<prompt> To prevent the spread of yellow fever across borders, the area surrounding airpos and seapos should be free from breeding of aedes mosquito. What is the area to be kept free of aedes mosquitoinsect vector?At Least 200m around the seaairposAt Least 300m around the seaairposAt Least 400m around the seaairposAt Least 500m around the seaairpos  <response>: As per the guidelines an area extending at least 400 m around an airposea po must be kept free from the breeding of insect vector. Also know: Aedes aegypti index - is the of houses and their premises in a well defined area, showing actual breeding of aedes aegypti larvae. It should not be more than 1 in towns and seapos in endemic areas to ensure freedom from yellow fever. Ref: Park, Edition 21, Page - 259. 