What is the chief measure in disease prevention?

• A. Sanitation
• B. Vaccination
• C. Quarantine
• D. Isolation

Answer: (A)

Reducing exposure to pathogens through environmental and personal hygiene measures is the main idea here. Sanitation covers clean water, proper waste disposal, safe food handling, and hygienic living and workspaces. When these conditions are improved, many infectious diseases are prevented simply by removing the ways pathogens can spread before people are exposed.

Vaccination is a powerful tool that protects individuals by building immunity to specific diseases, but it doesn’t prevent all infections and relies on vaccine availability and coverage. Quarantine and isolation are important for stopping disease spread after exposure or when someone is ill, but they are reactive controls rather than broad preventive measures applied to the whole population.

So, sanitation serves as the foundational preventive approach because it reduces transmission risk at the source, making it the chief measure in preventing disease.