CORONA VIRUS DISEASE 2019

Introduction:

  • Coronaviruses constitute the subfamily Orthocoronavirinae. In the family  Coronaviridae, order Nidovirales, and realm Riboviria. 
  • The name coronavirus is derived from the Latn corona. It means "crown" or  "halo", and it refers to the characteristic appearance reminiscent of a crown or a solar corona around the virions (virus particles).
  • They are enveloped viruses with a positive-sense single-stranded RNA genome  and a nucleocapsid of  helical symmetry. They are genome size of coronaviruses  and range from approximately 27 to 34  kilobases, the largest among known  RNA viruses. 

After the pandemic of Spanish Flu (1918-1919) with the estimated death toll of 50 to 100 million people, there have been several outbreaks of viral infections that have threatened human life. The Coronavirus (termed COVID-19 by WHO) is an RNA virus. There have been two outbreaks with Coronavirus, the Middle East Respiratory Syndrome (MERS) in 2012, and Severe Acute Respiratory Syndrome (SARS) in 2002-03(1-2). The present pandemic has gripped the world with a high rate of mortality. The primary presentation is respiratory system involvement in the form of fever, sore throat, cough, sneezing, and features of pneumonia leading to ARDS and multiorgan dysfunction syndrome (MODS). In the absence of vaccination and definitive therapy prevention of transmission is the only solution. At the end of 2019, a novel coronavirus was identified as the cause of a cluster of pneumonia cases in Wuhan, a city in the Hubei Province of China. Epidemiologic investigation in Wuhan at the beginning of the outbreak identified an initial association with a seafood market that sold live animals, where most patients had worked or visited. Now the person to person transmission (both droplet and fomites) is well documented. In the past two months, this virus has taken the whole world in its grip and the worst affected countries are Italy, China, the United States of America, Iran, Spain, South Korea, and France. On March 11, 2020 Director-General WHO declared COVID-19 situation a pandemic. Understanding about this illness is evolving. 

Types of COVID 

  There are seven different strains of coronavirus. 

  • 229E (alpha coronavirus) 
  • NL63 (alpha coronavirus) 
  • OC43 (beta coronavirus) 
  • HKU1 (beta coronavirus) 
  • MERS-CoV (the beta coronavirus is the one which causes Middle East Respiratory Syndrome or MERS) 
  • SARS-CoV (the beta coronavirus that causes the severe acute respiratory syndrome, or SARS) 
  • SARS-CoV-2 (is the novel coronavirus and is the one t causes coronavirus disease 2019, or COVID-19) 

SARS

SARS coronavirus (SARS - CoV) – virus identified in 2003. SARS-CoV is thought to be an animal virus. It is from an as-yet-uncertain animal reservoir, perhaps the bats, that can spread to other animals (civet cats). It first infected humans in the Guangdong province of southern China in 2002 .

Epidemiology 

  • Globally, as on May 4, there have been 36,03,874 confirmed cases, including  2,50,054 deaths. 
  • The COVID-19 situation is “especially serious” in Mumbai, Pune, Indore, Jaipur,  Kolkata, and a few  other places in West Bengal, the Home Ministry said on April 20. According to an AFP tally on April 20 the coronavirus pandemic had killed more than 170,000 people globally, close to two-thirds of them in hardest-hit  Europe. 
  • With ~ 69000 deaths, the United States has the highest mortality rate, followed  by Italy with ~29000.
  • On May 4 total cases in India -42,836 with Deaths 1395. 

Transmission 

  • Through respiratory droplets and contact routes, the COVID-19 virus is primarily transmitted between people.
  • Airborne transmission may be possible in specific settings and circumstances in  the context of COVID- 19, in which procedures or support treatments that generate aerosols are performed i.e.,endotracheal intubation, open suctioning, administration of nebulized treatment, manual ventilation before intubation,  turning the patient to the prone position, disconnecting the patient from the ventilator,non-invasive positive-pressure ventilation, tracheostomy,bronchoscopy, and cardiopulmonary resuscitation. 
  • There is also some evidence that COVID-19 infection may also lead to intestinal infection and may be present in feces. However, only one study has cultured the COVID-19 virus from a single stool specimen  to date. There have been no reports as such until now of fecal-oral transmission of the  

   COVID-19 virus to date. 

Clinical Features

       Patients may vary from being asymptomatic (Without fever, cough etc) to being seriously ill requiring ICU care .

       Usual symptoms are:

  1. Fever (83%)
  2. Cough (82%)
  3. Shortness of breath (31%)
  4. Sore throat (5%)
  5. Rhinorrhoea (4%)
  6. Diarrhea (2%)
  7. Bilateral pneumonia on imaging (75%)
  8. ARDS (10-17% of admitted patients)
  9. The incubation period is between 2-14 days.

Complications

   Other than ARDS requiring mechanical ventilation, complications are :

  • Arrythmia
  • Acute cardiac injury
  • Shock
  • Cardiomypopathy

Prevention

  • Hand hygiene- Clean your hands with alcohol-based hand rubs (20 seconds) /soap (60 
  • . If hands are visibly soiled, use soap and water for hand wash. Hand hygiene performed before and after using bathroom, before, during and after preparing food, before and after eating /drinking, after coughing, blowing or sneezing, after touching garbage, after touching mask or soiled PPE. Foot operated sanitizers should be put outside elevators, OPDs, screening areas, ICUs and wards.
  • Avoid close contact with person who has fever or cough.
  • If you have flu-like symptoms such fever, cough, running nose or sore throat, seek medical  help early.
  • While coughing or sneezing cover your face.
  • The consumption of raw and under-cooked animal products should be avoided
  • Use mask- If masks are worn, appropriate use and disposal is essential to ensure they are effective and to avoid any increase in risk of transmission associated with the incorrect use and disposal of masks
  • Avoid travel if you are unwell
  • Use of PPE -To avoid direct contact with patients’ blood, body fluids, secretions (including              respiratory secretions) and non-intact skin.

 

v Standard precautions should always be applied. Additional contact and droplet precautions should continue until the patient is asymptomatic. Standard precautions should always be routinely applied in all areas of health care facilities including OPD. Standard precautions are summarized below:

 

Diagnosis

Criteria for testing :

ICMR has revised criteria of testing

  • All symptomatic individuals who have undertaken international travel in the last 14 days.
  • All symptomatic contacts of laboratory confirmed cases.
  • All symptomatic health care workers.
  • All hospitalized patients with Severe Acute Respiratory Illness (fever AND cough and/or    shortness of breath)
  • Asymptomatic direct and high-risk contacts of a confirmed case should be tested once between day 5 and day 14 of coming in his/her contact.

Three specimens including serum, Respiratory secretions (broncho-alveolar lavage, sputum, tracheal aspirate) and upper respiratory secretions (Nasal or throat swab) should be sent for evaluation. Additional samples like urine and stools may also be safely stored for testing later. Samples should be stored at 2-8 degrees centigrade. These samples should be subjected to RT-PCR assays.

 COVID rapid tests Serological test detects IgM and IgG antibodies is serum or. (Not so widely available till now)

Treatment and Prevention

There is no specific treatment (Antiviral drug) for this virus infection. Therefore there is only supportive treatment can be offered. Also there is no vaccination is available for prevention. Antiviral drugs based on the genetic makeup of this virus are under research and testing. Besides antiviral drugs, antimalarial medications (hydroxychloroquine) has also been tried with some benefit. Hydroxychloroquine is approved for use for patients and for prophylaxis of contacts including Health Care Workers.

 

Dr. SONISHA GUPTA 

PROFESSOR AND HEAD DEPARTMENT PULMONOLOGY

SANTOSH DEEMED MEDICAL UNIVERSITY GHAZIABAD