2019 nCoV infection: A primer on the potential pandemic
M3 India Newsdesk Feb 03, 2020
In light of the recent, massive outbreak of Coronavirus (n-CoV) infection, Dr. Monish Raut puts together notes for doctors on what is known about the infection so far.
Coronaviruses (CoV) belong to a large family of viruses called as Coronaviridae. These are spherical in shapes with crown like projections on the surface. Symptoms of illness may vary from mild respiratory complaints to more severe diseases such as Severe Acute Respiratory Syndrome (SARS-CoV) and Middle East Respiratory Syndrome (MERS-CoV). They can transmit between animals and people.
The most recent outbreak in Wuhan City, Hubei Province, China reported in December 2019, is caused by a novel coronavirus (nCoV). Interestingly, this new strain was not previously recognised in humans. Within the span of a month, cases have been reported from other countries such as Singapore, South Korea, Thailand, USA, and Japan.
In India suspected cases have been identified in cities like Jaipur, Hyderabad, New Delhi, and Bengaluru. The first confirmed case of novel coronavirus infection has been reported in Kerala. The patient is a student from Wuhan university and had recently returned from China. Reportedly, more than 7000 cases have been confirmed so far, and the death toll has crossed 170 worldwide.
Source & emergence
The initially reported patients were vendors at the Wuhan South China Seafood City (South China Seafood Wholesale Market). Reports on source of this virus and mode of transmission indicated that some of the patients were vendors at the market. This indicates the possibility of zoonotic origin and the virus possibly having crossed over from animals to man.
However, according to new study published in the Journal of Medical Virology, 2019-nCoV the origin seems to be from snakes- the many-banded Krait (Bungarus multicinctus) and the Chinese cobra (Naja atra) commonly found in southeastern China. It also suggested that a change in one of the proteins of this virus might have helped it to bind to receptors on certain host cells explaining the transmission to humans. The theory of origin from snakes, however has been criticised by some experts.
Human coronaviruses can be categorised into:
- Alpha Coronavirus
- Beta Coronavirus (MERS, SARS)
- Novel Coronavirus 2019
Common symptoms have been acute, serious respiratory illness with fever, cough, breathing difficulties, pneumonia. In some patients, non-respiratory symptoms such as vomiting, nausea and diarrhoea have also been reported.
Transmission of infection
It spreads from animal to human and also from human to human. The main mode of spread is through respiratory droplets from an infected person’s cough or sneezes. It is similar to the mode of transmission of other respiratory pathogens.
Infection prevention and control (IPC) strategies
Considering the present knowledge of novel coronavirus and previous experiences with MERS-CoV and SARS-CoV, WHO has provided an interim guidance for infection prevention and control (IPC) strategies to limit the infection and transmission.
Clinical triage- Early recognition and immediate isolation of suspected cases are essential. Healthcare workers should be encouraged to use screening questionnaires and have a high level of clinical suspicion.
Screening questionnaire- Healthcare workers should screen patients based on answers received for the following:
- Visit to 2019-nCoV infected regions such as China, Japan, South Korea, Singapore, Thailand or other infected areas in the last 15 days .
- Close contact with people in infected regions such as China, Japan, South Korea, Singapore, Thailand or any other infected areas in the last 15 days.
- Presence of flu-like symptoms like fever, cough, or dyspnoea in the last 15 days.
- Close contact with someone experiencing flu-like symptoms such as fever, cough, and dyspnoea, in the last 15 days.
- Hospitalisation or exposure to patients with the above symptoms in the last 15 days.
Persons with positive answers to question 1 with 2, or symptoms should be considered as suspected cases.
- Suspected case- Patients with severe acute respiratory infection with a history of travel to Wuhan and close contact with a confirmed or probable case of 2019 nCoV.
- Probable case- A suspect case for whom testing (PCR assay) for 2019 nCoV was positive.
- Confirmed case- A person with laboratory confirmation (serological testing) of 2019-nCoV infection irrespective of clinical signs and symptoms.
The virus can be easily found in lower respiratory tract samples of symptomatic patients. Oropharyngeal and nasopharyngeal swabs can be collected from ambulatory patients. Sputum, endotracheal aspirate and bronchoalveolar lavage can be obtained from patients with severe respiratory disease.
Serum (2 samples- one in the acute phase and one in the convalescent phase possibly 2 to 4 weeks after acute phase) can be used to recognise the true agent. Testing should be performed at labs identified by ICMR’s viral research or National Institute of Virology, Pune.
Corona virus does not have any specific antiviral treatment presently. Supportive care can alleviate symptoms in infected patients. A vaccine for 2019-nCoV is still in the creation phase and early stage human testing can be expected in the coming months.
Recently, the AYUSH ministry has issued an advisory for the treatment of coronavirus infection. Apart from standard precautions, the advisory recommends the use of Ayurvedic, Unani and Homeopathic medicines, concoctions and immunomodulatory drugs for the treatment. Proponents suggests boosting immunity using these methods. However, in the absence of any proven research studies regarding coronavirus treatment, use of these traditional healthcare approaches are contraversial and debatable.
Standard precautions to be given to all patients
- Practice adequate hand and respiratory hygiene
- Use medical mask
- Cover mouth and nose during sneezing or coughing with tissue or flexed elbow
- Practice adequate hand hygiene after contact with respiratory secretions
Precautions for all healthcare personnel
- Use Personal Protective Equipment (PPE)
- Avoid needle-stick or sharps injury
- Manage safe disposal of biomedical waste
- Properly sterilise patient-care equipment and linen
- Clean environmental surfaces with water and detergent and disinfectants, such as sodium hypochlorite
- Avoid touching the nose, mouth, and eyes with potentially contaminated hands
- Maintain adequate hand hygiene
- During aerosol generating procedures such as intubation, tracheostomy, and bronchoscopy, use N95 mask
- Use surgical mask at all other times
- Use protection for face and eyes such as a face shield or goggles
- Use fluid resistant, clean, long-sleeved and non-sterile gown and gloves during procedures
Appropriate use of mask and its disposal is absolutely necessary to maintain its efficacy and reduce the transmission.
- Place mask carefully to cover mouth and nose, and tie securely to minimise any gaps between the face and the mask.
- While in use, avoid touching the mask.
- Whenever, there is contact with a used mask, for example when removing or washing, clean hands with soap and water or with an alcohol-based hand rub.
- Replace masks as soon as they become damp/humid.
- Do not reuse single-use masks. Discard single-use masks immediately upon removing.
Contact and droplet precautions
- Patients should be placed in adequately-ventilated (160 L/second/patient air flow), single rooms
- Patients suspected of nCoV infection can be placed together, if single rooms are not available
- Maintain a distance of at least 1 m between patient beds
- Assign dedicated healthcare workers for care of suspected and confirmed cases
- Procedures should be carried out in an adequately ventilated room (at least 160 l/s/patient natural ventilating air flow or negative pressure rooms with at least 12 air changes per hour (ACH) and controlled direction of air flow when mechanical ventilation is used)
- Only a minimum number of persons should be present in the patient's room
- Equipment used for patient examination such as thermometers, stethoscopes, and blood pressure cuffs should be disinfected with alcohol after every use.
- Movement of patient should be minimised
- Patient should wear surgical mask at all times, so that exposure to other healthcare workers, other patients, and visitors would be reduced
Disclaimer- The views and opinions expressed in this article are those of the author's and do not necessarily reflect the official policy or position of M3 India.
The author, Dr. Monish S Raut is a Consultant in Cardiothoracic Vascular Anaesthesiology. His area of expertise is perioperative management and echocardiography with numerous publications in various national and international indexed journals.
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