Passengers wear masks as they walk past a scanning machine monitoring people's temperature following the new coronavirus outbreak in China, at Bandaranaike international airport in Katunayake, Sri Lanka January 24, 2020. (Photo: REUTERS)
The 2019 novel coronavirus (2019-nCoV) appears to cause similar symptoms to severe acute respiratory syndrome (SARS), and seems to be capable of spreading from person to person and between cities, two studies published in medical journal The Lancet have reported.
These early findings involve only a small number of patients, and the authors stress the need to maximise the chances of containing the 2019-nCoV infection through careful surveillance, active contact tracing, and vigorous searches for the animal hosts and transmission routes to humans.
As of January 24, 2020, 835 laboratory-confirmed 2019-nCoV infections were reported in China, with 25 fatal cases. Many of the cases have been linked to the Huanan seafood market in Wuhan, China, where freshly killed game animals were reportedly sold, although the original source of infection remains unknown.
The 2019-nCoV is most closely related to coronaviruses from Chinese horseshoe bats. Currently, six coronaviruses (seven including 2019-nCoV) are known to cause diseases of the respiratory tract in people, but only SARS and the Middle East respiratory syndrome (MERS) have resulted in large outbreaks of fatal illness to date.
Currently, there are no specific coronavirus antiviral drugs or vaccines with proven efficacy in humans.
In the first study, researchers analysed 41 patients infected with laboratory-confirmed 2019-nCoV admitted to hospital in Wuhan between December 16, 2019, and January 2, 2020.
The authors combined clinical records, laboratory results, and imaging findings with epidemiological data. On average, patients were middle-aged (median age 49 years), most had visited the Huanan seafood market (27 patients), and most patients were men (30 patients).
Like SARS, the majority of cases affected healthy individuals, with less than a third of cases occurring in people with underlying chronic medical conditions such as diabetes (20 per cent), high blood pressure (15 per cent), and cardiovascular disease (15 per cent).
All the patients admitted to hospital had pneumonia and most had a fever (98%), cough (76%), and fatigue (44%). Over half of the patients also experienced shortness of breath (dyspnoea; 55%), whilst headache (8 per cent) and diarrhoea (3 per cent) were rare.
"Despite sharing some similar symptoms to SARS (eg, fever, dry cough, shortness of breath), there are some important differences, such as the absence of upper respiratory tract symptoms (runny nose, sneezing, sore throat) and intestinal symptoms, such as diarrhoea which affected 20-25% of SARS patients," said lead author Bin Cao from the China-Japan Friendship Hospital and Capital Medical University, China.
"It is hard to understand the mortality rate associated with this new virus currently, as we are only detecting severe cases in the initial stages of the epidemic, rather than the milder or asymptomatic cases," said co-author Dr Lili Ren from the Chinese Academy of Medical Sciences & Peking Union Medical College, China.
In their article, the authors noted several limitations of the study, including that due to the limited number of cases, assessing the risk factors for disease severity and mortality is difficult, and they call for larger studies in outpatient and community settings to confirm the full clinical spectrum of disease.
In the second paper, which is a first-of-its-kind genetic analysis, researchers studied a family of seven people who presented to hospital with unexplained pneumonia. They identified 2019-nCoV in five members who had recently visited Wuhan, and in one other family member who did not travel with them. Only a child, who was reported by their mother to have worn a surgical mask for most of the stay in Wuhan, was not infected. Importantly, another child was infected with 2019-nCoV, but showed no clinical symptoms-suggesting that individuals may be able to spread infections in the community without knowing that they are infected.
"Our findings are consistent with person-to person transmission of this new coronavirus in hospital and family settings, and the reports of infected travellers in other countries. Because asymptomatic infection appears possible, controlling the epidemic will also rely on isolating patients, tracing and quarantining contacts as early as possible, educating the public on both food and personal hygiene, and ensuring healthcare workers comply with infection control," said Professor Kwok-Yung Yuen from the University of Hong Kong-Shenzhen Hospital, who led the research.
WHO asks countries to be prepared
Taking note of the human to human transmission of the coronavirus first detected in China, the WHO has asked all countries to be prepared for containment, including active surveillance, early detection, isolation and case management, contact tracing and prevention of onward spread of 2019-nCoV infection, and to share full data with WHO.