Common Human Disease
The disease is defined as the condition of disturbed or deranged functioning of one or more organs or organ systems of the body, caused due to infections, defective diet or heredity. All human diseases can be broadly categorized into congenital diseases and acquired diseases.
Congenital diseases are present from birth; may be caused by a genetic abnormality or metabolic disorder. They may be permanent and was practically incurable. However, modern research helped to cure some inborn diseases through gene therapy, enzyme replacement therapy, etc.
Acquired diseases develop after the birth and can be subdivided into (a) Communicable or infectious disease or (b) Non- Communicable or Non-infectious disease.
The diseases which are transmitted from an infected person either directly or indirectly, are known as Communicable or Infectious diseases. Malaria and other diseases.
The disease that cannot be transmitted from an infected person to another healthy are either directly or indirectly are known as Non- Communicable or Non-infectious diseases. Cancer is deficiency diseases are an example of this type.
Communicable diseases are caused by pathogens like viruses, bacteria, fungi, helminth worms, etc. All the disease-causing organisms are called ‘Pathogens’.
Many pathogens use another organism, the ‘Vector’‘ to reach us. These vectors are actually parasites that we regularly come across. A parasite is an organism which lives in or on the body of another organism and derives its nutrition from tat of host organism, Parasites are two categories viz: 1. Ectoparasite E.g. bedbug 2. Endoparasite E.g. Plasmodium is a protozoan endoparasite of the mosquito (vector) and human beings