How Contagious is the Coronavirus?

A total of 148 deaths and 575 suspected cases of Ebola had been reported in the Democratic Republic of Congo and Uganda as of May 21, according to the Centers for Disease Control and Prevention. Almost all of these are in the DRC, with two confirmed cases in Uganda, including one death, from people who had traveled from the DRC. No further spread had been reported. The World Health Organization declared a public health emergency of international concern on May 17.

Ebola is a severe and often fatal disease which is spread through direct contact with blood, secretions or other bodily fluids of infected individuals or through contact with contaminated surfaces. While its basic R0, which is the measure for counting how easily disease spreads, is lower than several other diseases, transmission through close contact makes it highly dangerous in healthcare settings. According to data published by Encyclopædia Britannica, the average number of people infected by an individual with the Ebola disease (i.e. the R0 value) is 1.5 to 2.5.

By contrast, the Omicron variant of Covid-19 had a basic R0 value of spreading to eight to 10 people from every infected individual. Measles is even more contagious, with a value ranging from 12 to 18. It is spread by droplets released into the air by coughing and sneezing, with the virus able to remain in the air for up to two hours. Measles is preventable through the MMR vaccine, while Covid-19 vaccines help reduce transmission and greatly reduce the risk of severe disease.