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Table 2 Data leading to estimates of entomological inoculation rates in highlands and lowlands with and without treated nets

From: Variation of malaria transmission and morbidity with altitude in Tanzania and with introduction of alphacypermethrin treated nets

  HIGHLAND       LOWLAND      
Hamlet:- Ml, M2, M3, M6, M8, M9 M4, M5, M7, M10 M11 B1, B3, B5, B6, B8 B2, B4, B7, B9, B10
  Geom
Mean
%
Af
%
Am
Geom
Mean
%
Af
%
Am
Geom
Mean
%
Af
%
Am
Geom
Mean
%
Af
%
Am
Oct-Dec'98 1.65a 60 20 1.60a 43 45 10.40b 62 6 13.0b 36 4
Jan-Mar'99 1.57a 59 10 1.26a 45 16 31.47b 7 0 31.59b 4 0
Apr-Jun'99 3.65a 30 6 3.96a 35 7 47.70b 11 1 67.49b 8 0
Jul-Aug'99 1.27a 63 22 0.67a 38 35 6.09b 55 11 7.52b 39 2
Total on 4
trap nights
8.14    7.49    95.66    119.60   
Bites/pers/yearj 1114    1025    13093    16370   
%CSP +ve (no. tested) [15] 3.66% (709)    3.97% (478)    4.33% (2681)    4.49% (1381)   
EIR/year 40.1    37.4    566.9    735.0   
  NO NETS NETS IN NO NETS NETS IN
Oct-Dec'99 0.95a 50 29 0.26b
s;f [0.11 0.34]
18 79 1.12a 55 19 0.31b
s;f [0.35 0.28]
60 13
Jan-Mar'00 0.52a 75 4 0.10b
s;f [0; 0.12]
20 40 1.53C 26 0 0.40a
s;f [0.50 0.35]
11 0
Apr-Jun'00 1.19a 49 8 0.28b
s;f [0.34 0.24]
33 37 11.76c 19 1 7.29c
s;f [5.52 8.76]
12 0
Jul-Aug'00 0.31a 44 28 0.21a
s;f [0.17 0.24]
27 27 9.99b 68 3 2.04c
s;f [1.59 2.51]
58 0
Total on 4
trap nights
2.06    0.85    24.40    10.04   
Bites/pers./yearj 282    116    3339    1374   
%CSP +ve (no. tested) [16] 3.68% (380)a    2.74% (73)a    4.45% (629)a    2.73% (916)a
s:f [2.4; 3.0%]
  
EIR/year 10.4    3.2    148.6    37.5   
Reduction in EIR 69.2% 74.8%
  1. Geometric means of light trap catches in rooms with untreated nets in highland and lowland villages in the four seasons of the years before and after introduction of alphacypermethrin treated nets into half of the villages. From these data and data on sporozoite (CSP) rates determined by ELISA, entomological inoculation rates per person per year are calculated. Means in the same row with the same superscript do not differ significantly (t test, Kruskall Wallis or χ2); jcalculated from mean catch on 4 nights multiplied by 365/4 × 1.5 [8]; the species composition of the anopheline vector population is indicated in terms of the percentage that were An. funestus (Af) and An. marshallii s.l. (Am): the remainder were An. gambiae s.l. [Data in square brackets marked by s;f indicate light trap catches and CSP rates in villages with nets treated respectively with the SC or the Fastac (granular) formulations of alphacypermethrin]