Coronaviruses are single-stranded RNA viruses enveloped in a lipid shell. They can cause sickness to humans as well as several animal species, typically including birds and mammals such as camels, cats and bats. Coronaviruses are zoonotic, i.e., they can be transmitted from animals to humans: the in-depth epidemiological studies in the Y2003 SARS coronavirus revealed that the pathogen was transmitted from civet cats whereas MERS-CoV was shown to have been transmitted from camels to humans. At present, there are seven coronaviruses known to be capable of causing human infections and illness. The severity of coronavirus infections vary significantly from simple flu to more serious respiratory diseases. There are four human coronaviruses that generally cause mild or moderate symptoms in the upper respiratory tract while the Middle East respiratory virus (MERS-CoV) and SARS coronavirus are so severe that they may cause life-threatening respiratory diseases as well. (The human diseases caused by the SARS-coronavirus were eliminated by the epidemiology measures taken in 2003.) Investigating the causes of the pneumonia epidemic in Wuhan in late 2019, scientists identified a virus from the Beta Coronavirus family, currently known as 2019-nCoV Wuhan coronavirus, which is genetically closest to the SARS coronavirus. This newlyemerged virus was identified through a new-generation sequencing procedure from samples of patients with the Wuhan pneumonia epidemic and from direct virus cultures. The electromicroscopic images reveal the pathogen’s characteristic crown-like morphology.
Source of infection: currently unknown. The common epidemiological connections of the initial cases to the Wuhan seafood and live animal market make it highly likely that an animal available there may have had a role as a zoonotic source in the outbreak of the epidemic, but the exact species is currently unknown. The human-to-human transmission of the new Wuhan coronavirus has been confirmed: Humans can be a source of infection. To the best of our current knowledge, human-to-human transmission occurs when there is close contact (e.g., infections have occurred through exposure in the healthcare system, family or common household).
Manner of transmission: The human-to-human transmission of the new Wuhan coronavirus (2019-nCoV) has been confirmed. Coronaviruses are typically transmitted via close contact, in particular through respiratory droplets and the infected secreta.
Incubation period: according to the current data, 7 days on average (2-12 days).
Key symptoms: according to our current knowledge, the disease is associated with high temperature, cough, laboured respiration and radiological variances characteristic of pneumonia. The disease may be manifested with mild, moderate and severe symptoms, including severe pneumonia, ARDS, sepsis and septic shock.
Duration of pathogenicity: unknown.