A qualitative study of community perception and acceptance of biological larviciding for malaria mosquito control in rural Burkina Faso

Empowering rural communities for effective larval source management: A small-scale field evaluation of a community-led larviciding approach to control malaria in south-eastern Tanzania

Introduction

Larval source management, particularly larviciding, is mainly implemented in urban settings to control malaria and other mosquito-borne diseases. In Tanzania, the government has recently expanded larviciding to rural settings across the country, but implementation faces multiple challenges, notably inadequate resources and limited know-how by technical staff. This study evaluated the potential of training community members to identify, characterize and target larval habitats of Anopheles funestus mosquitoes, the dominant vector of malaria transmission in south-eastern Tanzania.

Methods

A mixed-methods study was used. First, interviewer-administered questionnaires were employed to assess knowledge, awareness, and perceptions of community members towards larviciding (N = 300). Secondly community-based volunteers were trained to identify and characterize aquatic habitats of dominant malaria vector species, after which they treated the most productive habitats with a locally-manufactured formulation of the biolarvicide, Bacillus thuringiensis var. israelensis. Longitudinal surveys of mosquito adults and larvae were used to assess impacts of the community-led larviciding programme in two villages in rural south-eastern Tanzania.

Results

At the beginning of the program, the majority of village residents were unaware of larviciding as a potential malaria prevention method, and about 20 % thought that larvicides could be harmful to the environment and other insects. The trained community volunteers identified and characterized 360 aquatic habitats, of which 45.6 % had Anopheles funestus, the dominant malaria vector in the area. The preferred larval habitats for An. funestus were deep and had either slow- or fast-moving waters. Application of biolarvicides reduced the abundance of adult An. funestus and Culex spp. species inside human houses in the same villages, by 46.3 % and 35.4 % respectively. Abundance of late-stage instar larvae of the same taxa was also reduced by 74 % and 42 %, respectively.

Conclusion

This study demonstrates that training community members to identify, characterize, and target larval habitats of the dominant malaria vectors can be effective for larval source management in rural Tanzania. Community-led larviciding reduced the densities of adult and late-stage instar larvae of An. funestus and Culex spp. inside houses, suggesting that this approach may have potential for malaria control in rural settings. However, efforts are still needed to increase awareness of larviciding in the relevant communities.

Association between indoor residual spraying and the malaria burden in Zambia and factors associated with IRS refusals: a case-control study in Vubwi District

BACKGROUND

Indoor residual spraying (IRS) has been implemented to prevent malaria in Zambia for several decades, but its effectiveness has not been evaluated long term and in Vubwi District yet. This study aimed to assess the association between IRS and the malaria burden in Zambia and Vubwi District and to explore the factors associated with refusing IRS.

METHODS

A retrospective study was used to analyze the association between IRS and malaria incidence in Zambia in 2001-2020 and in Vubwi District in 2014-2020 by Spearman correlation analysis. A case-control study was used to explore the factors associated with IRS refusals by households in Vubwi District in 2021. A logistic regression model was performed to identify factors associated with IRS refusals.

RESULTS

The malaria incidence reached its peak (391/1000) in 2001 and dropped to the lowest (154/1000) in 2019. The annual percentage change in 2001-2003, 2003-2008, 2008-2014, 2014-2018 and 2018-2020 was - 6.54%, - 13.24%, 5.04%, - 10.28% and 18.61%, respectively. A significantly negative correlation between the percentage of population protected by the IRS against the total population in Zambia (coverage) and the average malaria incidence in the whole population was observed in 2005-2020 (r = - 0.685, P = 0.003) and 2005-2019 (r = - 0.818, P < 0.001). Among 264 participants (59 in the refuser group and 205 in the acceptor group), participants with specific occupations (self-employed: OR 0.089, 95% CI 0.022-0.364; gold panning: OR 0.113, 95% CI 0.022-0.574; housewives: OR 0.129, 95% CI 0.026-0.628 and farmers: OR 0.135, 95% CI 0.030-0.608 compared to employees) and no malaria case among household members (OR 0.167; 95% CI 0.071-0.394) had a lower risk of refusing IRS implementation, while those with a secondary education level (OR 3.690, 95% CI 1.245-10.989) had a higher risk of refusing IRS implementation compared to those who had never been to school.

CONCLUSIONS

Increasing coverage with IRS was associated with decreasing incidence of malaria in Zambia, though this was not observed in Vubwi District, possibly because of the special geographical location of Vubwi District. Interpersonal communication and targeted health education should be implemented at full scale to ensure household awareness and gain community trust.

Willingness to accept and participate in a Microsporidia MB-based mosquito release strategy: a community-based rapid assessment in western Kenya

BACKGROUND

Microsporidia MB, an endosymbiont naturally found in Anopheles mosquitoes inhibits transmission of Plasmodium and is a promising candidate for a transmission-blocking strategy that may involve mosquito release. A rapid assessment was carried out to develop insight into sociodemographic factors, public health concerns, and malaria awareness, management, and prevention practices with the willingness to accept and participate in Microsporidia MB-based transmission-blocking strategy to develop an informed stakeholder engagement process.

METHODS

The assessment consisted of a survey conducted in two communities in western Kenya that involved administering a questionnaire consisting of structured, semi-structured, and open questions to 8108 household heads.

RESULTS

There was an overall high level of willingness to accept (81%) and participate in the implementation of the strategy (96%). Although the willingness to accept was similar in both communities, Ombeyi community was more willing to participate (OR 22, 95% CI 13-36). Women were less willing to accept (OR 0.8, 95% CI 0.7-0.9) compared to men due to fear of increased mosquito bites near homes. Household heads with incomplete primary education were more willing to accept (OR 1.6, 95% CI 01.2-2.2) compared to those educated to primary level or higher. Perceiving malaria as a moderate or low public health issue was also associated with a lower willingness to accept and participate. Experience of > 3 malaria cases in the family over the last six months and knowledge that malaria is transmitted by only mosquito bites, increased the willingness to accept but reduced the willingness to participate. Awareness of malaria control methods based on mosquitoes that cannot transmit malaria increases the willingness to participate.

CONCLUSION

The study showed a high level of willingness to accept and participate in a Microsporidia MB-based strategy in the community, which is influenced by several factors such as community, disease risk perception, gender, education level, knowledge, and experience of malaria. Further research will need to focus on understanding the concerns of women, educated, and employed community members, and factors that contribute to the lower disease risk perception. This improved understanding will lead to the development of an effective communication strategy.

Scaling artificial light at night and disease vector interactions into socio-ecological systems: a conceptual appraisal

There is burgeoning interest in how artificial light at night (ALAN) interacts with disease vectors, particularly mosquitoes. ALAN can alter mosquito behaviour and biting propensity, and so must alter disease transfer rates. However, most studies to date have been laboratory-based, and it remains unclear how ALAN modulates disease vector risk. Here, we identify five priorities to assess how artificial light can influence disease vectors in socio-ecological systems. These are to (i) clarify the mechanistic role of artificial light on mosquitoes, (ii) determine how ALAN interacts with other drivers of global change to influence vector disease dynamics across species, (iii) determine how ALAN interacts with other vector suppression strategies, (iv) measure and quantify the impact of ALAN at scales relevant for vectors, and (v) overcome the political and social barriers in implementing it as a novel vector suppression strategy. These priorities must be addressed to evaluate the costs and benefits of employing appropriate ALAN regimes in complex socio-ecological systems if it is to reduce disease burdens, especially in the developing world. This article is part of the theme issue 'Light pollution in complex ecological systems'.

WebGIS-Based Real-Time Surveillance and Response System for Vector-Borne Infectious Diseases

The diseases transmitted through vectors such as mosquitoes are named vector-borne diseases (VBDs), such as malaria, dengue, and leishmaniasis. Malaria spreads by a vector named Anopheles mosquitos. Dengue is transmitted through the bite of the female vector Aedes aegypti or Aedes albopictus mosquito. The female Phlebotomine sandfly is the vector that transmits leishmaniasis. The best way to control VBDs is to identify breeding sites for their vectors. This can be efficiently accomplished by the Geographical Information System (GIS). The objective was to find the relation between climatic factors (temperature, humidity, and precipitation) to identify breeding sites for these vectors. Our data contained imbalance classes, so data oversampling of different sizes was created. The machine learning models used were Light Gradient Boosting Machine, Random Forest, Decision Tree, Support Vector Machine, and Multi-Layer Perceptron for model training. Their results were compared and analyzed to select the best model for disease prediction in Punjab, Pakistan. Random Forest was the selected model with 93.97% accuracy. Accuracy was measured using an F score, precision, or recall. Temperature, precipitation, and specific humidity significantly affect the spread of dengue, malaria, and leishmaniasis. A user-friendly web-based GIS platform was also developed for concerned citizens and policymakers.

Local resource mobilization for malaria vector control among Rwandan rice farmers: a pilot study into the role of community ownership

BACKGROUND

Evidence suggests a vicious cycle between rice cultivation and malaria control in Rwanda. Rice fields offer an attractive breeding ground for malaria vectors, which increases the disease burden in rice farming communities, and, consequently, reduces productivity in the rice sector. Community-based larval source management in rice fields is propagated as a sustainable solution to break this cycle. A sense of agency and ownership of malaria control interventions, as well as the mobilization of resources at the local level, are often considered preconditions for success. However, an evidence gap exists regarding the interaction between the agentive and financial dimension of local sustainability.

METHODS

We conduct a larviciding pilot involving three groups; one group where rice farmers sprayed their fields under expert supervision, one group where rice farmers organised the larviciding campaign themselves, and a (non-sprayed) control group. We test whether the difference in agency between the intervention groups affects farmers' willingness-to-pay for a larviciding campaign. Willingness-to-pay is elicited in a contingent valuation exercise, more specifically a bidding game, and is assessed both before and after the pilot (n = 288). Difference-in-difference estimates are computed, using a propensity score matching technique. Supplementary data were collected in a survey and two focus group discussions for triangulation.

RESULTS

The high-agency (self-organised) group significantly outperforms the low-agency (expert-supervised) group in terms of maintaining its willingness to contribute financially. However, higher willingness-to-pay in the high-agency group does not appear to be driven by a stronger sense of ownership per se. The supplementary data indicate high levels of ownership in both treatment groups compared to the control group. A tentative explanation lies in diverging perceptions concerning the effectiveness of the pilot.

CONCLUSIONS

The study supports the idea that community-led organization of larval source management can prove instrumental in mobilizing finance for malaria control in low-income settings where rice production interferes with the fight against malaria. However, the causality is complex. Feelings of ownership do not appear the main driver of willingness-to-pay, at least not directly, which opens up the possibility of initiating community-driven malaria control interventions that promote the agentive and financial dimension of local sustainability simultaneously.

Knowledge, practices and perceptions of communities during a malaria larviciding randomized trial in the city of Yaoundé, Cameroon

Background

Urban malaria is becoming a major public health concern in major cities in Cameroon. To improve malaria vector control, a pilot larviciding trial was conducted to assess its impact on mosquito density and malaria transmission intensity in Yaoundé. The present study investigated perceptions and practices of communities on malaria control during the larviciding trial implemented in Yaoundé.

Methods

Quantitative and qualitative data were collected in non-intervention and intervention areas. Quantitative data were collected during three cross-sectional surveys using a structured pre-tested questionnaire while qualitative data were obtained through interviews. A total of 26 in-depth interviews and eight focus group discussions with community members were performed. A binary logistic regression model was used to assess the perception of the community on larviciding impact on some malaria or bed nets use indicators.

Results

People living in intervention areas were 2.64 times more likely to know the mode of malaria transmission (95% CI: 1.82–3.84; p<0.001) and 1.3 time more likely to know mosquito breeding habitats (95% CI: 1.06–1.56; p = 0.009) compared to those living in non-intervention areas. In intervention areas, interviewee opinions on larviciding were generally good i.e. most interviewees reported having noticed a reduction in mosquito nuisance and malaria cases following larviciding implementation; whereas in non-intervention areas no report of reduction of mosquito nuisance was recorded. LLINs were regularly used by the population despite the implementation of larviciding treatments. There was high interest in larviciding program and demand for continuation, even if this needs the community involvement.

Conclusion

The larviciding program in the city of Yaoundé did not negatively affected community members’ behaviour and practices concerning the use of treated nets. The study indicated the acceptance of larviciding program by the population. This positive environment could favour the implementation of future antilarval control activities in the city of Yaoundé.

Stakeholder perceptions on the deployment of multiple first-line therapies for uncomplicated malaria: a qualitative study in the health district of Kaya, Burkina Faso

Background

In Burkina Faso, malaria remains the first cause of medical consultation and hospitalization in health centres. First-line case management of malaria in the country’s health facilities is based on the use of artemisinin-based combination therapy (ACT). To optimize the use of these anti-malarial drugs in the perspective of mitigating the emergence of artemisinin resistance, which is a serious threat to malaria control and elimination, a pilot programme using multiple first-line therapies (MFTs) [three artemisinin-based combinations—pyronaridine–artesunate, dihydroartemisinin–piperaquine and artemether-lumefantrine] has been designed for implementation. As the success of this MFT pilot programme depends on the perceptions of key stakeholders in the health system and community members, the study aimed to assess their perceptions on the implementation of this strategy.

Methods

Semi-structured interviews, including 27 individual in-depth interviews and 41 focus groups discussions, were conducted with key stakeholders including malaria control policymakers and implementers, health system managers, health workers and community members. Volunteers from targets stakeholder groups were randomly selected. All interviews were recorded, transcribed and translated. Content analysis was performed using the qualitative software programme QDA Miner.

Results

The interviews revealed a positive perception of stakeholders on the implementation of the planned MFT programme. They saw the strategy as an opportunity to strengthen the supply of anti-malarial drugs and improve the management of fever and malaria. However, due to lack of experience with the products, health workers and care givers expressed some reservations about the effectiveness and side-effect profiles of the two anti-malarial drugs included as first-line therapy in the MFT programme (pyronaridine–artesunate, dihydroartemisinin–piperaquine). Questions were raised about the appropriateness of segmenting the population into three groups and assigning a specific drug to each group.

Conclusion

The adherence of both populations and key stakeholders to the MFT implementation strategy will likely depend on the efficacy of the proposed drugs, the absence of, or low frequency of, side-effects, the cost of drugs and availability of the different combinations.

Do health risk perceptions motivate water - and health-related behaviour? A systematic literature review

Health-related risk perceptions are important determinants of health behaviours and components of behaviour change theories. What someone thinks or feels will motivate or hinder their intention or hesitancy to implement a certain behaviour. Thus, a perceived potential risk to our health and well-being can influence our health-promoting and/or health-seeking behaviour. We aimed to review and synthesize available peer-reviewed literature to better understand the links between water and health-related risk perceptions and behaviours. We conducted the first systematic review of peer-reviewed literature on risk perceptions and behaviours in the context of water and health, published between 2000 and 2021. A total of 187 publications met the inclusion criteria. We extracted data relating to study characteristics and categorized our results according to the major themes emerging from the literature, namely drinking water, sanitation, hygiene and wasterelated topics, health risk factors, diseases and mental health implications, and preventative measures. Our review shows that the literature has grown over the past twenty years, reporting information from different countries belonging to different income groups around the globe, conducted in various settings and contexts, among different target populations, from various disciplinary angles, using different methods, theories and approaches. Our review provides evidence of health risk perceptions determining behaviour particularly related to drinking water sources and water safety. Evidence on disease prevention, health seeking, variations and changes in perception and behaviour over space, geography, socioeconomic differences and time, and the relevance of cultural context is provided. Our review shows that risk perception studies are vital for WASH governance in terms of policy, raising awareness, education and behaviour change. In order to make risk perception and behaviour studies even more relevant to effective public health planning and health messaging, future research needs to increasingly focus on early culturally sensitive interventions and changes in perceptions and behaviours over time.

'Where are the dead flies!': perceptions of local communities towards the deployment of Tiny Targets to control tsetse in the Democratic Republic of the Congo

The National Programme for the control of human African trypanosomiasis in Democratic Republic of Congo includes a large-scale vector control operation using Tiny Targets. These are small panels of insecticide-impregnated cloth that are deployed in riverine habitat where tsetse flies concentrate. The effectiveness of Tiny Targets depends partly on acceptance by local communities. In 2018, we conducted research to explore the perception and acceptability of Tiny Targets in two different village clusters where Tiny Targets had been deployed by the local community or external teams. We conducted fourteen focus group discussions and seven semistructured interviews in three villages from each cluster in the Yasa Bonga health zone. Our findings showed that acceptability was better in the cluster where communities were involved in the deployment of Tiny Targets. Also in this cluster, awareness about Tiny Targets was satisfactory and the project was implemented within local customs, which promoted a positive perception of Tiny Targets and their benefits. In the cluster where external teams deployed Tiny Targets, a lack of information and communication, stereotypes applied by communities towards the deployment teams and the impression of inadequate respect for local customs led to anxiety and a misleading interpretation of the purpose of Tiny Targets and negatively influenced acceptability. This study highlights the importance of involving communities for programme acceptance. Our research underlined how awareness campaigns and communication are essential, but also how working within the scope of community social norms and customs are equally important. Prospects for the successful use of Tiny Targets are greater when communities are involved because the use can be adapted to social norms.

Biolarviciding for malaria vector control: Acceptance and associated factors in southern Tanzania

In the struggle towards malaria elimination, the government of Tanzania scaled up nationwide biolarviciding to supplement existing vector control measures. As with any community-based intervention, success of biolarviciding depends on acceptability to the community. This study sought to ascertain acceptance of biolarviciding among communities in southern Tanzania. A mixed-method study involved administration of questionnaires to 400 community members, with 32 key informant interviews and five in-depth interviews also held in selected councils of southern Tanzania. A multistage sampling method was employed in selecting community members, with purposive sampling used in selecting key informant and in-depth interviewees. The study found high community acceptance (80.3%) despite very low (19.3%) knowledge on biolarviciding. Community perception that biolarvicide is effective in reducing malaria infection was found to be a significant predictor of community acceptance to biolarviciding: those who perceived biolarvicide as effective in reducing malaria were five times more likely to accept biolarviciding compared to those with a negative perception (odds ratio = 4.67, 95% CI: 1.89-11.50, P = 0.001). We conclude that biolarviciding received high acceptance among community members in southern Tanzania and therefore the implementation is likely to get strong support from community members. To enhance and make community acceptance sustainable, heath education to enhance the level of community knowledge on biolarviciding is recommended.

Community acceptance of environmental larviciding against malaria with Bacillus thuringiensis israelensis in rural Burkina Faso - A knowledge, attitudes and practices study

Background

Malaria control is based on early treatment of cases and on vector control. The current measures for malaria vector control in Africa are mainly based on long-lasting insecticidal nets (LLINs) and to a much smaller extent on indoor residual spraying (IRS). While bed net use is widely distributed and its role is intensively researched, Bti-based larviciding is a relatively novel tool in Africa. In this study, we analyze the perception and acceptability of Bti-based larval source management under different larviciding scenarios that were performed in a health district in Burkina Faso.

Objective

To research people’s perception and acceptance regarding biological larviciding interventions against malaria in their communities.

Methods

A cross-sectional study was undertaken using a total of 634 administered questionnaires. Data were collected in a total of 36 rural villages and in seven town quarters of the semi-urban town of Nouna.

Results

Respondents had basic to good knowledge regarding malaria transmission and how to protect oneself against it. More than 90% reported sleeping under a bed net, while other measures such as mosquito coils and insecticides were only used by a minority. The majority of community members reported high perceived reductions in mosquito abundance and the number of malaria episodes. There was a high willingness to contribute financially to larviciding interventions among interviewees.

Conclusions

This study showed that biological larviciding interventions are welcomed by the population that they are regarded as an effective and safe means to reduce mosquito abundance and malaria transmission. A routine implementation would, despite low intervention costs, require community ownership and contribution.

Narrative Review on Health-EDRM Primary Prevention Measures for Vector-Borne Diseases

Climate change is expanding the global at-risk population for vector-borne diseases (VBDs). The World Health Organization (WHO) health emergency and disaster risk management (health-EDRM) framework emphasises the importance of primary prevention of biological hazards and its value in protecting against VBDs. The framework encourages stakeholder coordination and information sharing, though there is still a need to reinforce prevention and recovery within disaster management. This keyword-search based narrative literature review searched databases PubMed, Google Scholar, Embase and Medline between January 2000 and May 2020, and identified 134 publications. In total, 10 health-EDRM primary prevention measures are summarised at three levels (personal, environmental and household). Enabling factor, limiting factors, co-benefits and strength of evidence were identified. Current studies on primary prevention measures for VBDs focus on health risk-reduction, with minimal evaluation of actual disease reduction. Although prevention against mosquito-borne diseases, notably malaria, has been well-studied, research on other vectors and VBDs remains limited. Other gaps included the limited evidence pertaining to prevention in resource-poor settings and the efficacy of alternatives, discrepancies amongst agencies' recommendations, and limited studies on the impact of technological advancements and habitat change on VBD prevalence. Health-EDRM primary prevention measures for VBDs require high-priority research to facilitate multifaceted, multi-sectoral, coordinated responses that will enable effective risk mitigation.

Bacterial larvicides used for malaria vector control in sub-Saharan Africa: review of their effectiveness and operational feasibility

Several trials and reviews have outlined the potential role of larviciding for malaria control in sub-Saharan Africa (SSA) to supplement the core indoor insecticide-based interventions. It has been argued that widespread use of long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS) interventions in many parts of Africa result in many new areas with low and focal malaria transmission that can be targeted with larvicides. As some countries in SSA are making good progress in malaria control, larval source management, particularly with bacterial larvicides, could be included in the list of viable options to maintain the gains achieved while paving the way to malaria elimination. We conducted a review of published literature that investigated the application of bacterial larvicides, Bacillus thuringiensis var. israelensis (Bti) and/or Bacillus sphaericus (Bs) for malaria vector control in SSA. Data for the review were identified through PubMed, the extensive files of the authors and reference lists of relevant articles retrieved. A total of 56 relevant studies were identified and included in the review. The findings indicated that, at low application rates, bacterial larvicide products based on Bti and/or Bs were effective in controlling malaria vectors. The larvicide interventions were found to be feasible, accepted by the general community, safe to the non-target organisms and the costs compared fairly well with those of other vector control measures practiced in SSA. Our review suggests that larviciding should gain more ground as a tool for integrated malaria vector control due to the decline in malaria which creates more appropriate conditions for the intervention and to the recognition of limitations of insecticide-based vector control tools. The advancement of new technology for mapping landscapes and environments could moreover facilitate identification and targeting of the numerous larval habitats preferred by the African malaria vectors. To build sustainable anti-larval measures in SSA, there is a great need to build capacity in relevant specialties and develop organizational structures for governance and management of larval source management programmes.