Coronaviruses, called ‘corona’ because they look like they have a halo in an electron microscope, are a family of viruses that cause common colds but can sometimes cause a more serious infection. They are RNA viruses (as opposed to DNA viruses) and they can infect many different species….a combination that leads to a high mutation rate when replicating. When a virus can mutate rapidly, it can cause more severe disease because the immune system doesn’t recognize it and that causes it to over-react, causing the majority of symptoms. Normally, common cold viruses mutate more slowly over time and each time we get infected our immune system recognizes some of the proteins on its surface (because we produce memory cells during infections), and then we can fight it off with minor annoying symptoms.
Coronaviruses have caused some severe infections in the past including SARS, Severe Acute Respiratory Syndrome, that killed about 774 people in 2003, and likely came from bats. MERS, Middle Eastern Respiratory Syndrome, that killed about 858 people in 2012 and likely came from camels.
The current Coronavirus outbreak began in China in Dec. 2019 and has so far infected 5500 people and has killed 106. It is thought that this has also come from wildlife, perhaps from Chinese cobra or krait snakes that are sold at the Wuhan market where the infection began.
Death rate comparison
SARS – 774 people died out of 8,096 infected = 9.5%
MERS – 858 people died out of 2494 infected = 34.4%
Wuhan Coronavirus (Jan. 29) – 109 people have died out 5578 infected so far = 1.9%
Wuhan Coronavirus (Jan. 31) – 213 deaths out of 9,923 infections – 2.1%
Wuhan Coronavirus (Feb. 1) – being called 2019nCoV. 259 deaths out of 12,024 people that have been tested but estimated that many thousands of people have the infection with normal common cold symptoms. The death rate is most likely the same as normal respiratory infections at 1% or less.
If interested in ongoing toll, click this link to the worldometer (actually very cool website with lots of interesting world population info)
Any flu-like respiratory infection – in any given year the CDC estimates that globally, 650,000 people die out of several millions of people that get infected – <1%
Fun Fact: There are over 200 viruses that cause respiratory infections like the common cold and the flu. These viruses include rhinoviruses (30-80%), coronaviruses (15%), adenoviruses (5%), influenza viruses (10-15%), and there are also human respiratory syncytial viruses, and human parainfluenza viruses.
How does the Coronavirus cause infection?
These viruses are transmitted through droplets coughed or sneezed from infected people into the air and on surfaces. It can be inhaled into the respiratory tract or it can be moved from surfaces by your hands to your face, just like any other cold or flu virus. The incubation period from time of exposure to symptoms is anywhere from 2-14 days. Once it enters the body it infects epithelial cells that line the respiratory tract, leading to symptoms such as coughing, shortness of breath, and fever. It enters cells and then uses our cellular machinery to replicate and then spread to nearby cells. Because the virus is highly mutated and unlike other common cold viruses our immune system has been in contact with, it causes our immune system to react very strongly. Many of the symptoms are caused by our own immune system trying to eradicate the new infection. The immune system kills infected cells and nearby healthy cells, causing a fever, mucus production, dilation of blood vessels and increased permeability of blood vessels, which causes fluid to leave the vascular system and enter the infected tissue. Excessive amounts of fluid in the lungs can cause respiratory distress and this is why some people needed to be put on a ventilator.
Who is dying from this infection?
Most of the people that have died from this infection are elderly and have other health conditions such as cirrhosis of the liver, hypertension, heart disease, have had strokes, Parkinson’s disease, diabetes, other pulmonary infections, COPD, or kidney disease. The first 17 people that died ranged from age 48-89 with an average age of 73 and all had one or more other serious health conditions. I have only heard of one case so far where it was a younger person, age 36, that did not have other underlying conditions, otherwise, young healthy people are not dying. Many people have fully recovered from the infection. Healthy people that have had the virus have been sick for about 1 week.
Here some of the key nutrients that help your immune system fight viral infections:
- Vitamin A is particularly important for your immune system in fighting viral infections and for protecting epithelial cells that line the respiratory tract and digestive tract. People deficient in vitamin A have a higher risk of complications from viral infections. The tolerable upper limit for vitamin A is 10,000 IU or 3000 ug per day.
- Vitamin C is an important antioxidant that helps to scavenge free radicals, which can damage cells. The immune system makes a huge amount of free radicals trying to kill viruses; vitamin C will help reduce the damage to your normal cells. A number of clinical trials have shown that vitamin C reduces the severity and duration of viral infections like the common cold. The tolerable upper limit for vitamin C is 2000 mg per day.
- Vitamin D is a very important immune regulator. Sometimes during viral infections our immune system can over-react, causing the majority of symptoms, if the pathogen has a lot of new surface proteins. Vitamin D helps to regulate the immune system so that it is less likely to over-react. The tolerable upper limit for vitamin D is 4000 IU per day.
- Zinc is a mineral found in meat, shellfish (oysters have the most) legumes, nuts and eggs and it plays a very important role in immune cell signalling pathways. Zinc also has anti-inflammatory and anti-oxidant properties. The tolerable upper limit for zinc is 40 mg per day.
Lastly, other things that are very important for immune function is getting enough sleep and reducing stress, stress inhibits proper immune function.