First of all we must eliminate all the possible causes for the diseases. For this, we must avoid all the things that promote these diseases. For dengue the main cause are mosquitoes. Mosquitoes like places that has water in them as it serves as a breeding ground for them. So, in the society we must switch off the leaking pipes and taps, if any drain is open then we must close them and do not keep anything which has water open.
For swine flu:
The best way to prevent yourself from Swine Flu is to get flu vaccination or flu shot on annual basis. This protects your body from getting infected by the disease;Wash your hands properly using soap or sanitiser. This prevents the germs to get into the body and infect us. It is very important to wash hands before intake of any meal;One of the most important preventive measure is to avoid contact with people suffering from swine flu. Coming in contact with the infected person may lead you to catch the virus;Although, the flu does not spread through food. But it is important to have properly handled cooked food. The raw food must be properly washed and cooked;People who are prone to diseases are recommended to wear masks on mouth and nose so that they do not intake the virus from the environment.