The document provides an overview of various species of coronaviruses that infect humans, including SARS-CoV-2, MERS-CoV, and others, detailing their origins, transmission mechanisms, and associated diseases. It highlights COVID-19, caused by SARS-CoV-2, including its symptoms, testing methods, and prevention strategies such as social distancing and hygiene practices. The document also describes the structure of coronaviruses and the basic reproduction number, indicating their infectivity and potential health impacts.

1. Dr. K. SELVAKUMAR
M.Sc., M.Phil., Ph.D., MBA-HM
Medical Biochemist

2. • Severe acute respiratory syndrome coronavirus 2 (SARS-
CoV-2),
• Middle East respiratory syndrome-related coronavirus
(MERS-CoV), or EMC/2012 (HCoV-EMC/2012), is a species of
coronavirus which infects humans, bats, and camels.
• The infecting virus is an enveloped, positive-sense, single-
stranded RNA virus which enters its host cell by binding to the
Dipeptidyl peptidase-4 (DPP4) receptor. The species is a
member of the genus Betacoronavirus and subgenus
Merbecovirus.
• Initially called 2012 novel coronavirus (2012-nCoV) or simply
novel coronavirus (nCoV), it was first reported in 2012 after
genome sequencing of a virus isolated from sputum samples
from a person who fell ill in a 2012 outbreak of a new flu.

3. Human coronavirus NL63
• Human coronavirus NL63 or HCoV-NL63 is a species
of coronavirus that was identified in late 2004 in a seven-
month-old child with bronchiolitis in the Netherlands.
• The infecting virus is an enveloped, positive-sense, single-
stranded RNA virus which enters its host cell by the ACE2
receptor.
• Infection with the virus has been confirmed worldwide, and
has an association with many common symptoms and
diseases. Associated diseases include mild to moderate upper
respiratory tract infections, severe lower respiratory tract
infection, croup and bronchiolitis

4. Human coronavirus HKU1 (HCoV-HKU1)
• Human coronavirus HKU1 (HCoV-HKU1) is a species
of coronavirus which originated from infected mice
• The infecting coronavirus is an enveloped, positive-
sense, single-stranded RNA virus which enters its
host cell by binding to the
N-acetyl-9-O-acetylneuraminic acid receptor.
• The virus has the Hemagglutinin esterase (HE) gene,
which distinguishes it as a member of the genus
Betacoronavirus and subgenus Embecovirus.
• It was discovered in January 2005 in two patients in
Hong Kong

5. • Human coronavirus 229E (HCoV-229E) is a
species of coronavirus which infects humans
and bats. The infecting virus is
an enveloped, positive-sense, single-
stranded RNA virus which enters its host cell by
binding to the APN (Alanine aminopeptidase)
receptor.
• Along with Human coronavirus OC43, it is one of
the viruses responsible for the common cold.
• The species is a member of the
genus Alphacoronavirus and
subgenus Duvinacovirus.
Human coronavirus 229E

6. • Human coronavirus OC43 (HCoV-OC43) is a member of the
species Betacoronavirus 1 which infects humans and cattle.
• The infecting coronavirus is an enveloped, positive-sense,
single-stranded RNA virus which enters its host cell by
binding to the N-acetyl-9-O-acetylneuraminic acid receptor.
• Along with Human coronavirus 229E, it is one of the viruses
responsible for the common cold.
• It has, like other coronaviruses from genus Betacoronavirus,
subgenus Embecovirus, an additional shorter spike-like
surface protein called hemagglutinin esterase (HE).
Human coronavirus OC43

7. • Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2).
• The disease was first identified in 2019 in Wuhan, China, and has since spread globally,
resulting in the 2019–20 coronavirus pandemic.
• Common symptoms include fever, cough, and shortness of breath. Muscle pain, sputum
production and sore throat are less common.
• While the majority of cases result in mild symptoms, some progress to severe
pneumonia and multi-organ failure.
• As of 20 March 2020, the rate of deaths per number of diagnosed cases is 4.1%; however, it
ranges from 0.2% to 15% depending on age and other health problems.
Coronavirus disease 2019 COVID-19

8. Electron Microscopic COVID 19
The basic reproduction number (Ro) of the virus has been estimated to be between 1.4 and 3.9.
This means that each infection from the virus is expected to result in 1.4 to 3.9 new infections
when no members of the community are immune and no preventive measures are taken.

9. • Each SARS-CoV-2 virion is approximately 50–200 nanometres in diameter.
• Like other coronaviruses, SARS-CoV-2 has four structural proteins, known as the S (spike), E (envelope), M
(membrane), and N (nucleocapsid) proteins; the N protein holds the RNA genome, and the S, E, and M
proteins together create the viral envelope.
• The spike protein, which has been imaged at the atomic level using cryogenic electron microscopy, is the
protein responsible for allowing the virus to attach to the membrane of a host cell.
Structure of COVID 19

10. Symptoms

11. Life Span

12. Causes
• It is primarily spread between people via respiratory droplets from coughs
and sneezes.
• The virus can remain viable for up to three days on plastic and stainless
steel, and for three hours in aerosols
• The lungs are the organs most affected by COVID-19 because the virus
accesses host cells via the enzyme ACE2, which is most abundant in the type
II alveolar cells of the lungs.

13. • The virus uses a special surface glycoprotein,
called "spike", to connect to ACE2 and enter the
host cell.
• The density of ACE2 in each tissue correlates with
the severity of the disease in that tissue and some
have suggested that decreasing ACE2 activity
might be protective, though another view is that
increasing ACE2 using Angiotensin II receptor
blocker medications could be protective. As the
alveolar disease progresses, respiratory failure
might develop and death may follow
Causes

14. Diagnosis
• The WHO has published several testing protocols for the disease. The standard
method of testing is real-time reverse transcription polymerase chain reaction (rRT-
PCR). The test can be done on respiratory samples obtained by various methods,
including a nasopharyngeal swab or sputum sample.
• Results are generally available within a few hours to two days.
• Blood tests can be used, but these require two blood samples taken two weeks apart
and the results have little immediate value.
• Chinese scientists were able to isolate a strain of the coronavirus and publish the
genetic sequence so that laboratories across the world could independently develop
polymerase chain reaction (PCR) tests to detect infection by the virus

15. Sample Collection & Transport

19. Gene and Sequences

20. Primers

21. Prevention
• Vaccine against SARS-CoV-2 is expected by 2021, a key part of managing the
COVID-19 pandemic is trying to decrease the epidemic peak, known as
flattening the epidemic curve through various measures seeking to reduce
the rate of new infections

22. Prevention
• To reduce the chances of infection
– stay home,
– avoid travel and public activities,
– wash hands with soap and warm water often and for at least 20 seconds
– practice good respiratory hygiene and avoid touching the eyes, nose, or
mouth with unwashed hands
• The Centers for Disease Control and Prevention (CDC)
recommends covering up the mouth and nose with a tissue
during any cough or sneeze and coughing or sneezing into the
inside of the elbow if no tissue is available. They also
recommend proper hand hygiene after any cough or sneeze.

23. Prevention
• Social distancing strategies aim to reduce contact of
infected persons with large groups by closing schools and
workplaces, restricting travel, and canceling mass
gatherings. Social distancing also includes that people
stay 6 feet apart
• According to the WHO, the use of masks is only
recommended if a person is coughing or sneezing or when
one is taking care of someone with a suspected infection.
• Avoid touching the eyes, nose, or mouth with unwashed
hands. Spitting in public places also should be avoided.

24. Statistics of Mortality

25. Fatality details of diseases

26. Current statistics :
21 March 2020
11.00 AM