This originally appeared in the July/August issue of Discover magazine. Support our science journalism by becoming a subscriber.
Coronavirus Disease 2019 (COVID-19) is a pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2, also called SARS-CoV-2. Here’s a closer look at how the new coronavirus affects the human body.
SARS-CoV-2 starts its journey in the nose, mouth or eyes, and travels down to the alveoli in the lungs. Alveoli are tiny sacs of air where gas exchange occurs.
(Credit: Avesta Rastan)
Gas Exchange
Each sac of air, or alveolus, is wrapped with capillaries where red blood cells release carbon dioxide (CO2) and pick up oxygen (O2). Two types of alveolar cells facilitate gas exchange: Type I cells are thin enough that the oxygen passes right through, and Type II cells secrete surfactant — a substance that lines the alveolus and prevents it from collapsing.
Viral Infection
The spike proteins covering the coronavirus likely bind to ACE2 receptors on Type II alveolar cells, allowing the virus to enter the cell via endosome or membrane fusion and release its RNA. The RNA “hijacks” the cell, telling it to assemble many more copies of the virus and release them, so they can infect neighboring cells.
Impaired Gas Exchange
When the immune system attacks the area of infection, it also kills healthy alveolar cells. This results in three things that hinder gas exchange:
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The alveoli collapse due to loss of surfactant from Type II cells.
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Less oxygen enters the bloodstream.
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More fluid enters the alveolus.
What Can You Do?
1. Preventive Actions
There is currently no proven treatment for COVID-19, so adopting the best practices for preventing infection is crucial. These include:
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Physical distancing — keep a distance of at least 6 feet between you and others outside of your home.
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Proper hand-washing — wash your hands for at least 20 seconds.
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Cough or sneeze into your elbow or a tissue and immediately wash your hands.
2. Stay Healthy
Make a routine of eating a well-balanced diet, drinking plenty of water, getting enough sleep, exercising and monitoring your mental health. Reach out to family and friends for support.
3. Stay Informed
With a situation that changes daily, it is crucial to stay informed so you know if any changes have occurred both globally and in your community. Make sure to look for evidence-based sources to avoid misinformation. And take a break from the news when you need it, for your mental health.
4. Donate
Consider donating to local businesses or online funding campaigns if you have financial flexibility. If you have spare time, consider volunteering for community initiatives, such as helping deliver food to those in need.
