The Most Common Sources of Infections 

Infections are a significant problem that human beings have to face. They can affect the body in the most unpleasant ways and they also have a multitude of causes, some of the completely uncontrollable. In many parts of the world, infections are a huge problem. Infections can be of numerous types, mostly depending on the most common sources of infection. Some people might have an infection without even knowing it (asymptomatic infections) while in others symptoms are obvious. Knowing which the sources of infections are can help you protect yourself better and avoid exposure as much as possible.

Generally speaking, sources of infections are called microorganisms and they can be of five main types: bacteria, viruses, fungi, rickettsia and protozoa. Some of these microorganisms are normally found in the human body in small amounts and are actually indispensable. Depending on the provenience of the infectious agent, sources of infection can be classified as endogenous and exogenous. In endogenous infections, the agent causing the problem comes from the human body. Some of the microorganisms living there exceed their limits and start causing damage. This might happen because the immunity is compromised and it is very common in patients who have had surgery or in undernourished people.

Exogenous sources of infections imply the fact that microorganisms from outside the human body find their way inside and cause illnesses or diseases. Exogenous sources of infections can also be split into three main categories: of human origin, of animal origin and of environmental origin. When humans are sources of infections, things are pretty complicated. They can spread infections when they are sick themselves and in these cases they are pretty easy to isolate in order to stop the spreading. However, humans can also be sources of infections without having any symptom at all, like some of those who have the HIV virus for instance. In some cases, humans can only be carriers of the microorganisms nausea sweating diarrhea that cause infections and they are hard to find and isolate.

Animal sources of infections usually affect humans in case of accidents or in case products of animal origin are consumed. People can get infected if they are bitten by an animal or if they get some insect stings. Foods like meat, milk or eggs can also get easily contaminated and the infectious agent reaches the human body when these products are consumed. In fact, all types of foods are considered common sources of infection. They might be contaminated right from the start or they might be infected while they are processed. More than that, some foods are an excellent environment for microorganisms to multiply.

Water, air and soil are significant sources of infection. It is known the fact that contaminated water can cause lots of illnesses, especially in under developed countries. Air and soil are not sources of infections in themselves because they mainly contain non-pathogenic agents. However, they can get contaminated with microorganisms carried by humans or animals and they can contribute to spreading them. Air usually becomes one of the most important sources of infection because infectious agents from the skin or the respiratory tract travel with it and affect other human bodies when inhaled or ingested. Soil on the other hand gets contaminated mainly with pathogenic agents from feces of either human or animal origin.