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Table 1 Immature density and relative breeding index (RBI) of Anopheles stephensi in overhead tanks (OHTs), wells and other breeding habitats

From: Overhead tank is the potential breeding habitat of Anopheles stephensi in an urban transmission setting of Chennai, India

Month/year OHT Well Other breeding habitatsb
No. surveyed % positivity Immature densitya Anopheles immature density RBI No. surveyed % positivity Immature densitya Anopheles immature density RBI No. surveyed % positivity Immature densitya Anopheles immature density RBI
APR ‘13 95 55.8 9.3 9 1 99 35.4 17.8 2.7 0.5 9 33.3 6.1 1.9 1
MAY ‘13 77 54.6 8.6 8.2 1 76 59.2 15.6 2.5 0.8 5 60 10.3 8.4 0.8
JUN ‘13 80 53.8 5.8 5.3 0.9 76 69.7 13 2.4 0.8 16 75 14.6 5.5 0.9
JUL ‘13 78 56.4 8.5 8.3 0.9 74 56.8 19.8 2.8 0.7 22 36.4 28.1 1.8 0.7
AUG ‘13 81 66.7 10.6 10.5 1 81 59.3 11.6 1.4 0.8 29 17.2 148.9 9.9 1
SEP ‘13 66 59.1 11.7 10.9 0.9 67 34.3 8.4 1.1 0.5 27 7.4 8.4 0.3 0.1
OCT ‘13 80 67.5 9.7 9.5 1 80 28.8 6.2 0.4 0.4 18 11.1 0.1 0.1 0.5
NOV ‘13 74 56.8 5.4 5.4 0.9 79 32.9 2.8 0.4 0.6 18 22.2 34.1 5 0.8
DEC ‘13 75 48 4.4 4.4 0.8 80 28.8 3.2 0.5 0.6 13 15.4 30.8 4 0.4
JAN ‘14 101 50.5 6.4 6.3 0.9 99 31.3 3.8 0.6 0.5 2 0 0 0 0
FEB ‘14 76 55.3 2.9 2.9 1 81 30.9 6.8 1 0.8 6 16.7 6.9 0.5 1
MAR ‘14 77 52 3.8 3.6 1 82 23.2 9 0.5 0.8 3 33.3 38.5 3.6 1
  1. RBI relative breeding index (number of habitats positive for An. stephensi divided by the total number of habitats positive for any mosquito)
  2. aIncludes the total density of Anopheles, Culex and Aedes species
  3. bOther breeding habitats include underground tanks or sumps, barrels or drums, plastic pots, plastic containers, cemented containers, curing pits in construction site