Even some euro bank notes may need a good scrubbing. Like dollar bills, these notes are made from cotton and they harbor an array of bacteria. Thomas Leuthard/The Preiser Project/Flickr hide caption

itoggle caption Thomas Leuthard/The Preiser Project/Flickr

An Egyptian Muslim prays during a ritual in Mina, Saudi Arabia, October 2013. Some people wore masks during the hajj pilgrimage last year to protect against the Middle East Respiratory Syndrome. Amr Nabil/AP hide caption

itoggle caption Amr Nabil/AP

Rose Komano, 18 and the mother of three, was the first Ebola patient to overcome the virus in southeastern Guinea, the epicenter of the outbreak. On April 3, she posed at a health clinic in the Gueckedou region. Misha Hussain /Reuters /Landov hide caption

itoggle caption Misha Hussain /Reuters /Landov

Street vendors sell chickens at a market in Phnom Penh, Cambodia, in early 2013. Last year Cambodia reported more cases of H5N1 bird flu than any other country. Mak Remissa/EPA /LANDOV hide caption

itoggle caption Mak Remissa/EPA /LANDOV

Advocates demonstrate in favor of cheaper generic drugs to treat hepatitis C in New Delhi on March 21. The disease is common among people who are HIV positive. Saurabh Das/AP hide caption

itoggle caption Saurabh Das/AP

The new normal in Guinea is washing hands with a mixture of water and bleach--shown here at the border entrance of Buruntuma, in the Gabu area on Tuesday. Tiago Petinga/EPA /LANDOV hide caption

itoggle caption Tiago Petinga/EPA /LANDOV

This one's virus-free: Matthew Followill, Nathan Followill and Caleb Followill of Kings of Leon performed in Los Angeles in December. Kevin Winter/Getty Images for Radio.com hide caption

itoggle caption Kevin Winter/Getty Images for Radio.com

Eight-year-old Manish, who caught polio years ago, learns to walk with leg braces at a rehabilitation center in New Delhi on Thursday. Manish Swarup/AP hide caption

itoggle caption Manish Swarup/AP

The fatality rate in an Ebola outbreak ranges from 25 percent to 90 percent, depending on the particular strain of the virus involved. Cynthia Goldsmith/ Centers for Disease Control and Prevention hide caption

itoggle caption Cynthia Goldsmith/ Centers for Disease Control and Prevention