China likely had first Covid case in October or November 2019, not December, UK scientists say

The study by researchers from the University of Kent in the UK also identifies when Covid-19 is likely to have spread to the first five countries outside of China.

A medical worker takes a swab sample from a man to test for coronavirus in Wuhan | Photographer: Hector Retamal | Bloomberg AFP via Getty Images | File

New Delhi: Scientists predict that the first case of Covid-19 occurred between early October and mid-November 2019 in China, most likely on 17 November.

The origins of the ongoing Covid-19 pandemic remain shrouded in mystery, with little data available on the first case. China has said that the first officially identified case occurred in early December 2019. However, reports suggest the first known case was reported in the country in mid-November.

In a study published in the journal PLOS Pathogens, researchers from the University of Kent in the UK tried to model the origin of the pandemic using a conservation science method that estimates when a species may have gone extinct.

The team repurposed a mathematical model used to determine the date of extinction of a species, based on recorded sightings of the species.

Using some of the earliest known cases that occurred in 203 countries, they used the method to determine the date when Covid-19 most likely originated.

“The method we used was originally developed by me and a colleague to date extinctions, however, here we use it to date the origination and spread of COVID-19,” David Roberts of the University of Kent said in a statement.

The analysis suggests that the first case occurred in China between early October and mid-November of 2019. The first case most likely arose on 17 November and the disease spread globally by January 2020.

These findings support growing evidence that the pandemic arose sooner and grew more rapidly than officially accepted, the researchers said.

Cases outside China

The analysis also identified when Covid-19 is likely to have spread to the first five countries outside of China, as well as other continents.

For instance, it estimates that the first case outside of China occurred in Japan on 3 January 2020 — earlier than the first officially detected case in Japan (16 January).

The first official case of Covid detected in Spain was on 30 January 2020 but the model suggests that the country had its first case on 12 January 2020. Similarly, though the US reported its first Covid case on 20 January, the model predicts that the first case likely occurred in the US on 16 January 2020.

The researchers note that their novel method could be applied to better understand the spread of other infectious diseases in the future. Meanwhile, better knowledge of the origins of Covid-19 could improve understanding of its continued spread.

(Edited by Neha Mahajan)