<prompt> To prevent Yellow Fever Aedes aegypti index should be less than?0.50125  <response>: Aedes aegypti index is a house index and defined as the percentage of houses and their premises,in a limited well defined area, showing actual breeding of Aedes aegylti larvae. This index should not be more than 1 in towns and seapos in endemic areas to ensure freedom from yellow fever. Reference; Park;s Textbook of preventive and social medicine, 24th edition.Pg no. 301 