Predicting the age of field Anopheles mosquitoes using mass spectrometry and deep learning.

Mosquito-borne diseases like malaria are rising globally, and improved mosquito vector surveillance is needed. Survival of Anopheles mosquitoes is key for epidemiological monitoring of malaria transmission and evaluation of vector control strategies targeting mosquito longevity, as the risk of pathogen transmission increases with mosquito age. However, the available tools to estimate field mosquito age are often approximate and time-consuming. Here, we show a rapid method that combines matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry with deep learning for mosquito age prediction. Using 2763 mass spectra from the head, legs, and thorax of 251 field-collected Anopheles arabiensis mosquitoes, we developed deep learning models that achieved a best mean absolute error of 1.74 days. We also demonstrate consistent performance at two ecological sites in Senegal, supported by age-related protein changes. Our approach is promising for malaria control and the field of vector biology, benefiting other disease vectors like Aedes mosquitoes.

Distribution and dynamics of Anopheles gambiae s.l. larval habitats in three Senegalese cities with high urban malaria incidence.

Urban malaria has become a challenge for most African countries due to urbanization, with increasing population sizes, overcrowding, and movement into cities from rural localities. The rapid expansion of cities with inappropriate water drainage systems, abundance of water storage habitats, coupled with recurrent flooding represents a concern for water-associated vector borne diseases, including malaria. This situation could threaten progress made towards malaria elimination in sub-Saharan countries, including Senegal, where urban malaria has presented as a threat to national elimination gains. To assess drivers of urban malaria in Senegal, a 5-month study was carried out from August to December 2019 in three major urban areas and hotspots for malaria incidence (Diourbel, Touba, and Kaolack) including the rainy season (August-October) and partly dry season (November-December). The aim was to characterize malaria vector larval habitats, vector dynamics across both seasons, and to identify the primary eco- environmental entomological factors contributing to observed urban malaria transmission. A total of 145 Anopheles larval habitats were found, mapped, and monitored monthly. This included 32 in Diourbel, 83 in Touba, and 30 in Kaolack. The number of larval habitats fluctuated seasonally, with a decrease during the dry season. In Diourbel, 22 of the 32 monitored larval habitats (68.75%) were dried out by December and considered temporary, while the remaining 10 (31.25%) were classified as permanent. In the city of Touba 28 (33.73%) were temporary habitats, and of those 57%, 71% and 100% dried up respectively by October, November, and December. However, 55 (66.27%) habitats were permanent water storage basins which persisted throughout the study. In Kaolack, 12 (40%) permanent and 18 (60%) temporary Anopheles larval habitats were found and monitored during the study. Three malaria vectors (An. arabiensis, An. pharoensis and An. funestus s.l.) were found across the surveyed larval habitats, and An. arabiensis was found in all three cities and was the only species found in the city of Diourbel, while An. arabiensis, An. pharoensis, and An. funestus s.l. were detected in the cities of Touba and Kaolack. The spatiotemporal observations of immature malaria vectors in Senegal provide evidence of permanent productive malaria vector larval habitats year-round in three major urban centers in Senegal, which may be driving high urban malaria incidence. This study aimed to assess the presence and type of anopheline larvae habitats in urban areas. The preliminary data will better inform subsequent detailed additional studies and seasonally appropriate, cost-effective, and sustainable larval source management (LSM) strategies by the National Malaria Control Programme (NMCP).

Characterization of the swarming behavior of Anopheles coluzzii and Anopheles gambiae (Diptera: Culicidae) populations in a hybrid zone of Senegal.

Anopheles gambiae and Anopheles coluzzii, often found in sympatry and synchronous, have undergone a premating reproductive isolation across their distribution range. However, in the Western coast of Africa, unexpected hybridization zones have been observed, and little is known about swarming behavior of these cryptic taxa. Here, we characterized the swarming behavior of An. coluzzii and An. gambiae to investigate its role in the high hybridization level in Senegal. The study was conducted in the south and central Senegal during the 2018 rainy season. Mating swarms of malaria vectors were surveyed at sunset and collected using an insect net. Meanwhile, indoor resting populations of malaria vectors were collected by pyrethrum spray catches. Upon collection, specimens were identified morphologically, and then members of the An. gambiae complex were identified at the species level by polymerase chain reaction (PCR). An. gambiae swarmed mainly over bare ground, whereas An. coluzzii were found swarming above various objects creating a dark-light contrast with the bare ground. The swarms height varied from 0.5 to 2.5 m. Swarming starting time was correlated with sunset whatever the months for both species, and generally lasted about 10 min. No mixed swarm of An. gambiae and An. coluzzii was found even in the high hybridization area. These results indicated a premating isolation between An. coluzzii and An. gambiae. However, the high hybridization rate in the sympatric area suggests that heterogamous mating is occurring, thus stressing the need for further extensive studies.

Urban malaria vector bionomics and human sleeping behavior in three cities in Senegal.

BACKGROUND: Malaria is endemic in Senegal, with seasonal transmission, and the entire population is at risk. In recent years, high malaria incidence has been reported in urban and peri-urban areas of Senegal. An urban landscape analysis was conducted in three cities to identify the malaria transmission indicators and human behavior that may be driving the increasing malaria incidence occurring in urban environments. Specifically, mosquito vector bionomics and human sleeping behaviors including outdoor sleeping habits were assessed to guide the optimal deployment of targeted vector control interventions. METHODS: Longitudinal entomological monitoring using human landing catches and pyrethrum spray catches was conducted from May to December 2019 in Diourbel, Kaolack, and Touba, the most populous cities in Senegal after the capital Dakar. Additionally, a household survey was conducted in randomly selected houses and residential Koranic schools in the same cities to assess house structures, sleeping spaces, sleeping behavior, and population knowledge about malaria and vector control measures. RESULTS: Of the 8240 Anopheles mosquitoes collected from all the surveyed sites, 99.4% (8,191) were An. gambiae s.l., and predominantly An. arabiensis (99%). A higher number of An. gambiae s.l. were collected in Kaolack (77.7%, n = 6496) than in Diourbel and Touba. The overall mean human biting rate was 14.2 bites per person per night (b/p/n) and was higher outdoors (15.9 b/p/n) than indoors (12.5 b/p/n). The overall mean entomological inoculation rates ranged from 3.7 infectious bites per person per year (ib/p/y) in Diourbel to 40.2 ib/p/y in Kaolack. Low anthropophilic rates were recorded at all sites (average 35.7%). Of the 1202 households surveyed, about 24.3% of household members slept outdoors, except during the short rainy season between July and October, despite understanding how malaria is transmitted and the vector control measures used to prevent it. CONCLUSION: Anopheles arabiensis was the primary malaria vector in the three surveyed cities. The species showed an outdoor biting tendency, which represents a risk for the large proportion of the population sleeping outdoors. As all current vector control measures implemented in the country target endophilic vectors, these data highlight potential gaps in population protection and call for complementary tools and approaches targeting outdoor biting malaria vectors.

Fine-scale mapping of urban malaria exposure under data scarcity: an approach centred on vector ecology.

BACKGROUND: Although malaria transmission has experienced an overall decline in sub-Saharan Africa, urban malaria is now considered an emerging health issue due to rapid and uncontrolled urbanization and the adaptation of vectors to urban environments. Fine-scale hazard and exposure maps are required to support evidence-based policies and targeted interventions, but data-driven predictive spatial modelling is hindered by gaps in epidemiological and entomological data. A knowledge-based geospatial framework is proposed for mapping the heterogeneity of urban malaria hazard and exposure under data scarcity. It builds on proven geospatial methods, implements open-source algorithms, and relies heavily on vector ecology knowledge and the involvement of local experts. METHODS: A workflow for producing fine-scale maps was systematized, and most processing steps were automated. The method was evaluated through its application to the metropolitan area of Dakar, Senegal, where urban transmission has long been confirmed. Urban malaria exposure was defined as the contact risk between adult Anopheles vectors (the hazard) and urban population and accounted for socioeconomic vulnerability by including the dimension of urban deprivation that is reflected in the morphology of the built-up fabric. Larval habitat suitability was mapped through a deductive geospatial approach involving the participation of experts with a strong background in vector ecology and validated with existing geolocated entomological data. Adult vector habitat suitability was derived through a similar process, based on dispersal from suitable breeding site locations. The resulting hazard map was combined with a population density map to generate a gridded urban malaria exposure map at a spatial resolution of 100 m. RESULTS: The identification of key criteria influencing vector habitat suitability, their translation into geospatial layers, and the assessment of their relative importance are major outcomes of the study that can serve as a basis for replication in other sub-Saharan African cities. Quantitative validation of the larval habitat suitability map demonstrates the reliable performance of the deductive approach, and the added value of including local vector ecology experts in the process. The patterns displayed in the hazard and exposure maps reflect the high degree of heterogeneity that exists throughout the city of Dakar and its suburbs, due not only to the influence of environmental factors, but also to urban deprivation. CONCLUSIONS: This study is an effort to bring geospatial research output closer to effective support tools for local stakeholders and decision makers. Its major contributions are the identification of a broad set of criteria related to vector ecology and the systematization of the workflow for producing fine-scale maps. In a context of epidemiological and entomological data scarcity, vector ecology knowledge is key for mapping urban malaria exposure. An application of the framework to Dakar showed its potential in this regard. Fine-grained heterogeneity was revealed by the output maps, and besides the influence of environmental factors, the strong links between urban malaria and deprivation were also highlighted.

Evolution of the Ace-1 and Gste2 Mutations and Their Potential Impact on the Use of Carbamate and Organophosphates in IRS for Controlling Anopheles gambiae s.l., the Major Malaria Mosquito in Senegal.

Widespread of insecticide resistance amongst the species of the Anopheles gambiae complex continues to threaten vector control in Senegal. In this study, we investigated the presence and evolution of the Ace-1 and Gste2 resistance genes in natural populations of Anopheles gambiae s.l., the main malaria vector in Senegal. Using historical samples collected from ten sentinel health districts, this study focused on three different years (2013, 2017, and 2018) marking the periods of shift between the main public health insecticides families (pyrethroids, carbamates, organophosphates) used in IRS to track back the evolutionary history of the resistance mutations on the Ace-1 and Gste2 loci. The results revealed the presence of four members of the Anopheles gambiae complex, with the predominance of An. arabiensis followed by An. gambiae, An. coluzzii, and An. gambiae-coluzzii hybrids. The Ace-1 mutation was only detected in An. gambiae and An. gambiae-coluzzii hybrids at low frequencies varying between 0.006 and 0.02, while the Gste2 mutation was found in all the species with a frequency ranging between 0.02 and 0.25. The Ace-1 and Gste2 genes were highly diversified with twenty-two and thirty-one different haplotypes, respectively. The neutrality tests on each gene indicated a negative Tajima's D, suggesting the abundance of rare alleles. The presence and spread of the Ace-1 and Gste2 resistance mutations represent a serious threat to of the effectiveness and the sustainability of IRS-based interventions using carbamates or organophosphates to manage the widespread pyrethroids resistance in Senegal. These data are of the highest importance to support the NMCP for evidence-based vector control interventions selection and targeting.

Rupture of an aneurysm of the gastroduodenal artery mimicking a tumor of the head of the pancreas in a case report.

Gastroduodenal artery aneurysms have a low incidence of less than 1.5% of all splanchnic aneurysms. Rupture is frequent and life-threatening. The diagnosis is made by CT scan and by coeliac angiography, which also plays a therapeutic role in stable or stabilized patients. Surgery remains the treatment of choice in case of hemodynamic instability. We reviewed the case of a ruptured aneurysm of the gastroduodenal artery mimicking a tumor of the pancreas' head in a patient who died following a hemorrhagic shock.

[Place of tomodensitometry in the management of acute intestinal occlusions in Dakar]. / Place de la tomodensitometrie dans la prise en charge des occlusions intestinales aigues a Dakar.

INTRODUCTION: Acute intestinal obstruction (AIO) is a syndrome defined by the cessation of intestinal transit caused by an obstacle or paralysis of intestinal peristalsis. It is a diagnostic and therapeutic emergency. The multi-bar CT scan has revolutionized the management of this pathology, as it allows the surgeon to answer different questions. The aim of our study was to describe the CT aspects of AIO, to determine the etiologies and to show the place of CT in the management of AIO. MATERIAL AND METHOD: This was a retrospective descriptive study conducted over 5 years (January 2010 to December 2015) on 81 patient files collected in the imaging departments of the CHU Aristide Le Dantec and the Hôpital Principal. The files retained were those whose diagnosis was established from the clinic, imaging and/or not from surgery. RESULTS: Mechanical occlusions represented 94.4% (76 cases) and functional occlusions 5.6% (05 cases). They were of the small bowel type in 70% of cases and colonic in 30%. The elementary lesions found were: transitional zone (36 patients), feces sign (28 patients), beak sign (06 patients), whirlpool sign (11 patients), signs of severity (36 patients). Seventy-two patients received surgery and 04 patients received medical treatment. The preoperative diagnosis was confirmed by surgery in 68 patients. Surgery corrected the diagnosis in 04 cases. Signs of severity were confirmed at surgery in all our patients. CONCLUSION: The CT scan has a major role in the therapeutic choice of AIO. It should be requested in first intention before an occlusive syndrome.

INTRODUCTION: L'occlusion intestinale aiguë (OIA) est un syndrome défini par l'arrêt du transit intestinal provoqué par un obstacle ou par une paralysie du péristaltisme intestinal. Il s'agit d'une urgence diagnostique et thérapeutique. Le scanner multibarrette a révolutionné la prise en charge de cette pathologie, car permettant de répondre aux différentes questions du chirurgien.Le but de notre étude était de décrire les aspects scanographiques des OIA, de déterminer les étiologies et de montrer la place de la TDM dans la prise en charge des OIA. MATÉRIEL ET MÉTHODE: Il s'agissait d'une étude rétrospective descriptive réalisée sur 05ans (Janvier 2010 à décembre 2015) portant sur 81 dossiers de patients colligés dans les services d'imagerie du CHU Aristide Le Dantec et de l'hôpital Principal. Les dossiers retenus sont ceux dont le diagnostic était établi à partir de la clinique, de l'imagerie et/ou non de la chirurgie. RÉSULTATS: Les occlusions mécaniques représentaient 94,4% (76 cas) et fonctionnelles 5.6% (05 cas).Elles étaient de type grêle dans 70% des cas et colique dans 30%.Les lésions élémentaires mises en évidence étaient : zone transitionnelle (36 patients), signe du fèces (28 patients), signe du bec (06 patients), signe du tourbillon (11 patients), signes de gravité (36 patients). Soixante-douze patients ont bénéficié d'une chirurgie et 04 patients d'un traitement médical. Le diagnostic préopératoire était confirmé par la chirurgie chez 68 patients. La chirurgie a redressé le diagnostic dans 04 cas. Les signes de gravité étaient confirmés à la chirurgie chez tous nos patients. CONCLUSION: La TDM occupe une place prépondérante dans le choix thérapeutique des OIA. Elle doit être demandée en première intention devant un syndrome occlusif.

[The abdominal pseudocyst: a complication of ventriculoperitoneal bypass about a case]. / Le pseudokyste abdominal : une complication de la derivation ventriculo-peritoneale à propos d'un cas.

The abdominal pseudocyst is a rare complication that can occur in subjects with a ventriculoperitoneal drain (VPD). We report the case of an 11-year-old adolescent with congenital hydrocephalus antecedent, for whom a ventriculoperitoneal shunt was made. He presented a progressive abdominal distension without notion of transit disorders. Abdominal ultrasound and uroscanner revealed an organized peritoneal effusion of great abundance, thin and regular wall, exerting a mass effect on the bladder and the ureters responsible for bilateral uretero-hydronephrosis. Above all, it has made it possible to individualize the distal ventriculo-peritoneal bypass catheter projecting in the effusion.

Le pseudokyste abdominal est une complication rare pouvant survenir chez les sujets porteurs d'une dérivation ventriculo-péritonéale (DVP). Nous rapportons le cas d'un adolescent de 11 ans, chez qui une DVP a été réalisée pour une hydrocéphalie congénitale. Il présentait une distension abdominale progressive sans notion de troubles de transit. L'imagerie (échographie, urosacnner) a permis de mettre en évidence un épanchement péritonéal de grande abondance organisé, à paroi fine et régulière, exerçant un effet de masse sur la vessie et les uretères, responsable d'une urétérohydronéphrose bilatérale. Le bout distal du cathéter de DVP a été visualisé dans la collection.

[Contribution of ultrasound in the management of acute intestinal intussusception of the infant]. / Apport de l'echographie dans les invaginations intestinales aigues du nourrisson.

OBJECTIVE: The objective of this work was to study the place of ultrasound in the positive diagnosis, etiology and choice of the therapeutic modality of acute intestinal intussusception. MATERIAL AND METHODS: This was a retrospective, descriptive, cross-sectional, multicenterstudy, carried out over a period of 18 months (January 1, 2016 to June 30, 2017) on 45 patient files collected in the radiologydepartments (Aristide Le Dantec and Albert Royer). Were included all patients aged less than 14 years, admitted with acute abdominal pain, whose diagnosis of IIA was retained on ultrasound. Pneumatic disinvagination was performed in patients without signs of severity. We studied the time of management, the ultrasound aspects of the invagination puddles, the therapeutic choice but also the radiosurgical concordance and the factors of failure of the pneumatic enema. Statistical analysis was done by SPSS version 21.0 software. RESULTS: Ultrasound was used to make the diagnosis of IIA in 43 cases (95.5%). The sonographic characteristics were as follows: 27.9% of the IIA were located in the right hypochondrium, 19 cases were ileo-caecal, 10 (22.2%) ileo-caeco-colic, 9 (20%) ileo-colic, 4 (8.9%) colo-colic and one (2.2%) gregelic; 44 cases were idiopathic and one case was a Meckel's diverticulum The management time was less than 48 hours in 34% of cases and 66% more than 48 hours. Pneumatic reduction was performed in 18 cases (40%), with success in 14 cases (77.8%) and one case of pneumoperitoneum complication. Surgery was performed in 31 cases (68.8%). The sensitivity and specificity of ultrasound in the diagnosis of signs of severity were 77.7% and 78.9%. Good agreement was observed between the results of the Doppler ultrasound and the intraoperative findings. Ultrasound parameters associated with failed pneumatic deinvagination were: outer cylinder thickness ≥10 mm, adenopathy at the level of the small-axis bladder ≥10 mm, effusion in the bladder, and hypovascularization of the bladder head. Hypovascularization of the boudin head was the only factor independently associated with failure of pneumatic disinvagination. CONCLUSION: Ultrasound is a powerful imaging modality in the positive diagnosis, etiology, severity and therapeutic choice of IIA.

OBJECTIF: L'objectif de ce travail était d'étudier la place de l'échographie dans le diagnostic positif, étiologique et le choix de la modalité thérapeutique des invaginations intestinales aigues. MATÉRIEL ET MÉTHODES: Il s'agissait d'une étude rétrospective, descriptive, transversale, multicentrique, réalisée sur une période de 18 mois (01 Janvier 2016 au 30 Juin 2017) portant sur 45 dossiers de patients colligés dans les services de radiologie (Aristide Le Dantec et Albert Royer). Ont été inclus tous les patients âgés de moins de 14 ans, admis dans un tableau de douleur abdominale aigue, dont le diagnostic d'IIA était retenu à l'échographie. Une désinvagination pneumatique a été réalisée chez les patients sans signe de gravité.Nous avons étudié le délai de prise en charge, les aspects échographiques des boudins d'invagination, le choix thérapeutique mais aussi la concordance radio-chirurgicale et les facteurs d'échec du Lavement pneumatique. L'analyse statistique a été faite par le logiciel SPSS version 21.0. RÉSULTATS: L'échographie a permis de faire le diagnostic d'IIA dans 43 cas (95,5%). Les caractéristiques échographiques étaient les suivantes : 27,9% des IIA siégeaient au niveau de l'hypochondre droit, 19 cas de forme iléo-caecales, 10(22,2%) cas iléo-caeco-colique, 9(20%) casiléo-colique, 4(8,9%)cascolo-colique et un cas (2,2%) grélo-grélique; 44 cas idiopathiques et un cas de diverticule de Meckel. Le delais de prise en charge était inférieur à 48heures dans 34 % des cas et 66% supérieur à 48heures. Une réduction pneumatique a été réalisée dans 18 cas (40%), avec succès dans 14 cas (77,8%) et un cas de complication à type de pneumopéritoine. Une chirurgie était réalisée dans 31 cas (68,8%). La sensibilité et la spécificité de l'échographie dans le diagnostic des signes de gravité étaient de 77,7% et 78,9%. Une bonne concordance étaitobservée entre les résultats de l'écho-Doppler et les constatations peropératoires. Les paramètreséchographiquesassociés à un échec de la désinvagination pneumatique étaient : une épaisseur du cylindre externe ≥10 mm, des adénopathies au niveau du boudin de petit axe ≥10 mm, un épanchement dans le boudin et une hypovascularisation de la tête du boudin. L'hypovascularisation de la tête du boudin était le seul facteur indépendamment associe à l'échec de la désinvagination pneumatique. CONCLUSION: L'échographie est une modalité performante d'imagerie dans le diagnostic positif, étiologique, de gravité et dans le choix thérapeutique des IIA.

Place de la tomodensitométrie dans la prise en charge des occlusions intestinales aigues à Dakar / Place of tomodensitometry in the management of acute intestinal occlusions in Dakar

ntroduction : L'occlusion intestinale aiguë (OIA) est un syndrome défini par l'arrêt du transit intestinal provoqué par un obstacle ou par une paralysie du péristaltisme intestinal. Il s'agit d'une urgence diagnostique et thérapeutique. Le scanner multibarrette a révolutionné la prise en charge de cette pathologie, car permettant de répondre aux différentes questions du chirurgien.Le but de notre étude était de décrire les aspects scanographiques des OIA, de déterminer les étiologies et de montrer la place de la TDM dans la prise en charge des OIA. Matériel et Méthode : Il s'agissait d'une étude rétrospective descriptive réalisée sur 05ans (Janvier 2010 à décembre 2015) portant sur 81 dossiers de patients colligés dans les services d'imagerie du CHU Aristide Le Dantec et de l'hôpital Principal. Les dossiers retenus sont ceux dont le diagnostic était établi à partir de la clinique, de l'imagerie et/ou non de la chirurgie. Résultats : Les occlusions mécaniques représentaient 94,4% (76 cas) et fonctionnelles 5.6% (05 cas). Elles étaient de type grêle dans 70% des cas et colique dans 30%. Les lésions élémentaires mises en évidence étaient : zone transitionnelle (36 patients), signe du fèces (28 patients), signe du bec (06 patients), signe du tourbillon (11 patients), signes de gravité (36 patients). Soixante-douze patients ont bénéficié d'une chirurgie et 04 patients d'un traitement médical. Le diagnostic préopératoire était confirmé par la chirurgie chez 68 patients. La chirurgie a redressé le diagnostic dans 04 cas. Les signes de gravité étaient confirmés à la chirurgie chez tous nos patients. Conclusion : La TDM occupe une place prépondérante dans le choix thérapeutique des OIA. Elle doit être demandée en première intention devant un syndrome occlusif

Introduction: Acute intestinal obstruction (AIO) is a syndrome defined by the cessation of intestinal transit caused by an obstacle or paralysis of intestinal peristalsis. It is a diagnostic and therapeutic emergency. The multi-bar CT scan has revolutionized the management of this pathology, as it allows the surgeon to answer different questions. The aim of our study was to describe the CT aspects of AIO, to determine the etiologies and to show the place of CT in the management of AIO. Material and Method: This was a retrospective descriptive study conducted over 5 years (January 2010 to December 2015) on 81 patient files collected in the imaging departments of the CHU Aristide Le Dantec and the Hôpital Principal. The files retained were those whose diagnosis was established from the clinic, imaging and/or not from surgery. Results: Mechanical occlusions represented 94.4% (76 cases) and functional occlusions 5.6% (05 cases). They were of the small bowel type in 70% of cases and colonic in 30%. The elementary lesions found were: transitional zone (36 patients), feces sign (28 patients), beak sign (06 patients), whirlpool sign (11 patients), signs of severity (36 patients). Seventytwo patients received surgery and 04 patients received medical treatment. The preoperative diagnosis was confirmed by surgery in 68 patients. Surgery corrected the diagnosis in 04 cases. Signs of severity were confirmed at surgery in all our patients. Conclusion: The CT scan has a major role in the therapeutic choice of AIO. It should be requested in first intention before an occlusive syndrome

Le pseudo kyste abdominal: une complication de la dérivation ventricule péritonéale à propos d'un cas / The abdominal pseudocyst: a complication of ventriculoperitoneal bypass about a case

Le pseudokyste abdominal est une complication rare pouvant survenir chez les sujets porteurs d'une dérivation ventriculo-péritonéale (DVP). Nous rapportons le cas d'un adolescent de 11 ans, chez qui une DVP a été réalisée pour une hydrocéphalie congénitale. Il présentait une distension abdominale progressive sans notion de troubles de transit. L'imagerie (échographie, urosacnner) a permis de mettre en évidence un épanchement péritonéal de grande abondance organisé, à paroi fine et régulière, exerçant un effet de masse sur la vessie et les uretères, responsable d'une urétérohydronéphrose bilatérale. Le bout distal du cathéter de DVP a été visualisé dans la collection

The abdominal pseudocyst is a rare complication that can occur in subjects with a ventriculoperitoneal drain (VPD). We report the case of an 11-year-old adolescent with congenital hydrocephalus antecedent, for whom a ventriculoperitoneal shunt was made. He presented a progressive abdominal distension without notion of transit disorders. Abdominal ultrasound and uroscanner revealed an organized peritoneal effusion of great abundance, thin and regular wall, exerting a mass effect on the bladder and the ureters responsible for bilateral uretero-hydronephrosis. Above all, it has made it possible to individualize the distal ventriculo-peritoneal bypass catheter projecting in the effusion

Evolution of the Pyrethroids Target-Site Resistance Mechanisms in Senegal: Early Stage of the Vgsc-1014F and Vgsc-1014S Allelic Frequencies Shift.

The evolution and spread of insecticide resistance mechanisms amongst malaria vectors across the sub-Saharan Africa threaten the effectiveness and sustainability of current insecticide-based vector control interventions. However, a successful insecticide resistance management plan relies strongly on evidence of historical and contemporary mechanisms circulating. This study aims to retrospectively determine the evolution and spread of pyrethroid resistance mechanisms among natural Anopheles gambiae s.l. populations in Senegal. Samples were randomly drawn from an existing mosquito sample, collected in 2013, 2017, and 2018 from 10 sentinel sites monitored by the Senegalese National Malaria Control Programme (NMCP). Molecular species of An. gambiae s.l. and the resistance mutations at the Voltage-gated Sodium Channel 1014 (Vgsc-1014) locus were characterised using PCR-based assays. The genetic diversity of the Vgsc gene was further analyzed by sequencing. The overall species composition revealed the predominance of Anopheles arabiensis (73.08%) followed by An. gambiae s.s. (14.48%), Anopheles coluzzii (10.94%) and Anopheles gambiae-coluzii hybrids (1.48%). Both Vgsc-1014F and Vgsc-1014S mutations were found in all studied populations with a spatial variation of allele frequencies from 3% to 90%; and 7% to 41%, respectively. The two mutations have been detected since 2013 across all the selected health districts, with Vgsc-L1014S frequency increasing over the years while Vgsc-1014F decreasing. At species level, the Vgsc-1014F and Vgsc-1014S alleles were more frequent amongst An. gambiae s.s. (70%) and An. arabiensis (20%). The Vgsc gene was found to be highly diversified with eight different haplotypes shared between Vgsc-1014F and Vgsc-1014S. The observed co-occurrence of Vgsc-1014F and Vgsc-1014S mutations suggest that pyrethroid resistance is becoming a widespread phenomenon amongst malaria vector populations, and the NMCP needs to address this issue to sustain the gain made in controlling malaria.

Hymenopteran Parasitoids of Hard Ticks in Western Africa and the Russian Far East.

Some parasitoids of the genus Ixodiphagus (Hymenoptera, Chalcidoidea: Encyrtidae) are well-known natural enemies of ticks. In this study, we investigate the occurrence of parasitoid wasps in adult hard ticks from Western Africa (Côte d'Ivoire and Senegal) and Far Eastern Europe (Russia) using molecular methods. The morphological identification allowed the classification of 785 collected specimens of six species of ticks: Rhipicephalus (Boophilus) microplus (41%), Ixodes persulcatus (33%), Dermacentor silvarum (11%), Haemaphysalis concinna (7%), Amblyomma variegatum (5%), and Haemaphysalis japonica (3%). The newly developed MALDI-TOF MS protocol identified tick species in spite of their different storage (dried or in 70% ethanol) conditions for a long period. Molecular screening of ticks by a new standard PCR system developed in this study revealed the presence of parasitoid wasp DNA in 3% (28/785) of analyzed ticks. Ixodiphagus hookeri was detected in 86% (24/28) of infested ticks, including 13 I. persulcatus, 9 R (B) microplus, and one H. concinna and D. silvarum. While an unidentified parasitoid wasp species from the subfamily Aphidiinae and Braconidae family was detected in the remaining 14% (4/28) infested ticks. These infested ticks were identified as I. persulcatus. Our findings highlight the need for further studies to clarify the species diversity of parasitoid infesting ticks by combining molecular and morphological features. The novel molecular and MALDI-TOF MS protocols could be effective tools for the surveillance and characterization of these potential bio-control agents of ticks.

Mapping the breeding sites of Anopheles gambiae s. l. in areas of residual malaria transmission in central western Senegal.

Despite the deployment of several effective control interventions in central-western Senegal, residual malaria transmission is still occurring in some hotspots. To better tailor targeted control actions, it is critical to unravel the underlying environmental and geographical factors that cause the persistence infection in hotspot villages. "Hotspots villages" were defined in our study as those reporting more than six indigenous malaria cases during the previous year. A total of ten villages, including seven hotspots and three non-hotspots, were surveyed. All potential mosquito breeding sites identified in and around the ten study villages were regularly monitored between 2013 and 2017. Monitoring comprised the detection of anopheline larvae and the collection of epidemiological, hydrogeological, topographical, and biogeographical data. The number of larval breeding sites described and monitored during the study period ranged from 50 to 62. Breeding sites were more numerous in hotspot sites in each year of monitoring, with 90.3% (56/62) in 2013, 90.9% (50/55) in 2014, 90.3% (56/62) in 2015 and 86% (43/50) in 2017 (Fisher exact test; p = 1). In the non-hotspot areas, the data for the same years were, respectively, 9.7% (6/62), 9.1% (5/55), 9.7% (6/62) and 14% (7/50) (p = 1). The Hotspot villages were characterized mostly by saline or moderately saline hydro-morphic and halomorphic soils allowing water retention and a potential larval breeding sites. By contrast, non-hotspot villages were characterized mainly by a high proportion of extremely permeable sandy-textured soils, which due to their porosity had low water retention. The annual number of confirmed malaria cases was correlated with the frequency and extent of breeding sites. Malaria cases were significantly more frequent in the hamlets located near breeding sites of An. gambiae s.l., gradually decreasing with increasing remoteness. This study shows that the characteristics of larval breeding sites, as measured by their longevity, stability, proximity to human habitation, and their positivity in Anopheles larvae are likely determining factors in the persistence of malaria hotspots in central-western Senegal. The results of this study shed more light on the environmental factors underlying the residual transmission and should make it possible to better target vector control interventions for malaria elimination in west-central Senegal.

Insecticide Resistance Profiling of Anopheles coluzzii and Anopheles gambiae Populations in the Southern Senegal: Role of Target Sites and Metabolic Resistance Mechanisms.

The emergence and spread of insecticide resistance among the main malaria vectors is threatening the effectiveness of vector control interventions in Senegal. The main drivers of this resistance in the Anopheles gambiae complex (e.g., An. gambiae and Anopheles coluzzii) remains poorly characterized in Senegal. Here we characterized the main target site and metabolic resistances mechanisms among the An. gambiae and An. coluzzii populations from their sympatric and allopatric or predominance area in Senegal. Larvae and pupae of An. gambiae s.l. were collected, reared to adulthood, and then used for insecticides susceptibility and synergist assays using the WHO (World Health Organisation) test kits for adult mosquitoes. The TaqMan method was used for the molecular characterization of the main target site insecticide resistance mechanisms (Vgsc-1014F, Vgsc-1014S, N1575Y and G119S). A RT-qPCR (Reverse Transcriptase-quantitative Polymerase Chaine Reaction) was performed to estimate the level of genes expression belonging to the CYP450 (Cytochrome P450) family. Plasmodium infection rate was investigated using TaqMan method. High levels of resistance to pyrethroids and DDT and full susceptibility to organophosphates and carbamates where observed in all three sites, excepted a probable resistance to bendiocarb in Kedougou. The L1014F, L1014S, and N1575Y mutations were found in both species. Pre-exposure to the PBO (Piperonyl butoxide) synergist induced a partial recovery of susceptibility to permethrin and full recovery to deltamethrin. Subsequent analysis of the level of genes expression, revealed that the CYP6Z1 and CYP6Z2 genes were over-expressed in wild-resistant mosquitoes compared to the reference susceptible strain (Kisumu), suggesting that both the metabolic resistance and target site mutation involving kdr mutations are likely implicated in this pyrethroid resistance. The presence of both target-site and metabolic resistance mechanisms in highly pyrethroid-resistant populations of An. gambiae s.l. from Senegal threatens the effectiveness and the sustainability of the pyrethroid-based tools and interventions currently deployed in the country. The Kdr-west mutation is widely widespread in An. coluzzii sympatric population. PBO or Duo nets and IRS (Indoor Residual Spraying) with organophosphates could be used as an alternative measure to sustain malaria control in the study area.

Multiple insecticide resistance target sites in adult field strains of An. gambiae (s.l.) from southeastern Senegal.

BACKGROUND: High coverage of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) are the cornerstones of vector control strategy in Senegal where insecticide resistance by the target vectors species is a great of concern. This study explores insecticide susceptibility profile and target-site mutations mechanisms within the Anopheles gambiae complex in southeastern Senegal. METHODS: Larvae of Anopheles spp. were collected in two sites from southeastern Senegal Kedougou and Wassadou/Badi in October and November 2014, and reared until adult emergence. Wild F0 adult mosquitoes were morphologically identified to species. Susceptibility of 3-5-day-old An. gambiae (s.l.) samples to 11 insecticides belonging to the four insecticide classes was assessed using the WHO insecticide susceptibility bioassays. Tested samples were identified using molecular techniques and insecticide resistance target-site mutations (kdr, ace-1 and rdl) were determined. RESULTS: A total of 3742 An. gambiae (s.l.) were exposed to insecticides (2439 from Kedougou and 1303 from Wassadou-Badi). Tests with pyrethroid insecticides and DDT showed high level of resistance in both Kedougou and Wassadou/Badi. Resistance to pirimiphos-methyl and malathion was not detected while resistance to bendoicarb and fenitrothion was confirmed in Kedougou. Of the 745 specimens of An. gambiae (s.l.) genotyped, An. gambiae (s.s.) (71.6%) was the predominant species, followed by An. arabiensis (21.7%), An. coluzzii (6.3%) and hybrids (An. gambiae (s.s.)/An. coluzzii; 0.4%). All target site mutations investigated (Vgsc-1014F, Vgsc-1014S, Ace-1 and Rdl) were found at different frequencies in the species of the Anopheles gambiae complex. Vgsc-1014F mutation was more frequent in An. gambiae (s.s.) and An. coluzzii than An. arabiensis. Vgsc-1014S was present in An. gambiae (s.l.) populations in Wassadou but not in Kedougou. Ace-1 and rdl mutations were more frequent in An. gambiae (s.s.) in comparison to An. arabiensis and An. coluzzii. CONCLUSIONS: Resistance to all the four insecticide classes tested was detected in southeastern Senegal as well as all target site mutations investigated were found. Data will be used by the national Malaria Control Programme.

Updates on malaria epidemiology and profile in Cabo Verde from 2010 to 2019: the goal of elimination.

BACKGROUND: Located in West Africa, Cabo Verde is an archipelago consisting of nine inhabited islands. Malaria has been endemic since the settlement of the islands during the sixteenth century and is poised to achieve malaria elimination in January 2021. The aim of this research is to characterize the trends in malaria cases from 2010 to 2019 in Cabo Verde as the country transitions from endemic transmission to elimination and prevention of reintroduction phases. METHODS: All confirmed malaria cases reported to the Ministry of Health between 2010 and 2019 were extracted from the passive malaria surveillance system. Individual-level data available included age, gender, municipality of residence, and the self-reported countries visited if travelled within the past 30 days, therby classified as imported. Trends in reported cases were visualized and multivariable logistic regression used to assess risk factors associated with a malaria case being imported and differences over time. RESULTS: A total of 814 incident malaria cases were reported in the country between 2010 and 2019, the majority of which were Plasmodium falciparum. Overall, prior to 2017, when the epidemic occurred, 58.1% (95% CI 53.6-64.6) of infections were classified as imported, whereas during the post-epidemic period, 93.3% (95% CI 86.9-99.7) were imported. The last locally acquired case was reported in January 2018. Imported malaria cases were more likely to be 25-40 years old (AOR: 15.1, 95% CI 5.9-39.2) compared to those under 15 years of age and more likely during the post-epidemic period (AOR: 56.1; 95% CI 13.9-225.5) and most likely to be reported on Sao Vicente Island (AOR = 4256.9, 95% CI = 260-6.9e+4) compared to Boavista. CONCLUSIONS: Cabo Verde has made substantial gains in reducing malaria burden in the country over the past decade and are poised to achieve elimination in 2021. However, the high mobility between the islands and continental Africa, where malaria is still highly endemic, means there is a constant risk of malaria reintroduction. Characterization of imported cases provides useful insight for programme and enables better evidence-based decision-making to ensure malaria elimination can be sustained.

Development of a multiplex qPCR-based approach for the diagnosis of Dirofilaria immitis, D. repens and Acanthocheilonema reconditum.

BACKGROUND: Dirofilaria immitis, D. repens and Acanthocheilonema reconditum are the main causative agents of zoonotic canine filariosis. METHODS: We developed a combined multiplex approach for filaria and Wolbachia detection using the 28S-based pan-filarial and 16S-based pan-Wolbachia qPCRs, respectively, involving a fast typing method of positive samples using triplex qPCR targeting A. reconditum, D. immitis and D. repens, and a duplex qPCR targeting Wolbachia of D. immitis and D. repens. The approach was complemented by a duplex qPCR for the differential diagnosis of heartworms (D. immitis and Angiostrongylus vasorum) and pan-filarial cox1 and pan-Wolbachia ftsZ PCRs to identify other filarial parasites and their Wolbachia, respectively. A total of 168 canine blood and sera samples were used to validate the approach. Spearman's correlation was used to assess the association between filarial species and the strain of Wolbachia. Positive samples for both the heartworm antigen-test after heating sera and at least one DNA-positive for D. immitis and its Wolbachia were considered true positive for heartworm infection. Indeed, the presence of D. repens DNA or that of its Wolbachia as well as A. reconditum DNA indicates true positive infections. RESULTS: The detection limit for Wolbachia and filariae qPCRs ranged from 5 × 10-1 to 1.5 × 10-4 mf/ml of blood. When tested on clinical samples, 29.2% (49/168) tested positive for filariae or Wolbachia DNA. Filarial species and Wolbachia genotypes were identified by the combined multiplex approach from all positive samples. Each species of Dirofilaria was significantly associated with a specific genotype of Wolbachia. Compared to the true positives, the approach showed excellent agreement (k = 0.98-1). Unlike D. immitis DNA, no A. vasorum DNA was detected by the duplex qPCR. The immunochromatographic test for heartworm antigen showed a substantial (k = 0.6) and a weak (k = 0.15) agreements before and after thermal pre-treatment of sera, respectively. CONCLUSIONS: The proposed approach is a reliable tool for the exploration and diagnosis of occult and non-occult canine filariosis. The current diagnosis of heartworm disease based on antigen detection should always be confirmed by qPCR essays. Sera heat pre-treatment is not effective and strongly discouraged.

Role of plants in the transmission of Asaia sp., which potentially inhibit the Plasmodium sporogenic cycle in Anopheles mosquitoes.

Biological control against malaria and its transmission is currently a considerable challenge. Plant-associated bacteria of the genus Asaia are frequently found in nectarivorous arthropods, they thought to have a natural indirect action on the development of plasmodium in mosquitoes. However, virtually nothing is known about its natural cycle. Here, we show the role of nectar-producing plants in the hosting and dissemination of Asaia. We isolated Asaia strains from wild mosquitoes and flowers in Senegal and demonstrated the transmission of the bacteria from infected mosquitoes to sterile flowers and then to 26.6% of noninfected mosquitoes through nectar feeding. Thus, nectar-producing plants may naturally acquire Asaia and then colonize Anopheles mosquitoes through food-borne contamination. Finally, Asaia may play an indirect role in the reduction in the vectorial capacity of Anopheles mosquitoes in a natural environment (due to Plasmodium-antagonistic capacities of Asaia) and be used in the development of tools for Asaia-based paratransgenetic malaria control.