Infectious Agents

     At present, our world is cautiously traversing human health.  Daytime and nighttime relief medications were easily available and used everywhere, prior to the pandemic.  What has changed?  Scientists, Doctors, and a variety of other analysts are modifying existing medical data in order to placate COVID-19.  We don face masks and utilize social distancing.  Is this adequate?  Stopping plights before they establish themselves is a great means of disentanglement. Mitigate infectiuos agents.

     Infectious agents are like soldiers in a war.  Biological war.  Germ warfare.  This sort of war uses infectious agents with the intent to kill humans, animals and plants.  These soldiers invade, take control and destroy. 

     There are six major types of infectious agents.  They are bacteria, viruses, fungi, protozoa, prions and helminths ( the-scientist.com ). These agents are all in shape.  Bacteria and protozoans are microscopic, single-celled organisms.  Viruses are smaller.  Fungi grow like plants.  Helminths look like worms. All infectious agents spawn an infectious disease.

     The most popular of the group is the virus.  Viruses are a relatively large group of submicroscopic, infectious agents. Viruses are nonliving.  They are extremely complex molecules that typically contain a protein coat surrounding an RNA, or DNA core of genetic material.  This sort of infectious agent is capable of growth and multiplication, only via living cells.  These living cells are called hosts.  The virus takes over the host cell. The virus multiplies.

     There are some different types of viruses.  Viruses can be classified based upon their phenotypic characteristics, core content, chemical composition, capsid structure, size, shape, genome structure and modes of replication.

• DNA VIRUS-  

There are two different types of DNA virus:

Single-stranded (ss) DNA virus

Double-stranded (ds) DNA virus

• RNA VIRUS-

Double-stranded (ds) RNA virus

Single-stranded (ss) RNA virus

• STRUCTURE and SYMMETRY-

Complex virus

Radial symmetry virus

Cubical or Icosahedral symmetry shaped virus

Rod shaped

Spiral shaped

Helical symmetry virus

• REPLICATION PROPERTIES and SITE of REPLICATION

Replication within the cytoplasm of the host cell

Replication within the nucleus and the cytoplasm of the host cell

Replication within the nucleus of the host cell

Replication of the virus through the double-stranded DNA intermediate

Replication of the virus through a single-stranded RNA intermediate

• HOST TYPE-

Animal virus

Plant virus

Bacteriophage

Insect virus

• MODE of TRANSMISSION-

Airborne infection

Fecal oral route

Sexually transmitted disease

Transfusion

Zoonoses

     Infectiuos agents, viruses, are complicated assemblies of molecules.  A virus includes proteins, nucleic acids, lipids, and carbohydrates.  When viruses are on their own , they can not do anything until  they enter a living cell. Without cells, viruses would not be able to multiply.

     The protein capsid provides a major criterion for the classification of viruses. The capsid surrounds the virus and is composed of a finite number of protein subunits known as capsomeres.  Capsomeres are found in viruses, and surround nucleic acids.

     Viruses aren't living and can only multiply when inside of a living host cell.  This means that when the host cell dies, the virus has limited amount of time until it dies, too. There are many factors as to how long the virus is still infectious after the host dies.

     The virus is in the news, right now.  COVID-19 vaccines are in huge supply.  Our society hasn't reached herd immunity, yet.  It is a potent infectious agent.  They're are other types of infectious agents.  We shall offensively defend our world against them all.