Here's what happens after your body is infected with the coronavirus
- Coronaviruses cause respiratory diseases, which is why the lungs are usually affected first
- Early symptoms include fever, cough and shortness of breath. These symptoms can appear as early as 2 days or as late as 14 days after exposure to the virus
- However, damage can also occur in other areas of the body, especially during severe courses of the disease
There are still a lot of things we don't know about the novel coronavirus, which has already infected over 500,000 people worldwide and killed thousands.
But one thing is clear - in severe cases, the virus can have devastating effects on the body, affecting far more than just the lungs. Here's what we know so far about how COVID-19 can affect different systems of the body.
COVID-19 affects the lungs
Like other coronavirus diseases including SARS and MERS, COVID-19 is a respiratory disease, which is why the lungs are usually affected first.
Early symptoms include fever, cough and shortness of breath. These symptoms can appear as early as 2 days after the initial infection or as late as 14 days later (1).
The severity of COVID-19 disease ranges from mild or no symptoms to severe and sometimes fatal disease progression. Initial data from China found that around 81 of those infected had a mild course of the disease, while the remaining cases had a severe or critical course (2).
Older people or people suffering from chronic diseases have a higher risk of a serious course of the disease (3).
This variability is also reflected in how COVID-19 affects the lungs. Some people have only mild respiratory symptoms, while others develop non-life-threatening pneumonia (4). However, there is also a subgroup of patients who develop severe lung damage.
"What we regularly see in patients who are seriously ill with COVID-19 is a condition called acute respiratory distress syndrome - ARDS for short," says Dr. Laura E. Evens, a member of the Society of Critical Care Medicine Leadership Council at the University of Washington Medical Center in Seattle.
However, ARDS is not unique to COVID-19. A whole range of events including infections, trauma and sepsis can trigger this syndrome (5).
ARDS causes lung damage, which results in fluid leaking from the small blood vessels in the lungs. This fluid accumulates in the air sacs of the lungs, making it difficult for the lungs to transfer oxygen from the air into the blood.
Although there is not yet enough information about the type of lung damage that occurs in the lungs during COVID-19 disease, a recent report suggests that this damage is similar to that observed in SARS and MERS (6).
A recent source that looked at 138 patients hospitalized for COVID-19 concluded that patients began to experience respiratory distress on average 5 days after the first symptoms (7). ARDS developed on average 8 days after the onset of symptoms.
Treatment for ARDS includes oxygen supplementation and mechanical ventilation with the aim of getting more oxygen into the blood (8).
There is no specific treatment for ARDS. They simply try to support the patient through the process as best they can and allow the body to heal while the immune system fights the underlying cause.
Other organs attacked by COVID-19
The lungs are the primary organ attacked by COVID-19, but in serious cases of illness the rest of the body can also be affected. Of the patients who become seriously ill, a good proportion also develop dysfunction in other organ systems. However, this can be the case with any serious infection.
The damage to these organs is not always caused directly by the infection, but can also result from the body's reaction to the infection.
Stomach and intestines
Some people with COVID-19 report digestive symptoms such as nausea or diarrhea, although these symptoms are less common than problems with the lungs (9).
Although coronaviruses seem to find it much easier to enter the body via the lungs, the digestive tract is not out of reach for these viruses either.
Previous reports have identified the viruses that cause SARS and MERS in intestinal biopsy samples and stool samples (11, 12).
Two recent studies report that stool samples from some people with COVID-19 have tested positive for the virus (11, 12).
However, scientists do not yet know whether transmission of COVID-19 via feces is possible.
Heart and blood vessels
COVID-19 can also attack the heart and blood vessels. This can manifest itself in symptoms such as cardiac arrhythmia, insufficient blood flow to the body tissue or very low blood pressure, which requires treatment.
So far, however, there is no evidence that the virus can directly damage the heart (14).
Liver and kidneys
When liver cells are inflamed or damaged, they can release higher than normal levels of enzymes into the bloodstream. Elevated liver enzyme levels are not always a sign of a serious problem, but these lab results have also been observed in people with SARS or MERS (15).
A recent report found signs of liver damage in a person with COVID-19 (16). However, doctors say it is not clear whether it was the virus or the drugs used to treat it that caused this damage.
Some patients hospitalized with COVID-19 also showed acute kidney damage that was so severe that in some cases a kidney transplant was necessary (17). This also occurred in SARS and MERS (18, 19).
During the SARS outbreak, scientists even found the virus that causes this disease in the kidney ducts.
However, according to the World Health Organization (WHO), there is little evidence to show that the virus directly caused kidney damage (20).
Dr. James Cherry, a professor of pediatrics at the David Geffen School of Medicine at UCLA, says the kidney damage could be due to other changes that occur during a coronavirus infection. For example, less oxygen circulates in the body when you have pneumonia and this can damage the kidneys.
Immune system
With every infection, the body's immune system reacts by attacking the foreign virus or bacteria. However, even though the immune system can rid the body of infections, it can sometimes cause collateral damage to the body.
This can take the form of an intense inflammatory response, sometimes referred to as a "cytokine storm". The immune cells produce cytokines to fight the infection, but if too many cytokines are released, this can cause problems in the body.
A lot of the damage that occurs in the body during COVID-19 disease is due to complex immune responses. The infection itself can cause an intense inflammatory response in the body, which can affect the function of multiple organ systems in the body.
Another interesting thing about the immune system is that there are currently almost no cases of COVID-19 in children under the age of 9 (21). Scientists are not sure if children cannot become infected or if their symptoms are so mild that no one notices them.
It is known that children also suffer less severe courses of other types of infections, including measles and pneumococcal disease, than adults. This could be because children have a more straightforward immune response, whereas older people can sometimes overreact. It is this excessive immune response that causes some of the damage that occurs during an infection.
There is evidence that this was the case with SARS and scientists suspect it may also be the case with COVID-19.
What you can do to avoid getting sick in the first place....
Better than any treatment or cure is of course always to avoid getting sick in the first place - which is particularly important with a disease like COVID-19, for which there is no real treatment yet.
In the case of viral diseases, the promotion of optimal immune system function should be the top priority, which is influenced by a variety of factors. Important factors for optimal immune system function include sufficient sleep, as little stress as possible and, of course, exercise. The right "dosage" is important when exercising, as training that is too extreme, which puts a lot of strain on the body and pushes its ability to regenerate to its limits, can reduce immune function for several hours after training.
Another important factor is a balanced and healthy diet that includes as much fresh fruit and vegetables as possible. In addition, there are a number of supplements that have been proven to promote and improve immune function. Here is a brief overview:
Probiotics
Intestinal flora plays an important role in immune system function. Probiotic supplements provide the body with healthy gut bacteria and studies have shown that they can reduce the risk of respiratory diseases, including COVID-19 (22, 23, 24, 25). To promote the growth of the healthy bacteria supplied, it is recommended to use a pebiotic product that serves as food for these bacteria and promotes their multiplication.
Curcumin
Curcumin, the active ingredient in turmeric, is another natural substance that can improve the function of the immune system due to its antioxidant and anti-inflammatory effects, in addition to many other positive effects on health.
Antioxidants
Antioxidants, which include vitamin C, support the function of the immune system via various mechanisms. This is also the reason why fresh fruit and vegetables, which are rich in antioxidants, strengthen the immune system and reduce susceptibility to disease.
Vitamin D
Although vitamin D is primarily associated by most people with healthier bones, it also plays an important role in optimal immune system function. Studies show that the risk of respiratory tract infections increases with a vitamin D deficiency or an insufficient supply of vitamin D, which conversely means that an optimal vitamin D supply makes you less susceptible to these diseases (28, 29).
Zinc
Zinc also plays an important role in many aspects of immune function, which means that a zinc deficiency can impair the function of the immune system. Furthermore, zinc has been shown to reduce the duration and severity of respiratory illnesses when taken at the onset (26)
Ginseng
Ginseng not only supports optimal functioning of the immune system, but can also reduce both the duration and severity of existing respiratory infections (30, 31, 32). This applies to both Panax ginseng and Siberian ginseng, which is traditionally used in Eastern European countries to prevent colds.
Vitamin C
Vitamin C is not without reason the classic supplement for supporting immune function, based in part on its antioxidant and anti-inflammatory effects. In fact, a study review that looked at over a hundred individual studies came to the conclusion that supplementation with 100 to 200 mg of the vitamin can prevent respiratory infections (27).
Garlic extracts (garlicin)
Garlic has antimicrobial and antiviral properties and can activate certain genes of the immune system, resulting in a significant improvement in the function of NK and T cells of the immune system (33, 36). Several studies have shown that garlic supplementation can both reduce the risk of respiratory disease and reduce the duration of illness (34, 35). In order to benefit from these advantages without the annoying smell of garlic, supplements that contain the active ingredient of garlic - garlicin - in concentrated form are recommended.
Green tea extract
Green tea is rich in flavonoids - in particular epigallocatechin gallate, or EGCG for short. EGCG has pronounced antioxidant effects and studies have shown that it can improve immune function. In addition, the theanine contained in green tea supports the production of germ-killing compounds in the T-cells of the immune system.
References:
- https://www.cdc.gov/coronavirus/2019-ncov/about/symptoms.html
- http://weekly.chinacdc.cn/en/article/id/e53946e2-c6c4-41e9-9a9b-fea8db1a8f51
- https://jamanetwork.com/journals/jama/fullarticle/2761044
- https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30374-3/fulltext
- https://www.lung.org/lung-health-and-diseases/lung-disease-lookup/ards/learn-about-ards.html
- https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30076-X/fulltext
- https://jamanetwork.com/journals/jama/fullarticle/2761044
- https://www.mayoclinic.org/diseases-conditions/ards/diagnosis-treatment/drc-20355581
- https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html
- https://www.sciencedirect.com/science/article/pii/S0016508503012150
- https://advances.sciencemag.org/content/3/11/eaao4966
- https://www.nejm.org/doi/full/10.1056/NEJMoa2001191
- https://www.medrxiv.org/content/10.1101/2020.02.06.20020974v1
- https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30076-X/fulltex
- https://annals.org/aim/fullarticle/1817260/clinical-course-outcomes-critically-ill-patients-middle-east-respiratory-syndrome
- https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30076-X/fulltext
- https://jamanetwork.com/journals/jama/fullarticle/2761044
- https://www.kidney-international.org/article/S0085-2538(15)50506-1/fulltext
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4689825/
- https://apps.who.int/iris/bitstream/handle/10665/207501/9290612134_eng.pdf?sequence=1&isAllowed=y
- http://weekly.chinacdc.cn/en/article/id/e53946e2-c6c4-41e9-9a9b-fea8db1a8f51
- https://www.ncbi.nlm.nih.gov/pubmed/19747410
- https://www.ncbi.nlm.nih.gov/pubmed/20803023
- https://www.ncbi.nlm.nih.gov/pubmed/23020819
- https://www.ncbi.nlm.nih.gov/pubmed/25927096
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3273967/
- https://www.ncbi.nlm.nih.gov/pubmed/29099763
- https://pubmed.ncbi.nlm.nih.gov/28202713
- https://pubmed.ncbi.nlm.nih.gov/19237723
- https://www.ncbi.nlm.nih.gov/pubmed/19592479
- https://www.ncbi.nlm.nih.gov/pubmed/16247099
- https://pubmed.ncbi.nlm.nih.gov/16566675/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4103721/
- https://www.ncbi.nlm.nih.gov/pubmed/11697022
- https://www.ncbi.nlm.nih.gov/pubmed/22280901
- https://www.ncbi.nlm.nih.gov/pubmed/26423732