Coronavirus 2019-nCoV
A new strain of coronavirus, named 2019-nCoV, was first reported in China on December 31, 2019. The new strain was identified by next generation sequencing (NGS) of cultured virus and directly from samples received from several pneumonia patients. A Chinese government-appointed expert stated on January 20, 2020, that more than 200 human cases of pneumonia have been reported. At least three people have died and nine others are critically ill. The outbreak was originally linked to the Hunan Seafood Market in Wuhan City, Hubei Province. Besides seafood, the market also sold live poultry and exotic animal meats. The early cases suggested a primary zoonotic source. However, the illness has also affected people who were not exposed to the market. One patient infected 14 medical personnel. Cases have subsequently been reported in Beijing, Shanghai and Shenzhen, which are hundreds of miles from Wuhan. Cases have also been identified in Thailand, Japan and South Korea, involving people who visited Wuhan, China. These developments are consistent with human to human transmission.
Millions of Chinese are traveling for the Lunar New Year holiday, greatly increasing the likelihood of viral spread on a broader scale. The severity of the outbreak will largely depend on how many people a viral carrier can infect.
Coronaviruses are a large family of viruses that circulate among animals, including camels, cats and bats. Coronaviruses derive their name from their electron microscopic image which resembles a crown or corona. Six strains of coronavirus have infected humans. The most notable recent examples include MERS and SARS, which spread from person to person and caused major pandemics. The SARS pandemic originated in southern China in 2002, infected more than 8,000 people globally and caused some 800 deaths. The MERS pandemic emerged in Saudi Arabia in 2012 and infected approximately 2,500 people and caused 850 deaths.
European guidelines recommend that any person fulfilling the epidemiological and clinical criteria should be tested for 2019-nCoV. Epidemiological criteria include any person with travel-history to Wuhan City, China in the 14 days before the onset of illness or any person being in close contact with a laboratory-confirmed case of 2019-nCoV in the 14 days before the onset of illness.
Clinical criteria include any person with clinical symptoms compatible with severe acute respiratory infection seeking healthcare or admitted to hospital with clinical or radiological evidence of pneumonia or any person with fever or recent history of fever (>=38°C) and acute respiratory infection (sudden onset with the following symptoms: shortness of breath, cough or sore throat).
Until validated PCR assays become available, specimens need to be submitted to reference laboratories. These laboratories may use a pan-coronavirus assay for amplification followed by sequencing of amplicons from non-conserved regions for characterization and confirmation. Confirmation by sequencing is necessary because four human coronaviruses (HcoVs) are endemic globally: HCoV-229E, HCoV-NL63, HCoV-HKU1 as well as HCoV-OC43. The latter two are the betacoronaviruses MERS-CoV and SARS. Alternatively, amplification and detection of 2019-nCoV specific sequences can be diagnostic without the necessity for further sequencing.
WHO suggests that the following specimens be collected:•
- Respiratory specimens include nasopharyngeal and oropharyngeal swab in ambulatory patients and sputum and/or endotracheal aspirate or bronchoalveolar lavage in patients with more severe respiratory disease
- Serum for acute and convalescent serological testing, once serologic assays become available
References
https://www.cdc.gov/coronavirus/novel-coronavirus-2019.html
Laboratory testing for 2019 novel coronavirus (2019-nCoV) in suspected human cases: Interim guidance 14 January 2020.
WHO/2019-nCoV/laboratory/2020.2 https://www.ecdc.europa.eu/en/publications-data/laboratory-testing-suspect-cases-2019-ncov-using-rt-pcr
