Infection And Immunity

What is Infection?

Infection in humans defines an organism that is receiving sustenance or nourishment from a host – or the human body. An infection begins if the organism feeds on and multiplies at an increased rate in or on the host and this affects health. Organisms that cause infections are parasites, bacteria, prions, viruses and fungi. Most people can fight off infections fairly quickly, but chronic infections can be caused by viruses such as herpes or hepatitis. Prolonged bacterial infections generally infect those with lingering diseases such as diabetes or those with weak immune systems.

You can become infected by a virus by inhaling, being bitten by infected parasites or insects or through sexual contact. Anti-viral medications can help by undermining the virus”s ability to reproduce or by boosting the patient”s immune system. As a note, viruses are tiny organisms that invade the host and attach to a cell. A virus will enter the cell and release genetic material that causes the virus to multiply. A cell filled with viral genetic material will ultimately die, release new viruses and the infection cycle takes over.

Bacterial infections are caused by single cell microorganisms that live on any surface imaginable. Bacteria reside in human bodies, on skin, in the mouth, and in urinary and digestive tracts. Most bacteria do not cause harm and some are actually good. There are a relatively small number of bacteria that cause disease and infections and these include cholera, dysentery, plague, pneumonia, typhoid, or tuberculosis. Bacterial meningitis as well as ear infections, colds and flu, gastritis and food poisoning are caused by bacteria. Urinary tract infections and skin infections as well as chlamydia and other STS are bacteria based. Bacteria cause localized redness, inflammation and pain.

Fungal infections reproduce through small airborne spores that are either inhaled or picked upon the skin. If you are a patient on long-term antibiotics you may develop a fungal infection. Antibiotics can reduce good bacteria which cause fungi to infect the wound and the wound becomes infected.

Prion infections contain proteins that are generally harmless, but when the prion mutates abnormally it becomes rogue and attacks the structure of the brain or the nervous system. Prions are often fatal. Infections from prions come from mad cow disease, Creutzfeldt-Jacob disease or fatal familial insomnia. Alzheimer”s may be a prion infection.


What is Immunity?

Medically defined, immunity is the body”s defense system against infections. The immune system comprises a network of cells, chemicals and tissues that fight and kill infectious organism when they invade the body. Immune protection includes resistance that is active or passive and natural or artificial. A vaccination places an active or inactive disease in your body so your immune system can produce the right antibodies for that particular disease. This is done through the immune response which allows the immune system to attack substances that cause infections. Chicken pox is a prime example.

Immunities are developed when antigens or foreign substances invade the body, are detected, and cells work together to recognize these antigens. Response mechanisms are triggered. The B lymphocytes are told to produce antibodies or specialized proteins that lock onto antigens and kill them. Once produced these antibodies exist in your body and if the same antigen enters the body the immune system’s antibodies are ready to destroy the invader. Basically that is immunity.



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