New Delhi: US President Joe Biden is the latest to join an increasingly vocal section of experts and leaders calling for a more thorough investigation into the origins of Covid-19. Biden Wednesday called for a “deeper US intelligence investigation” into the origins, once again fanning the theory that the virus is not natural and leaked from a laboratory.
This comes just days after a report in the Wall Street Journal, an American daily, revealed that three researchers at the Wuhan Institute of Virology fell sick and had to be hospitalised a month before Covid-19 cases were officially registered in December 2019.
However, immunologist Dr Anthony Fauci — who has been credited with leading the US’ fight against Covid — cautioned that uncertainty about the virus origins is likely to persist.
“He also warned that uncertainty may persist, noting that the origin of the 2014 Ebola outbreak still isn’t fully understood,” a BloombergQuint report notes.
ThePrint looks at what happened in 2014 and what is known about the Ebola outbreak.
What happened in 2014
While the Ebola virus was first recognised in humans in 1976 as cases of hemorrhagic fever were reported in Sudan and Zaire, west African countries reported its worst-ever outbreak between 2014 and 2016.
On 26 December 2013, an 18-month-old boy in Guinea’s Meliandou developed fever, black stools and vomiting, and succumbed to them two days later.
By January 2014, several members of his family had begun developing similar symptoms and met the same fate as the baby boy. “The same was true for several midwives, traditional healers, and staff at a hospital in the city of Gueckedou who treated them,” the World Health Organization (WHO) noted.
By now, cases had spread to at least four sub-districts and all those who had attended funerals also fell sick and succumbed to the virus.
However, it had still not been categorised as an outbreak.
“The exact source of this infection has not been identified but likely involved contact with wild animals,” said WHO, echoing Dr Fauci’s statement about the persisting uncertainty seven years later.
The 18-month-old boy was reportedly seen playing around a hollow tree infested with bats.
The Meliandou village has just 31 households and falls under the forest region of the Gueckedou district. Foreign mining and timber operations have destroyed over 80 per cent of the flora and “brought potentially infected wild animals, and the bat species thought to be the virus’ natural reservoir, into closer contact with human settlements.”
The WHO publicly announced an Ebola outbreak only on 23 March 2014, when 49 cases and 29 deaths had been officially reported.
However, this was preceded by major investigations by international organisation Médecins Sans Frontières (MSF) or Doctors Without Borders, WHO’s Regional Office for Africa and Guinea’s health ministry.
The first such investigation was conducted by a small team of local health officials in January 2014. Upon recording symptoms such as diarrhoea, vomiting, and severe dehydration, they believed it was a cholera outbreak — “one of the area’s many endemic infectious diseases” — but no concrete evidence to support this claim was found.
Later, a successive microscopic examination conducted by MSF found bacteria in the samples tested “supporting the conclusion that the unknown disease was likely cholera.”
Since no one considered it to be Ebola, cases continued to spread as no protective measures were taken. Even a major joint investigation conducted by the Guinea’s Ministry of Health, WHO AFRO, and MSF covering several districts only “found epidemiological links among outbreaks previously not known to be connected and identified Gueckedou City as the epicentre for transmission of a disease that still had no known cause”.
It was not until 21 March 2014, when France’s Institut Pasteur in Lyon — a WHO Collaborating Centre — confirmed a filovirus to be the causing agent, “narrowing the diagnosis down to either Ebola virus disease or Marburg hemorrhagic fever.”
On 22 March, the lab confirmed it to be the “most lethal virus in the Ebola family” — Zaire.
How is Ebola transmitted and the uncertainty of its origin
The Ebola virus is found in animal reservoirs and can be transmitted to humans in the case of “inadvertent contact”.
Once the zoonotic transmission takes place, the virus is extremely contagious. Between humans, the virus spreads only by direct contact with blood or bodily fluids. The virus can enter the body through the nose, mouth, eyes, open wounds or cuts on the skin.
“Because Ebola virus can trigger a massive inflammatory response, and its viral proteins mediate immune evasion processes, the infection can result in great lethality,” Dr Michael Gale Jr, a professor of immunology at the University of Washington School of Medicine and director of the UW Center for Innate Immunity and Immune Disease, writes.
While WHO — like Fauci — maintains uncertainty about the origin of the 2014 Ebola outbreak, several bodies including the US’ National Center for Biotechnology Information and the Centre for Disease Control and Prevention cite retrospective studies to suggest that the 18-month-old boy was “infected by contact with insectivorous bats”.
By the time, the international public health emergency ended in June 2016, over 28,000 people had been infected and more than 11,000 had died as the disease spread from Guinea to Liberia, Sierra Leone, the UK, US, Spain, Senegal, Italy, Mali and Nigeria.