PATHOLOGY FOR COVID-19

Question 1

INTRODUCTION OF CORONA VIRUS

Answer 1

COVID-19, short for “coronavirus disease 2019,” is the official name
given by the World Health Organization (WHO)
• COVID-19 was initially discovered in Wuhan, China (2019).
• It is caused by the Severe Acute Respiratory Syndrome
Coronavirus-2 (SARS-CoV-2)
• COVID-19 is also called novel coronavirus pneumonia
• It is categorized as an HG3 organism (hazard group 3).
• Other viruses in this category (HG3) include rabies, poliovirus,
dengue virus, hepatitis virus B, C, D and E, and HIV 1 and 2.

Question 2

TYPES OF CORONA VIRUS

Answer 2

The name corona - refers to a crown

• Virus has crown-like spikes on their surface on
electron microscope
• There are many different coronaviruses
identified in animals
• only a small number of coronaviruses can
cause disease in humans.
• Some coronaviruses such as 229E, NL63, OC43
and HKU1 are common causes of illness, including
respiratory illness, in humans throughout the world.

Question 3

COVID-19 (CLINICAL)

Answer 3

• Most patients recover - mild viral syndrome
Upper respiratory tract in mild disease
• Causes a viral pneumonia, most recover - mild symptoms
• Bilateral lobes of the lung involved in more severe disease

Question 4

Clinical – prognosis OF COVID-19

Answer 4

• The death rate increases in patients with:
• underlying cardiovascular disease
• diabetes
• chronic respiratory disease
• hypertension
• Underlying cancer
• Underlying immunosuppressio

Question 5

Chest X-ray :

Answer 5

• Lung shows opacities / areas of consolidation

* Right: Bilaterally lungs show groundglass opacitie

Question 6

Clinical investigations

Answer 6

• Nasopharyngeal or oropharyngeal swabs (sent to virology for PCR)
• Other samples - sputum and bronchoalveolar lavage (BAL)
• Contact tracing
• SARS-COV-2 PCR testing (commonly done)
• Rapid Antigen testing (quick / cheaper)
• Cardiovascular :
• Biomarkers for Troponin T/I, Brain natriuretic peptide (BNP), Ddimers
• ECG, and echocardiography

Question 7

Pathogenesis

Answer 7

• This invades cells through the angiotensin-converting enzyme 2 (ACE2)
receptor.
• this receptor is present in the lungs, heart, and blood vessels
• Also enters via TMPRSS2 (Transmembrane Serine Protease 2)
• After a SARS-CoV-2 attaches to a target cell, the virion releases RNA into
the cell, initiating replication of the virus which further disseminates to
infect more cells.
• Cytokine Storm: This is known as the cytokine release syndrome (CRS),
is a form of systemic inflammatory response (SIRS) that can be triggered
by a variety of factors such as infections.
• Leukocytes are activated and release inflammatory cytokines, which in
turn activate yet more white blood cells.

Question 8

Lung pathology findings

Gross

Answer 8

• From pulmonary oedema to lung consolidation
• Increased lung weight
• Macroscopic pulmonary emboli may be present
• Purulent inflammation, if secondary infection is superimposed

Question 9

Lung pathology findings

microscopically

Answer 9

A range of findings have been documented microscopically:
• Diffuse alveolar damage (DAD)
• Fibrin exudation, with formation of hyaline membranes
• Pulmonary oedema, capillary congestion
• Fibrin thrombi in pulmonary arteries
• Type 2 pneumocyte hyperplasia
• Intra-alveolar macrophages
• Organising pneumonia
• Bronchopneumonia

Question 10

Cardiovascular system (CVS) pathology

Answer 10

• Arterial thrombotic complications
• Disseminated intravascular coagulopathy (DIC)
• Venous thromboembolism (VTE)
• myocarditis
• arrhythmias
• pericarditis

Question 11

Treatment modalities

Answer 11

• Ventilation
• Vaccines 
• Other: remdesivir, ivermectin, chloroquine, serum therapy, interferon treatment, 
mental health, herbal medication, etc.
• New Diagnostic Methods
• Autopsies

Question 12

Epidemiology / Statistics

• New variants:

Answer 12

• Genome sequencing,
• 501Y.V2 first discovered in South Africa,
• Lineage B.1.1.7, also known as 20I/501Y.V1  UK variant