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International outbreak of novel SARS-CoV-2 coronavirus infection

Please note: this is a rapidly-evolving situation, so the information presented in these pages (which is in line with that provided by international authorities, like the WHO and ECDC) may not always reflect the latest available data and information.


On 31 December 2019, Chinese health authorities reported a cluster of pneumonia cases of unknown aetiology in the city of Wuhan (Hubei province, China). Many of the initial cases reported a history of exposure to Wuhan’s South China Seafood City market (a potential transmission from live animals was suspected). On 9 January 2020, the China CDC (the Chinese centre for disease control and prevention) identified a novel coronavirus (provisionally named 2019-nCoV) as the causative agent for these cases. Chinese health authorities also confirmed human-to-human transmission of the virus. On 11 February, the World Health Organization (WHO) announced that the respiratory disease caused by 2019-nCoV had been officially named COVID-19 (Corona Virus Disease 2019).


The virus responsible for the COVID-19 cases, and provisionally named 2019-nCoV by international health authorities, was eventually classified and designated as SARS-CoV-2 by the Coronavirus Study Group (CSG) of the International Committee on Taxonomy of Viruses. The CSG - which is responsible for developing the official classification of viruses and taxonomy of the Coronaviridae family - assessed the novelty of the human pathogen and, based on phylogeny, taxonomy and established practice, formally associated this virus with Severe Acute Respiratory Syndrome coronaviruses (SARS-CoVs), thus designating it as Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). To facilitate communication, the Coronavirus Study Group also proposed the following naming convention for individual isolates: SARS-CoV-2/Isolate/Host/Date/Location.


World Health Organization assessments

On 11 March 2020, after assessing the levels of spread and severity of the SARS-CoV-2 infection, the World Health Organization (WHO) declared that the COVID-19 outbreak recorded over the past months can be characterized as a pandemic, but despite that can still be controlled.


On 30 January 2020, following a second meeting of the Emergency Committee, the WHO Director-General had already declared the international SARS-CoV-2 outbreak a Public Health Emergency of International Concern (PHEIC), as defined in the International Health Regulations (IHR, 2005). You can read the relevant statement on the WHO website.


Useful resources


Page last reviewed: March 28, 2020

Publication date: January 16, 2020

Authors: Giovanni Rezza, Antonino Bella, Flavia Riccardo, Patrizio Pezzotti, Fortunato “Paolo” D’Anconae, Andrea Siddu - Dipartimento Malattie infettive, ISS