Another crazy week with the Corona !!
Although it is quite scary to see New York develop exponential cases, we must keep in mind that New York was one of the first states to put in place drive-thru testing. Hence, the number of tests they have performed over the last 10 days have been exponentially more than any other state. With more tests comes more positive results.
Although we have all heard of the term “virus”, many do not know the exact definition of a virus.
So, let’s spend a few minutes trying to understand what exactly is a virus, and how does it differ from other types of infections, such as a “bacteria”.
As with the last couple of posts, this is very science-heavy – I have tried to make it as simple as possible, but it is still quite complex.
An “infection” is different from “inflammation”.
- An “infection” happens when a foreign organism:
- enters the human body,
- uses that person’s body to sustain itself, reproduce, and colonize.
- Such infectious organisms are known as “pathogens”.
- Examples of pathogens include:
- Bacteria
- Virus
- Fungi
- Protozoa
- Parasites
- Prions
- The most common types of pathogens are bacteria and viruses.
What is “inflammation”?
- Inflammation is the body’s response to an infection or injury
- A healthy inflammatory response leads to the destruction of an infection
- If the inflammatory response is not robust or not prepared for the infection, the infection continues to get worse until the body’s inflammatory defense system starts fighting back
- As mentioned in a prior post, IgG and IgM are 2 key elements of the inflammatory response, helping to fight the infection
- Sometimes, the immune can be so robust that the “inflammation” starts to cause damage above and beyond the infection (more on this below and in a future post)
Bacterial Infections:
- Bacteria are single-celled microorganisms
- They are “living” beings, that need “food” to produce energy, can move, and reproduce
- Estimated to be around “one nonillion” bacteria on earth (a nonillion is a ONE followed by 30 ZEROS)
- Estimated to be trillions of different strains of bacteria, with only a few of these causing human disease
- Some bacteria “live” inside the human body (in our gut or airways) or on our skin, without causing any harm
- Some bacteria are deadly, such as:
- bubonic plague
- tuberculosis
- typhoid
- typhus
- dysentery
- diphtheria
- cholera
- Some common examples of bacterial infections are:
- Bacterial meningitis = bacterial infection of the brain
- Bacterial pneumonia = bacterial infection of the lungs
What is a Virus?:
- A virus is NOT a living organism
- A virus is a piece of genetic code, surrounded by and protected by a layer of protein and fat
- There are millions of types of viruses
- Only around 5,000 have been identified
How does a Virus cause an infection?
- Viruses need a living “host” to multiply
- A “host” can be a human or any animal (e.g. a bat, anteater, dog, etc)
- As viruses enter the cells of the host (e.g. enter the lung cells of humans), they release the genetic material
- The genetic material forces the host cell to multiply, causing the multiplication of the viral genetic material
- When the host cell dies, the genetic material (virus) is released, which go onto infecting new cells
- Some viruses enter the host and force an uncontrolled replication of host cells, leading to cancer
- Human Papilloma Virus (HPV) can cause cervical cancer
- Epstein Barr Virus (EBV) can cause stomach cancer and Lymphoma
- Hepatitis B Virus (HBV) can cause liver cancer
- Hepatitis C Virus (HCV) can cause liver cancer and lymphoma
- Some common viral infections
- Covid-19
- Annual Flu
- Common cold – caused by Rhinovirus, Coronavirus, and Adenovirus
- Human Immunodeficiency (HIV)
- Hepatitis C
- Viral meningitis
- Genital herpes (HSV)
How to kill a bacterial infection?
- There are many types of antibiotics
- Bacteria are killed with antibiotics
- Currently used antibiotics are “broad spectrum”, which means 1 antibiotic can kill many types of bacteria
- In most cases, you do NOT have to take a specifically engineered antibiotic for a specific bacteria
- Which antibiotic, dosage (milligrams), dosing schedule (how many times a day), and duration (how many days) will vary depending on the infection being treated
- Antibiotics do NOT kill viruses
How to kill a viral infection?
- Viruses CANNOT be killed
- Rather, anti-viral medications are used to halt the spread of the viral genome
- Since viruses are basically genetic material, there is no such thing as a “broad spectrum” antiviral
- Each anti-viral is SPECIFIC for that virus
- Since viruses are pieces of genetic material, they MUTATE rapidly
- EXAMPLE – An anti-viral designed for this year’s “flu” may not work for next year’s “flu” since the flu vaccine will have mutated
How to prevent a virus from replicating and spreading within our bodies?
- Prevent the virus from getting inside your body
- This is the basic premise of social distancing, PPE, and constant hand cleaning
- Once the virus gets inside your body, try to prevent the virus from “attaching” to the host cell and getting “inside” the host cell
- Once attached to the host cell and “internalized” into the host cell, try to prevent virus from “releasing” it’s genetic material
- Once viral gene is “released” inside the host cell, try to prevent the multiplication of the viral genome
- Once viral gene has multiplied, try to prevent the formation of new viral particles
- Once viral particles have been formed inside host cell, try to prevent release of viral particles which would infect other cells
COVID-19: If an anti-viral cannot be developed or has not yet been developed, what can be done to help the body “fight” the infection?
- As of March 27, 2020, we do NOT have an anti-viral medication to treat the Covid-19 infection
- Many existing drugs, used for other infections, are being “tried” and “tested” for possible use against Covid-19
- Examples of existing drugs being tested in Covid-19:
- Chloroquine
- used for Malaria, RA, SLE
- prevents the entry into human cells
- Hydroxychloroquine
- similar to Chloroquine
- used for Malaria, RA, SLE
- prevents the entry into human cells
- Remdesivir
- created for Ebole, but failed
- now being tested for Covid-19
- many scientists feel this drug has a VERY high potential of working
- Kaletra + Lopinavir + Ritonavir Combination Therapy
- used for HIV patients
- initgially, a lot of excitement that these meds would work
- on March 18 (NEJM), Chinese researchers reported very little efficacy
- still being tested by other research groups
- Tocilizumab
- used for Rheumatoid Arthritis (RA)
- suppresses an erratic immune system
- clinical trials underway
- Chloroquine
- Examples of existing drugs being tested in Covid-19:
- Various drug companies are trying to target the various aspects of a viral infection (as listed above)
- Some Pharma companies are also trying IVIg to boost the immune system
- We mentioned in a previous post that our bodies produce IgM and IgG antibodies to fight infections
- If our immune system is healthy, the infection will be stopped, and our bodies now produce IgG to fight the same infection in the future
- Pharma is now actively collecting the blood of various patients who have RECOVERED from Covid-19
- These recovered patients should have IgG in their blood
- The blood is filtered and separated into it’s various components
- The Antibodies found in the various patients are pooled together, re-formulated, and infused (thru IV) into sick patients
- The hope and goal is for the pooled IgG to enter the sick body, to try to help fight the infection, while the sick body has time to make it’s own IgG
Phew !!!
We got through some of the basics (and yes, only the basics)!
The daily information is like drinking water out of a fire-hose – a LOT of information that cannot be understood or followed easily.
The above is very complicated, but I hope that having some type of framework will help you follow the news.
The next few posts will discuss why “soap” works and why “the lungs can fail” during a Covid-19 infection.
Stay Safe !
- Sudhir S. Athni, MD