The place where a disease breaks out is not necessarily the place of disease origin.Graphic: Huo Siyu/Global Times

The supply chains to Huanan market included cold-chain products and animal products from 20 countries, including those where samples have been reported as positive for SARS-CoV-2 before the end of 2019 and those where close relatives of SARS-CoV-2 are found. Graphic: Huo Siyu/Global Times

Introduction through a laboratory incident was considered to be an extremely unlikely pathway. Graphic: Huo Siyu/Global Times

Some of the suspected positive samples were detected even earlier than the first case in Wuhan, suggesting the possibility of missed circulation in other countries. Graphic: Huo Siyu/Global Times

Suggestions on the next phase of virus origins tracing as listed in the joint WHO-China report. Suggestion 1: Conduct further retrospective and systematic research around earlier cases and possible hosts for SARS-CoV-2 around the world.Graphic: Huo Siyu/Global Times

Suggestions on the next phase of virus origins tracing as listed in the joint WHO-China report. Suggestion 2: Continue to develop an integrated database that includes global SARS-CoV-2 genome and raw sequences with epidemiological and clinical data, and linked analysis results. Graphic: Huo Siyu/Global Times

Suggestions on the next phase of virus origins tracing as listed in the joint WHO-China report. Suggestion 3: Help tracing the origin of SARS-CoV-2 and the closest common ancestor to the virus, including analysis of trade and history of trade in animals and products in other markets.Graphic: Huo Siyu/Global Times

Suggestions on the next phase of virus origins tracing as listed in the joint WHO-China report.Suggestion 4: Trace the cold chain product supplier countries where SARS-CoV-2 positive testing was preliminarily reported before the end of 2019. Graphic: Huo Siyu/Global Times