Causes of infectious disease

Causal factors of infectious diseases is the causative agent (microorganism). He enters into a complex biological interaction with the human body, leading to an infectious process, and then - an infectious disease. As a rule, each infectious disease has its originator. Although there are exceptions, when one disease may be several pathogens (sepsis). Conversely, when a pathogen (streptococcus) causes different diseases (tonsillitis, scarlet fever, erysipelas). Every year, opening up new infectious agents.
Many infectious agents are visible under an ordinary microscope, but sometimes they can only be seen when magnified thousands of times through an electron microscope. At a meeting with the pathogens of infectious diseases people get sick. This may be due to congenital or acquired resistance of a number of people to the disease-causing microbes. Important in the prevention of infectious diseases is the constant adherence to infection prevention measures.
In the human body to the penetration of pathogens are the protective barriers of the body: dry clean healthy skin, hydrochloric acid and gastric enzymes in white blood cells (white blood cells), which capture and destroy pathogens. Protective forces are effective in the quenched, a healthy human body.
The main causative agents of infectious diseases are protozoa, bacteria, spirochetes, rickettsia, chlamydia, mycoplasma, viruses, etc. The majority of infections are caused by bacteria and viruses..
Protozoa - unicellular creatures able to carry out a variety of functions peculiar to specific tissues and organs more highly developed organisms.
The bacteria - single-celled organisms spherical (cocci), cylindrical (rod) or spiral (spirillae) form.
Spirochetes - motile bacteria characterized by filamentous, helical shape.
Rickettsia, Chlamydia - intracellular parasitic microorganisms, occupying an intermediate position between the bacteria and viruses.
Mycoplasmas - microorganisms having no cell wall, but is parasitic cells.
Viruses - acellular microscopic life forms that can penetrate certain living cells and multiply therein.
How and in what way there is an infection in intestinal infections
When intestinal infection occurs through the mouth, often with food and water. In the external environment pathogens from patients and bacteria carriers stand out with the faeces or vomit, and sometimes in the urine. The microorganisms of intestinal infections can persist for a long time in the soil, in the water, as well as on various subjects (wooden handles, furniture). They are resistant to low temperatures in a wet environment to survive longer. Quickly multiply in dairy products, as well as minced meat, jelly, pudding, water (especially in summer).
In some intestinal infections, particularly cholera, most importantly, virtually the only important water route of transmission. Water transmission path can be a major dysentery caused by Shigella Flexner.
It is clear that in this case the water is contaminated with faeces when released into bodies of water waste water from toilets, sewerage and so on. N. A particularly high degree of water pollution in the lower reaches of major rivers in regions with hot climates.
The transfer of the pathogen in food occurs through dirty hands of food handlers, as well as flies. Especially dangerous pollution of food that are not subjected to heat treatment.
Flies, eating excrement, swallow huge number of microbes. The body flies placed almost ten million germs. Vagrants in the kitchen, home, in the dining room, the flies land on food. For every fly can be isolated from the intestine up to 30 thousand dysentery bacteria.
People who do not observe the rules of personal hygiene, especially vulnerable to infectious diseases and the distributors themselves are enteric infections.
For intestinal infections, in addition to those mentioned, include typhoid and paratyphoid A and B, viral hepatitis A and E, and others.