Citizen science for malaria vector surveillance in Rwanda

Rwanda made tremendous achievements in reducing malaria morbidity and mortality through the scale up of vector control interventions including long lasting insecticide nets (LLINs) and indoor residual spraying (IRS) from 2005 up to 2011. However, malaria remains a major public health concern in the country. With the resurgence of malaria since 2012, improving vector control is urgent. Inadequate financial resources and ecological changes which increase the risk of malaria transmission are among factors that have caused this upsurge. Hence, malaria resurgence has hindered to sustain the progress made in malaria reduction and control. Entomological surveillance is one of the most important strategies for malaria prevention and control being undertaken in Rwanda. Although, mosquito monitoring programmes are established in 12 sentinel sites, maps of malaria risk for the whole country is needed. In this way available resources for malaria control can be deployed in an efficient way. However, there are significant costs associated with the expansion of the mosquito monitoring programmes. The implementation of a citizen science programme for (malaria) mosquito surveillance has the potential to overcome these limitations. In this thesis biological, environmental and institutional factors have been described as contributors to the malaria resurgence in Rwanda. citizen science approach as a new and alternative strategy to contribute to the improvement of malaria mosquito surveillance in low resource settings for the vector control surveillance system in Rwanda are presented. The implementation of a sustainable citizen science programme for malaria vector surveillance requires the participation of citizens. Prior the implementation of citizen science, entomological and household surveys conducted in the studied areas demonstrate that mosquito abundance and species composition of malaria vectors collected using Centers for Disease Control and Prevention (CDC) light traps inside houses combined with demographic characteristics such as building materials of the houses (for example tiled roofs, walls made of mud and wood), as well as the number of occupants in the house, predicted the number of mosquitoes (Culicidae) in the houses. While the presence of eaves plus walls made of mud and wood predicted malaria vector abundance. The results suggest that the perception of mosquito nuisance denoted in a questionnaire could be used as a global indicator of malaria vector hotspots. Hence, involving citizens in reporting mosquito nuisance can complement malaria mosquito surveillance and control. Results also demonstrate that prior the implementation of a citizen science programme for malaria vector surveillance , co-designing processes of a citizen science programme (CSP) with citizens who have valuable context-specific knowledge and skills is required in order a CSP in a rural area to be feasible. The results suggest that the handmade plastic bottle trap baited with CO2 and light represents an option for inclusion in mosquito surveillance activities in a citizen science context in rural areas. Additionally, the spatio-temporal distribution of mosquito nuisance and malaria vectors collected through citizen science described in this thesis provide insight into the ecology of malaria vectors and can thereby help to better understand malaria transmission patterns in Rwanda. The applicability of using remote sensing and citizen science data in determining the environmental predictors of malaria vector distribution in the studied areas are also presented. Malaria hotspots were found more in the southern part of Ruhuha, especially in Busasamana and Kibaza, the villages that also reported the highest mosquito abundance and nuisance levels

Citizen science for monitoring the spatial and temporal dynamics of malaria vectors in relation to environmental risk factors in Ruhuha, Rwanda

Background: As part of malaria prevention and control efforts, the distribution and density of malaria mosquitoes requires continuous monitoring. Resources for long-term surveillance of malaria vectors, however, are often limited. The aim of the research was to evaluate the value of citizen science in providing insight into potential malaria vector hotspots and other malaria relevant information, and to determine predictors of malaria vector abundance in a region where routine mosquito monitoring has not been established to support vector surveillance. Methods: A one-year citizen science programme for malaria mosquito surveillance was implemented in five villages of the Ruhuha sector in Bugesera district, Rwanda. In total, 112 volunteer citizens were enrolled and reported monthly data on mosquitoes collected in their peridomestic environment using handmade carbon-dioxide baited traps. Additionally, they reported mosquito nuisance experienced as well as the number of confirmed malaria cases in their household. Results: In total, 3,793 female mosquitoes were collected, of which 10.8% were anophelines. For the entire period, 16% of the volunteers reported having at least one confirmed malaria case per month, but this varied by village and month. During the study year 66% of the households reported at least one malaria case. From a sector perspective, a higher mosquito and malaria vector abundance was observed in the two villages in the south of the study area. The findings revealed significant positive correlations among nuisance reported and confirmed malaria cases, and also between total number of Culicidae and confirmed malaria cases, but not between the numbers of the malaria vector Anopheles gambiae and malaria cases. At the sector level, of thirteen geographical risk factors considered for inclusion in multiple regression, distance to the river network and elevation played a role in explaining mosquito and malaria mosquito abundance. Conclusion: The study demonstrates that a citizen science approach can contribute to mosquito monitoring, and can help to identify areas that, in view of limited resources for control, are at higher risk of malaria

Monitoring mosquito nuisance for the development of a citizen science approach for malaria vector surveillance in Rwanda

Background: Many countries, including Rwanda, have mosquito monitoring programmes in place to support decision making in the fight against malaria. However, these programmes can be costly, and require technical (entomological) expertise. Involving citizens in data collection can greatly support such activities, but this has not yet been thoroughly investigated in a rural African context. Methods: Prior to the implementation of such a citizen-science approach, a household entomological survey was conducted in October–November 2017 and repeated one year later in Busoro and Ruhuha sectors, in southern and eastern province of Rwanda, respectively. The goal was to evaluate the perception of mosquito nuisance reported by citizens as a potential indicator for malaria vector hotspots. Firstly, mosquito abundance and species composition were determined using Centers for Disease Control and Prevention (CDC) light traps inside the houses. Secondly, household members were interviewed about malaria risk factors and their perceived level of mosquito nuisance. Results: Tiled roofs, walls made of mud and wood, as well as the number of occupants in the house were predictors for the number of mosquitoes (Culicidae) in the houses, while the presence of eaves plus walls made of mud and wood were predictors for malaria vector abundance. Perception of mosquito nuisance reported indoors tended to be significantly correlated with the number of Anopheles gambiae sensu lato (s.l.) and Culicidae collected indoors, but this varied across years and sectors. At the village level, nuisance also significantly correlated with An. gambiae s.l. and total mosquito density, but only in 2018 while not in 2017. Conclusions: Perception of mosquito nuisance denoted in a questionnaire survey could be used as a global indicator of malaria vector hotspots. Hence, involving citizens in such activities can complement malaria vector surveillance and control

A citizen science approach for malaria mosquito surveillance and control in Rwanda

Despite the implementation of a number of interventions aimed at controlling malaria, Rwanda is experiencing a countrywide resurgence of simple malaria cases over the past five years. To support malaria control, mosquito surveillance activities, such as systematic reporting of the distribution, the diversity and the infectivity rate of malaria vectors throughout the country, have been undertaken. However, mosquito monitoring programmes are not carried out to monitor the impact of all vector control interventions or to determine the distribution of mosquito species in all areas, especially in the remote regions of the country. With a target of reducing malaria mortality by 2020, implementation of mosquito surveillance in those regions is urgently needed as well. In this paper, a Citizen science approach as a capacity resource for malaria vector monitoring for the Rwandan National Malaria Control Programme is presented. The ultimate aim is to complement existing mosquito surveillance currently in place by providing key information on the spatio-temporal distribution of mosquito nuisance and malaria vectors. This will contribute to an insight into the ecology of malaria vectors and thereby to a better understanding of malaria transmission patterns in Rwanda

Citizen science for monitoring the spatial and temporal dynamics of malaria vectors in relation to environmental risk factors in Ruhuha, Rwanda

Background: As part of malaria prevention and control efforts, the distribution and density of malaria mosquitoes requires continuous monitoring. Resources for long-term surveillance of malaria vectors, however, are often limited. The aim of the research was to evaluate the value of citizen science in providing insight into potential malaria vector hotspots and other malaria relevant information, and to determine predictors of malaria vector abundance in a region where routine mosquito monitoring has not been established to support vector surveillance. Methods: A 1-year citizen science programme for malaria mosquito surveillance was implemented in five villages of the Ruhuha sector in Bugesera district, Rwanda. In total, 112 volunteer citizens were enrolled and reported monthly data on mosquitoes collected in their peridomestic environment using handmade carbon-dioxide baited traps. Additionally, they reported mosquito nuisance experienced as well as the number of confirmed malaria cases in their household. Results: In total, 3793 female mosquitoes were collected, of which 10.8% were anophelines. For the entire period, 16% of the volunteers reported having at least one confirmed malaria case per month, but this varied by village and month. During the study year 66% of the households reported at least one malaria case. From a sector perspective, a higher mosquito and malaria vector abundance was observed in the two villages in the south of the study area. The findings revealed significant positive correlations among nuisance reported and confirmed malaria cases, and also between total number of Culicidae and confirmed malaria cases, but not between the numbers of the malaria vector Anopheles gambiae and malaria cases. At the sector level, of thirteen geographical risk factors considered for inclusion in multiple regression, distance to the river network and elevation played a role in explaining mosquito and malaria mosquito abundance. Conclusions: The study demonstrates that a citizen science approach can contribute to mosquito monitoring, and can help to identify areas that, in view of limited resources for control, are at higher risk of malaria

Co-Designing a Citizen Science Program for Malaria Control in Rwanda

Good health and human wellbeing is one of the sustainable development goals. To achieve this goal, many efforts are required to control infectious diseases including malaria which remains a major public health concern in Rwanda. Surveillance of mosquitoes is critical to control the disease, but surveillance rarely includes the participation of citizens. A citizen science approach (CSA) has been applied for mosquito surveillance in developed countries, but it is unknown whether it is feasible in rural African contexts. In this paper, the technical and social components of such a program are described. Participatory design workshops were conducted in Ruhuha, Rwanda. Community members can decide on the technical tools for collecting and reporting mosquito species, mosquito nuisance, and confirmed malaria cases. Community members set up a social structure to gather observations by nominating representatives to collect the reports and send them to the researchers. These results demonstrate that co-designing a citizen science program (CSP) with citizens allows for decision on what to use in reporting observations. The decisions that the citizens took demonstrated that they have context-specific knowledge and skills, and showed that implementing a CSP in a rural area is feasible. View Full-Tex