The prevailing means of transmission is via virus-containing microdroplets expelled when someone who is infected either sneezes or coughs. According to the U.S. Centers for Disease Control and Prevention, genetic material of SARS-CoV-2, the virus responsible for COVID-19, has been found in fluids in both the upper and lower respiratory tract, meaning that the saliva and mucus of an infected person is likely to contain the virus.
Less is known about other body fluids and products. One recent study from Sun-Yat Sen University in China found that genetic material from the virus is present in fecal samples from infected individuals. The CDC agrees that fecal transmission is possible and also reports that infectious SARS-CoV-2 has been found in blood. Even less is known about other bodily fluids, including urine, vomit, breast milk and semen. But CDC guidance for people who are sick and not hospitalized is nonetheless to “clean and disinfect all surfaces that may have blood, stool or other body fluids on them.”—Jeffrey Kluger