Autopsy Findings in COVID-19 Patients

Introduction:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in the death of millions of people all over the world. Many countries were successful in bringing down the COVID cases by lockdowns, strict social distancing rules, and vaccination. However, SARS-CoV-2 that causes COVID-19 (the coronavirus disease 2019), has significantly impacted people's health and lives.

For a more thorough understanding of the disease process and treatment, scientists have conducted autopsies on the victims, which has provided a more detailed understanding of the histopathological and anatomical findings of the disease. It has also given a rough idea about the mechanism of action and disease pathology, but more remains unclear. We have included the significant findings obtained through postmortem and how the virus affects multiple systems in the body.

What Do We Know About SARS-CoV-2 So Far?

SARS-CoV-2 is a novel RNA (ribonucleic acid) virus. It has a similar genomic sequence, clinical presentation, and behavior to SARS-CoV, the virus that caused SARS in 2003. The virus has a surface spike glycoprotein that binds to the protein angiotensin-converting enzyme 2 (ACE2) which is located in the tissues of the lungs, heart, digestive tract, lymph nodes, brain, etc. SARS-CoV-2 is more virulent and affects multiple systems in the human body.

Clinical Presentation:

The severity of clinical manifestations of COVID-19 ranges from asymptomatic forms to severe respiratory failure. Based on the following categories, the clinical manifestations include-

1. Asymptomatic - Such patients do not exhibit any symptoms but might still spread the infection to others.

2. Mild - Mild fever, headache, tiredness, dry cough, nasal congestion, sore throat, and muscle pain. Some people also experience shallow breathing and shortness of breath. Almost 81 % of all patients exhibit mild to moderate symptoms.

3. Severe - Shortness of breath, oxygen saturation less than 93 %, and rapid breathing. Around 14 % of the cases have these symptoms. The patient can have pneumonia, sepsis, or acute respiratory distress syndrome.

4. Critical - Critically ill patients exhibit cardiac symptoms, respiratory failure, septic shock, and multiple organ failure (MOF). Only 5 % of patients show critical symptoms.

Other symptoms of COVID-19 include,

• Loss of taste and smell.
• Fatigue.
• Diarrhea.
• Red and irritated eyes.
• Skin rash.
• Nausea and vomiting.

Causes of Death From COVID-19:

The following are the main causes of death from COVID-19-

1. Acute respiratory distress syndrome (ARDS) - The small air sacs in the lungs fill with fluid, depriving the organs in the body of oxygen.

2. Sepsis - It is a life-threatening and extreme response of the body’s immune system to an infection.

3. Acute cardiac injury - Results in elevated cardiac markers, such as troponin. It is considered equivalent to myocardial infarction (MI).

4. Type I respiratory failure - Lung damage results in a lack of oxygen.

5. Heart failure - The heart muscles do not pump sufficient blood.

6. Alkalosis - Increased bicarbonate in the blood increases the alkalinity and decreases acid in the blood.

7. Acute kidney injury - Kidney damage or kidney failure due to infection.

8. Hypoxic encephalopathy - Brain injury due to a lack of oxygen supply.

9. Hyperkalemia - Higher potassium levels in the blood.

Various studies have shown hyperinflammatory response to the virus is the main cause of death as it affects the heart vessels, kidney, liver, and other vital organs.

What Are the Postmortem Findings in COVID-19 Victims?

1) Lung Findings:

• Pulmonary Capillary Congestion - Accumulation of fluid in the lung capillaries, affecting the exchange of oxygen and carbon dioxide.

• DAD - Diffuse alveolar damage (DAD) is damage to the gas-exchange surfaces (alveoli) in the lungs. This leads to edema (swelling), fibrosis (scarring), and impaired oxygen exchange.

• Bronchopneumonia - A type of pneumonia that results in inflammation of the small air sacs in the lungs (alveoli).

• Emphysema - Here, alveoli get damaged, resulting in shortness of breath.

• Pulmonary Embolism - Blood clots block the arteries present in the lungs.

• Pulmonary Hemorrhage - Bleeding from the upper or lower respiratory tract.

• Amyloidosis of Vessels - Abnormal protein called amyloid starts depositing in different parts of the lungs and its vessels.

• Pulmonary Vasculitis - Inflammation and destruction of blood vessels present in the lungs.

2) Heart Findings:

• Myocardial Hypertrophy - The thickening of heart muscles.

• Senile Amyloidosis - Deposition of abnormal protein in heart muscles.

• Pericarditis - Inflammation of the pericardium, which is the fibrous connective tissue surrounding the heart.

• Cardiac Fibrosis - Abnormal thickening of heart muscles or heart valves.

• Acute Myocardial Infarction - Blockage in one or more arteries of the heart.

• Myocardial Necrosis - Cell death (necrosis) of heart muscles.

3) Liver Findings:

• Fatty Liver - Abnormal fat deposition in the liver.

• NASH - Nonalcoholic fatty acid disease (NASH) is an advanced stage of fatty liver.

• Hepatic Necrosis - Lack of oxygen supply to the liver results in shock and cell death.

4) Lymph Node Findings:

• Lymphatic Congestion - The lymph nodes get blocked or clogged.

• Increased Plasmablasts - Plasmablasts are immature plasma cells that secrete antibodies.

5) Spleen Findings:

• Splenitis - Inflammation of the spleen.

6) Kidney Findings:

• Acute Tubular Necrosis - Low blood flow to the kidneys damages the cells present in renal tubules.

• Glomerulosclerosis - Scarring or hardening of the tiny blood vessels (glomeruli) in the kidney.

• Disseminated Intravascular Coagulation - Here, blood clots block small blood vessels of the kidneys, resulting in acute kidney injury.

• Hypertensive Nephropathy - Kidney failure.

Live SARS-CoV-2 Virus Found During Autopsy:

During the first autopsy conducted in India, doctors were able to isolate the live SARS-CoV-2 virus 18 hours after the patient’s death. This 62-year-old COVID-19 patient died after 14 days of treatment and had active viruses in the mouth, throat, and nasal area. The various swabs that the doctors took from the mouth, throat, and nose all tested positive in the RT-PCR test. But, there was no trace of the virus on the skin or the surface of internal organs like the lungs.

Similarly, a forensic practitioner most likely was infected by a deceased patient in Thailand. This is why it is not surprising to find live SARS-CoV-2 virus for up to hours or days after death. The virus can be present in the nasal secretions and can also be replicating in the cells of the body that have not yet died. Though the duration till which the coronavirus could stay alive in human corpses is inconclusive and unclear, scientists assert that the viral genome persists in the corpse’s tissues for more than 30 days. Hence, it can be hypothesized that disease transmission from the deceased can occur until a certain period after death, even after disinfecting the corpse.