What is the Corona Virus?
Corona viruses have attracted attention for causing epidemics in the 21st century. However, their existence goes much further back in time. Human CoV (HCoV) in particular has been infamous for causing epidemics better known as Severe Acute Respiratory Syndrome (2003, Guangdong, China) and Middle East Respiratory Syndrome (2012, Saudi Arabia). The novel Corona Virus (nCoV 2019), hitting current headlines, surfaced on December 31 2019 in Wuhan, China.
Baseline analysis has revealed that nCoV 2019 has some similarities (in amino acid structure) to SARS CoV. This is a head start to understand the virus but active research to predict the trajectory of the evolving epidemic is underway, globally. Therefore, it is crucial to know the pattern of CoV infections.
CoV are large, enveloped, positive stranded RNA viruses divided in four genera – alpha, beta, gamma and delta. Alpha and beta genera cause human infections.
Not all HCoV cause epidemics. Four HCoV (229E, NL63, OC43, and HKU1) are endemic and account for 10% to 30% of upper respiratory tract infections in adults, globally.
What are the possible causes behind an outbreak?
Corona viruses (CoV) are ecologically diverse. The ancestral origin of most CoV is traced to bats, but the intermediate host can vary. In case of SARS it was raccoons and dromedary camel in case of MERS.
The origin of this nCoV has been traced to wet markets in Wuhan, China that sell exotic animals for human consumption.
What are the common risk factors?
nCoV is spread by large droplets (not aerosol).
A part of the virus (S glycoprotein) has receptors in (Angiotensin Converting Enzyme 2) ACE2, found in the lower respiratory tract, which could explain the symptoms: Cough, Difficulty in breathing and Fever.
Elderly people were affected more and healthcare settings also witnessed a high number of casualties due to hospital-acquired infections.
What are the symptoms to look out for?
In case of nCoV, analysis of the first 41 confirmed patients in Wuhan revealed that most patients were men, average age about 49 years, no adolescents or children. Most common symptoms were similar to any viral pneumonia – fever, cough, fatigue. Chest CT findings were similar to those seen in cases of viral pneumonia.
The current mortality is pinned at 3% (106 people). A recent report from Imperial College, London has concluded that one infectious person can infect two to three susceptible people.
Modelling reports from the College estimate that, on average, each case infected 2.6 other people until January 18, 2020. This implies that control measures need to block well over 60% of transmission to be effective in controlling the outbreak. The modelling also forecast up to 20,000 cases before the end of the month.
However, the above findings suggest that this is less infectious than measles which, despite a vaccine, can infect 10-12 susceptible/unvaccinated individuals. So, there is cause for concern but panic is unwarranted.
Perhaps primed by the experience of dealing with SARS CoV, the progress in determining what causes the infection, the development of confirmatory diagnostics and deployment of quarantine measures has been impressive.
How should citizens protect themselves?
There are no confirmed cases in India yet. Several suspected cases have been quarantined in Delhi and other cities, but we must refrain from creating and responding to panic rumors.
Watch for official updates from the Ministry of Health and Family Welfare that has clearly outlined the treatment guidelines, monitoring/ surveillance measures, advisory on travel, and measures for prevention and infection control.
As no vaccine provides immunity from all CoV, those who are frequent travelers must be watchful of respiratory symptoms in frequent travelers.
|If you are travelling/have had exposure to person(s) travelling to China/other countries with reported cases
Source: Ministry of Health and Family Welfare, Government of India
How should the health system be equipped to meet an emergency, should the need arise?
SARS epidemic spread to 12 countries but MERS was contained in the Middle East, mostly. SARS had a high number of cases, but MERS had more deaths.
Public Health measures implemented by China could serve as an example of a responsive health system. After the first suspected case surfaced on 31st Dec 2019, the Wuhan wet market was shut down on 1st Jan 2020.
As a measure of social distancing, China has been proactive in quarantine measures. Following isolation of the first 59 suspected persons, rapid confirmatory laboratory tests were developed. A total of 17 cities are now under lockdown, with several areas banning long-distance bus services, including Beijing, Shanghai and the eastern province of Shandong, home to 200 million people. On Monday, Chongqing municipality, which has a population of 30 million, adopted similar measures.
Epidemiologists and data scientists have made their efforts accessible to the public, by sharing real-time results via social platforms.
Despite diverse efforts to contain the epidemic effectively, health systems are often impacted by poor public reasoning caused by misinformation spread through uninformed ‘forwards’ on WhatsApp and social media. Follow only authentic sources; below are some resources for those who wish to know more: