The 2019 Novel Coronavirus (2019-nCoV): Novel Virus, Old Challenges (2020/02/05)

In late December 2019, global attention shifted to China after several local health facilities reported clusters of patients
with pneumonia of unknown origin epidemiologically linked to the Huanan Seafood Wholesale Market in the municipality of Wuhan, one of the country’s central cities. Local health authorities identified a novel betacoronavirus, provisionally
called 2019-nCoV,1
the third zoonotic coronavirus in three decades to cross species infecting humans and raising global
health concerns. Chinese government took extraordinary measures, to control the outbreak by closing The Market and by
imposing a lockdown, first in Wuhan and later in twelve other Chinese cities. However, by the end of January 2020, there
were 9826 confirmed cases (98.9% in China) a number that is estimated to be much higher 2
and that is increasing every
hour. The disease has now spread worldwide, with cases confirmed in 23 countries other than China, mainly in Southeast
Asia but also in the United States of America and several European countries. On the 30th of January, the World Health
Organization’s Emergency Committee agreed that the outbreak now meets the criteria for a Public Health Emergency of
International Concern.3 We are seeing the evolution of what is developing into a serious outbreak.
As the scientific community joins efforts to better understand the origin, pathogenesis and transmissibility of the virus,
key questions remain unanswered.
Concerning the origin of the virus, it was initially suggested that snakes were the most probable animal reservoir for
the 2019-nCoV.4
More recently, researchers concluded that the most closely related genome sequences to the 2019-nCoV
were two coronaviruses that originated in bats (88% of shared genetic sequence).5
Despite the link to these mammals, several facts suggest that another animal, yet to be discovered, is acting as an intermediate host between bats and humans.5
Published data show us that patients typically present with mild respiratory symptoms and fever, often evolving to
pneumonia. Complications such as severe pneumonia, acute respiratory distress and cardiac injury have been described
in China.6
While case fatality rate is as high as 14.6% in a cohort of 41 patients6
, it is close to 2% considering all reported
These numbers should be interpreted with caution, as the true number of infections and deaths is probably underestimated (mild cases are more likely to be underestimated, which would yield a lower case fatality rate).
Up until now, there is no specific antiviral treatment recommended for 2019-nCoV infection.8
The combined use of
lopinavir and ritonavir is under study in China and, more recently, it was suggested that baricitinib, a Janus kinase inhibitor
should be trialled as a potential therapeutic weapon.9

Author: Raquel Duarte, Isabel Furtado, Luís Sousa, et al.