Infectious diseases are diseases caused by germs (microbes). First of all, we need to understand that not all germs like bacteria, viruses, fungi, and parasites cause disease. In fact, a host of bacteria normally live on the skin, eyelids, nose, and mouth, and gut.
These bacteria are called normal flora and are considered common inhabitants. These normal florae are helpful to us! The bacteria in our bowels break down foods and form vitamin K, an essential vitamin for all of us.
The common bacteria on our skin and our mouth protect us by preventing or reducing the possibility that we will become infected with harmful bacteria and fungi.
The normal balance of bacteria can be upset by antibiotics and some illnesses. Viral infections often damage body surfaces and set the stage for infection by harmful bacteria.
Frequently, bacteria are present on a body surface such as the nose or throat or in the bowels, but there is no illness. This is called carriage of the bacteria, and the person with the bacteria is called a carrier. There is no illness in the carrier, but the carrier sometimes can transmit or spread the bacteria to another person. Many bacteria carried out can cause infection and disease.
Symptoms Of Infectious Diseases
Symptoms indicating an infectious disease will vary depending on the organism that is causing the infection. For the most part, however, common symptoms include extreme fatigue and fever. Other indications include:
They can also have very specific symptoms. These diseases are treated differently, depending on how severe they are and how much they affect your immune system.
While you cannot go to the doctor for a cold, if your symptoms persist for more than a few days, you should see a doctor. You can also prevent some diseases by getting the vaccine.
Causes Of Infectious Diseases
Infectious diseases in humans are microorganisms including:
- Viruses that multiply inside and invade healthy cells.
- Bacteria or small, single-celled organisms that are capable of causing disease.
- Parasites are organisms that live inside host bodies that cause disease.
- Fungi, which includes many different types of fungi.
Infectious diseases spread in many ways. In many cases, direct contact with a sick person, either through skin-to-skin contact (including sexual contact) or touching another person, transmits the disease to a new host. Infectious diseases are also spread by exposure to body fluids such as blood and saliva.
Sometimes the incubation is short (e.g., a day or so for the flu), while other times it is quite long (eg, 2 weeks for chickenpox and many years for human immunodeficiency virus [HIV]).
In some cases, infectious diseases travel through the air for a long time in small particles. Healthy people swallow these particles and later become ill.
However, some diseases have become resistant to drugs. You should always consult a doctor about the best treatment option for your particular symptoms or illness.