Table 2 Results from chemical residue analysis. Median deltamethrin residue (in mg/m2) and the proportion of nets with a deltamethrin concentration of at least 4 mg/m2.
A | Average net chemical residue in mg/m2 at different times of follow-up | |||||
|---|---|---|---|---|---|---|
Type of net | Baseline (n) Median IQR | 6 Months (n) Median IQR | 12 Months (n) Median IQR | 18/20 Months (n) Median IQR | 24/27 Months (n) Median IQR | 36/39 Months (n) Median IQR |
PermaNet 1st generation | (10) 47.5 32.9 – 52.2 | (40) 2.5 1. 6 – 7.1 | (40) 2.1 0.7 – 3.9 | (43) 1.0 0.5 – 2.8 | (40) 1.6 0.8 – 3.3 | (38) 0.5 0.3 – 0.9 |
PermaNet 2nd generation | (10) 69.2 56.8 – 75.4 | (40) 65.6 58.1 – 78.5 | (40) 55.8 39.1 – 82.4 | (40) 44.5 34.5 – 67.4 | (38) 32.3 21.4 – 48.7 | (40) 28.7 11.2 – 37.9 |
Conventional net | (10) 16.9 10.0 – 25.4 | (40) 0.7 0.4 – 1.4 | Not done | Not done | Not done | Not done |
Conventional net retreated | (13) 42.8 12.5 – 77.1 | (34) 3.1 1.6 – 11.5 | (11) 1.4 0.3 – 26.4 | Not done | Not done | Not done |
B | Proportion of nets with deltamethrin ≥ 4 mg/m 2 at different times of follow-up | |||||
Type of net | Baseline (n) % 95% CI | 6 Months (n) % 95% CI | 12 Months (n) % 95% CI | 18/20 Months (n) % 95% CI | 24/27 Months (n) % 95% CI | 36/39 Months (n) % 95% CI |
PermaNet 1st generation | (10) 100 66.2 – 100 | (40) 40.0 24.9 – 56.7 | (40) 22.5 10.8 – 38.5 | (43) 15.0 5.6 – 29.8 | (40) 17.5 7.3 – 32.8 | (38) 5.3 0.1 – 17.7 |
PermaNet 2nd generation | (10) 100 66.2 – 100 | (40) 100 91.2 – 100 | (40) 100 91.2 – 100 | (40) 100 91.2 – 100 | (38) 97.4 86.2 – 99.9 | (40) 90.0 76.3 – 97.2 |
Conventional net | (10) 100 66.2 – 100 | (40) 5.0 0.6 – 16.9 | Not done | Not done | Not done | Not done |
Conventional net retreated | (13) 100 75.3 – 100 | (34) 47.1 29.8 -64.9 | (11) 45.5 16.7 – 76.6 | Not done | Not done | Not done |