A dust storm moves across the barren plains of northern Kenya in March 2006. Viruses are swept up into the atmosphere via dust storms and ocean spray, and then fall back down to the surface.
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Some viruses are already known to spread through sexual contact. But for others, doctors don't have a clue about the possibility of infecting a partner via sex.
Andrzej Wojcicki/Science Source
In 2003, Acanthamoeba polyphaga mimivirus, also known as mimivirus, was the first giant virus to be described. It's larger than many bacteria, and was found in a water sample from a hospital cooling tower in England.
Didier Raoult/Science Source
Once called the "Dutchmen" because of their large noses and large bellies, proboscis monkeys live only in Borneo. Ecosystems that have a lot of diverse animals, like this monkey, also tend to have a lot of diverse viruses.
These are insect cells infected with the Guaico Culex virus. The different colors denote cells infected with different pieces of the virus. Only the brown-colored cells are infectious, because they contain the complete virus.
Michael Lindquist/Cell Press