A virus is a tiny parasite which can infect living organisms. It is made only of a nucleic acid + a protein coat. Usually the nucleic acid is RNA; sometimes it is DNA.
Their method is to get their nucleic acid strand into a prokaryote or eukaryote cell. The (usually) RNA strand then takes over the cell machinery to reproduce itself and the protein coat. The cell then bursts open, spreading the virus.
All viruses act in this way, and there are no free-living viruses. Viruses are ubiquitous (everywhere), and all organisms suffer their attacks.
Viruses are much smaller than bacteria. They were not visible until the invention of the electron microscope. A virus has a simple structure. It has no internal cellular structure, no cell wall or cell membrane, just the protein coat that holds the string of nucleic acid.
With eukaryote cells, the virus’ protein coat is able to enter the target cells via certain cell membrane receptors. With prokaryote bacteria cells, the bacteriophage physically injects the nucleic acid strand into the host cell.
Viruses have the following characteristics:
- Infectious particles, causing many types of disease;
- Contain nucleic acid core RNA or DNA;
- Surrounded by a protective protein coat;
When the host cell has finished making more viruses, it undergoes lysis, or breaks apart. The viruses are released and are then able to infect other cells. Viruses can remain intact for a long time, and will infect cells when the time and conditions are right.
Some specialised viruses are worth noting. Bacteriophages have evolved to enter bacterial cells, which have a different type of cell wall from eukaryote cell membranes. Envelope viruses, when they reproduce, cover themselves with a modified form of the host cell membrane, thus gaining an outer lipid layer that helps entry. Some of our most difficult-to-combat viruses, like influenza and HIV, use this method.
Viral infections in animals provoke an immune response that usually eliminates the infecting virus. Immune responses can also be produced by vaccines, which confer an artificially acquired immunity to the specific viral infection. However, some viruses including those causing AIDS and viral hepatitis evade these immune responses and result in chronic infections. Antibiotics have no effect on viruses, but several antiviral drugs have been developed.
Evading the immune system
Not all virus infections produce a protective immune response. These persistent viruses evade immune control by sequestration (hiding away); blocking antigen presentation; cytokine resistance; evading natural killer cell activity; escape from apoptosis (cell death), and antigenic shift (changing surface proteins). HIV virus evades the immune system by constantly changing the amino acid sequence of the proteins on the surface of the virion. Other viruses, called neurotropic viruses, move along nerves to places the immune system cannot reach.
True origins of Viruses
Your body can eliminate any virus in a short time, such as hours or days. It can even keep up with a steady stream that is coming from tapeworm stages! Let us apply these new insights to several diseases we are familiar with.
Epstein Barre Virus (EBV) is a mysterious disease because in spite of building up antibodies. it attacks repeatedly. There is a pattern showing that a person with EBV also has Eurytrema (pancreatic fluke) in the pancreas. When the fluke is gone, EBV is no longer found in the white blood cells. This suggest that the virus comes from the fluke. As each fluke dies and is finally removed, the body’s white blood cells can catch up with the viruses and you begin to feel better again, which can be as quick as one day. But reinfection with an EBV-carrying Eurytrema (plus a wood alcohol containing beverage to allow the fluke to go to the pancreas) can spark the next recurrence.
Shingles is a recurrence of chicken pox. Ascaris are always present in persons with shingles! Unfortunately, killing the Ascaris does not cure shingles. Herpes Zoster (the shingles/chicken pox virus) is known to hide in nerve cells. Perhaps Ascaris facilitates it’s release, or simply suppresses the immune system in a way that allows it to suddenly multiply.
Polio was once a scourge. At that time, we can theorize that a new large parasite was making its appearance. Was a new animal association taking place in the early 1900’s? Life was indeed becoming more urban with horse manure on all streets. Owning a dog for a house pet was becoming an acceptable life style. Could the tapeworms of these animals give us a tapeworm stage that hosts polio virus? Many polio sufferers also had migraines. These are caused by Strongyloides, a horse threadworm. Does Strongyloides host polio virus?
The HIV virus infects us during the time the intestinal Fasciolopsis buskii, is being hosted. Persons test negative to HIV shortly after the fluke and its stages are eliminated.
Coxsackie viruses give us some of our encephalitises. It has never been seen Coxsackie viruses without the bacteria, Bacteroides fragilis, and It has never been seen Bacteroides fragilis without Ascaris (a roundworm) It has been concluded that one lives inside the other!
We may be deriving viruses from all the roundworms, flukes, tapeworms and bacteria that infect us! It would be a fascinating study, simply to examine each of these parasites singly, searching for their viruses with an electron microscope. They could also be searched for using immunological methods.
It is a time of great change for this planet as pollution spreads from pole to pole. The growth of industrial activity mining, chemical manufacturing, the food “industry”, and personal habits like smoking have spread new chemicals to every corner of the globe. The element polonium, which is radioactive and in tobacco smoke, is harmful to human lungs, but may not be harmful to a small lung parasite, like Pneuocystis carnii.
Benzene, which is a solvent and extremely harmful to humans, may not be harmful to fluke parasites living within us. Propyl alcohol facilitates the intestinal fluke but is toxic to us. Parasites are doing abnormal things. Is this because of pollution?
The tables are gradually being turned against us in favor of our parasites and pathogens. Such large changes are called evolutionary. Is the human species doomed, or will some of us “adapt”. Will some of us survive to pass on our “better” genes to a new population of cancer-resistant, AIDS-resistant, Alzheimer’s-resistant, etc-resistant humans? How many of us will die trying? The common cold should not be so common!
Viruses and cancer
Some viruses may incorporate their DNA (or DNA copied from viral RNA) into host DNA, with effects on the control of cell growth. This may sometimes lead to transformation, in other words a tumour.
However, integration does not always lead to transformation and is not mandatory for transformation. The association of viruses with tumours in animals was ﬁrst suspected 90 years ago but only in the 1960s was a virus (EBV) shown convincingly to be associated with a human tumour (Burkitt’s lymphoma).
Now the role of oncogenes that are activated for causing cancer is being better understood to know why all viruses and all infections do not cause cancer in all individuals.