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Infectious Diseases - Means of Spread

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Means Of Spread:

  • Many microbial agents can commonly move from an affected person to someone else in a variety of ways. In other words, they can be ‘communicated’, and so are also called communicable diseases. Such disease-causing microbes can spread through the air. This occurs through the little droplets thrown out by an infected person who sneezes or coughs. Someone standing close by can breathe in these droplets, and the microbes get a chance to start a new infection. Examples of such diseases spread through the air are the common cold, pneumonia and tuberculosis.
  • We all have had the experience of sitting near someone suffering from a cold and catching it ourselves. Obviously, the more crowded our living conditions are, the more likely it is that such airborne diseases will spread.
  • Diseases can also be spread through water. This occurs if the excreta from someone suffering from an infectious gut disease, such as cholera, get mixed with the drinking water used by people living nearby. The cholera causing microbes will enter a healthy person through the water they drink and cause disease in them. Such diseases are much more likely to spread in the absence of safe supplies of drinking water.
  • Sexually transmitted diseases are not spread by casual physical contact. Casual physical contacts include handshakes or hugs or sports, like wrestling, or by any of the other ways in which we touch each other socially. Other than the sexual contact, the virus causing AIDS (HIV) can also spread through blood-to-blood contact with infected people or from an infected mother to her baby during pregnancy or through breast feeding.
  • Many diseases are transmitted by other animals. These animals carry the infecting agents from a sick person to another potential host. These animals are thus the intermediaries and are called vectors.
  • Mosquitoes are the most common vectors we know. In many species of mosquitoes the female needs highly nutritious food in the form of blood in order to be able to lay mature eggs. Mosquitoes feed on many warm-blooded animals, including us. In this way, they can transfer diseases from person to person.

    Where do the disease-causing germs live in our body?

    There are a number of tissues and organs in our body where these microbes can get attached to.

    Generally, the point of entry decides where they will go. For instance, any microbe that enters through the nose is likely to settle at the lungs.

    This can also be seen through the signs and symptoms of a disease as only those organs and tissues issues seem affected where these microbes enter.

    But there are some other common diseases also that are not tissue-specific.

    Inflammation – Our body has an immune system in which it creates the cells that can fight against the disease-causing germs. This process of recruiting cells to kill the infectious agents present in our body is called Inflammation. The inflammation process shows different effects on our body such as fever or swelling.

    Hence, we can say that the likelihood we are going to be affected by the disease is determined by the immune system of our body.

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