Assessment of Genetic Diversity of Rice in Registered Cultivars and Farmers’ Fields in Burkina Faso

The genetic diversity of cultivated rice in farmers’ fields remains understudied in West Africa despite the importance of rice for food security in this region. In this study, we genotyped rice samples from Burkina Faso using the C6AIR SNP (Single Nucleotide Polymorphism) array (IRRI), including 27 registered cultivars and 50 rice samples collected in rice fields from three geographical zones in western Burkina Faso. Most of the registered cultivars clustered with the indica genetic group, except seven assigned to japonica and one admix. All but one of the rice samples from farmers’ fields belonged to the indica group. The other field sample, which unexpectedly clustered with the Aus genetic group, originated from a rainfed lowland site known to differ in terms of agronomic practices, and which revealed to be highly differentiated from the five other sites. Apart from this peculiar site, the rice grown in irrigated areas did not differ from rice sampled in rainfed lowlands. Finally, obtained genetic data confirmed the high frequency of one cultivar, in congruence with farmers’ interviews. We argue on the importance to document and preserve the high agro-biodiversity observed in rice from Burkina Faso as a prerequisite to face the current challenges of growing rice demand and global change.

Is migration an effective adaptation to climate-related agricultural distress in sub-Saharan Africa?

Migration is often considered a form of climate change adaptation by which individuals, households, and communities seek to reduce the risks associated with climate change. In this study, we examine first-time seasonal migration out of a village in North-Western Burkina Faso to neighbouring countries, triggered by more irregular rainfall patterns. Through a set of 52 qualitative interviews, we analyse the perceptions of migrants themselves as well as the sending community regarding migration consequences. Men migrated in the off-season, whereas women stayed behind. Most migrant men and wives of migrants perceive migration to have negative consequences for their socio-economic situation and their health. Despite this, a lack of options and deteriorating environmental conditions might force the men to move again. We interpreted the range of narratives provided by women and men against the background of the scientific literature on migration as climate change adaptation. While migration could be beneficial, this study challenges the notion of migration as an effective adaptation strategy for people in climate-vulnerable settings, who lack other options.

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

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.

Spatiotemporal Survey of Multiple Rice Diseases in Irrigated Areas Compared to Rainfed Lowlands in the Western Burkina Faso

Multiple constraints affect rice yields and global production in West Africa. Among these constraints are viral, bacterial and fungal pathogens. We aimed to describe the spatiotemporal patterns of occurrence and incidence of multiple rice diseases in farmers’ fields in contrasting rice growing systems in western Burkina Faso. For this purpose, we selected a set of three pairs of sites, each comprising an irrigated area and a neighboring rainfed lowland, and studied them over four consecutive years. We first performed interviews with the rice farmers to better characterize the management practices at the different sites. This study revealed that the transplanting of rice and the possibility of growing rice twice a year are restricted to irrigated areas, while other practices, such as the use of registered rice cultivars, fertilization and pesticides, are not specific but differ between the two rice growing systems. Then, we performed symptom observations at these study sites to monitor the following four diseases: yellow mottle disease, Bacterial Leaf Streak (BLS), rice leaf blast and brown spot. The infection rates were found to be higher in irrigated areas than in rainfed lowlands, both when analyzing all observed symptoms together (any of the four diseases) and when specifically considering each of the two diseases: BLS and rice leaf blast. Brown spot was particularly prevalent in all six study sites, while yellow mottle disease was particularly structured geographically. Various diseases were frequently found together in the same field (co-occurrence) or even on the same plant (coinfection), especially in irrigated areas.

Epidemiology of malaria in an area with pyrethroid-resistant vectors in south-western Burkina Faso: a pre-intervention study

BackgroundThe objective of this study was to update malaria epidemiological profile prior to the implementation of a randomized controlled trial aiming to evaluate the efficacy of new vector control tools in complementary to the use of long-lasting insecticidal nets in Burkina Faso.MethodsWe carried out active and passive cross-sectional surveys to estimate the prevalence and incidence of malaria infection from August 2016 to July 2017 in 27 villages of the Diebougou health district.ResultsWith the passive survey, we extracted data from 4814 patients included in the study from August 2016 to July 2017. Malaria incidence showed a seasonal distribution, with an overall incidence rate estimated at 414.3 per 1000 person-years. In the active cross sectional surveys, we enrolled 2839, 2594 and 2337 participants respectively in September 2016, December 2016 and June 2017. Prevalence of malaria infection were respectively 41.5%, 43.5% and 32.3% in September 2016, in December 2016 and June 2017. Multivariate analysis showed that girls seemed to have a lower risk of malaria infection (OR = 0.86; 95% CI = 0.79 - 0.95; p = 0.004). The risk of malaria infection was significantly lower in third survey (June 2017) at the beginning of the rainy season (OR = 0.69; 95% CI = 0.6 - 0.8; p < 0.001) compared to the first survey (September 2016) which was performed during the rainy season. Children aged 6 to 59 months had a higher risk of malaria infection compared to those aged 10 to 17 years (OR = 0.58; 95% CI = 0.51 - 0.66).ConclusionMalaria burden remains high in this region of Burkina Faso despite substantial efforts made in malaria control during this current decade. Children under 5 years old were subject of malaria burden in this setting. This results reinforce the urgent need to develop alternative control strategies to complement those already existing.

Motivations and expectations driving community participation in entomological research projects: Target Malaria as a case study in Bana, Western Burkina Faso

Background Most field entomology research projects require active participation by local community members. Since 2012, Target Malaria, a not-for-profit research consortium, has been working with residents in the village of Bana, in Western Burkina Faso, in various studies involving mosquito collections, releases and recaptures. The long-term goal of this work is to develop innovative solutions to combat malaria in Africa with the help of mosquito modification technologies. Since the start of the project, Bana residents have played an important role in research activities, yet the motivations and expectations that drive their participation remain under-investigated. This study examines the factors that motivate some members of the local community to contribute to the implementation of Target Malaria’s activities, and, more broadly, explores the reasons that animate citizen participation in entomological research work in malaria-endemic regions. Methods A qualitative approach was used to survey the factors motivating members of the local community to assist in the implementation of Target Malaria’s entomological research activities in Bana. Eighty-five individual in-depth and semi-structured interviews were conducted, followed by three focus groups, one with youths who had participated in mosquito collections, and two with adult men and women from the village. All data collected were fully transcribed, processed, and subjected to thematic content analysis. Results Data showed that the willingness of local community members to participate in entomological research activities was informed by a wide range of motivational factors. Although interviewees expressed their motivations under different semantic registers, the data showed a degree of consistency around five categories of motivation: (a) enhance domestic protection from mosquitoes and malaria, (b) contribute to a future world free of the disease, (c) acquire knowledge and skills, (d) earn financial compensation, and (e) gain social prestige for the village.Conclusion These varying motivations reflect a set of differing personal and collective perceptions about the participation process, combining short and long-term, individual and collective motivations. Beyond the specific circumstances of this case, the study highlights the complex reasons that drive collective participation in entomological research and vector control activities. Detailed knowledge of community expectations should underpin any effort to mobilize local participation in field research activities.

Host range and species diversity of Tephritidae of three plant formations in Western Burkina Faso

In Western Burkina Faso, the host range of fruit flies was evaluated in three plant formations between May 2017 and April 2019. Samples of 61 potential hosts were collected and incubated for fruit fly emergence. Twenty-seven hosts including cultivated and wild fruit were identified. Among cultivated fruit species, mango, and guava were the most infested while high infestation incidences were observed in the fruit of the indigenous plants Vitellaria paradoxa, Annona senegalensis, Sarcocephalus latifolius, and Saba senegalensis. Low infestation rates were observed in Anacardium occidentale, Citrus species, Opilia celtidifolia, and Cissus populnea. The highest infestation index (1648.57 flies kg−1) was observed from V. paradoxa. Eleven new host fruit infested with many fruit fly species are reported in Burkina Faso. A total of 18 fruit fly species were reared; Bactrocera dorsalis (42.94%), Ceratitis cosyra (29.93%), and Ceratitis silvestrii (22.33%) dominated those that emerged. Four fruit fly species have been detected for the first time in Burkina Faso. The main suitable fruit hosts are abundant and available from May through August during the rainy season and become rare and have low infestation from November to April during the dry season. This is the first study of its kind in the region. This study shows that the three plant formations had an impact on population dynamics of the three tephritid species of economic importance in Western Burkina Faso. This information should be integrated into the development of a fruit fly pests management strategy.