House index (HI) A quick survey of systematically selected houses in various sectors of the garrison was done by the Task Force to ascertain the number of houses where Aedes larvae were found in water containers. The percentage of houses which were positive for Aedes larvae would give an indicator of the risk of transmission, as >5% HI is indicative of a risk of transmission happening in the area. In our experience out of a total of 650 houses surveyed, 35 were found to have Aedes breeding in and around them giving a house index of 5.38%.
Container index (CI) During the vector survey the number of containers or receptaclesinfected with larvae or pupae (as a percentage) was noted to give us a CI of 4.16%.
Breteau index (BI) This is the number of containers searched for and found positive for Aedes larvae breeding in the houses as above. An index of more than 20 is indicative of a risk of transmission, while index below 5 indicates low risk of transmission. Our experience revealed a BI of