60 Fun Facts About Ebola

Ebola is named after a river in which present-day country?

The 1976 Yambuku outbreak happened near the Ebola River in what was then Zaire.

Which animals are believed to be the natural host of ebolaviruses?

They can carry and spread the virus without getting sick; three species of fruit bat were found to be likely carriers.

How many known ebolaviruses are there, and how many of them are dangerous to humans?

Reston and Bombali viruses are the two not thought to make people ill.

Ebola outbreaks have had death rates between 25% and 90%; roughly what is the average?

Which virus is involved and how quickly treatment starts make a big difference to the odds.

What is Ebola's maximum incubation period, the standard monitoring window for contacts?

Symptoms usually appear within 4 to 10 days; models suggest around 5% of cases may take longer than three weeks.

How does Ebola spread between people?

There are no documented cases of airborne spread between humans, and no spread by insects has been reported.

Ebola virions are filamentous particles that may appear in the shape of what?

They can also look like a 'U' or a '6', and may be coiled or branched; particles are 80 nanometres wide but up to 14,000 long.

How many genes does an ebolavirus genome contain?

The genome is single-stranded RNA and codes for seven structural proteins including the glycoprotein spike that lets it enter cells.

Ebolaviruses are most closely related to which other family of haemorrhagic fever viruses?

The 1976 samples were initially thought to be a new strain of Marburg virus before being recognised as something new.

Which ebolavirus is considered the most dangerous and responsible for the most outbreaks?

It caused the 1976 Yambuku outbreak, the West African epidemic and the Kivu epidemic.

Which two ebolaviruses are not thought to cause disease in humans?

Both have caused disease in other primates, and Reston virus can also infect pigs.

Which two of Ebola's structural proteins play the key role in blocking the body's interferon response?

VP24 stops the STAT1 signal reaching the nucleus and VP35 directly inhibits interferon-beta, letting the virus race ahead of the immune system.

Which type of immune cell is the first to be infected by Ebola virus?

The infection triggers programmed cell death and carries the virus to nearby lymph nodes.

For how long can Ebola virus persist in the semen of a male survivor?

Survivors are advised to use condoms for at least a year or until two negative tests, and the virus was found in one man's eye two months after his blood was clear.

In the worst-hit West African country in 2014, what share of Ebola infections came from burial rituals?

Dead bodies remain infectious, which is why safe burial teams became a central part of every response.

Which farm animal can transmit Ebola to primates without contact, as the virus concentrates in its lungs?

Humans and other primates carry the virus mainly in their blood, not their lungs, which is why airborne spread between people has not been seen.

The first case of the 1976 Yambuku Ebola outbreak had just returned from a trip near the border of which country?

Mabalo Lokela had visited the Ebola River on that trip; he was first treated for malaria with quinine and died 14 days after his symptoms began.

According to Peter Piot, how did the nuns at Yambuku Mission Hospital inadvertently spread the 1976 outbreak?

The outbreak lasted 26 days; the quarantine, the locals' precautions and stopping the injections were all credited with ending it.

Which Congolese doctor took the blood sample from a Belgian nun that Peter Piot used to identify the virus?

He is also credited as the first scientist to come into direct contact with the disease and survive.

What was the fatality rate of the 1976 Zaire outbreak, in which 280 of 318 patients died?

The Sudan outbreak the same year, caused by a different ebolavirus, killed 151 of 284 people.

The 1976 Sudan outbreak began with a storekeeper at a factory in the town of Nzara that processed what?

That first case was hospitalised on 30 June and died on 6 July; the outbreak went unrecognised until the Zaire cases some months later.

The prototype Ebola virus variant 'Mayinga' is named after whom?

Mayinga N'Seka's name lives on in the lab strain, and Tom Clancy borrowed it for the airborne 'Ebola Mayinga' of his novel Executive Orders.

The 2003 DRC outbreak set the record for the highest Ebola death rate. What was it?

It infected 143 people and killed 128; by contrast the West African epidemic's fatality rate was around 40%.

In which country was a new ebolavirus species identified during a 2007 outbreak?

Bundibugyo virus was tentatively named after the district; it has caused only one other outbreak, in eastern DRC in 2012.

How did a Russian scientist die of Ebola in 2004?

Ebola had earlier been investigated by the Soviet Biopreparat programme for possible weaponisation.

The 2013-16 West African epidemic was traced to a toddler who died in December 2013 in which country?

The boy, later identified as Emile Ouamouno, lived in the village of Meliandou; his mother, sister and grandmother died soon after.

Roughly how many people were infected in the West African epidemic, the largest ever recorded?

The WHO counted 11,323 deaths as of May 2016 and warned that even those numbers were probably underestimates.

On what date in 2014 did the WHO declare the West African epidemic an international emergency?

Its Director-General said the affected countries 'simply do not have the capacity to manage an outbreak of this size and complexity on their own'.

In 2014 the WHO reported that what share of the epidemic's dead were healthcare workers?

Working closely with patients' body fluids made them especially vulnerable; a later CDC report put Guinean health workers' infection rate at 42 times that of others.

Whom did Time magazine name Person of the Year for 2014?

Editor Nancy Gibbs praised 'a group of men and women willing to stand and fight'; survivor-turned-nurse Salome Karwah was among the health workers on the covers.

Thomas Eric Duncan, the first person diagnosed with Ebola in the US, had flown to which state?

He was sent home from hospital on his first visit, returned four days later and died on 8 October 2014; two nurses who treated him were infected and recovered.

The first transmission of Ebola outside Africa involved a nurse in which country?

Teresa Romero caught it caring for a priest repatriated from West Africa; she tested negative on 20 October 2014.

British nurse Pauline Cafferkey was diagnosed with Ebola in 2014 after returning from which country?

She was flown to RAF Northolt and treated in the Royal Free Hospital's high-level isolation unit, and was readmitted to hospital several times in later years.

The New York doctor who tested Ebola-positive in October 2014 had been volunteering with which organisation?

Craig Spencer recovered and was discharged from Bellevue Hospital on 11 November.

How many days without new cases must pass before the WHO declares an Ebola outbreak over?

That is twice the maximum incubation period; a 90-day period of heightened surveillance usually follows.

The 2018-2020 Kivu epidemic was notable as the first Ebola outbreak to occur in what kind of setting?

Armed groups fighting over mineral wealth around Beni repeatedly attacked treatment centres and forced vaccinations to be suspended.

A July 2019 Ebola case in which city led the WHO to declare the Kivu outbreak a global emergency?

The man had passed through three health checkpoints under different names; Rwanda briefly closed the border that runs along the city's edge.

Per a 2018 Lancet survey, what share of Beni and Butembo respondents believed Ebola was a hoax?

Those beliefs correlated with people being less willing to seek care or accept vaccination.

Under what brand name is the rVSV-ZEBOV Ebola vaccine sold?

It is a vesicular stomatitis virus engineered to carry an Ebola surface glycoprotein; the two-dose Zabdeno/Mvabea regimen came from Johnson & Johnson and was withdrawn in 2026.

The 2015 trial that proved the Ebola vaccine used which strategy borrowed from smallpox eradication?

Closest contacts of each new case were vaccinated either immediately or after 21 days; the immediate group had no cases after day ten.

Which country's national institution first developed the rVSV-ZEBOV vaccine?

The European Commission authorised it in November 2019 and WHO prequalification followed within 48 hours, the fastest ever.

How soon after injection does the rVSV-ZEBOV vaccine appear to give full protection?

Around 345,000 people received it during the Kivu epidemic under a compassionate-use protocol.

Ansuvimab, approved in December 2020 under the brand name Ebanga, is what kind of treatment?

It only has documented efficacy against Zaire ebolavirus, not against Sudan virus, which is why the 2022 Uganda outbreak was so hard to treat.

Which two common painkillers does the WHO advise avoiding for Ebola patients because of bleeding risk?

Care is mostly supportive: rehydration by mouth or drip, plus treatment for fever, nausea, pain and anxiety.

How long does boiling take to destroy ebolaviruses?

Heating at 60 degrees Celsius for 30 to 60 minutes also works, as do bleach and alcohol-based disinfectants.

At which biosafety level must Ebola virus be handled?

The CDC also lists it as a Category A bioterrorism agent, though it becomes ineffective quickly in open air, limiting its use as a weapon.

Richard Preston's The Hot Zone dramatised an Ebola outbreak among lab monkeys where?

The 1989 incident involved a shipment of crab-eating macaques; six animal handlers seroconverted but none fell ill.

From which country had the lab monkeys in the 1989 outbreak that inspired The Hot Zone been imported?

The strain, later named Reston virus, has since turned up in monkeys in Pennsylvania, Texas and Italy, and in pigs.

Repeated Ebola outbreaks are thought to have killed roughly how many gorillas?

Chimpanzee tracking indices in one Congolese sanctuary fell 88% between 2002 and 2003; eating infected meat, not grooming, is the main risk for chimps.

A 2005 survey found that dogs near an Ebola outbreak carried antibodies to the virus but showed what?

About 32% of dogs closest to the outbreak had been exposed, versus 9% farther away, probably from scavenging infected carcasses.

Which ebolavirus caused a 2022 East African outbreak with no vaccine available?

The licensed vaccine and antibody treatments target Zaire ebolavirus only, which left responders with supportive care alone.

Which ebolavirus caused the 2026 epidemic declared in the DRC's Ituri province?

It was the DRC's 17th Ebola epidemic; the WHO declared it a Public Health Emergency of International Concern just two days after it was announced.

Which eye problem is the most common eye complication in Ebola survivors?

The virus can persist in the eye long after the blood is clear; light sensitivity, excess tearing and vision loss have all been described.

Death from Ebola, when it occurs, is most often due to what?

It typically comes six to sixteen days after symptoms begin, which is why early rehydration makes such a difference to survival.

How many physicians did Liberia have for its whole population when Ebola struck in 2014?

That worked out to one doctor for every 70,000 citizens, and some hospitals were abandoned outright.

Which was the first African country declared Ebola-free during the West African epidemic?

The WHO called it a 'spectacular success story', crediting the early quarantine work of Dr Ameyo Stella Adadevoh.

In which Malian city was the country's first Ebola case, a two-year-old girl, confirmed in 2014?

She had arrived from Guinea and died the next day; her father had worked for the Red Cross there.

In July 2015, three new Liberian Ebola cases had all shared a meal of what, prompting an investigation?

Tests on the animal's remains came back negative for the virus.

Which Liberian president ordered the country's borders closed on 27 July 2014?

A few crossing points such as Roberts International Airport stayed open with screening centres.

How much productivity did the World Bank project the three worst-hit countries would lose to Ebola?

In Liberia's Montserrado County up to 20% of firms closed, with restaurants hit hardest.