An artist on Rio de Janeiro's Copacabana beach puts the final touches on a sand sculpture of the assassin bug, which spreads Chagas disease. The sculpture was part of an event in 2009 commemorating the 100th anniversary of the discovery of the disease. Vanderlei Almeida/AFP/Getty Images hide caption

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A nurse weighs an Afghan child at a U.S.-funded clinic in Farza, Afghanistan, in September. A new U.S.-sponsored survey shows dramatic gains in life expectancy and other aspects of health care in Afghanistan. But some experts are questioning the accuracy of the results. John Moore/Getty Images hide caption

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An Indian boy receives a polio vaccination from an Indian health worker in Amritsar last year. Narinder Nanu/AFP/Getty Images hide caption

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An image of Mycobacterium tuberculosis bacteria captured with an electron microscope. CDC hide caption

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Snake handler Subhendu Malllik holds up an Indian baby cobra hatchling after it emerged from an egg on the outskirts of Bhubaneswar, India, in June. The venomous snake is indigenous to South Asia. Asit Kumar/AFP/Getty Images hide caption

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