Lancet studies outline significant findings on Coronavirus outbreak
China: Amid the rising fear of deadly coronavirus outbreak which is reported to not have entered India yet, but has at least 800 confirmed cases worldwide. The researchers in the journal Lancet have reported on the clinical outcomes of the first set of infected individuals and the epidemiological and radiological characteristics of the novel virus in two studies.
Coronaviruses (nCoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV). A novel coronavirus is a new strain that has not been previously identified in humans. Common signs of infection include respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. In more severe cases, the infection can cause pneumonia, severe acute respiratory syndrome, kidney failure, and even death.
In the first study, Prof Chaolin Huang, Jin Yin-tan Hospital, Wuhan, China, and colleagues, examined the first 41 patients confirmed to be infected with 2019 novel coronavirus (2019-nCoV) and admitted to Jin Yin-tan Hospital in Wuhan between December 16, 2019, and January 2, 2020. They combined patient data from clinical records, laboratory tests, and CT exams in their assessment. The patients had a median age of 49, 66% had visited the Huanan seafood market in Wuhan, and more than two-thirds were otherwise healthy individuals.
Key findings of the study include:
- Most of the infected patients were men (30 [73%] of 41); less than half had underlying diseases (13 [32%]), including diabetes (eight [20%]), hypertension (six [15%]), and cardiovascular disease (six [15%]).
- Median age was 49·0 years (IQR 41·0–58·0). 27 (66%) of 41 patients had been exposed to Huanan seafood market.
- One family cluster was found. Common symptoms at onset of illness were fever (40 [98%] of 41 patients), cough (31 [76%]), and myalgia or fatigue (18 [44%]); less common symptoms were sputum production (11 [28%] of 39), headache (three [8%] of 38), haemoptysis (two [5%] of 39), and diarrhoea (one [3%] of 38).
- Dyspnoea developed in 22 (55%) of 40 patients (median time from illness onset to dyspnoea 8·0 days.
- 26 (63%) of 41 patients had lymphopenia.
- All 41 patients had pneumonia with abnormal findings on chest CT.
- Complications included acute respiratory distress syndrome (12 [29%]), RNAaemia (six [15%]), acute cardiac injury (five [12%]) and secondary infection (four [10%]). 13 (32%) patients were admitted to an ICU and six (15%) died.
- Compared with non-ICU patients, ICU patients had higher plasma levels of IL2, IL7, IL10, GSCF, IP10, MCP1, MIP1A, and TNFα.
"Despite sharing some similar symptoms to SARS (e.g., fever, dry cough, shortness of breath), there are some important differences, such as the absence of upper respiratory tract symptoms (e.g., rhinorrhoea, sneezing, sore throat) and intestinal symptoms, such as diarrhea," senior author Dr. Bin Cao from Capital Medical University said in a statement.
Another study, also published in The Lancet; by Kwok-Yung Yuen from the University of Hong Kong-Shenzhen Hospital, investigated the way the coronavirus disseminated among a family of six members that visited Wuhan from December 29, 2019, to January 4, 2020.
Key findings include:
- Of six family members who travelled to Wuhan, five were identified as infected with the novel coronavirus.
- One family member, who did not travel to Wuhan, became infected with the virus after several days of contact with four of the family members.
- None of the family members had contacts with Wuhan markets or animals, although two had visited a Wuhan hospital.
- Five family members (aged 36–66 years) presented with fever, upper or lower respiratory tract symptoms, or diarrhoea, or a combination of these 3–6 days after exposure.
- They were presented to The University of Hong Kong-Shenzhen Hospital, Shenzhen 6–10 days after symptom onset.
- They and one asymptomatic child (aged 10 years) had radiological ground-glass lung opacities.
- Older patients (aged >60 years) had more systemic symptoms, extensive radiological ground-glass lung changes, lymphopenia, thrombocytopenia, and increased C-reactive protein and lactate dehydrogenase levels.
- The nasopharyngeal or throat swabs of these six patients were negative for known respiratory microbes by point-of-care multiplex RT-PCR, but five patients (four adults and the child) were RT-PCR positive for genes encoding the internal RNA-dependent RNA polymerase and surface Spike protein of this novel coronavirus, which were confirmed by Sanger sequencing.
- Phylogenetic analysis of these five patients' RT-PCR amplicons and two full genomes by next-generation sequencing showed that this is a novel coronavirus, which is closest to the bat severe acute respiratory syndrome (SARS)-related coronaviruses found in Chinese horseshoe bats.
The most likely explanation for the family's infections is that one individual acquired the coronavirus while visiting a relative at the Wuhan hospital, then later transmitted it to the rest of her family, the authors said. One of the infected individuals had no clinical symptoms of disease, indicating that asymptomatic infected individuals may continue to spread the virus unwittingly.
"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," Yuen said in a statement.
"As there are no existing coronavirus antivirals or vaccines of proven efficacy in humans, a pressing need remains to develop best supportive care and a vaccine. Every effort should be given to understand and control the disease, and the time to act is now," representatives from the Chinese Academy of Medical Sciences, Chinese CDC, Oxford University clinical research unit in Vietnam, and University of Virginia School of Medicine said in a linked commentary.
They underscored the importance of widespread awareness and improving current understanding of the coronavirus.
References:
"Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China," by Huang et al. DOI: https://doi.org/10.1016/S0140-6736(20)30183-5
"A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster," by Yuen et al. DOI: https://doi.org/10.1016/S0140-6736(20)30154-9
