Disease Causative Agents

Typhoid fever is caused by Salmonella Typhi and spreads through contaminated water and food. Improved sanitation, clean water, and handwashing prevent transmission. Tetanus is soil-borne, tuberculosis is airborne, and trachoma spreads through flies/contact.

Antibiotics are not effective against cold and flu because they are caused by viruses.

The causal organism is bacteria.

Polio, chicken pox, and influenza are the diseases for which the causal organism is virus, whereas malaria is an example of a bacterial disease. 

Antibiotics are the preparation made from modified bacteria, which act against any bacterial infection, whereas, pathogen refers to the disease causing organisms. Carrier organisms transmit disease from a diseased person to a healthy one and invaders refer to any organisms, which enter into our body irrespective of the fact whether it is useful or harmful. 

Pathogens are microorganisms that cause disease, including bacteria, viruses, fungi, and protozoa. Antibiotics are drugs used to treat bacterial infections, not the organisms themselves. 'Invaders' is too vague a term. Carriers are organisms that harbor pathogens without showing symptoms themselves.

Communicable diseases spread from person to person through pathogens like bacteria or viruses. Cholera (waterborne bacterial), chickenpox (viral), and tuberculosis (airborne bacterial) are all infectious communicable diseases. Arthritis is a non-communicable chronic condition involving joint inflammation and degeneration.

A common disease which develops among the coal mine workers is silicosis. Exposure to coal mine dust and crystalline silica results in pneumoconiosis with initiation and progression of pulmonary fibrosis.

Virus causes Hepatitis-B.

Allergy is not a communicable disease.

Antibodies attack the pathogen which enters the body, and destroys it. This gives protection to our body,

Virus causes foot and mouth disease in cattle.

Bacillus anthracis causes anthrax.

Typhoid fever is caused by the bacterium Salmonella typhi and not by any virus.

This option is correct because poliomyelitis is usually spread from person to person through infected faeces entering the mouth. It may also be spread by food or water containing human faeces and less commonly from infected saliva. Balantidiasis is a zoonotic disease and is acquired by humans via the feco-oral route from the normal host, the pig, where it is asymptomatic. Contaminated water is the most common medium of transmission.