Don't just sneeze without a tissue! That's the message of this early pandemic era graffiti in Dakar, Senegal. The World Health Organization has just issued an updated report on the way SARS-CoV-2 spreads. Take our quiz to see if you're up on your COVID terminology. Seyllou/AFP via Getty Images hide caption
Globally, there are more than 400 million UTIs a year. This illustration depicts the most common kind of UTI—bladder (blue) inflammation caused by E. coli (red). TUMEGGY/Getty Images/Science Photo Library hide caption
A patient infected with chikungunya looks out from mosquito netting at a hospital in San Lorenzo, Paraguay. The country has counted over 100,000 cases of the mosquito-borne virus this year. Jorge Saenz/AP hide caption
This undated photo made available by the Centers for Disease Control and Prevention shows a strain of Candida auris cultured in a petri dish. Shawn Lockhart/AP hide caption
In the video game and HBO show The Last of Us, an infectious fungi turns humans into zombies. David McNew/Getty Images hide caption
Staff volunteers queue to receive a fourth dose of the Pfizer COVID-19 vaccine at Sheba Medical Center in Israel on Dec. 27, 2021, as the hospital conducted a trial of a fourth jab of the vaccine. Jack Guez/AFP via Getty Images hide caption
There's increasing emphasis on wearing masks while flying. How much protection do they offer against COVID-19? James D. Morgan/Getty Images hide caption
Outdoor dining in Bonn, Germany. Indoor dining is riskier than outdoor meals, experts say. Outdoor air can disrupt viral particles that have been expelled. Andreas Rentz/Getty Images hide caption
Minks at a mink farm. Yuri Tutov/AFP via Getty Images hide caption
Childhood infections may increase the risk of developing certain mental illnesses in childhood and adolescence. Kathleen Finlay/Getty Images/Image Source hide caption
Sheila Dhand, a wound care nurse, treats many people who use drugs via mobile unit. Elana Gordon / WHYY hide caption
Kristopher Kelly near his home in Concrete, Wash., in February. He broke his pelvis and all his ribs in a work accident last year. The resulting infection he developed in the hospital almost killed him. Ian C. Bates for NPR hide caption
A 4-year-old regulation in New York state requires doctors and hospitals to treat sepsis using a protocol that some researchers now question. Getty Images/iStockphoto hide caption
A newborn has its umbilical cord cut after birth in a Nigerian hospital. In a contest last week, MBA students came up with plans to get moms and dads to use an antiseptic on the cord stump to ward off infection. Courtesy of Karen Kasmauski/USAID's flagship Maternal and Child Survival Program hide caption
Four days after Rory Staunton cut himself in gym class, he died from septic shock. Courtesy of Rory Staunton Foundation hide caption
Brazilian soldiers go house to house as they attempt to eradicate the larvae of the mosquito that causes the Zika virus. Mario Tama/Getty Images hide caption
A copper bedrail can kill germs on contact. Courtesy of CopperBioHealth hide caption