogadishu. ROBERTO SCHMIDT/AFP hide caption

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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

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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