Microbes And Disease

Microbes or microorganisms are small, unicellular organisms which cannot be seen with our naked eyes. Some microbes are useful in our day to day life while some are harmful to our health. The microorganisms which are harmful to us are called pathogens. Various kinds of pathogens include bacteria, viruses, protozoa, and a few variations of worms as well. Once they invade the host cell, they disrupt or damage the normal cellular activities. This leads to diseases on a larger scale.



There are several diseases caused by these microbes.Here is the list of microbes with their

  • Viral diseases, as the name sounds it is caused by the virus. These include both acute and infectious diseases like the common cold, to chronic disease like AIDS.  Apart from these acute diseases, it is also responsible for mumps, polio, rabies etc.
  • Diseases caused by bacteria include diphtheria, typhoid, cholera etc.
  • Malaria and sleeping sickness are the diseases caused by protozoa.
  • Worms like roundworms, tapeworms could cause diseases like Ascariasis and Taeniasis respectively.

The source and means of transfer of these infections are quite different. The path which bacterias spread disease is different from that of viruses. The main source of bacterial infection is none other than contaminated food and water while viral diseases spread mainly through the air. Hence, bacterial and viral diseases are usually communicable. Other means of transfer of pathogens include direct physical contact i.e. blood transfusion, breastfeeding, sexual contact etc…

Certain pathogenic diseases are organ or tissue-specific. For example, Tuberculosis affects the lungs of the individuals while Jaundice causing viruses targets the liver.



There is the quote, ‘prevention is better than cure’. Drugs like antibiotics or antibacterials are used to destroy or slow down the growth of bacteria. These antibiotics, however, are not effective for viral infections. The depth or severity of infection depends on the amount and rate at which microbes spread.

For more details about microbial diseases and their prevention, visit Byju’s.

Practise This Question

Angiosperms are classified into monocots and dicots on the basis of the number of _________ .