Dr Rajiv Kumar Gupta
World health organisation (WHO) China country office was informed of cases of pneumonia of unknown cause on 31st December; detected in Wuhan city, Hubei province of China. On 7th January, 2020, Chinese authorities identified a new strain of coronavirus as the causative agent of the disease. The virus was named as SARS-CoV-2 by WHO and the disease caused by it as COVID-19. The disease since then has spread in more than 100 countries with death toll crossing 6000 and confirmed cases well above one lakh and fifteen thousand while going to the press.
Corona virus are a large family of viruses some of which cause illness in people like common cold to more severe diseases like Severe Acute Respiratory Syndrome(SARS) and Middle East Respiratory Syndrome(MERS). 70% – 80% of emerging and re-emerging infectious diseases are known to be zoonotic in origin. The current virus shares 79% genetic affinity with SARS-CoV and 50% with MERS-COV.
In humans, the transmission of SARS-CoV 2 can occur in respiratory secretions- directly through droplets from coughing or sneezing and indirectly through contaminated objects or surfaces as well as close contacts. Nosocomial(hospital acquired) transmission has been described as an important driver in the epidemiology of SARS and MERS and has also been documented in COVID-19. Evidence shows that current virus is detectable in other body fluids and excreta which makes it critical to keep the surroundings clean and frequently wash hands with soap and water. A spill over event is when a virus that is circulating in an animal species is found to have been transmitted to humans.
Natural history of COVID-19 is still evolving and current estimates show that incubation period of COVID-19 to be between 2-14 days. Most common symptoms include fever, fatigues, dry cough and breathing difficulty, upper respiratory tract symptoms like sore throat, rhinorrhoea and gastrointestinal symptoms like diarrhoea and nausea/vomiting are present in about 20% of COVID-19 cases. When a person with COVID-19 cough’s or exhales, small droplets from the nose or mouth land on surfaces and objects around them. When other people touch these surfaces and then touch their eyes, nose, mouth or they may breathe in droplets from an infected person, they can catch the virus. Herein lies the importance of advisory regarding frequent hand washing. People should wash their hands frequently with soap and water for 20-30seconds. In case of non-availability of soap and water, alcohol based hand sanitisers can be used as an alternative.
As per analysis of the biggest cohort report by Chinese CDC, about 81% of the cases are mild, 14% require hospitalisation and 5% require ventilator and critical care management. Case fatality rate(CFR) in COVID-19 is about 2-3% which is much higher than that of seasonal influenza(0.1%). CFR in SARS-2003 was around 15% while in MERS-2014 it was 35-37%. First large analysis of more than 44,000 cases from China found that death rate was ten times higher in very old people compared to young people. However, evidences reveal that older people with associated co-morbidities like Hypertension, Diabetes Mellitus, Cardiovascular diseases, asthma etc., may become seriously ill. The Chinese study further revealed that deaths in 0-19 years age group were 0.1% of total COVID related deaths, in 20-39 years age group it was 2.5% of the total, while in 80 years and above this figure was 14.8%. Sars-Cov-2 stays infective longer than seasonal flu viruses and along with longer incubation period makes containment efforts an enormous challenge.
Current evidence shows that SARS-COV2 is more stable in low temperature and low humidity which explains an outbreak in sub tropical Hong Kong in spring and Air Conditioned(AC) environments. On the other hand, there was no major community outbreak in hot countries like Indonesia, Malaysia or Thailand. All SARS virus have been particularly cruel to Health care workers who in absence of a vaccine have Personal Protective Equipment(PPE) to fall back on. Transmission of all corona virus has been higher in health care settings and during close family/social contacts which necessitates to study indirect route of transmission like aerosolization of virus and transmission through AC ducts in apartment buildings.
Besides hand hygiene, other health advisories are being propagated by national and local health authorities to the public through electronic and print media. All these precautions need to be followed in letter and spirit to ward off COVID-19. Stay at least 1 metre(three feet) away from anyone who is coughing or sneezing. Avoid touching your eyes, nose, mouth. Practice good respiratory hygiene, cough or sneeze into a tissue or into your bent elbow, used tissues should be discarded off at the earliest and those not well should stay at home. Since corona virus have animal reservoirs, outbreaks in humans can be contained if community transmission doesn’t happen.
In the current scenario, large scale laboratory testing is critical as is the information sharing. Till date, GoI has expanded the network of labs designated to test COVID-19 to 52. In UT of J&K, GMC Jammu and Srinagar are likely to start testing soon. Cases need to be rapidly detected and their contacts comprehensively and rapidly traced. Infection prevention and control practices in health facilities and communities should be reviewed and upgraded as and where necessary. People who do not have symptoms don’t need to wear a medical mask. But people with symptoms and those who are caring sick people should wear masks. So there is need for rational use of mask and no panic buying for them.
Regarding food imported into India including from SARS-CoV 2 affected countries, FSSAI had constituted a committee of experts to examine the possibilities of the presence of the virus in imported food items. The committee opined that as of now, there is no conclusive evidence of food borne transmission of the virus. GoI has set up a dedicated health line 011-23978046 and ncov2019@gmail.com for any health related query on COVID-19.
There is yet no specific treatment for COVID-19 and current management consists of symptomatic and supportive treatment. Vaccines are in development but they are still 12-18 months away before being put in commercial use. Many anti-viral drugs are undergoing clinical trials, India should embark on a path of R&D to develop new tools- diagnostics, therapeutics and vaccines for this disease. Among other things that need to be monitored include geographic spread of virus, transmission intensity, disease trends, characterisation of virologic features and assessment of impact of disease on health care. 3 Ps to defeat Sars-Cov-2
1. Protect yourselves
2. Protect your loved once
3. Protect your community
Government of India has recently incorporated awareness message about COVID-19 in mobile ringtones to make the public aware of the necessary precautions. Public health measures need to be tailored to particular situations and can be frequently evaluated and updated based on changing epidemiology. Co-ordination and collaboration are essential to combat this common threat. The need of the hour is Caution and not to Panic.
(The author is Professor Community Medicine GMC Jammu)
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