Table 4.
A comparison of parous An. gambiae s.l. collected from IRS and non-IRS districts between 2011 and 2014
| Study district/year compared | Compared parity rate (%) | % Change | Pooled sample proportion | Standard error | Z test statistic | p value | Remark |
|---|---|---|---|---|---|---|---|
| Savelugu Nanton District (SND) | |||||||
| 2011–2012 | 44.8 → 37.4% | −16.5 | 0.421 | 0.029 | 2.549 | 0.011* | Change from ACP to PM |
| 2012–2013 | 37.4 → 27.5% | −26.5 | 0.324 | 0.031 | 3.222 | 0.001* | Sprayed with PM |
| 2013–2014 | 27.5 → 28.1% | +2.1 | 0.277 | 0.034 | −0.168 | 0.867 | Sprayed with PM |
| Tolon Kumbungu District (TKD) | |||||||
| 2011–2012 | 53.3 → 46.6% | −12.6 | 0.499 | 0.021 | 3.242 | 0.001* | IRS continued with ACP |
| 2012–2013 | 46.6 → 50.4% | +8.0 | 0.490 | 0.018 | −2.071 | 0.038 | IRS withdrawn |
| 2013–2014 | 50.4 → 68.5% | +36.0 | 0.567 | 0.019 | −9.793 | 0.000* | IRS withdrawn |
| Tamale Metropolis (TML) | |||||||
| 2011–2012 | 68.6 → 65.8% | −4.1 | 0.671 | 0.016 | 1.730 | 0.084 | No IRS |
| 2012–2013 | 65.8 → 64.3% | −2.2 | 0.649 | 0.015 | 0.991 | 0.322 | No IRS |
| 2013–2014 | 64.3 → 72.3% | +12.5 | 0.681 | 0.013 | −6.113 | 0.000* | No IRS |
ACP alpha-cypermethrin, PM pirimiphos-methyl
* p value significant at 0.05 significance level; −ve% represents percentage reduction; +ve% represents percentage increase