Since time immemorial, microorganisms have inhabited the world and have lived in all possible natural, environmental, and biological habitats of the world. A large proportion of the microorganisms are necessary for other organisms’ survival, whereas, few are disease causing or pathogenic. Severe health enormities such as infectious diseases can result from pathogenic strains of microorganisms. Infectious diseases may include “cholera, malaria, tuberculosis, AIDS, pneumonia” and many more. According to the records, it has come into focus that the spread of these infectious diseases have increased drastically and have accelerated the death toll all around the world. All of the infectious diseases are contagious and transmittable that is, the germs causing the disease can transfer from the infected person to the uninfected person. There are several ways, which enable these germs to spread in order to transmit the disease from one person to another. Since some germs cannot live exterior to human body, the resulting diseases can only pass on through direct contact of humans, while few diseases are transmissible through different mediums such as food, water, air, or animals.
Mostly developing countries are the victims of infectious diseases as living standards of the people are lower and the hygiene conditions in such nations are not appropriate. In recent times, through medical researches it has come under identification that those diseases, which previously become extinct, are now causing infections again, the biggest example is of tuberculosis. ...Show more