Affecting multiple organs
Covid-19 can have a wide-ranging effect on many organs in our body.
THE last time, you were telling me about many unusual Covid-19 symptoms, such as Covid toes, skin rashes. and loss of smell and taste (From taste to toes, StarHealth, May 31). What about the gut?
Yes. The SARS-CoV-2 virus that causes Covid-19 binds to our lung cells using the cell’s ACE2 (angiotensin-converting enzyme 2) receptor.
This receptor is also present in our intestinal cells.
The theory is that the virus is in our saliva.
When we swallow our saliva, the virus gets into our guts and binds to our intestinal cells using their ACE2 receptors.
Once this happens, we get diarrhoea, nausea and vomiting.
Sometimes, a Covid-19 patient may only experience these symptoms, without any lung problems like a dry cough or difficulty breathing.
Covid-19 patients with gut problems tend to be diagnosed later and have longer infections.
On average, Covid-19 patients have diarrhoea for five days.
Wait, if Covid-19 patients have diarrhoea, does that mean we have to be careful about using toilets then?
Yes. For example, if one of your family members has Covid-19, it might be advisable to allocate one toilet for their use only, or at least allocate one toilet paper roll for their sole use.
You should also disinfect the toilet seat the patient is using after each use and wash your hands.
I have also heard of the kidney being affected?
You are right.
It occurs through the same mechanism; the kidney also carries ACE2 receptors on its cell membranes.
Some studies are finding that as much as one-third of Covid-19 patients admitted to hospital, develop kidney problems, resulting in acute renal (kidney) impairment, or worse, outright acute renal failure. Some patients even require dialysis.
Patients who develop kidney problems are usually the ones who also have the worst lung symptoms.
It may be that the amount of virus in them is very high and/or their immune system is acting up very badly.
When the immune system is heavily provoked, what happens is that it releases a cytokine storm.
The blood vessels are affected and they start to leak fluid.
When there is less fluid going into the kidneys, they do not get enough oxygen and their tubular cells get damaged.
Gosh! What are the other organs Covid-19 affects?
There is also the liver. Once again, this is an organ with cells rich in ACE2 receptors.
Over half the patients hospitalised for Covid-19 develop some kind of liver impairment.
This is diagnosed by a blood test showing elevated liver enzymes.
Luckily, the liver is not usually affected so badly by Covid-19 that it results in acute liver failure.
The theory for this is that the kidneys may be directly affected by the virus, but the liver is not, and any ill effects on it are more a result of the body’s own cytokine storm.
I really think I don’t want to risk getting Covid-19! Are there any other organs affected?
You are wise. It really is not worth the risk as we can be one of those that are affected very badly.
As for your question, the brain is also affected.
The brain? How?
It has all to do with the ACE2 receptors again.
You see, many blood vessel cells also have these receptors.
As blood vessels are present all over our body, any effects on them are not restricted to a specific organ, like the lung, kidneys and intestines.
So if Covid-19 directly affects the blood vessels of a patient, they will cause blood clots more easily as they are damaged.
In autopsies done on deceased Covid-19 patients, blood clots are apparent throughout many organs in their bodies.
This suggests that many blood vessels and organs are affected by the disease.
Once you have blood clots, you may have complications like stroke where blood clots travel to the arteries of the brain and clog them up.
Doctors have also observed patients with dizziness, confusion, delirium, altered mental state and muscle weakness.
This has to do with the brain getting inflamed.
Wait, when blood clots form in blood vessels, not only a stroke can happen, right? This can also cause a heart attack.
True, blood clots can lead to a heart attack or a pulmonary embolism when a clot gets into your lungs.
In fact, Accident and Emergency departments in some hospitals have received patients with heart attacks who turn out to have Covid-19 when they were tested.
Covid-19 can also attack the heart directly by inflaming the heart muscles.
This is known as myocarditis. It can lead to chest pain, abnormal heart rhythms and heart failure.
There is also a condition called “happy hypoxia”.
This is when a Covid-19 patient has very low levels of oxygen as shown on the monitor, but appears to be breathing more or less normally.
Many doctors have theorised that this condition could be due to blood clotting in the lungs.
Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, email starhealth@thestar.com.my. The information contained in this column is for general educational purposes only. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.