Hello steemians, today I would want to discuss a group of living things that are quite dangerous to our health and beneficial. We come In contact with them unknowingly and are not aware about that.
Viruses are very tiny parasites that cannot be seen with our naked eye unless with the use of a microscope, In fact, they are smaller than bacteria. They find It difficult to live outside the body of their host or even reproduce outside their host, that is why they are called Intracellular parasites.
Some of these viruses cannot be seen with the use of optical microscope but can rather be viewed through scanning and transmission electron microscope.
The reduction hypothesis also known as regressive hypothesis stated that viruses started as organisms that are independent and later became parasites. Over periods of time the virus do away with genes that do not favor their parasitism and become completely dependent on their host.
The escape hypothesis tells us that virus came from parts of RNA or DNA that actually escaped from the genes of larger organisms which gave them the ability to become independent and mobile between cells.
And the Virus-first hypothesis stated that virus evolved from complex molecules of proteins and nucleic acid either on or before the time the first cells on earth appeared billions of years ago.
They live and reproduce inside the living cells of their host, they affect every type of living things, animals, plants and even microorganisms. They can be found In almost every ecosystem and the study of viruses Is called Virology.
The size of this organism compared to how abundant It Is, Is very surprising, a Professor of biology made an article In 2010 titled Nature Education and In this article, he said the polio virus Is about ten thousand times smaller than a grain of salt, hmmmmmmn this Is really fascinating.
Whenever they are not In the process of Infecting a cell or when they are not Inside an Infected cell, they exist as particles that are Independent and these viral particles are Identified as virions.
These infectious agent particles contain the genetic material that carries genetic data, a macromolecule coat called capsid that protects the genetic material and an envelop of lipids that surrounds the macromolecule coat.
A virus Is capable of Infecting few species or Infecting many species and this Is known as the host range, narrow (few) and broad (many).
Generally, there are four main structures of viral types, the helical, Icosahedral, prolate, envelope, and complex.
Some viruses can be Inactive like the virus that cause cold sores and chicken pox. What do I mean Inactive? When someone Is Infected with cold sore It erupts and later heals.
The virus In the cells are now dormant and Is reactivated after a trigger like stress and these may lead to some new symptoms. This virus makes more copies of Itself and releases new virions and kills more cells In Its host.
The DNA virus consist of Herpes virus, Pox virus, Papova virus, Adeno virus and Parvo virus while the RNA virus includes Picrona virus, Calici virus, Toga virus, Flavi virus, Corona virus, Retro virus, Bunya virus, Orthomyxo virus, Paramyxo virus, Rhabod virus, and Arena virus.
Infection Is the successful establishment of a disease-causing organism In Its host after It might have entered Inside the cells or tissues of Its host. Viral infection Is the Infection caused by viruses In the body.
The existence of a virus Is dependent on Its reproduction, a virus transmits from one person to the other, from mother to fetus.
Transmission can be through coughing, sneezing, touch, contaminated water or food, healthcare settings, and Insects that carry the virus from person to person.
As the virus multiplies In the body cells It affects the host and after the period of incubation In which the virus infection begins to grow, symptoms starts to show slowly.
Diseases caused by viruses Include Common Cold, Measles, Rubella, Smallpox, Chicken Pox, Mumps, Shingles, Cold Sores, Hepatitis, Rabies, Severe Acute Respiratory Syndrome, Polio, Hanta Fever, Ebola, Epstein-Barr, Dengue Fever, Zika Virus and Lassa Fever. Some viruses can lead to cancer like the Human Papilloma Virus.
Some viruses are very vital In our life, they are non-Infectious viruses. They live In our intestines and help us to digest our foods, some other viruses also protect us against dangerous bacteria like the Escherichia coli.
Just as a bacterial Infection Is treated with antibiotics so also viral Infections need antiviral drugs to treat them or vaccines to prevent them. Sometimes the only treatment nearly possible is relieving the symptom.
Antiviral drugs do not kill the pathogen but it reduces or inhibit their growth and slows down the process of the disease.
Antivirals are available to treat the viral infection especially the Herpes Simplex Virus, Hepatitis B virus, Hepatitis C virus, Chickenpox, Shingles, and Influenza.
The most effective and cheapest way of preventing viral diseases is VACCINATION, some diseases like smallpox have been eliminated through the use of vaccines.
https://www.medicalnewstoday.com/articles/158179.php
https://accessmedicine.mhmedical.com/content.aspx?bookid=1792§ionid=120718060&jumpsectionID=120718063
https://en.wikipedia.org/wiki/Virus
https://www.ncbi.nlm.nih.gov/books/NBK21523/
