United Nations Aids Executive Director Michel Sibide hugs Secretary of State Hillary Clinton after they they presented the a road map for stopping HIV around the world.
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An artistic model of a coronavirus infecting a cell. The family of viruses can cause mild infections, like the common cold, and severe pneumonia-like infections, such as SARS.
Last year, Tom Mather caught 15,000 deer ticks in the woods of southern Rhode Island. "People really need to become tick literate," the University of Rhode Island researcher says.
Brian Mullen for NPR
Students paste red ribbons on a window to mark World AIDS Day in Nanjing, China, in 2006. Between 2007 and 2011, the number of newly diagnosed HIV cases in China has nearly quadrupled to 40,000.
Lyme disease is spread by deer ticks like this one. A study finds that some people can be reinfected many times with the bacteria that cause the disease.
Lauree Feldman/Getty Creative Images
Mosquitoes are sorted at the Dallas County mosquito lab in Dallas, Texas on Aug. 16, 2012. Dallas County has seen the highest number of cases of West Nile virus of any county in Texas: 379 this year, as of Oct. 25.
LM Otero/ASSOCIATED PRESS
When a case of the potentially lethal H5N1 bird flu was found in British poultry in 2007, Dutch farmers were told to keep their poultry away from wild birds by closing off outdoor areas with wire mesh.
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