There are several indices based on numbers of immature mosquitoes that can be used for mosquito vector surveillance. An increase in an index is associated with an increase in mosquitoes and an increased risk of mosquito-borne disease.
Parameters:
(1) number of water-holding containers examined
(2) number of houses examined (a house is one unit of accomodation and surrounding premises, irrespective of number of people residing there)
(3) presence of larvae
(4) presence and number of pupae
|
Index
|
Abbreviation
|
|
house
|
HI
|
|
container
|
CI
|
|
pupa
|
PI
|
|
Breteau
|
BI
|
house index =
= (number of houses with pupae and/or larvae) / (number of houses counted) * 100%
container index =
= (number of water-holding containers with pupae and/or larvae) / (number of containers counted) * 100%
pupae index = number of pupae per 100 houses =
= (number of pupae counted) / (number of houses) *100
Breteau index =number of positive containers per 100 houses
= (number of water-holding containers with pupae and/or larvae) / (number of houses) * 100
The selected index is monitored over time for a trend increase. It is important that the measurement be as standandized as possible.
Sources of variation:
(1) number of water-holding containers per house
(2) number of larvae and pupae per container
