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Table 2 Monthly biting rate, human density, human blood index, vector density and vector to human ratio in study villages, Ghana

From: Onchocerciasis transmission in Ghana: the human blood index of sibling species of the Simulium damnosum complex

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)
  1. 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)