<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511.
<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511. The black line encloses the control, the red line the intervention area. The 24 sentinel sites for larval surveys are marked as stars.
<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511.
<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511. The black line encloses the control, the red line the intervention area. The 24 sentinel sites for larval surveys are marked as stars.
Background: Vector control activities, namely long-lasting insecticidal nets (LLIN) and indoor re... more Background: Vector control activities, namely long-lasting insecticidal nets (LLIN) and indoor residual spraying (IRS), have contributed significantly to the decreasing malaria burden observed in The Gambia since 2008. Nevertheless, insecticide resistance may threaten such success; it is important to regularly assess the susceptibility of local malaria vectors to available insecticides. Methods: In the transmission seasons of 2016 and 2017, Anopheles gambiae (s.l.) larvae were sampled in or around the nine vector surveillance sentinel sites of the Gambia National Malaria Control Programme (GNMCP) and in a few additional sampling points. Using WHO susceptibility bioassays, female adult mosquitoes were exposed to insecticide-impregnated papers. Molecular identification of sibling species and insecticide resistance molecular markers was done on a subset of 2000 female mosquitoes. Results: A total of 4666 wild-caught female adult mosquitoes were exposed to either permethrin (n = 665), deltamethrin (n = 744), DDT (n = 1021), bendiocarb (n = 990) or pirimiphos-methyl (n = 630) insecticide-impregnated papers and control papers (n = 616). Among the 2000 anophelines, 1511 (80.7%) were Anopheles arabiensis, 204 (10.9%) Anopheles coluzzii, 75 (4%) Anopheles gambiae (s.s.), and 83 (4.4%) An. gambiae (s.s.) and An. coluzzii hybrids. There was a significant variation in the composition and species distribution by regions and year, P = 0.009. Deltamethrin, permethrin and DDT resistance was found in An. arabiensis, especially in the coastal region, and was mediated by Vgsc-1014F/S mutations (odds ratio = 34, P = 0.014). There was suspected resistance to pirimiphos-methyl (actellic 300CS) in the North Bank Region although only one survivor had the Ace-1-119S mutation. Conclusions: As no confirmed resistance to bendiocarb and actellic 300CS was detected, the national malaria control programme can continue using these insecticides for IRS. Nevertheless, the detection of Ace-1 119S mutation warrants extensive monitoring. The source of insecticide pressure driving insecticide resistance to pyrethroids and DDT detected at the coastal region should be further investigated in order to properly manage the spread of resistance in The Gambia.
<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511.
Mobile phones are increasingly used in community health programmes, but the use of video job-aids... more Mobile phones are increasingly used in community health programmes, but the use of video job-aids that can be displayed on smart phones has not been widely exploited. We investigated the use of video job-aids to support the delivery of seasonal malaria chemoprevention (SMC) in countries in West and Central Africa. The study was prompted by the need for training tools that could be used in a socially distanced manner during the COVID-19 pandemic. Animated videos were developed in English, French, Portuguese, Fula and Hausa, illustrating key steps for administering SMC safely, including wearing masks, washing hands, and social distancing. Through a consultative process with the national malaria programmes of countries using SMC, successive versions of the script and videos were reviewed to ensure accurate and relevant content. Online workshops were held with programme managers to plan how to use the videos in SMC staff training and supervision, and the use of the videos was evaluated in Guinea through focus groups and in-depth interviews PLOS DIGITAL HEALTH
Background Routine continuous distribution (CD) of insecticide-treated nets (ITNs) has been an im... more Background Routine continuous distribution (CD) of insecticide-treated nets (ITNs) has been an important part of an overall ITN strategy to complement mass campaigns since the early 2000s. The backbone of CD implementation for many sub-Saharan African countries is distribution through antenatal care (ANC) and Expanded Programme for Immunizations (EPI) channels. Performance of these channels is often not monitored closely at the national level, nor is it reviewed globally, unlike the oversight provided to mass campaigns. The question as to why every eligible pregnant woman and child attending these services does not get an ITN remains important and yet, unanswered. Methods ANC and EPI issuing rates from seven countries were reviewed with the aim of conducting a blinded multi-country analysis. Monthly data from January to December 2021 was extracted from each country’s health management information system and analysed jointly with a National Malaria Control Programme (NMCP) focal poin...
<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511. application took place weekly. The monitoring of the sentinel sites was done 1–3 days after application. CG formulation was applied in week (wk) 1, 2 and 3, WDG formulation was applied from week 4. Differences in immature densities were analysed using Mann-Whitney tests at a significance level of p &lt; 0.05. Different letters (a, b) on bars indicate a significant difference at the specific sampling date.
In malaria-endemic areas, residents of modern houses have less malaria than those living in tradi... more In malaria-endemic areas, residents of modern houses have less malaria than those living in traditional houses. This study will determine if modern housing provides incremental protection against clinical malaria over the current best practice of long-lasting insecticidal nets (LLINs) and prompt treatment in The Gambia, determine the incremental cost-effectiveness of the interventions, and analyze the housing market in The Gambia. A two-armed, household, cluster-randomized, controlled study will be conducted to assess whether improved housing and LLINs combine to provide better protection against clinical malaria in children than LLINs alone in The Gambia. The unit of randomization will be the household, defined as a house and its occupants. A total of 800 households will be enrolled and will receive LLINs, and 400 will receive improved housing before clinical follow-up. One child aged 6 months to 13 years will be enrolled from each household and followed for clinical malaria using ...
Citation for published item: Jatta, Ebrima and Jawara, Musa and Bradley, John and Je ries, David ... more Citation for published item: Jatta, Ebrima and Jawara, Musa and Bradley, John and Je ries, David and Kandeh, Balla and Knudsen, Jakob B. and Wilson, Anne L. and Pinder, Margaret and D'Alessandro, Umberto and Lindsay, Steve W. (2018) 'How house design a ects malaria mosquito density, temperature, and relative humidity: an experimental study in rural Gambia.', Lancet planetary health., 2 (11). e498-e508.
In sub-Saharan Africa, cooler houses would increase the coverage of insecticide-treated bednets, ... more In sub-Saharan Africa, cooler houses would increase the coverage of insecticide-treated bednets, the primary malaria control tool. We examined whether improved ventilation, using windows screened with netting, cools houses at night and reduces malaria mosquito house entry in The Gambia. Identical houses were constructed, with badly fitting doors, the only mosquito entry points. Two men slept in each house and mosquitoes captured using light traps. First, temperature and mosquito density was compared in four houses with 0, 1, 2 and 3 screened windows. Second, carbon dioxide (CO<sub>2</sub>), a major mosquito attractant, was measured in houses with (i) no windows, (ii) screened windows and (iii) screened windows and screened doors. Computational fluid dynamic modelling captured the spatial movement of CO<sub>2</sub>. Increasing ventilation made houses cooler, more comfortable and reduced malaria mosquito house entry; with three windows reducing mosquito densities by 95% (95%CI = 90–98%). Screened windows and doors reduced the indoor temperature by 0.6°C (95%CI = 05–0.7°C), indoor CO<sub>2</sub> concentrations by 31% between 21 : 00 and 00 : 00 h and malaria mosquito entry by 76% (95%CI = 69%–82%). Modelling shows screening reduces CO<sub>2</sub> plumes from houses. Under our experimental conditions, cross-ventilation not only reduced indoor temperature, but reduced the density of house-entering malaria mosquitoes, by weakening CO<sub>2</sub> plumes emanating from houses.
The study sites for the West African ICEMR are in three countries (The Gambia, Senegal, Mali) and... more The study sites for the West African ICEMR are in three countries (The Gambia, Senegal, Mali) and are located within 750 km of each other. In addition, the National Malaria Control Programmes of these countries have virtually identical policies: 1] Artemisinin Combination Therapies (ACTs) for the treatment of symptomatic Plasmodium falciparum infection, 2] Long-Lasting Insecticide-treated bed Nets (LLINs) to reduce the Entomololgic Inoculation Rate (EIR) and 3] Sulfadoxine-Pyrimethamine for the Intermittent Preventive Treatment of malaria during pregnancy (IPTp). However, the prevalence of P. falciparum malaria and the status of malaria control vary markedly across the four sites with differences in the duration of the transmission season (from 4-5 to 10-11 months), the intensity of transmission (with EIRs from unmeasurably low to 4-5 per person per month), multiplicity of infection (from a mean of 1.0 to means of 2-5) and the status of malaria control (from areas which have virtually no control to areas that are at the threshold of malaria elimination). The most important priority is the need to obtain comparable
Seasonal malaria chemoprevention (SMC) aims to prevent malaria in children during the high malari... more Seasonal malaria chemoprevention (SMC) aims to prevent malaria in children during the high malaria transmission season. The Achieving Catalytic Expansion of SMC in the Sahel (ACCESS-SMC) project sought to remove barriers to the scale-up of SMC in seven countries in 2015 and 2016. We evaluated the project, including coverage, effectiveness of the intervention, safety, feasibility, drug resistance, and cost-effectiveness. For this observational study, we collected data on the delivery, effectiveness, safety, influence on drug resistance, costs of delivery, impact on malaria incidence and mortality, and cost-effectiveness of SMC, during its administration for 4 months each year (2015 and 2016) to children younger than 5 years, in Burkina Faso, Chad, The Gambia, Guinea, Mali, Niger, and Nigeria. SMC was administered monthly by community health workers who visited door-to-door. Drug administration was monitored via tally sheets and via household cluster-sample coverage surveys. Pharmacov...
<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511.
<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511. The black line encloses the control, the red line the intervention area. The 24 sentinel sites for larval surveys are marked as stars.
<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511.
<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511. The black line encloses the control, the red line the intervention area. The 24 sentinel sites for larval surveys are marked as stars.
Background: Vector control activities, namely long-lasting insecticidal nets (LLIN) and indoor re... more Background: Vector control activities, namely long-lasting insecticidal nets (LLIN) and indoor residual spraying (IRS), have contributed significantly to the decreasing malaria burden observed in The Gambia since 2008. Nevertheless, insecticide resistance may threaten such success; it is important to regularly assess the susceptibility of local malaria vectors to available insecticides. Methods: In the transmission seasons of 2016 and 2017, Anopheles gambiae (s.l.) larvae were sampled in or around the nine vector surveillance sentinel sites of the Gambia National Malaria Control Programme (GNMCP) and in a few additional sampling points. Using WHO susceptibility bioassays, female adult mosquitoes were exposed to insecticide-impregnated papers. Molecular identification of sibling species and insecticide resistance molecular markers was done on a subset of 2000 female mosquitoes. Results: A total of 4666 wild-caught female adult mosquitoes were exposed to either permethrin (n = 665), deltamethrin (n = 744), DDT (n = 1021), bendiocarb (n = 990) or pirimiphos-methyl (n = 630) insecticide-impregnated papers and control papers (n = 616). Among the 2000 anophelines, 1511 (80.7%) were Anopheles arabiensis, 204 (10.9%) Anopheles coluzzii, 75 (4%) Anopheles gambiae (s.s.), and 83 (4.4%) An. gambiae (s.s.) and An. coluzzii hybrids. There was a significant variation in the composition and species distribution by regions and year, P = 0.009. Deltamethrin, permethrin and DDT resistance was found in An. arabiensis, especially in the coastal region, and was mediated by Vgsc-1014F/S mutations (odds ratio = 34, P = 0.014). There was suspected resistance to pirimiphos-methyl (actellic 300CS) in the North Bank Region although only one survivor had the Ace-1-119S mutation. Conclusions: As no confirmed resistance to bendiocarb and actellic 300CS was detected, the national malaria control programme can continue using these insecticides for IRS. Nevertheless, the detection of Ace-1 119S mutation warrants extensive monitoring. The source of insecticide pressure driving insecticide resistance to pyrethroids and DDT detected at the coastal region should be further investigated in order to properly manage the spread of resistance in The Gambia.
<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511.
Mobile phones are increasingly used in community health programmes, but the use of video job-aids... more Mobile phones are increasingly used in community health programmes, but the use of video job-aids that can be displayed on smart phones has not been widely exploited. We investigated the use of video job-aids to support the delivery of seasonal malaria chemoprevention (SMC) in countries in West and Central Africa. The study was prompted by the need for training tools that could be used in a socially distanced manner during the COVID-19 pandemic. Animated videos were developed in English, French, Portuguese, Fula and Hausa, illustrating key steps for administering SMC safely, including wearing masks, washing hands, and social distancing. Through a consultative process with the national malaria programmes of countries using SMC, successive versions of the script and videos were reviewed to ensure accurate and relevant content. Online workshops were held with programme managers to plan how to use the videos in SMC staff training and supervision, and the use of the videos was evaluated in Guinea through focus groups and in-depth interviews PLOS DIGITAL HEALTH
Background Routine continuous distribution (CD) of insecticide-treated nets (ITNs) has been an im... more Background Routine continuous distribution (CD) of insecticide-treated nets (ITNs) has been an important part of an overall ITN strategy to complement mass campaigns since the early 2000s. The backbone of CD implementation for many sub-Saharan African countries is distribution through antenatal care (ANC) and Expanded Programme for Immunizations (EPI) channels. Performance of these channels is often not monitored closely at the national level, nor is it reviewed globally, unlike the oversight provided to mass campaigns. The question as to why every eligible pregnant woman and child attending these services does not get an ITN remains important and yet, unanswered. Methods ANC and EPI issuing rates from seven countries were reviewed with the aim of conducting a blinded multi-country analysis. Monthly data from January to December 2021 was extracted from each country’s health management information system and analysed jointly with a National Malaria Control Programme (NMCP) focal poin...
<b>Copyright information:</b>Taken from "Microbial larvicides for malaria contro... more <b>Copyright information:</b>Taken from "Microbial larvicides for malaria control in The Gambia"http://www.malariajournal.com/content/6/1/76Malaria Journal 2007;6():76-76.Published online 7 Jun 2007PMCID:PMC1899511. application took place weekly. The monitoring of the sentinel sites was done 1–3 days after application. CG formulation was applied in week (wk) 1, 2 and 3, WDG formulation was applied from week 4. Differences in immature densities were analysed using Mann-Whitney tests at a significance level of p &lt; 0.05. Different letters (a, b) on bars indicate a significant difference at the specific sampling date.
In malaria-endemic areas, residents of modern houses have less malaria than those living in tradi... more In malaria-endemic areas, residents of modern houses have less malaria than those living in traditional houses. This study will determine if modern housing provides incremental protection against clinical malaria over the current best practice of long-lasting insecticidal nets (LLINs) and prompt treatment in The Gambia, determine the incremental cost-effectiveness of the interventions, and analyze the housing market in The Gambia. A two-armed, household, cluster-randomized, controlled study will be conducted to assess whether improved housing and LLINs combine to provide better protection against clinical malaria in children than LLINs alone in The Gambia. The unit of randomization will be the household, defined as a house and its occupants. A total of 800 households will be enrolled and will receive LLINs, and 400 will receive improved housing before clinical follow-up. One child aged 6 months to 13 years will be enrolled from each household and followed for clinical malaria using ...
Citation for published item: Jatta, Ebrima and Jawara, Musa and Bradley, John and Je ries, David ... more Citation for published item: Jatta, Ebrima and Jawara, Musa and Bradley, John and Je ries, David and Kandeh, Balla and Knudsen, Jakob B. and Wilson, Anne L. and Pinder, Margaret and D'Alessandro, Umberto and Lindsay, Steve W. (2018) 'How house design a ects malaria mosquito density, temperature, and relative humidity: an experimental study in rural Gambia.', Lancet planetary health., 2 (11). e498-e508.
In sub-Saharan Africa, cooler houses would increase the coverage of insecticide-treated bednets, ... more In sub-Saharan Africa, cooler houses would increase the coverage of insecticide-treated bednets, the primary malaria control tool. We examined whether improved ventilation, using windows screened with netting, cools houses at night and reduces malaria mosquito house entry in The Gambia. Identical houses were constructed, with badly fitting doors, the only mosquito entry points. Two men slept in each house and mosquitoes captured using light traps. First, temperature and mosquito density was compared in four houses with 0, 1, 2 and 3 screened windows. Second, carbon dioxide (CO<sub>2</sub>), a major mosquito attractant, was measured in houses with (i) no windows, (ii) screened windows and (iii) screened windows and screened doors. Computational fluid dynamic modelling captured the spatial movement of CO<sub>2</sub>. Increasing ventilation made houses cooler, more comfortable and reduced malaria mosquito house entry; with three windows reducing mosquito densities by 95% (95%CI = 90–98%). Screened windows and doors reduced the indoor temperature by 0.6°C (95%CI = 05–0.7°C), indoor CO<sub>2</sub> concentrations by 31% between 21 : 00 and 00 : 00 h and malaria mosquito entry by 76% (95%CI = 69%–82%). Modelling shows screening reduces CO<sub>2</sub> plumes from houses. Under our experimental conditions, cross-ventilation not only reduced indoor temperature, but reduced the density of house-entering malaria mosquitoes, by weakening CO<sub>2</sub> plumes emanating from houses.
The study sites for the West African ICEMR are in three countries (The Gambia, Senegal, Mali) and... more The study sites for the West African ICEMR are in three countries (The Gambia, Senegal, Mali) and are located within 750 km of each other. In addition, the National Malaria Control Programmes of these countries have virtually identical policies: 1] Artemisinin Combination Therapies (ACTs) for the treatment of symptomatic Plasmodium falciparum infection, 2] Long-Lasting Insecticide-treated bed Nets (LLINs) to reduce the Entomololgic Inoculation Rate (EIR) and 3] Sulfadoxine-Pyrimethamine for the Intermittent Preventive Treatment of malaria during pregnancy (IPTp). However, the prevalence of P. falciparum malaria and the status of malaria control vary markedly across the four sites with differences in the duration of the transmission season (from 4-5 to 10-11 months), the intensity of transmission (with EIRs from unmeasurably low to 4-5 per person per month), multiplicity of infection (from a mean of 1.0 to means of 2-5) and the status of malaria control (from areas which have virtually no control to areas that are at the threshold of malaria elimination). The most important priority is the need to obtain comparable
Seasonal malaria chemoprevention (SMC) aims to prevent malaria in children during the high malari... more Seasonal malaria chemoprevention (SMC) aims to prevent malaria in children during the high malaria transmission season. The Achieving Catalytic Expansion of SMC in the Sahel (ACCESS-SMC) project sought to remove barriers to the scale-up of SMC in seven countries in 2015 and 2016. We evaluated the project, including coverage, effectiveness of the intervention, safety, feasibility, drug resistance, and cost-effectiveness. For this observational study, we collected data on the delivery, effectiveness, safety, influence on drug resistance, costs of delivery, impact on malaria incidence and mortality, and cost-effectiveness of SMC, during its administration for 4 months each year (2015 and 2016) to children younger than 5 years, in Burkina Faso, Chad, The Gambia, Guinea, Mali, Niger, and Nigeria. SMC was administered monthly by community health workers who visited door-to-door. Drug administration was monitored via tally sheets and via household cluster-sample coverage surveys. Pharmacov...
Uploads
Papers by Balla Kandeh