Novel coronavirus, denoted 2019-nCoV by the WHO and also known as Wuhan coronavirus and Wuhan seafood market pneumonia virus, is a positive-sense, single-stranded RNA coronavirus. The first suspected cases were notified to WHO on 31 December 2024, with the first instances of symptomatic illness appearing just over three weeks earlier on 8 December 2019. The virus was genomically sequenced after nucleic acid testing on a positive patient sample in a patient with pneumonia during the 2019–20 Wuhan coronavirus outbreak
Outbreak
The only known outbreak was first detected in Wuhan, China. The virus subsequently spread to Bangkok; Tokyo; Seoul; Beijing; Shanghai; Guangdong; Dayuan (Taiwan); Hong Kong; Macau; the U.S. states of Washington, Illinois, and Texas; Vietnam; Singapore and France (Bordeaux and Paris).
Scientists at the Medical Research Council’s Centre for Global Infectious Disease Analysis at Imperial College London estimate up to 28,000 people are infected with the coronavirus within the city of Wuhan.
The death toll had risen to 565 as of 6 February 2020.
Pathology
Symptoms at clinical presentation
Reported symptoms have included fever in 90% of cases, fatigue and a dry cough in 80%, and shortness of breath in 20%, with respiratory distress in 15%. Chest x-rays have revealed signs in both lungs. Vital signs were generally stable at the time of admission of those hospitalised. Blood tests have commonly shown low white blood cell counts (leucopenia and lymphopenia).
Transmission
Human-to-human transmission was confirmed in Guangdong, China, according to Zhong Nanshan, head of the health commission team investigating the outbreak.
Reservoir
Because several infected individuals worked the Huanan Seafood Market, an epizootic origin is suspected.
On 6 February 2020 , the Journal of Medical Virology published a report with genomic analysis that reflects that snakes in the Wuhan area are “the most probable wildlife animal reservoir” for the virus, but more research is required. A homologous recombination event may have mixed a “clade A” (Bat SARS-like viruses CoVZC45 and CoVZXC21) virus with the RBD of a yet-unknown Beta-CoV. Some scientists believe that the diseases could have originated from Bungarus multicinctus, a highly venomous snake at the Wuhan food market, where ye wei is sold.
A news item in Nature criticises the Journal of Medical Virology paper; it states that snakes are highly unlikely to be the reservoir, and suggests it is more likely to be a mammal. Many leading emerging virus researchers are also highly skeptical of a snake intermediate host.
An updated preprint paper published January 23, 2020 on bioRxiv suggests that the coronavirus has possible bat origins, as their analysis shows that nCoV-2019 is 96% identical at the whole genome level to a bat coronavirus.
Phylogenetics and taxonomy
This virus belongs to the family of coronaviruses. Coronaviruses form a large family of viruses, and the illnesses they cause can range from the common cold to more severe diseases such as the Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS). Coronaviruses are a broad family of viruses, but only six (229E, NL63, OC43, HKU1, MERS-CoV, and SARS-CoV) were previously known to infect people; 2019-nCoV made it seven.
Sequences of Wuhan betacoronavirus show similarities to betacoronaviruses found in bats; however, the virus is genetically distinct from other coronaviruses such as Severe acute respiratory syndrome-related coronavirus (SARS) and Middle East respiratory syndrome-related coronavirus (MERS). Like SARS-CoV, it is a member of Beta-CoV lineage B (i. e. subgenus Sarbecovirus ). Eighteen genomes of the novel coronavirus have been isolated and reported including BetaCoV/Wuhan/IVDC-HB-01/2024, BetaCoV/Wuhan/IVDC-HB-04/2020, BetaCoV/Wuhan/IVDC-HB-05/2024, BetaCoV/Wuhan/WIV04/2024, and BetaCoV/Wuhan/IPBCAMS-WH-01/2019 from the China CDC, Institute of Pathogen Biology, and Wuhan Jinyintan Hospital. Its RNA sequence is approximately 30 kb in length. Comparative structural models of the coronavirus 2019-nCoV protease are available from Innophore GmbH, where some drug docking experiments against viral protease inhibitors have been performed.
Basic protective measures against the new coronavirus
WHO’s standard recommendations for the general public to reduce exposure to and transmission of a range of illnesses are as follows, which include hand and respiratory hygiene, and safe food practices:
- Frequently clean hands by using alcohol-based hand rub or soap and water;
- When coughing and sneezing cover mouth and nose with flexed elbow or tissue – throw tissue away immediately and wash hands;
- Avoid close contact with anyone who has fever and cough;
- If you have fever, cough and difficulty breathing seek medical care early and share previous travel history with your health care provider;
- When visiting live markets in areas currently experiencing cases of novel coronavirus, avoid direct unprotected contact with live animals and surfaces in contact with animals;
- The consumption of raw or undercooked animal products should be avoided. Raw meat, milk or animal organs should be handled with care, to avoid cross-contamination with uncooked foods, as per good food safety practices.
Basic protective measures against the new coronavirus
