The World Health Organisation (WHO) said that the coronavirus originated in animals, but found it 'unlikely' that it was introduced to humans directly by bats.
It also said it was 'extremely unlikely' that the virus escaped from a Chinese lab.
Transmission could have also taken place beyond the wet market in Wuhan, central China, where the virus was thought to have emerged.
"The first cases were reported at the market. However, in other areas of Wuhan, transmission was also occurring," Liang Wannian, an expert with China’s Health Commission, said as the WHO's findings in Wuhan after a near month-long visit were announced.
Mr Liang said there was no substantial spread of the virus in Wuhan before the 2019 outbreak.
The WHO said that bats were not necessarily directly responsible for transmitting the virus to humans.
“All the work that has been done on the virus and trying to identify its origin continue to point towards a natural reservoir of the virus in bat populations," said Peter Karim Ben Embarek, programme manager at the WHO.
"But since Wuhan is not an environment for bats, the direct jump from a bat to the city of Wuhan is unlikely, so we have looked to see what other species could have introduced the virus in particular in the market."
Mr Liang said the coronavirus was circulating before the initial cases were reported in Wuhan.
The WHO also said that a laboratory being responsible for the virus' spread to humans was extremely unlikely.
There was no indication of coronavirus transmission before December 2019, the WHO said.
There is evidence of some spread at the seafood market in December but it’s “not the whole story,” said the WHO, which mapped the spread of the virus among earlier cases linked to the market and used genetic sequencing to identify the nature of the transmission.
“We know there was a spread of the virus among individuals who were not linked to the market so the picture is not clear… But the spread through frozen foods is not ruled out as some of the frozen wild animals are known reservoirs of Covid.”
While lab accidents do happen, they are extremely rare, Mr Embarek said. “We also looked at the Wuhan Institute of Virology and the state of that laboratory and it was very unlikely that anything could escape from such a place.”
"The findings suggest that the laboratory incident hypothesis is extremely unlikely in explaining the introduction of the virus into the human population, therefore, we do not suggest further work into that hypothesis for understanding the virus," Mr Embarek said.
Investigations showed that the virus was spreading beyond Wuhan and that these cases were missed.
"Based on research done on the virus from other studies around the world, the data suggests there was circulation preceding the initial cases and those cases that were missed were already circulating in other regions," Mr Liang said.
"We have also conducted research among 233 health institutions in Wuhan by searching records of those who had been sick based on their symptoms in the period of October 1 to December 10, 2019 and have reviewed the testing of blood obtained from the data banks and tested antibodies in blood samples," he said.
Around 50,000 samples from 30 species of wild animals have also been tested and all were negative, he added.
-
A woman wearing a face mask rides a bicycle with a child, following an outbreak of the coronavirus disease in Wuhan, Hubei province, China. Reuters -
Britain's Prime Minister Boris Johnson visits SureScreen Diagnostics, amidst the coronavirus disease outbreak, in Derby, Britain. Reuters -
Choir members sing during the Sunday mass without wearing masks and social distancing at Ufunuo na Uzima Church in Dar es Salaam. For more than six months, Tanzania has tried to convince the world it has been cured of the coronavirus, through prayer, while refusing to take measures to curb its spread. However dissent is mounting along with deaths attributed to "pneumonia", with even a politician in semi-autonomous Zanzibar admitting he has the virus. AFP -
A woman lifts a funeral display into a car in the flower district as the coronavirus disease (COVID-19) outbreak continues, ahead of Valentine's Day in Los Angeles, California, U.S. Reuters -
French Health Minister Olivier Veran receives a dose of the AstraZeneca-Oxford Covid-19 vaccine at the South Ile-de-France Hospital Group, in Melun, on the outskirts of Paris, during an AstraZeneca vaccine injections campaign for people under the age of 65. AFP -
A patient is given a Covid-19 vaccination in a pop-up vaccination site at the Abyssinian Baptist Church in the Harlem neighborhood of New York, New York, USA. According to data about New York State vaccination rates released last week, thirteen percent of the state's 65-years-old or older population is African-American, but only 4 percent have received the COVID-19 vaccine, numbers that Governor Andrew Cuomo has connected to less access to vaccinations and a distrust in government vaccinations. EPA -
A woman thanks god after being vaccinated against covid-19 at a drive-in center in Sao Paulo, Brazil. A drive-in center to vaccinate elders against covid-19 went into operation at the Pacaembu stadium in Sao Paulo, as part of a health program against the pandemic. EPA -
People wearing face masks to protect against the spread of the coronavirus walk through China Town in Yokohama, Kanagawa prefecture, near Tokyo. AP -
Contest winners celebrate at the end of a competition where they were selected as this year's Carnival characters: Pepino, right, Chola, center, and Chuta, all of whom represent gaiety in La Paz, Bolivia. The winning trio of Carnival must be adept at spreading happiness and never tire of dancing, however due to the COVID-19 pandemic, their performances will be broadcast online, and parades have also been canceled. AP -
A group of operators of coin-operated unmanned karaoke rooms, called 'coin noraebang', stages a protest against the government's quarantine guidelines in Seou, South Korea. Protesters called for the lifting of curbs on their businesses amid the COVID-19 pandemic. EPA
