Question

What body process are affected by infection? How does infection affect these processes?

Answer 1

In order to get into the body, bacteria must come into direct physical contact with it. This can happen in many different ways. An individual may acquire bacteria in any of the following ways.

•             By direct contact with an infected person. A common example of this method of infection is Meningitis, which is caused by the bacterium Neisseria Meningitidis.

•             Through dust or liquid droplets in the air. Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, can be contracted in this way, by coming into contact with sputum expectorated (coughed-up) by a person infected by Mycobacterium tuberculosis.

•             By consuming contaminated food or water. Many infections happen this way, such as Salmonella, Cholera and Typhoid.

•             By puncture wounds, such as animal or insect bites. Examples include the Rabies virus, which can be contracted through a bite from an infected animal, and Malaria, which can be contracted through a bite from a mosquito that carries the malaria virus.

Infection does not necessarily lead to disease. Infection occurs when viruses, bacteria, or other microbes enter your body and begin to multiply. Disease, which typically happens in a small proportion of infected people, occurs when the cells in your body are damaged as a result of infection, and signs and symptoms of an illness appear.

In response to infection, your immune system springs into action. White blood cells, antibodies, and other mechanisms go to work to rid your body of the foreign invader. Indeed, many of the symptoms that make a person suffer during an infection—fever, malaise, headache, rash—result from the activities of the immune system trying to eliminate the infection from the body.

Pathogenic microbes challenge the immune system in many ways. Viruses make us sick by killing cells or disrupting cell function. Our bodies often respond with fever (heat inactivates many viruses), the secretion of a chemical called interferon (which blocks viruses from reproducing), or by marshaling the immune system’s antibodies and other cells to target the invader. Many bacteria make us sick the same way, but they also have other strategies at their disposal. Sometimes bacteria multiply so rapidly they crowd out host tissues and disrupt normal function. Sometimes they kill cells and tissues outright. Sometimes they make toxins that can paralyze, destroy cells’ metabolic machinery, or precipitate a massive immune reaction that is itself toxic.

Bacterial infections disrupt the normal functions of the body and cause all kinds of illnesses. They injure the cells and tissues of the body, compromise the immune system, and deplete nutrients in the body. Bacterial infections may also disrupt the balance of healthy bacteria in the intestines and other parts of the body.

In addition to allowing disease-causing bacteria to grow, the elimination of good bacteria throws the immune system out of whack. The result can be simple allergies or very debilitating autoimmune diseases. Without the right balance of bacteria, your body might suffer from constant inflammation.

Inflammation is the body’s alarm system, which calls white blood cells to heal a wound or to get rid of an infection. Chronic inflammation, however, can make the body more susceptible to autoimmune diseases and cancer, such as causing inflammatory bowel disease which if uncontrolled can cause colon cancer.

There are two ways bacteria can harm the human body: toxicity – the bacteria produce toxins which damage specific tissues in the body. invasiveness – the bacteria multiply rapidly at the site of infection and overwhelm the body's defense mechanisms. The bacteria may then spread to other parts of the body.