scholarly journals Entomological baseline data collection and power analyses in preparation of a mosquito swarm-killing intervention in south-western Burkina Faso

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Abdoulaye Niang ◽  
Simon P. Sawadogo ◽  
Abdoul A. Millogo ◽  
Nwamaka O. Akpodiete ◽  
Roch K. Dabiré ◽  
...  

Abstract Background Insecticides are currently the main tools used to reduce the transmission of malaria; therefore, the development of resistance to insecticides in malaria vectors is of major concern for malaria control. The resistance level to pyrethroids is particularly high in the Western region of Burkina Faso and may affect the efficacy of insecticidal bed nets and indoor residual spraying. Adult mosquito swarming and other nocturnal behaviours exhibit spatial and temporal patterns that suggest potential vulnerability to targeted space spraying with effective insecticides. Indeed, targeted space-spraying against adult mosquito swarms has been used to crash mosquito populations and disrupt malaria transmission. Methods Prior to impact assessment of swarm killing, a baseline data collection was conducted from June to November 2016 in 10 villages divided into two areas in western Burkina Faso. The data considered both ecological and demographic characteristics to monitor the key entomological parameters. Results The mean number of swarms observed was 35 per village, ranging from 25 to 70 swarms according to the village. Female density in both areas varied significantly as a function of the village and the period of collection. The human biting rate was significantly affected by the period of collection and depended upon whether the collection was carried out indoors or outdoors. Averages of parity rate were high in both areas for all periods of collection, ranging from 60 to 90%. These values ranged from 80 to 100% for inseminated females. Sporozoite rates ranged between 1.6 and 7.2% depending upon the village. The molecular identification of resting and swarming mosquitoes showed the presence of the three major malaria vectors in Burkina Faso, but in different proportions for each village. Conclusions The distribution of the potential swarm markers and swarms in villages suggested that swarms are clustered across space, making intervention easier. Power simulations showed that the direct sampling of swarms provides the highest statistical power, thereby reducing the number of villages needed for a trial.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dieudonné Diloma Soma ◽  
Barnabas Zogo ◽  
Domonbabele François de Sales Hien ◽  
Aristide Sawdetuo Hien ◽  
Didier Alexandre Kaboré ◽  
...  

Abstract Background The rapid spread of insecticide resistance in malaria vectors and the rebound in malaria cases observed recently in some endemic areas underscore the urgent need to evaluate and deploy new effective control interventions. A randomized control trial (RCT) was conducted with the aim to investigate the benefit of deploying complementary strategies, including indoor residual spraying (IRS) with pirimiphos-methyl in addition to long-lasting insecticidal nets (LLINs) in Diébougou, southwest Burkina Faso. Methods We measured the susceptibility of the Anopheles gambiae (s.l.) population from Diébougou to conventional insecticides. We further monitored the efficacy and residual activity of pirimiphos-methyl on both cement and mud walls using a laboratory susceptible strain (Kisumu) and the local An. gambiae (s.l.) population. Results An. gambiae (s.l.) from Diébougou was resistant to DDT, pyrethroids (deltamethrin, permethrin and alphacypermethrin) and bendiocarb but showed susceptibility to organophosphates (pirimiphos-methyl and chlorpyrimiphos-methyl). A mixed-effect generalized linear model predicted that pirimiphos-methyl applied on cement or mud walls was effective for 210 days against the laboratory susceptible strain and 247 days against the local population. The residual efficacy of pirimiphos-methyl against the local population on walls made of mud was similar to that of cement (OR = 0.792, [0.55–1.12], Tukey’s test p-value = 0.19). Conclusions If data on malaria transmission and malaria cases (as measured trough the RCT) are consistent with data on residual activity of pirimiphos-methyl regardless of the type of wall, one round of IRS with pirimiphos-methyl would have the potential to control malaria in a context of multi-resistant An. gambiae (s.l.) for at least 7 months.


2020 ◽  
Author(s):  
Nourou Barry ◽  
Patrice Toé ◽  
Lea Pare/Toe ◽  
Javier Lezaun ◽  
Mouhamed Drabo ◽  
...  

Abstract BackgroundMany field entomology research projects involve local communities in mosquito-collection activities. Since 2012, Target Malaria, a not-for-profit research consortium, has been working with community members in various studies of mosquito collection, release and recapture in the village of Bana, in Western Burkina Faso. Target Malaria’s long-term goal is to develop innovative solutions to combat malaria in Africa with the help of mosquito modification technologies. Since the start of the project, members of local communities have shown interest in playing an active role in the implementation of the project’s research activities, but their actual motivations for such an interest remain under-investigated. This study therefore aimed to examine the factors that motivate the local community to contribute to the implementation of Target Malaria’s activities in the village of Bana. MethodsA qualitative approach was used to examine the factors motivating the local community to assist in the implementation of Target Malaria’s entomological research activities in Bana. 85 individual in-depth and semi-structured interviews were conducted, followed by interviews with three focus groups, one with youths who had participated in mosquito collections and two with men and women from the village. All data collected were fully transcribed, processed, and submitted for thematic content analysis. ResultsData showed that the willingness of local community members to participate in the entomological research activities of Target Malaria was informed by a wide range of motivational factors. Although the actors interviewed expressed their motivations under different semantic registers, the data showed a degree of consistency between different motivations advanced. These similarities enabled us to classify all of the motivational factors under 5 distinct categories: (a) assist in field research, (b) contribute to a better future, (c) acquire knowledge, (d) earn financial compensation, and (e) gain social prestige.ConclusionThese varying motivations reflected fundamentally different personal and collective perceptions about the participation process. In addition, this study shows that the interest of research on participation is a useful part of understanding public perceptions.


2021 ◽  
Author(s):  
Abebe Asale ◽  
Zewdu Abro ◽  
Bayu Enchalew ◽  
Alayu Tesager ◽  
Aklilu Belay ◽  
...  

Abstract Background: Key program components of malaria control in Ethiopia include community empowerment and mobilization, vector control using long-lasting insecticidal nets (LLINs), indoor residual spraying (IRS), prompt diagnosis and treatment, and disease surveillance. However, the effectiveness of these interventions is often undermined by various challenges, including insecticide and drug resistance, the plasticity of malaria vectors feeding and biting behavior, and certain household factors that lead to misuse and poor utilization of LLINs. The primary objective of this study was to document households’ perceptions towards malaria and assess the prevalence of the disease and the constraints related to the ongoing interventions in Ethiopia (LLINs, IRS, community mobilization house screening). Method: The study was conducted in Jabi Tehnan district, Northwestern Ethiopi,a from November 2019 to March 2020. A total of 3,010 households distributed over 38 kebeles (villages) were randomly selected for socio-economic and demographic survey. Focus group discussions (FGDs) were conducted in 11 different health clusters taking into account agro-ecological differences. A total of 1,256 children under 10 years of age were screened for malaria parasites using microscopy in order to determine malaria prevalence. Furthermore, five-year malaria trend analysis was undertaken based on data obtained from the district health office to understand the disease dynamics.Result: Malaria knowledge in the area was high as all FGD participants correctly identified mosquito bites during the night as sources of malaria transmission. Delayed health seeking behavior remains a key behavioral challenge in malaria control as it took patients on average 4 days before reporting the case at the nearby health facility. On average households lost 2.53 working days per person-per malaria episode and theey spent US$ 18 per person perepisode. Out of the 1,256 randomly selected under 10 children tested for malaria parasites, 11 (0.89%) were found to be positive. Malaria disproportionately affected the adult segment of the population more, 50% of the total cases reported from households whose age was 15 and beyond. The second most affected group was the age group between 5 and 14 years followed by children under 10, with 31% and 14% burden,respectively.Conclusion: Despite the achievement of universal coverage in terms of LLINs access, utilization of vector control interventions in the area remained low.Using bed nets for unintended purposes remained a major challenge. Therefore, continued community education and communication work should be prioritised in the study area to bring about the desired behavioral changes.


2013 ◽  
Vol 37 ◽  
pp. 5661-5672 ◽  
Author(s):  
Andrew Duguid ◽  
Robert Butsch ◽  
J. William Carey ◽  
Michael Celia ◽  
Nikita Chugunov ◽  
...  

2019 ◽  
Author(s):  
D.D Soma ◽  
B Zogo ◽  
P Taconet ◽  
A Somé ◽  
S Coulibaly ◽  
...  

AbstractBackgroundTo sustain the efficacy of malaria vector control, the World Health Organization (WHO) recommends the combination of effective tools. Before designing and implementing additional strategies in any setting, it is critical to monitor or predict when and where transmission occurs. However, to date, very few studies have quantified the behavioural interactions between humans and Anopheles vectors. Here, we characterized residual transmission in a rural area of Burkina Faso where long lasting insecticidal nets (LLIN) are widely used.MethodsWe analysed data on both human and malaria vectors behaviours from 27 villages to measure hourly human exposure to vector bites in dry and rainy seasons using mathematical models. We estimated the protective efficacy of LLINs and characterised where (indoors vs. outdoors) and when both LLIN users and non-users were exposed to vector bites.ResultsThe percentage of the population who declared sleeping under a LLIN the previous night was very high regardless of the season, with an average LLIN use ranging from 92.43% to 99.89%. The use of LLIN provided > 80% protection against exposure to vector bites. The proportion of exposure for LLIN users was 29-57% after 05:00 and 0.05-12 % before 20:00. More than 80% of exposure occurred indoors for LLIN users and the estimate reached 90% for children under five years old in the dry cold season.ConclusionsThis study supports the current use of LLIN as a primary malaria vector control tool. It also emphasises the need to complement LLIN with indoor-implemented measures such as indoor residual spraying (IRS) and/or house improvement to effectively combat malaria in the rural area of Diébougou. Furthermore, malaria elimination programmes would also require strategies that target outdoor biting vectors to be successful in the area.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Abebe Asale ◽  
Zewdu Abro ◽  
Bayu Enchalew ◽  
Alayu Teshager ◽  
Aklilu Belay ◽  
...  

Abstract Background Use of long-lasting insecticidal nets (LLINs), indoor residual spraying (IRS), community-based malaria education, prompt diagnosis and treatment are key programme components of malaria prevention and control in Ethiopia. However, the effectiveness of these interventions is often undermined by various challenges, including insecticide and drug resistance, the plasticity of malaria vectors feeding and biting behaviour, and certain household factors that lead to misuse and poor utilization of LLINs. The primary objective of this study was to document households’ perceptions towards malaria and assess the prevalence of the disease and the constraints related to the ongoing interventions in Ethiopia (LLINs, IRS, community mobilization house screening). Methods The study was conducted in Jabi Tehnan district, Northwestern Ethiopia, from November 2019 to March 2020. A total of 3010 households from 38 villages were randomly selected for socio-economic and demographic survey. Focus group discussions (FGDs) were conducted in 11 different health clusters considering agro-ecological differences. A total of 1256 children under 10 years of age were screened for malaria parasites using microscopy to determine malaria prevalence. Furthermore, 5-year malaria trend analysis was undertaken based on data obtained from the district health office to understand the disease dynamics. Results Malaria knowledge in the area was high as all FGD participants correctly identified mosquito bites during the night as sources of malaria transmission. Delayed health-seeking behaviour remains a key behavioural challenge in malaria control as it took patients on average 4 days before reporting the case at the nearby health facility. On average, households lost 2.53 working days per person-per malaria episode and they spent US$ 18 per person per episode. Out of the 1256 randomly selected under 10 children tested for malaria parasites, 11 (0.89%) were found to be positive. Malaria disproportionately affected the adult segment of the population more, with 50% of the total cases reported from households being from among individuals who were 15 years or older. The second most affected group was the age group between 5 and 14 years followed by children aged under 5, with 31% and 14% burden, respectively. Conclusion Despite the achievement of universal coverage in terms of LLINs access, utilization of vector control interventions in the area remained low. Using bed nets for unintended purposes remained a major challenge. Therefore, continued community education and communication work should be prioritized in the study area to bring about the desired behavioural changes.


2020 ◽  
Author(s):  
Narelle Campbell ◽  
Annie Farthing ◽  
Susan Witt ◽  
Jessie Anderson ◽  
Susan Lenthall ◽  
...  

BACKGROUND The successful recruitment and retention of health professionals to rural and remote areas of Australia is a health policy priority. Student undergraduate or graduate entry nursing or allied health learning placements in the Northern Territory of Australia (most of which is considered remote) may influence rural or remote work location decisions. OBJECTIVE The aim of the study is to determine where allied health professionals and nurses who have had a student placement/s in the Northern Territory of Australia end up practising. METHODS This research is an observational cohort study with a baseline data collection and then repeated annual data collection over 10 years (2017/18-2029). The baseline data collection is a demographic profile of allied health and nursing students and their evaluation of their NT placement using a nationally consistent questionnaire. Annual Work Location Surveys will track work location and the influences on work location decisions. RESULTS This study will generate unique data on the remote and rural work locations of nursing and allied health professional students who had a placement in the Northern Territory of Australia. It will be able to determine what are the most important characteristics of those who take up remote and rural employment (even if outside NT), and identify barriers to remote employment. CONCLUSIONS The study will add to the literature on rates of allied health and nursing professionals working in a remote or rural setting following remote or rural learning placements. The results will be of interest to government and remote health workforce planners. CLINICALTRIAL Australian New Zealand Clinical Trials Registry number: ACTRN12620000797976


2020 ◽  
Author(s):  
Sawdetuo Aristide HIEN ◽  
Dieudonné Diloma Soma ◽  
Simon Pengwende Sawadogo ◽  
Serge Bèwadéyir Poda ◽  
Moussa Namountougou ◽  
...  

Abstract Background The fight against vector is essential in malaria prevention strategies in several endemic countries in Africa. In Burkina Faso, malaria transmission is seasonal in most parts of country, so a single round of spraying should provide effective protection against malaria, provided the insecticide remains effective over the entire malaria transmission season. The outcomes of indoor residual spraying towards curtailing malaria transmission are firstly to decrease the life span of vector mosquitoes and also to reduce the malaria vectors density. Methods CDC light trap and early morning collections by pyrethrum spray catches were performed monthly to determine the change in malaria vector indices in sprayed (Diebougou) and unsprayed sites (Dano). The female’s malaria vectors collected by both methods were used to determine their blood feeding, biting and sporozoites rate and malaria transmission risk estimated by entomological inoculation rate. Results Anopheles gambiae complex composed to Anopheles gambiae, Anopheles coluzzii and Anopheles arabiensis were present throughout the transmission season, but An. gambiae was the predominant species collected (P =0.0005), comprising 88% of the total collected and the most infected species. Malaria vectors densities were significantly lower in sprayed villages (n=4,303) compared with unsprayed villages (n=12,569) during post-spraying period (P = 0.0012). In addition, mean human biting rate of An. gambiae sl and An . funestus ss were significantly lower in sprayed areas compared to unsprayed areas (P<0.05). Overall, malaria vector transmission risk was significant lower in villages which received IRS (P=0.0001) whatever the malaria vectors species ( An. gambiae sl and An. funestus ss). Conclusions The results showed that in the sprayed area (Diebougou), vector densities, human biting rates and malaria transmission risks were very lower than unsprayed areas (Dano). The findings also showed a change in vector behavior especially within An. funestus which became more zoophagic following IRS. The indoor residual spraying could be recommanded as control tool in areas where malaria transmission occured a given period of year.


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