Why We Get Infected From Any Diseases

Escherichia coli (E. coli) is a bacterium that lives in the intestines of animals and humans and emits feces. When a dead animal decomposes, bacteria present in the animal's body are released, exposing humans to potentially pathogenic agents. Humans can become infected if they eat contaminated food, but infections can also occur through direct contact with infected animals or objects or when infected animals contaminate infected people.

Infectious diseases are transmitted from one person to another through the direct transmission of bacteria, viruses and other germs. This can happen when people with these germs touch, kiss, cough or sneeze on someone who is not infected. These germs can also be transmitted through the exchange of body fluids or through sexual contact.

Infectious diseases are the leading cause of disease and death in the United States and around the world. They are caused by microscopic germs such as bacteria and viruses that enter the body and cause problems. Infections occur when microscopic organisms, so-called pathogens (bacteria, viruses, fungi and parasites), invade the body, multiply and interfere with normal functions.

However, for certain people with underlying conditions, heart disease, cancer, serious injury or taking medications that weaken the immune system, it can be difficult to avoid infection.

Viral infections can lead to a range of symptoms, from asymptomatic to open symptoms of serious illness. Examples are staphylococci, which can cause host infections such as boils, and gonococci, which cause transmissible infections such as gonorrhea.

Spirochaete bacteria are responsible for a number of diseases, including the sexually transmitted infection syphilis. The tropical disease cholera, which is characterized by severe diarrhea and dehydration, is caused by the Vibrio bacteria. Viruses are responsible for a variety of diseases including colds, measles, chicken pox, genital herpes and flu.

Scientists estimate that more than 6 out of 10 known human infectious diseases are transmitted by animals and 3 out of 4 emerging human infectious diseases originate from animals. Certain diseases are also transmitted through the air, including tuberculosis and rubella viruses.

Most bacterial diseases can be treated with antibiotics, but antibiotic resistant strains are beginning to emerge. When bacteria cause disease, antibiotic treatment kills the bacteria and ends the disease.

It is possible to vaccinate against the main disease-causing viruses such as measles and polio, as well as against bacterial diseases such as the H. flu type B (Hib), tetanus and whooping cough. Viruses pose a challenge to the body's immune system because they hide in the cells.

This type of protection will become more sophisticated as organisms become more complex. Multicellular animals have special cells and tissues to cope with the risk of infection. Bacteria that are small (no more than a million fit into the head of a pin) have systems to protect themselves against infection by viruses.

Diseases can be transmitted by direct contact with infected skin, mucus membranes and bodily fluids including cold sores, Herpes simplex virus type 1 and sexually transmitted diseases such as AIDS. Pathogens can also be transmitted via indirect contact when an infected person touches a surface such as the door handle, worktop or tap, creating microbes that can be transmitted to another person who touches the surface or touches their eyes, mouth or nose. Microorganisms that can cause disease or pathogens can enter our body through the mouth, eyes, nose or urogenital opening, through wounds, bites or breakthroughs of the skin barrier.

Air diseases are caused by pathogenic microbes in small excrements when an infected person coughs, sneezes, laughs or has close personal contact with the aerosolization of microbes. Droplets spread by sneezing, coughing or speaking can transmit diseases when they come into contact with mucous membranes in another person's eye, mouth or nose.

Antibodies produced by the immune system bind to the bacteria and help destroy them. Small bacteria and viruses can cause a variety of diseases, from the common cold to AIDS. Single-cell organisms are responsible for diseases such as sore throats, urinary tract infections and tuberculosis.

Infectious diseases are transmitted from person to person through direct or indirect contact. The easiest way to catch most infectious diseases is to come into contact with an infected person or animal.

Animals carry harmful germs that can spread to humans and cause diseases, and these are called zoonoses or zoonoses. Diseases transmitted by animals to humans via direct contact with animals, contaminated surfaces and water, consumption of animal products (including meat, milk and insects) or transmission by animals are called zoonotics (pronounced zo, not ik) or zoos (non-ik disease). Hunters and their dogs are often exposed to infectious diseases by not only infected animals, but also insects, vectors and contaminated soil and water.

Insects such as mosquitoes, ticks, flies, fleas and mites act as vectors that can transmit infection to another animal or person from an infected animal. Insects that suck blood can become infected if they feed on an infected host such as a bird, animal or human. Avoid hunting if you feel sick. Some people are more susceptible to disease because their immune systems are weakened by other diseases or diseases.

Environmental reservoirs (soil, water and vegetation) contain infectious organisms that can be transmitted to humans. Legionnaires' disease, for example, is a disease that spreads through the water supply of cooling towers and evaporative condensers. Leptospira bacteria can infect humans and their dogs when open wounds contaminate water or food or come into contact with mucous membranes in the nasal, oral and eye mucous membranes.

Zoonotic diseases (zoonosis, plural zoonosis) are diseases in animals that are transmitted to humans. In many cases, direct contact with a sick person (skin contact, also sexual contact or contact with another person) is the contact which passes the disease to a new host.

This list includes zoonotic diseases and related issues affecting people in Washington State. Brochures, reports and other manuals can be found in our publications on animal vector diseases. For provisions on the prevention of animal-borne diseases, including notification requirements, see the rules and guidelines on zoonoses.