WHO Statement Regarding Cluster of Pneumonia Cases in Wuhan, China
Chinese authorities have made a preliminary determination of a novel (or new) coronavirus, identified in a hospitalized person with pneumonia in Wuhan. Chinese investigators conducted gene sequencing of the virus, using an isolate from one positive patient sample. Preliminary identification of a novel virus in a short period of time is a notable achievement and demonstrates China’s increased capacity to manage new outbreaks.
Initial information about the cases of pneumonia in Wuhan provided by Chinese authorities last week – including the occupation, location and symptom profile of the people affected – pointed to a coronavirus (CoV) as a possible pathogen causing this cluster. Chinese authorities subsequently reported that laboratory tests ruled out SARS-CoV, MERS-CoV, influenza, avian influenza, adenovirus and other common respiratory pathogens.
Coronaviruses are a large family of viruses with some causing less-severe disease, such as the common cold, and others more severe disease such as MERS and SARS. Some transmit easily from person to person, while others do not. According to Chinese authorities, the virus in question can cause severe illness in some patients and does not transmit readily between people.
Globally, novel coronaviruses emerge periodically in different areas, including SARS in 2002 and MERS in 2012. Several known coronaviruses are circulating in animals that have not yet infected humans. As surveillance improves more coronaviruses are likely to be identified.
China has strong public health capacities and resources to respond and manage respiratory disease outbreaks. In addition to treating the patients in care and isolating new cases as they may be identified, public health officials remain focused on continued contact tracing, conducting environmental assessments at the seafood market, and investigations to identify the pathogen causing the outbreak.
In the coming weeks, more comprehensive information is required to understand the current status and epidemiology of the outbreak, and the clinical picture. Further investigations are also required to determine the source, modes of transmission, extent of infection and countermeasures implemented. WHO continues to monitor the situation closely and, together with its partners, is ready to provide technical support to China to investigate and respond to this outbreak.
The preliminary determination of a novel virus will assist authorities in other countries to conduct disease detection and response. Over the past week, people with symptoms of pneumonia and reported travel history to Wuhan have been identified at international airports.
WHO does not recommend any specific measures for travellers. WHO advises against the application of any travel or trade restrictions on China based on the information currently available.