Which of the following diseases is caused by bacteria?

Infectious diseases are caused by microorganisms such as bacteria, viruses, fungi, and protozoa. Among these, bacterial diseases result from harmful bacteria entering the body and producing toxins that damage tissues or disrupt normal body functions.

Tetanus is a classic example of a bacterial disease. It is caused by the bacterium Clostridium tetani, commonly found in soil, dust, and animal feces. The bacterium enters the body through wounds or cuts and produces a toxin called tetanospasmin, which affects the nervous system. The main symptoms include muscle stiffness, spasms, difficulty swallowing, and jaw lock (lockjaw). Without treatment, tetanus can be fatal, making vaccination extremely important.

Comparison with other options:

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  Malaria → caused by a protozoan parasite (Plasmodium species), transmitted by mosquitoes. Not bacterial.

  
  


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  Cancer → a non-infectious disease caused by uncontrolled cell growth; not caused by bacteria.

  
  


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  None of these → incorrect.

  
  

Bacterial infections like tetanus can be prevented through vaccination, proper wound care, and hygiene. Early diagnosis and administration of tetanus antitoxin or antibiotics are essential for treatment.

Understanding which diseases are bacterial is a fundamental concept in biology, microbiology, and everyday science. It helps students distinguish between types of pathogens and their effects on human health.

Thus, the correct answer is Tetanus (Option B), a bacterial disease that highlights the importance of preventive measures and awareness about infectious agents.