Coronavirus disease 2019 (COVID-19)

A cluster of pneumonia of unknown etiology was reported in Wuhan City, Hubei Province of China on 31 December 2019.  On 7 January, Chinese authority identified a new type of coronavirus as a cause of pneumonia outbreak, which is different from any other human coronaviruses discovered so far. The new strain is named as 2019-nCoV. Afterwards on 11February 2020, this virus is named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and disease is named as COVID-19 by World Health Organisation (WHO).

To date, other six human coronaviruses (HCoVs) have been identified. Out of these, four are globally circulated in the human population and contribute to approximately one-third of common cold infections in humans. The other two viruses are Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS Coronavirus) causing severe respiratory diseases. Coronaviruses such as SARS and MERS, are zoonotic, and can be transmitted from animals (civet cats and dromedary camels, respectively) to humans.

(SARS-CoV was first reported in 2002-2003 in Guangdong, China and MERS coronavirus was first identified in Saudi Arabia in 2012).

The precise zoonotic (animal) origin of the 2019‑nCoV is still uncertain. The virus has been identified in environmental samples from a live animal market in Wuhan, China and some human cases have been epidemiologically linked to this market.

Epidemiological evidence shows that 2019‑nCoV can be transmitted from one individual to another. In the previous outbreaks of other coronaviruses such as MERS-CoV and SARS, human-to-human transmission occurred most commonly through droplets, personal contact, and contaminated objects. The modes of transmission of 2019‑nCoV are similar.

According to WHO, additional investigations are needed to determine how the patients were infected, the extent of human-to-human transmission, the clinical spectrum of disease, and the geographic range of infection.

On 30 January 2020, the Director-General of WHO declared the 2019‑nCoV outbreak a public health emergency of international concern under the International Health Regulations (IHR) (2005).

COVID-19 outbreak was declared as pandemic by WHO on 11 March 2020. According to WHO, it is a controllable pandemic and urged all countries to take a comprehensive approach considering their circumstances and with containment measures as the central pillar.

Get more information about COVID-19 in India:
For guidelines & advisories visit:  @MoHFW_INDIA . 
For technical queries related to COVID-19 email at and other queries on and @CovidIndiaSeva .

For any query call at the Ministry of Health & Family Welfare helpline no. : +91-11-23978046 or 1075 (Toll-free) or helpline numbers of States/UTs

For Laboratory details about COVID-19 testing visit:

Social stigma and COVID-19

Maintain a healthy diet during COVID-19 pandemic

Breastfeeding and COVID-19


Common symptoms of infection may be in the form of respiratory symptoms such as-

  • fever,
  • cough,
  • shortness of breath and
  • breathing difficulties.

Other possible symptoms include -fatigue, muscle or body aches, headache, loss of taste or smell, sore throat, runny nose, nausea or vomiting and Diarrhea.

In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death.

Symptoms may appear 2-14 days after exposure to the virus.

Most people (about 80%) recover from the disease without needing hospital treatment. Older people, and those with underlying medical problems like high blood pressure, heart and lung problems, diabetes, or cancer, are high risk groups of developing serious illness. 

People of all ages who experience fever and/or cough associated with difficulty breathing/shortness of breath, chest pain/pressure, or loss of speech or movement should seek medical attention immediately.


COVID-19 is caused by the SARS-CoV-2 virus. A novel coronavirus is a new strain of coronavirus that has not been previously identified in humans. Coronaviruses (CoV) are a large family of viruses that can cause mild illness in the form of common cold to severe respiratory diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV).

Coronaviruses are zoonotic, it means they can be transmitted between animals and people. Previous investigations showed that other coronavirus, such as SARS-CoV was transmitted from civet cats to humans and MERS-CoV from dromedary camels to humans.

The precise origin of the SARS-CoV-2 is still uncertain. The virus has been identified in environmental samples from a live animal market in Wuhan, China and some human cases have been epidemiologically linked to this market.

Mode of transmission:

COVID-19 commonly spreads during close contact:

The SARS-CoV-2 virus most commonly spreads during close contact. When people with COVID-19 cough, sneeze, speak, sing or breathe heavily they produce small liquid particles of different sizes ranging from larger ‘respiratory droplets’ to smaller ‘aerosols’ containing virus. The virus can get in to mouth, nose or eyes of other people (those who are in direct or close contact (less than 1 metre apart) with an infected person) through these particles and cause infection.


COVID-19 can be spread by airborne transmission:

Sometimes, COVID-19 can be spread by airborne transmission which can occur in enclosed settings with crowded and inadequately ventilated spaces, where infected people spend long periods of time with others.

COVID-19 spreads less commonly through contact with contaminated surfaces:

COVID-19 can also be transmitted by touching the contaminated surfaces (infected people can contaminate surfaces/ objects by sneezing, coughing, or touching them, such as tables, doorknobs and handrails) and then touching their eyes, noses or mouths without having cleaned their hands first.

Risk factors:

The major risk factors for severe disease are:

  • Age more than 60 years (increasing with age).
  • Underlying non-communicable diseases (NCDs): diabetes, hypertension, cardiac disease, chronic lung disease, cerebro-vascular disease, chronic kidney disease, immune-suppression and cancer

Variants –Multiple variants have been reported globally. These are identified from the United Kingdom (UK), South Africa and Brazil. These variants spread more easily and rapidly than other variants.


Two kinds of tests are available for COVID-19 diagnosis: tests for current infection (viral tests-molecular assays) and tests for past infection (antibody tests/serology tests).

Molecular assays: 2019-nCoV can be diagnosed by molecular assays in samples from upper respiratory tract collected as nasopharyngeal and oropharyngeal swabs and from lower respiratory tract by sputum (if possible for those patients with productive coughs) and or endotracheal aspirate or bronchoalveolar lavage in patients with more severe respiratory diseases.

Molecular based tests consist of real time RT-PCR, TrueNAAT/CBNAAT. It only indicates the presence of viral material during infection and do not indicate if a person was infected and subsequently recovered.

Proper infection control measures should be maintained when collecting specimens.

Serology tests: These are blood-based tests used to identify people who have been exposed to COVID-19 virus by looking at their immune response. These tests are used for surveillance purposes to know about the prevalence of a disease in a population by identifying individuals who have developed antibodies to the virus.

An antibody test may not be able to show a current infection, because it can take 1-3 weeks after infection to make antibodies.

National Institute of Virology, Pune, India is among the various laboratories have been identified internationally to provide reference testing support for 2019-nCoV.

Get more information:

Information of testing strategy

Total Operational Laboratories reporting to ICMR



People who think they may have been exposed to COVID-19 should take precautionary measures to prevent further transmission of infection and should be quarantined, and if symptoms appear they should contact their healthcare provider immediately.

Patients with suspected or confirmed mild COVID-19 are advised for isolation to break the chain of transmission. They can be managed with symptomatic treatment such as antipyretics for fever and pain, adequate nutrition and appropriate rehydration.

Patients with suspected or confirmed moderate COVID-19 (pneumonia) are managed at Dedicated Covid Health Centre with close monitoring for signs or symptoms of disease progression. Severe cases are managed at dedicated Covid hospitals*.

Isolation- Those people who are suffering from COVID-19 should stay away from others even in their homes. This is called isolation.

Quarantine-Those people who might have been exposed to COVID-19 should stay away from others. This is called quarantine.



Revised guidelines for Home Isolation of very mild/pre-symptomatic/asymptomatic COVID-19 cases, Ministry of Health & Family Welfare, Government of India, July 2020 accessed from

*Clinical Management Protocol: COVID-19, Government of India, Ministry of Health and Family Welfare, Directorate General of Health Services, (EMR Division) Version 5, 03.07.20, page12, accessed from

COVID-19 can be prevented by following COVID appropriate behaviour and getting vaccine.

Follow COVID appropriate behavior:

When COVID-19 is spreading in the community, stay safe by taking some simple precautions, such as physical distancing, wearing a mask, keeping rooms well ventilated, avoiding crowds, cleaning your hands, and coughing into a bent elbow or tissue.

To make your environment safe avoid the 3Cs: spaces that are Closed, Crowded, or involve Close contact. Prefer to meet people outside asoutdoor gatherings are safer than indoor ones.

If you have minor symptoms such as cough, headache, mild fever, stay home and isolate, and consult your health care provider. If you need to go out, wear a medical mask to avoid infecting others.

If you have fever, cough and difficult breathing, seek medical attention immediately.

COVID-19 Vaccines:

As of January 2021, Over 170 COVID-19 vaccine candidates are being developed by different agencies globally. Of these at least 60 candidate vaccines are in different phases of human trials and several vaccines are approved for the human use. Globally, various scientific techniques are being used for safe and effective COVID-19 vaccine such as:

Virus vaccines: These vaccines use the virus itself in a weakened or inactivated form. There are two types of virus vaccines against coronavirus, weakened virus and inactivated virus vaccines.

Viral-vector vaccines: In the development of these vaccines, a virus (such as adenovirus or measles) is used as vector or carrier and is genetically engineered to produce coronavirus proteins in the body, triggering protective immunity against it. The two types of viral-vector vaccines under development are replicating viral vector (can replicate within cells) and non-replicating viral vector (cannot replicate within cells).

Nucleic-acid vaccines: Nucleic acid vaccines use genetic material from a disease-causing virus or bacterium (a pathogen) to stimulate protective immunity against it. The genetic material could be DNA or RNA.

Protein subunit vaccines: Protein subunit vaccines use fragments of protein from the disease-causing virus to trigger protective immunity against it. The two types of protein-based vaccines being developed against the coronavirus are the protein subunit vaccines and virus-like particle vaccines.

In India, two types of vaccines Covishield and Covaxine have been rolled out for vaccination in a phased manner. Covishield is based on viral vector technology and Covaxine is a whole virion inactivated corona virus vaccine. Two doses of vaccine are given at four weeks apart.

Everyday preventive actions to help prevent the spread of respiratory viruses should be followed, these include:

  • Wash your hands often with soap and water for at least 20 seconds. Use an alcohol-based hand sanitizer that contains at least 60% alcohol if soap and water are not available.
  • Avoid touching your eyes, nose, and mouth with unwashed hands.
  • Avoid close contact with people who are sick.
  • Cover your cough or sneeze with a tissue, then throw the tissue in the trash.
  • Clean and disinfect frequently touched objects and surfaces.
  • Maintain at least 1 meter (3 feet) distance between yourself and other people, particularly those who are coughing, sneezing and have a fever.
  • Wear cloth face coverings in public settings where other social distancing measures are difficult to maintain. 
  • Stay home and self-isolate even with minor symptoms such as cough, headache, mild fever, until you recover.
  • If you have a fever, cough and difficulty breathing, seek medical attention.

As a general precaution, practice general hygiene measures when visiting live animal markets, wet markets or animal product markets-

  • Ensure regular hand washing with soap and potable water after touching animals and animal products
  • Avoid touching eyes, nose or mouth with hands;
  • Avoid contact with sick animals or spoiled animal products.
  • Strictly avoid any contact with other animals in the market (e.g., stray cats and dogs, rodents, birds, bats).
  • Avoid contact with potentially contaminated animal waste or fluids on the soil or structures of shops and market facilities.
  • Avoid consumption of raw or undercooked animal products: Handle raw meat, milk or animal organs with care, to avoid cross-contamination with uncooked foods, as per good food safety practices

Contacts should be monitored for 14 days from the last unprotected contact.

  • A contact is a person involved in any of the following:
  • Providing direct care for 2019-nCoV patients, working with health care workers infected with novel coronavirus, visiting patients or staying in the same close environment of a 2019-nCoV patient.
  • Working together in close proximity or sharing the same classroom environment a with 2019-nCoV patient
  • Traveling together with 2019-nCoV patient in any kind of conveyance
  • Living in the same household as a 2019-nCoV patient within a 14‐day period after the onset of symptoms in the case under consideration

Key advice for older adults and people with pre-existing conditions:

  • When you have visitors to your home, exchange “1 metre greetings”, like a wave, nod, or bow.
  • Ask visitors and those you live with to wash their hands.
  • Regularly clean and disinfect surfaces in your home, especially areas that people touch a lot.
  • If someone you live with isn’t feeling well (especially with possible COVID-19 symptoms), limit your shared spaces.
  • If you become ill with symptoms of COVID-19, contact your healthcare provider by telephone before visiting your healthcare facility.
  • Make a plan in preparation for an outbreak of COVID-19 in your community.
  • When you go out in public, follow the same preventative guidelines as you would at home.
  • Stay up to date using information from reliable sources.

With a combination of public health measures disease spread can be prevented and controlled,such as

  • Rapid identification, diagnosis and management of the cases,
  • Limit human-to-human transmission including reducing secondary infections among close contacts and health care workers, by
  • identification and follow up of the contacts
  • infection prevention and control in healthcare settings
  • Implementation of health measures for travellers,
  • Awareness- raising in the population and risk communication
  • Preventing transmission amplification events


  • PUBLISHED DATE : Jul 15, 2020
  • CREATED / VALIDATED BY : Dr. Aruna Rastogi
  • LAST UPDATED ON : Feb 24, 2021


Write your comments

This question is for preventing automated spam submissions
The content on this page has been supervised by the Nodal Officer, Project Director and Assistant Director (Medical) of Centre for Health Informatics. Relevant references are cited on each page.