Malaria vectors have acquired widespread resistance throughout sub-Saharan Africa to many of the currently used insecticides. Hence, there is an urgent need to develop alternative strategies including the development of new insecticides for effective management of insecticide resistance. To maintain progress against malaria, it is necessary to identify other residual insecticides for mosquito nets. In the present WHOPES phase II analogue study, the utility of chlorfenapyr, a pyrrole class insecticide mixed with alpha-cypermethrin on a long-lasting mosquito bed net was evaluated against Anopheles gambiae s.l. Bed nets treated with chlorfenapyr and alpha-cypermethrin and mixture of both compounds were tested for their efficacy on mosquitoes. Washed (20 times) and unwashed of each type of treated nets and were tested according to WHOPES guidelines. Efficacy of nets were expressed in terms of blood-feeding inhibition rate, deterrence, induced exophily and mortality rate. The evaluation was conducted in experimental huts of Vallée du Kou seven (VK7) in Burkina Faso (West Africa) following WHOPES phase II guidelines. In addition, a WHOPES phase I evaluation was also performed. Mixture treated nets killed significantly (P < 0.05) more mosquitoes than solo alpha-cypermethrin nets, unwashed and washed. Proportionally, this equated to mortalities of 78 and 76% (for mixture nets) compared to only 17 and 10% (for solo alpha-cypermethrin) to An. gambiae, respectively. In contrast mixture net proportions were not significantly (P > 0.05) different from nets treated with chlorfenapyr 200 mg/m2 unwashed (86%). The washed and unwashed nets treated with the mixtures resulted in personal protection against An. gambiae s.l. biting 34 and 44%. In contrast the personal protection observed for washed and unwashed alpha-cypermethrin treated nets generated (14 and 24%), and chlorfenapyr solo treated net was rather low (22%). Among all nets trialled, the combination of chlorfenapyr and alpha-cypermethrin on bed nets provided better mortality in phase II after 20 washes. Results suggest that this combination could be a potential insecticide resistance management tool for preventing malaria transmission in areas compromised by the spread of pyrethroid resistance.

The malaria parasite, which is transmitted by several Anopheles mosquito species, requires more time to reach its human-transmissible stage than the average lifespan of mosquito vectors. Monitoring the species-specific age structure of mosquito populations is critical to evaluating the impact of vector control interventions on malaria risk. We present a rapid, cost-effective surveillance method based on deep learning of mid-infrared spectra of mosquito cuticle that simultaneously identifies the species and age class of three main malaria vectors in natural populations. Using spectra from over 40, 000 ecologically and genetically diverse An. gambiae, An. arabiensis, and An. coluzzii females, we develop a deep transfer learning model that learns and predicts the age of new wild populations in Tanzania and Burkina Faso with minimal sampling effort. Additionally, the model is able to detect the impact of simulated control interventions on mosquito populations, measured as a shift in their age structures. In the future, we anticipate our method can be applied to other arthropod vector-borne diseases.

Every year, malaria kills approximately 405,000 people in Sub-Saharan Africa, most of them children under the age of five years. In many countries, progress in malaria control has been threatened by the rapid spread of resistance to antimalarial drugs and insecticides. Novel genetic mosquito control approaches could play an important role in future integrated malaria control strategies. In July 2019, the Target Malaria consortium proceeded with the first release of hemizygous genetically-modified (GM) sterile and non-transgenic sibling males of the malaria mosquito Anopheles coluzzii in Burkina Faso. This study aimed to determine the potential fitness cost associated to the transgene and gather important information related to the dynamic of transgene-carrying mosquitoes, crucial for next development steps. Bayesian estimations confirmed that GM males had lower survival and were less mobile than their wild type (WT) siblings. The estimated male population size in Bana village, at the time of the release was 28,000 - 37,000. These results provide unique information about the fitness and behaviour of released GM males that will inform future releases of more effective strains of the A. gambiae complex.

Adult females An. gambiae were exposed in 3 min cone test to treated nets with PPF before or after they were blood fed. The effects of PPF on ovaries development, females oviposition and eggs hatching were assessed. Both unfed and fed mosquitoes exposed to PPF exhibited nearly complete inhibition of fecundity (70-100%) and fertility (90-100%). After females have been exposed once to PPF, the sterilizing effect on their fecundity was observed over 3 consecutive blood meals suggesting that PPF might have an irreversible sterilizing effect. Observation of the ovaries of exposed females to PPF under microscope revealed that the ovaries failed to develop even after several blood meals. The combination of PPF to pyrethroids on bednets could provide better malaria control tool and prevent the further development and spread of pyrethroid resistance in malaria vectors.

Gastrointestinal parasites infections are widespread in Africa and their prevalence infections vary from country to country. This study aimed at assessing the prevalence of opportunistic intestinal parasites infection and other gastrointestinal parasites infection among patients attending the laboratory of Parasitology and Mycology of the University Hospital Souro Sanou of Bobo-Dioulasso. A hospital cross-sectional based study was conducted from April to August, 2012. Participants were persons whom parasitological examination of stools has been prescribed by a clinician. The stools examination methods included direct wet saline examination, lugol’s iodine staining technique, formol-ether concentration and modified Ziehl-Neelsen staining. We recorded age and sex information for each patient. The overall prevalence of intestinal parasite infections was 65.3 % (190/291). Majority of the parasitic infections was waterborne (64.3 %) consisting of high prevalence of Cryptosporidium sp. (26.5 %) and Entamoeba histolytica/dispar (23.4 %). The prevalence of opportunistic parasites was 28.9 % and Cryptosporidium sp. was the most prevalent species followed by Blastocystis sp. (1.0 %), Cyclospora sp. (0.7 %) and Isospora belli (0.7 %). The prevalence of intestinal helminthes was 1.7 %. The prevalence of intestinal parasitism in general remains high in Bobo-Dioulasso requiring the establishment of adequate diagnostic techniques, treatment and prevention.

Background: There is a global consensus that new intervention tools are needed for the final steps toward malaria elimination/eradication. In a recent study in Burkina Faso, the Lehmann Funnel Entry Trap (LFET) has shown promising results in the reduction of mosquito densities, even in areas where insecticide resistance is as high as 80%. The LFET requires no chemicals and is self-operated. However, one of the issues with the original LFET is the size of the funnel, which often occupies too much space within users’ homes. Here, the performance of three new, smaller-sized LFET prototypes that combine a screening and killing effect on mosquitoes was assessed. Methods: The study was carried out over three months during the rainy season in low and high malaria vector density sites, Soumousso and Vallée du Kou, respectively. The original LFET (or ‘Prototype 1’/‘P1’) was modified to produce three new prototypes, which were referred to as prototype 2 (‘the Medium’ or ‘P2’), prototype 3 (P3) and prototype 4 (P4). Each of the new prototypes was tested on eight days per month over the three-month period to assess their effectiveness in trapping and killing mosquitoes entering houses through the windows compared to the original LFET. Results: Overall, 78,435 mosquitoes (mainly Anopheles gambiae sensu lato) were collected in the two study sites, both in the traps and in the houses. A total of 56,430 (72%) mosquitoes were collected from the traps. In Vallée du Kou, the original LFET caught a greater number of mosquitoes than the medium (prototype 2), whereas no difference was observed between the other new prototypes (3 and 4) and the medium. In Soumousso, both the original and medium LFETs collected significantly greater numbers of mosquitoes compared to prototypes 3 and 4. Conclusion: This study has shown that the new LFET prototypes are effective in trapping mosquitoes in high mosquito density settings. A large-scale study with one of the prototypes will be needed to assess community acceptance of the traps and their ability to control malaria vectors.