Where Did Ebola Come From?

Ebola, a rare but often fatal virus that spreads from animals to humans, was first identified in 1976. Since then, roughly 35,000 cases and more than 15,000 deaths have been reported, according to a 2020 article in Global Health: Science and Practice. Over the past 50 years, the virus has surfaced in scattered outbreaks across several countries in Central and West Africa.

Scientists first detected Ebola during a 1976 outbreak in Zaire, now the Democratic Republic of Congo (DRC), near the Ebola River. According to the World Health Organization, at the same time, a separate outbreak of the closely related Sudan virus occurred in what is now South Sudan. Both were severe. The DRC outbreak had an 88 percent fatality rate among 318 reported cases, according to the Centers for Disease Control and Prevention, while the Sudan outbreak saw a 53 percent fatality rate among 284 reported cases.

When the 1976 outbreak began, doctors initially suspected malaria, typhoid or yellow fever. According to the CDC, researchers found similarities to the Marburg virus, discovered a decade earlier, but blood samples sent to international labs revealed something new. Because the first known cases occurred near the Ebola River, researchers named the virus after it. 

The virus spread quickly in the DRC’s Yambuku Mission Hospital, where unsterilized needles were reused, infecting staff and forcing the facility to close after multiple deaths, according to The New England Journal of Medicine. “Many infected people and their contacts fled to their home villages out of fear and suspicion of the nonfunctioning Western medical system, seeking treatment from traditional healers,” the journal adds. 

According to the CDC, Ebola is caused by infection with orthoebolaviruses, a group that includes four viruses known to infect humans: Ebola, Sudan, Tai Forest and Bundibugyo. These viruses have been found primarily in sub-Saharan Africa, with mortality rates ranging from about 35 to 90 percent.

Ebola is a zoonotic disease, meaning it originates in animals. It spreads among infected wildlife, including fruit bats, primates and porcupines. 

“Infected animals can spread the virus to other animals through contact with infected body fluids or items contaminated by these fluids,” the CDC notes. It also spreads through human-to-human contact through blood or other bodily fluids or contaminated items such as bedding, needles or medical equipment.

While smaller outbreaks followed in 1976, 1977 and 1979, Ebola disappeared for 15 years, according to the journal Microbes and Infection. 

It returned with the largest-recorded Ebola epidemic, lasting from 2014 to 2016, in West Africa with more than 28,600 cases across Guinea, Sierra Leone and Liberia and a fatality rate of 39 percent. According to the CDC, weak surveillance, fragile health systems and poor infection control fueled the outbreak’s spread, prompting the WHO to declare a public health emergency. 

The world’s second-largest outbreak took place from 2018 to 2020 in the DRC, resulting in 3,481 cases and 2,299 deaths. The response was complicated by the region’s active conflict zone, which made it difficult for health workers to reach communities and maintain safe operations.   

On May 15, 2026, the DRC reported the 17th Ebola outbreak. The virus soon spread to Uganda, with more than 600 reported cases and 139 deaths as of May 20, 2026.