Our immunity is regulated by numerous organs, each organ plays a different role and strengthens our immunity in different ways.
An infection occurs when our body is invaded and affected by an agent or organism that can cause symptoms, illness, or disease. The agent can be a virus, and the organism can be bacteria, a fungus (or yeast), or a parasite. This article will discuss only bacterial and viral infections, with a special focus on COVID-19.
Some infections are even beneficial for the host. For example, probiotics are the “good” bacteria that colonize our intestines and some other parts of our body and help keep us healthy!
Some infections are symptomless and cause no harm. Some are symptomless in the beginning, but gradually cause damage to the body over many years. Some cause nasty symptoms to appear rapidly, and may even cause death within a short period of time.
COVID-19 infection is a good example to illustrate the above. It is an infection caused by a coronavirus (BARS-CoV-2) which is similar to the coronaviruses which caused SARS (Severe Acute Respiratory Syndrome M 2002-2003) and MERS (Middle East Respiratory Syndrome in 2012.) Other species of coronaviruses are known to cause the common cold in humans.
ABOUT OF THOSE INFECTED BY COVID-19 HAVE NO OR MILD SYMPTOMS.
About 15% have moderate to severe symptoms that require hospitalization, and about 5% have severe symptoms requiring ventilator support. ICU care, COVID-19 can affect many organs, especially the lungs, heart, kidneys, liver, and the blood coagulation system.
From this severe group, some die within 1 week of the onset of symptoms, while others die later. Fortunately, most recover. The unfortunate part is that the asymptomatic infected persons can
transmit the infection to others without knowing. COVID-19 is more dangerous to the elderly and those with chronic diseases like hypertension and diabetes because their immunity is already weak. Young children are relatively spared because their immunity is stronger.
We can see how an invisible agent can cause so much harm to the world, not only in terms
of health, but it has also jammed the entire world’s economy and changed our life tremendously. After months of lock-down, we now have to be accustomed to the “New Normal” (masks, frequent hand-washing, social distancing and avoiding large crowds) for maybe several years until a safe and effective vaccine becomes available.
So what are the differences between viral and bacterial infection? First of all, viruses are not living organisms. They are just genetic material that can infect living organisms and may have natural hosts in which they cause mild symptoms or no harm. A virus is just a string of genetic material (RNA or DNA) that carries the instructions to replicate all its components so that millions of copies of itself can be reproduced by the cell it infects. It hijacks the cell’s manufacturing system and raw materials. The infected cells eventually burst and die, releasing millions of viruses to infect more cells. Eventually, the affected organ will suffer and even fail. If major organs are involved, the death of the host may ensue.
Viruses may have natural hosts in which they cause mild symptoms or no harm. The COVID-19 virus is thought to have originated from bats, then onto pangolins, and then onto humans. This is called a zoonotic infection (animal-to-human). In the process, the virus also underwent some
genetic mutations (changes) that enhanced its virulence. The COVID-19 (SARS-CoV-2) virus has a double-layered lipid envelope protecting its RNA core. Several types of proteins are interspersed in this envelope. The outermost layer is made of glycoprotein spikes which give a crown-like appearance. Hence its name (corona = crown). These spikes are used to latch on receptors on the target cell to gain entry.
The virus can survive (remain intact and infectious) outside the body for hours to days depending on the type of surface and prevailing conditions. It can only multiply if it gets into a target cell.
The lipid envelope can be easily destroyed by soap. Hence hand-washing with soap can “kill” (destroy) it. Sanitizers containing alcohol (at least 65% concentration) or other virucidal ingredients can be used when soap is not available. The virus can also be destroyed by heat and extreme pH. In the body, it is destroyed by our immune system (by macrophages, killer cells, or antibodies produced by B-cells). Some viruses can be deactivated by antiviral drugs.
There are many viral infections – the common cold (many viruses), measles, mumps, rubella, hepatitis (A, B, C, D, E, etc), chickenpox, shingles, seasonal influenza (many viruses), dengue, chikungunya, HIV (AIDS), viral pneumonia, viral gastroenteritis, HPV, viral warts and many more. Swine flu, bird flu, SARS, MERS, and COVID-19 caused epidemics and pandemics.
Most viral infections are overcome by the body’s own immune cells. Recovery may take some time, after much suffering. Sometimes the body loses the battle and dies. Sometimes the virus
remains in the body without causing further damage (eg. Hepatitis B carriers), yet remains infectious (can spread to others). Some viral infections are treatable with antiviral medicines which either block them from entering cells, prevent their replication through various mechanisms or destroy their structure. For Example, chickenpox, and shingles can be effectively treated with antiviral drugs; and HIV survival is much improved with modern drug treatment; but there are no effective drugs against most other viral infections.
Vaccines prevent infection by introducing the attenuated (deactivated) virus, or viral components that will induce the immune system to effectively fight the real virus should we become infected. While vaccines have saved us from many viral diseases (e.g. smallpox has been eliminated, and polio is now rare), not all vaccines are 100% effective. So, what about bacterial infections?
Bacteria are single-celled organisms that can multiply even outside the body if the conditions are right. Some can survive in extreme conditions. Bacteria are much larger than viruses. They
come in many shapes and sizes.
There are thousands of bacteria species and many cause infections in humans. Some
examples – conjunctivitis, throat infections, tonsillitis, tooth decay, gum disease, ear
infections, bacterial pneumonia, food poisoning, urinary infection, typhoid, cholera, syphilis, gonorrhea, TB, acne, abscess, septicemia, and many more. Some bacteria are natural residents in certain parts of our body as “commensals”. They may be beneficial (eg. good gut bacteria, good vaginal bacteria) or become harmful if they get transferred to another part (eg. bacteria in the nose and mouth can infect skin wounds). The symptoms of bacterial and viral infections can be similar and doctors have to be familiar with the infections or diseases to make a diagnosis. The exact symptoms depend on the organ being infected.
Sometimes blood and other specimens have to be sent to the lab for confirmation. Correct diagnosis is important because treatment is different. Viral infections usually require symptomatic treatment only (rest, adequate sleep, sufficient fluids; and analgesics and antipyretics if necessary). Unfortunately, there are antiviral drugs against only a few viral infections.
Bacterial infections need to be treated with antibiotics to prevent prolonged suffering. Although the healthy body can fight these infections, some bacterial infections can progress to dangerous
consequences if not treated. However, it is best to confirm the diagnosis before starting treatment to prevent overuse and abuse of antibiotics. There are hundreds of antibiotics available, but the
bacteria develop resistance against them over time.
The overuse of antibiotics has caused the problem of antibiotic resistance to become widespread and problematic. There are now bacteria that resist all known antibiotics and will cause fatal infections. The most frequent symptoms presenting at the medical clinics are fever, sore throat, coughs, and runny or blocked nose.
These are mostly due to viral infections, but some doctors routinely prescribe antibiotics, which is wrong. Only if the symptoms do not improve after 3 days or so of rest and cough & fever medicines (if necessary), should the doctor suspect bacterial infection and do a throat swab
or sputum culture, and prescribe antibiotics only if the bacterial infection is proven. Unfortunately, many doctors just prescribe antibiotics from the beginning, often at the patients’ insistence! Antibiotics do not kill viruses.
The best defense against both bacterial and viral infections is good hygiene. A healthy diet, healthy lifestyle, sufficient exercise, and living in a healthy and clean environment can help us maintain a healthy immune system. Moreover, the immune system has a significant role as
It protects our body from pathogens like bacteria, viruses, or parasites and then removes them from the body. It also will identify and neutralize harmful substances from the environment and
fight disease-causing changes in the body such as cancer cells. Our immunity is regulated by numerous organs, each organ plays a different role and strengthens our immunity in different
You may consider these natural foods (or in supplement form) known to improve immunity: American ginseng, grape seed extract, lingzhi, tiger milk mushroom, spinach, spirulina, chlorella, elderberry, maitake mushroom, seaweed, and colostrum.
Should an infection occur, consult a health practitioner if there are obvious symptoms of a certain disease (e.g. swellings or rashes) or if the symptoms are severe so that appropriate tests and
treatment can be done. Otherwise, home rest and remedies are sufficient for most mild infections, unless the symptoms worsen or remain for more than 3 days.