Coronavirus Disease, officially named as COVID-19, started as an epidemic in a live animal market in Wuhan, China, and spread throughout the world at an alarming rate. It was declared a pandemic by WHO on 11th March, 2020. The virus causing the disease was initially named 2019 Novel Coronavirus (2019-nCoV), but later officially renamed by WHO as Severe Acute Respiratory Syndrome- Coronavirus 2 (SARS-CoV-2). This virus is related to SARS-CoV and MERS-CoV that caused epidemics in China and Saudi Arabia in 2002 and 2012, respectively. The virus primarily affects the lungs, and causes death in a small proportion of patients due to Acute Respiratory Distress Syndrome (ARDS). The data on this new disease is very early, and might change as new data emerges. Disclaimer: The images used in this presentation do not belong to me.

1. Coronavirus Disease 2019
(COVID-19)
Dr. Himanshu Khatri MD
Assistant Professor, Department of Microbiology
Saraswati Medical College, Unnao
Presented on: 13th March 2020

2. COVID-19
• Current outbreak of an infectious disease
throughout the world.
• Outbreak was declared a Public Health
Emergency of International Concern on 30
January 2020.
• WHO has officially named it Coronavirus
Disease 2019 (COVID-2019)

3. As on 7th March, 2020
• More than 90 countries affected
• Worst affected: China (>80,000 cases)
• South Korea: >5,000 cases
• Italy and Iran: around 3,000 cases
• More than 1 lakh infected
• More than 3,000 deaths
• Travel advisory for China, South Korea, Italy,
Iran, and Japan

4. What causes COVID-19?
• A virus
• Virus was initially called 2019 novel
coronavirus (2019-nCoV)
• Later renamed by WHO as severe acute
respiratory syndrome coronavirus 2 (SARS-
CoV-2)
• SARS-CoV-2 belongs to a group of viruses
called Coronaviruses
• Corona (Latin=crown)

6. What are the infections caused by
Coronaviruses?
• Respiratory: Common cold, sore throat,
pneumonia, etc.,
• Gastro-intestinal: diarrhea
• Most cause mild disease
• Severe disease were earlier caused by:
1. SARS-CoV: China (2003) [CFR:9.6%]
2. MERS-CoV: Saudi Arabia (2012) [CFR: 34.4%]

7. • Coronaviruses infect
both humans and
animals

8. How did COVID-19 start?
• In December, 2019, a
cluster of pneumonia
cases was reported in a
live animal (even selling
wild animals) market in
Wuhan, China
• However, person to
person transmission has
resulted in a large
number of cases
worldwide

9. What is the source?
• COVID-19 is a
zoonotic disease
• Animal reservoir of
COVID-19 are
probably bats
• Intermediate host is
probably pangolin
Pangolin

10. Why did the virus infect humans?
• Probably the virus mutated to adapt in
humans (host adaptation)
OR
• Increased contact between humans and
animals containing the mutated virus

11. What are the important modes of
transmission?
• Primarily through droplets containing virus
during coughing, sneezing (upto 1 meter)
[DROPLET ROUTE]
• Also, contact of droplets with eyes, nose, and
mouth with contaminated hands/fomites
[CONTACT ROUTE]

12. What are the other modes of
transmission?
• Rarely airborne route, but this does not seem
an important route
• Virus is isolated in stool, but feco-oral route
does not seem important route
• Additionally, from/to animals???

15. How long does the virus survive on
surfaces?
• Probably from a few hours upto several days
depending on the type of surface (based on
data on SARS-CoV)
• Probably for 20-30 minutes on hand

16. What is the incubation period?
• For most cases: 2-14 days
• Average: 5 days

17. When are the patients infectious?
• Some in the incubation period may shed the
shed the virus, but their impact on the spread
is minimal
• Asymptomatic persons can also shed the virus,
but asymptomatic patients are rare
• Virus shedding is maximum in patients
exhibiting severe symptoms
• Virus shedding may occur after resolution of
symptoms

19. How does the virus cause disease?
• Protein S-spikes of the virus bind to
Angiotensin Converting Enzyme-2 (ACE-2)
receptors
• ACE-2 receptors are present in lungs, heart,
kidneys, stomach, intestines, and other
organs

20. Pathogenesis…cont’d
• Virus may spread to different organs through
blood (viremia)
• Virus multiplies intracellularly and causes cell
death by diverting the cell’s protein synthesis
apparatus for its own use

22. How does the virus kill?
• Atypical Pneumonia Acute Respiratory
Distress Syndrome (most common)
• Kidney failure
• Cardiac failure
• Secondary bacterial pneumonia and sepsis

23. What are the specimens used for
diagnosis of COVID-19?
1. Nasal or throat swabs,
2. Sputum,
3. Broncho-alveolar lavage, etc.,

24. How is COVID-19 diagnosed?
• Reverse Transcriptase-Polymerase Chain
Reaction (RT-PCR) [Sensitivity of upto 70%,
but high specificity]
• No serological test available so far

25. COVID-19 testing centers in India

26. Is there a more sensitive test than RT-
PCR?
• Yes!
• Chest CT (Sensitivity of >95%, but less
specificity than RT-PCR)
• CT findings: Scattered bilateral ground glass
opacities consolidation crazy paving
pattern
• Chest X-ray not so sensitive as CT, but useful in
resource poor settings

27. Ground glass opacities in Chest CT

28. How many develop severe disease?
• Mild to moderate: 80%
• Severe (requiring admission and oxygen): 14%
• Critical (requiring ICU admission and life
support): 6%
Most cases are mild less reporting
disease more widespread than actual figures.

29. What is the case fatality/death rate
(CFR)?
• Death rate=Number of deaths/Number of
cases
• Crude fatality rate: 3.4%
• <0.4% (< 50 years) to 14.8% (>80 years)
• Disease in children: relatively rare and mild
(CFR:0.2%)
• Note: This is very early data from China

30. CFR of COVID-19 based on age

31. What is the death rate in different
comorbid conditions?
Pre-existing condition Death rate of all cases
Cardiovascular disease 13.2%
Diabetes 9.2%
Chronic respiratory
disease
8.0%
Hypertension 8.4%
Cancer 7.6%
None 1.4%

32. When can patients be discharged from
the hospital?
• Absence of fever without use of anti-pyretics
• Absence of any other symptoms like cough
• Negative test for virus (RT-PCR) from
respiratory specimens taken atleast 24 hours
apart

33. Is there a specific vaccine or
treatment?
• Not yet!
• However, vaccines and treatment are in
development, and may be available in a few
months
• Some early candidate drugs: Chloroquine,
Favipiravir (anti-Influenza), and Remdesivir
(anti-Ebola)

34. How are patients managed in the
hospital?
• Only supportive care is given:
1. fluids,
2. oxygen,
3. ventilator,
4. dialysis,
5. inotropes, etc.,

35. How can we prevent the transmission?
• Avoid close contact with cases
• Maintain social distancing (> 1 meter)
• Do frequent (every 30 minutes) hand hygiene
(wash/rub), and avoiding touching of eyes,
nose, and mouth
• Avoid gatherings unless absolutely necessary
• Avoid close contact with animals
• Cook animal products thoroughly

36. Hand Hygiene
Hand Rub Hand Wash (when soiled)

37. What is Cough Etiquette?
• During coughing or sneezing, cover the mouth
and nose with disposable tissue (inner side of
elbows if tissue is not available) and
immediately discard the tissue
• Hand hygiene after coughing or sneezing
• It should be practiced by everyone,
irrespective of having COVID-19 or not

39. Should everyone wear masks?
Which are better, face masks or N95 masks?
• No!
• Masks are very effective for halting spread of virus
from sick patients (not only of COVID-19)
• Masks are not advised for general population
• However, masks offer some protection and are
advised for health care workers and for close
contacts

40. What are N95 masks and HAZMAT
suits?
• N95 masks are more effective than face masks
for the exposed, but require training to wear
• Safety goggles are required in addition by
Health Care Workers to prevent entry through
the eyes
• HAZMAT (Hazardous Materials) suit offer best
protection to Health Care Workers

41. N95 masks

42. HAZMAT Suits

43. What should I do if I develop
respiratory symptoms?
• If fever, cough, and shortness of breath,
contact a doctor
• The advisory of eliciting a history of travel to
countries having the epidemic and close
contacts may become less important once
declared a pandemic

44. Is it an epidemic or a pandemic?
• Declared a pandemic on 11th March, 2020
• Goal will now shift from containment of
spread to mitigation of effects

45. Flattening the epidemic curve

46. What is the possible outcome of
COVID-19?
• The pandemic may infect the majority of
population (60-70%) until herd immunity
develops, before dying out
• Mortality will be seen in a small proportion
• If a vaccine/treatment becomes available,
mortality will be much lower

47. Summary
• COVID-19 is a disease with high transmission, but relatively
low mortality
• Spreads by droplet and contact route
• Patients primarily develop fever and respiratory symptoms
• Most recover on their own, and few require special care
• Masks are advised for sick patients and close contacts/care
givers only
• Frequent hand hygiene and cough etiquette should be
practised by everyone
• Close contact with cases, and gatherings should be avoided,
especially by the vulnerable population (elderly and with
underlying conditions)
• Vaccines and treatment may be available in a few months

48. THANK YOU