Table 2.
Monthly biting rate, human density, human blood index, vector density and vector to human ratio in study villages, Ghana
| Region | Village | Season | MBR | Human host density (H) | All trapping techniques | Vector collector-caught flies only | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| HBI (95 % BCI) | V (95 % BCI) | V/H | HBI (95 % BCI) | V (95 % BCI) | V/H | |||||
| Brong-Ahafo | Asubende | Dry Feb 2011 | 2,061 | 108 | 0.65 (0.58, 0.71) | 39,603 (35,917–44,480) | 367 (333–412) | 0.70 (0.56, 0.82) | 36,712 (31,280–46,497) | 340 (290–431) |
| Agborlekame | Dry Feb 2011 | 775 | nd | 0.33 (0.01, 0.77) | nd | nd | nd | nd | nd | |
| Volta | Asukawkaw Ferry | Wet Aug 2009 | nd | 5,459 | 0.40 (0.18, 0.64) | nd | nd | 1.00 (0.23, 1.00) | nd | nd |
| Dry March 2010 | 5,777 | 0.74 (0.68, 0.80) | 4,904,478 (4,570,053–5,340,204) | 898 (837–978) | 0.67 (0.59, 0.74) | 5,424,605 (4,893,429–6,151,412) | 994 (896–1,127) | |||
| Dry Feb 2011 | 5,429 | 0.99 (0.97, 1.00) | 3,453,718 (3,419,227–3,551,323) | 633 (626–651) | 1.00 (0.98, 1.00) | 3,410,288 (3,410,288–3,481,386) | 625 (625–638) | |||
| Dodi Papase | Wet Aug 2009 | nd | 5,254 | 0.86 (0.56, 1.00) | nd | nd | nd | nd | nd | |
| Dry March 2010 | 2,357 | 0.98 (0.94, 1.00) | 1,458,110 (1,431,769–1,533,702) | 278 (273–292) | 0.99 (0.95, 1.00) | 1,445,328 (1,427,147–1,522,330) | 275 (272–290) | |||
| Dry Feb 2011 | 4,371 | 0.98 (0.94, 1.00) | 2,701,299 (2,654,646–2,835,194) | 514 (505–540) | 1.00 (0.97, 1.00) | 2,642,575 (2,642,575–2,741,938) | 503 (503–522) | |||
| Pillar 83 /Djodji | Wet July 2009 | nd | 188 | nd | nd | nd | nd | nd | nd | |
| Dry March 2010 | 7,171 | 0.69 (0.63, 0.74) | 225,288 (209,692–244,864) | 1,198 (1,115–1,302) | 1.00 (0.98, 1.00) | 155,129 (155,129–159,325) | 825 (825–847) | |||
| Dry Feb 2011 | 9,329 | 0.91 (0.88, 0.93) | 222,982 (217,243–230,326) | 1,186 (1,156–1,225) | 0.98 (0.96, 0.99) | 206,089 (203,430–211,314) | 1,096 (1,082–1,124) | |||
| Western | Bosomase | Wet Aug 2009 | 5,481 | 188 | 0.73 (0.59, 0.85) | 162,045 (139,771–203,188) | 862 (743–1081) | 0.63 (0.42, 0.83) | 187,736 (144,996–290,028) | 999 (896–1,127) |
| Dry Feb 2010 | 1,209 | 0.88 (0.80, 0.95) | 29,641 (27,741–33,093) | 158 (148–176) | 1.00 (0.84, 1.00) | 26,154 (26,154–32,700) | 139 (139–174) | |||
| Ashanti | Gyankobaa | Wet Aug 2009 | 4,121 | 274 | 0.41 (0.37, 0.46) | 316,258 (284,223–355,258) | 1,154 (1,037–1,297) | 0.47 (0.42, 0.53) | 276,101 (246,778–312,882) | 1,008 (901–1,142) |
Abbreviations: MBR monthly biting rate (no. of bites/person/month) as per vector collector (see [13]), HBI human blood index, H human host density, V vector density, V/H vector to human host ratio, nd not determined, BCI Bayesian credible intervals. In all calculations the length of the gonotrophic cycle (g) was assumed to be 3.5 days, expressed in months (3.5 × 12/365 = 0.1151)