Table 4.
Laboratory trials using Bacillus thuringiensis var. israelensis and Bacillus sphaericus against malaria vectors in sub-Saharan Africa
| Site (Country) | Bacterial strain (potency) | Product (formulations) | Species tested (larval instar) |
Exposure time (h) | LC50 | LC90/95 | References |
|---|---|---|---|---|---|---|---|
| ICIPE (Kenya) | Bti (2700 ITU/mg) | VectoBac® (WDG) | An. gambiae (s.s.) (3rd) | 24 | 0.021 | 0.201 | [67] |
| Bs (650 BsITU/mg) | VectoLex® (WDG) | An. gambiae (s.s.) (3rd) | 24 | 0.004 | 0.038 | ||
| Bti (10000 ITU/mg) | Bactimos® (PP) | An. gambiae (s.s.) (3rd) | 24 | 0.006 | 0.090 | ||
| Bs (1600 ITU/mg) | (TP) | An. gambiae (s.s.) (3rd) | 24 | 0.002 | 0.018 | ||
| Ouagadougou (Burkina Faso) | Bti (3500 ITU/mg) | Bactimos® (WP) | An. gambiae (s.l.) (3rd and 4th) | 24 | 0.081 | 0.231a | [70] |
| Bti (2000 ITU/mg) | VectoBac® (WP) | An. gambiae (s.l.) (3rd and 4th) | 24 | 0.110 | 0.375a | ||
| Bti (1500 ITU/mg) | Teknar (FC) | An. gambiae (s.l.) (3rd and 4th) | 24 | 0.662 | 1.743a | ||
| Bs (not stated) | 1593 IF-119 (SD) | An. gambiae (s.l.) (3rd and 4th) | 48 | 0.043 | 0.107a | ||
| Bs (not stated) | 2362 IF-118 (SD) | An. gambiae (s.l.) (3rd and 4th) | 48 | 0.022 | 0.130a | ||
| MRC, Farafenni (Gambia) | Bs (650 Bs ITU/mg) | VectoLex® (WDG) | An. gambiae (s.s.) (3rd) | 24 | 0.004 | 0.023 | [69] |
| Bti (3000 ITU/mg) | VectoBac® (WDG) | An. gambiae (s.s.) (3rd) | 24 | 0.039 | 0.132 | ||
| KEMRI, Kisumu (Kenya) | Bti (7000 ITU/mg) | Not stated | An. gambiae (s.l.) (3rd) | 24 | 0.062 | 0.797 | [21] |
| Bs (1000 ITU/mg) | Not stated | An. gambiae (s.l.) (3rd) | 48 | 0.058 | 0.451 | ||
| KCCR, Kumasi (Ghana) | Bti (3000 ITU/mg) | VectoBac® (WDG) | An. gambiae (3rd) | 24 | 0.026 | 0.136 | [68] |
| Bobo-Dioulasso (Burkina Faso) | Bs (not stated) | (FC) | An. gambiae (s.s.) (3rd) | 48 | 0.342 | 1.807 | [20] |
| UFS, Muheza (Tanzania) | Bs (not stated) | Spherimos (FC) | An. funestus (4th) | 48 | 1.0 | 6.0 | [26] |
| KCCR, Kumasi (Ghana) | Bs (not stated) | VectoLex® (WDG) | An. gambiae (s.l.) (3rd and 4th) | 24 | 0.0027 | 0.0086 | [66] |
| NOCMVD, Nazareth (Ethiopia) | Bti (not stated) | IPS-82 | An. arabiensis (3rd) | 48 | 0.0018b | – | [65] |
| Bs (not stated) | SPH-88 | An. arabiensis (3rd) | 48 | 0.0076b | – | ||
| NICD, Johannesburg (South Africa) | Bti (not stated) | Not stated | An. quadriannulatus (3rd) | 24 | 2.97 | 5.02 | [64] |
| – | An. arabiensis (3rd) | 24 | 3.72 | 10.10a | |||
| – | An. gambiae (3rd) | 24 | 3.76 | 7.70a | |||
| – | An. merus (3rd) | 24 | 3.82 | 6.65a | |||
| – | An. funestus (3rd) | 24 | 4.44 | 13.50a |
aLC90/95: a dose marked with a represents LC90; unmarked doses represent LC95
bDoses provided in µg/l were converted to mg/l for a uniform presentation. Concentrations reported in mg/l except for study [64] are given in 104 spores/ml
Abbreviations: Bti, Bacillus thuringiensis var. israelensis; Bs, Bacillus sphaericus; ITU, international toxic units; WDG, water-dispersible granules; PP, primary powder; TP, technical powder; FC, flowable concentrate; SD, spray dried; ICIPE, International Centre of Insect Physiology and Ecology; MRC, Medical Research Council; KCCR, Kumasi Centre for Collaborative Research; UFS, Ubwari Field Station; NOCMVD, National Organization for the Control of Malaria and other Vector-borne Diseases; NICD, National Institute of Communicable Diseases; LC, lethal concentration (concentration that kills 50/95% of the test subjects)