To prevent air borne diseases
Stay away from the diseased person.
Wear a mask when you need to contact a diseased person.
Cover your mouth and nose while coughing or sneezing to prevent the spread of the disease.
To prevent water borne diseases
Ensure proper disposal of sewage.
Ensure safe drinking water supply.
To prevent vector borne diseases
Provide a clean environment, which helps in preventing vectors like mosquitoes from breeding.
Availability of proper nutrition. If proper and sufficient nutrition is not available, the immune system of the body will not function properly.