In Africa, vector-borne diseases are a major public health issue, especially in cities. Urban greening is increasingly considered to promote inhabitants’ well-being. However, the impact of urban green spaces on vector risk remains poorly investigated, particularly urban forests in poor hygienic conditions. Therefore, using larval sampling and human landing catches, this study investigated the mosquito diversity and the vector risk in a forest patch and its inhabited surroundings in Libreville, Gabon, central Africa. Among the 104 water containers explored, 94 (90.4%) were artificial (gutters, used tires, plastic bottles) and 10 (9.6%) were natural (puddles, streams, tree holes). In total, 770 mosquitoes belonging to 14 species were collected from such water containers (73.1% outside the forested area). The mosquito community was dominated by Aedes albopictus (33.5%), Culex quinquefasciatus (30.4%), and Lutzia tigripes (16.5%). Although mosquito diversity was almost double outside compared to inside the forest (Shannon diversity index: 1.3 vs. 0.7, respectively), the species relative abundance (Morisita–Horn index = 0.7) was similar. Ae. albopictus (86.1%) was the most aggressive species, putting people at risk of Aedes-borne viruses. This study highlights the importance of waste pollution in urban forested ecosystems as a potential driver of mosquito-borne diseases.

Background and Purpose: Diarrhoeagenic E. coli (DEC) is one of the germs responsible for childhood diarrhea in developing countries. This study aims at determining the prevalence of the five main pathotypes of DEC isolated from faeces of children under five years old with diarrhea or not, living in the city of Koula-Moutou. Methodology: Isolates of E. coli were phenotypically screened on chromID TM agar and molecularly by multiplex PCR to detect the presence of enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enterohemorragic E. coli (EHEC) and enteroinvasive E. coli (EIEC). The evaluation of their sensitivity to 12 β-lactam antibiotic molecules was carried out by Kirby Bauer method. This method has also made it possible to characterize phenotypically the different β-lactamases produced. Results and Conclusion: Overall, at least one DEC pathovar was detected in the 63 E. coli strains with phenotypic and molecular frequencies of 63.5% and 68.5% respectively. Thus, ETEC (28.3%) and EHEC (28.3%) were the most frequent DEC in diarrheal isolates. ETEC/EHEC hybrid was recorded in both groups with rates of 7.5% in diarrheal cases and 10.0% for controls. The results showed produced carbapenemase type β-lactamases

RESUMEObjectifs : Dans le but de connaitre la densité apparente et la composition spécifique des glossines dans un ancien foyer de la Trypanosome humaine africaine au Gabon, une enquête entomologique a été menée dans deux biotopes du Parc National de Moukalaba Doudou (Sud Gabon) : le village Doussala et la forêt attenant à ce village. Méthodologie et résultats : Les captures ont été effectuées à l'aide de pièges Vavoua placés en forêt et au village Doussala durant la grande saison sèche. Au total, 4071 glossines ont été capturées : 3141 (77,2%) l'ont été en forêt et 930 (22,8%) au village. En forêt, six espèces ont été capturées avec des abondances différentes : G. fuscipes fuscipes (DAP=11,1 G/P/J), G. nashi (DAP=0,49 G/P/J), G. frezili (DAP=0,25 G/P/J), G. fusca congolensis (DAP=0,18 G/P/J), G. palpalis palpalis (DAP=0,09 G/P/J) et G. tachinoides (DAP=0,01 G/P/J). Tandis qu'au village, cinq espèces ont été identifiés, il s'agit de G. fuscipes fuscipes qui a une DAP de 3,48 G/P/J. Les autres espèces à savoir G. tachinoides, G. palpalis palpalis, G. nashi et G frezili ont des densités apparentes respectivement de 0,06 G/P/J ; 0,02 G/P/J ; 0,01 G/P/J et 0,01 G/P/J. Conclusion et application : Tous les éléments du complexe pathogène nécessaire à la transmission de la Trypanosome humaine africaine sont présents dans ce parc. Ces résultats bien que préliminaires invitent à élaborer des stratégies de lutte et de contrôle des vecteurs de parasitoses. Mots clés : piège Vavoua, Doussala, Trypanosome, Glossines, Gabon. ABSTRACT:Distribution of biological vectors of human African Trypanosomiasis in the National Park of Moukalaba Doudou (South Gabon). Objective: In order to know the apparent density and specific composition of the flies in a former home of human African trypanosomes in Gabon, an entomological investigation was conducted in primary forest and Doussala village in the National Park of Moukalaba Doudou (Gabon South). Distribution des Glossines vecteurs de la Trypanosomose humaine africaine dans le Parc National de Moukalaba Doudou (Sud-ouest Gabon). Journal of Applied 7958Methodology and Results:The catches were taken with the Vavoua traps placed in primary forest and the village Doussala during the long dry season. A total of 4071 tsetse with 3141 (77.2%) in the forest and 930 (22.8%) in the village were captured. In the forest, sixs pecies were captured with different abundances G. fuscipes fuscipes (DAP=11.1 G/ P/ J), G. nashi (DAP=0.49 G/ P/ J), G frezili (DAP=0.25 G / P /J), G fusca congolensis (DAP=0.18 G / P /J), G palpalis palpalis (DAP= 0.09 G / P /J) and G tachinoides (DAP= 0.01 G/ P /J).While in the town five species have been identified, it is G. fuscipes fuscipes DAP which has a 3.48 G / P/ J. Other species namely G tachinoides, G palpalis palpalis, G. nashi and G frezili have apparent densities of 0.06 G / P /J, respectively; 0.02 G / P /J; 0.01 G / P /J and 0.01 G / P/ J. Conclusion and Application:All elements of the complex pathogenic necessary for the transmission of human African trypanosome...

Background: Pediatric diarrhea caused by a range of pathogens, including intestinal parasites, is one of main causes of death among children under 5 years of age. The distribution of these parasitic infections overlaps in many environmental, socioeconomic and epidemiological settings. Their distribution and prevalence varies from region to region. In the current study, we assess the prevalence of intestinal parasites among pediatric patients with syndromic diarrheal disease living in Franceville, Gabon. Methods: A cross-sectional study conducted in the Amissa Bongo Regional Hospital and Chinese-Gabonese Friendship Hospital in Franceville, between November 2016 and August 2017, enrolled a total of 100 diarrheic children between 0 and 180 months of age. Parasite detection in stool samples was performed using molecular diagnostic by PCR. Difference in means were tested by Student's t test and ANOVA while principal component analysis was used to determine the correlation between parasite distributions and age groups. Results: The overall prevalence of intestinal parasite infection was 61% (61/100). Hymenolepis sp and Cryptosporidium hominis/parvum were the most common parasites (31 and 19%, respectively), followed by Encephalitozoon intestinalis (15%), Trichuris trichiura (4%), Dientamoeba fragilis (4%), and Enterocytozoon bieneusi (2%). The polyparasitism rate was 19.7%, with 83.3% double and 16.7% triple infections. Protozoan infections (66.7%) were more prevalent than helminths infections (33.3%). Seasonal association of the circulation of intestinal parasite was statistically significant (p = 0.03). Correlations between different parasites was also observed. Conclusion: The prevalence of intestinal parasitic infections is highest in diarrheic pediatric children. The prevalence of parasitic infections indicates that protozoa and helminths are the most common parasites in the Franceville environment. This study reinforces the importance of routine examination of diarrheic stool samples for the diagnostic of intestinal parasites. Further analyses are required to better understand the local epidemiology and risk factors associated with the transmission of intestinal parasites in Franceville, Gabon.

RESUMELa présence des glossines et l'activité journalière de Glossina fuscipes fuscipes dans le parc national de Moukalaba-Doudou ont été évaluées à l'aide du piège Vavoua durant douze jours pendant la grande saison sèche dans trois habitats différents à raison de quatre jours par habitats : savane, forêt et milieu anthropisé. Dans chaque milieu, un dispositif de trois pièges a été utilisé. 697 glossines au total ont été capturées soit 59,26% en forêt, 34,14% en milieu anthropisé et 6,60% en savane. Les glossines capturées ont été identifiées comme appartenant aux taxons suivant : Glossina fuscipes fuscipes Newstead 1911, G. palpalis palpalis Robineau-Desvoidy 1830, G. frezili Gouteux 1987, G. tachinoides Westwood1850, G. nashi Potts1955. Le rythme circadien d'activité de Glossina fuscipes fuscipes montre de façon générale que cette espèce a un rythme de type unimodal avec un maximum de capture marquée en milieu de journée. Selon les différents habitats, les pics d'activités journalières de cette espèce varie. Il est unimodal en forêt et savane, et bimodal en milieu anthropisé. Suivant le sexe, l'activité journalière de Glossina fuscipes fuscipes dans les trois biotopes est très hétérogène. Chez les mâles, le rythme circadien d'activité est bimodal en milieu anthropisé et unimodal en savane et en forêt, alors que chez les femelles ce cycle est unimodal dans les trois milieux.

Gabon is located in the malaria hyper-endemic zone, where data concerning malaria vector distribution remains fragmentary, making it difficult to implement an effective vector control strategy. Thus, it becomes crucial and urgent to undertake entomological surveys that will allow a better mapping of the Anopheles species present in Gabon. In this review, we examined different articles dealing with Anopheles in Gabon from ProQuest, Web of Science, PubMed, and Google scholar databases. After applying the eligibility criteria to 7543 articles collected from four databases, 42 studies were included that covered a 91-year period of study. The review revealed a wide diversity of Anopheles species in Gabon with a heterogeneous distribution. Indeed, our review revealed the presence of 41 Anopheles species, of which the most abundant were members of the Gambiae and Nili complexes and those of the Funestus and Moucheti groups. However, our review also revealed that the major and minor vectors of malaria in Gabon are present in both sylvatic, rural, and urban environments. The observation of human malaria vectors in sylvatic environments raises the question of the role that the sylvatic environment may play in maintaining malaria transmission in rural and urban areas. Ultimately, it appears that knowledge of biodiversity and spatial distribution of Anopheles mosquitoes is fragmentary in Gabon, suggesting that additional studies are necessary to complete and update these entomological data, which are useful for the implementation of vector control strategies.

Introduction Malaria remains a significant public health problem in sub-Saharan Africa. Child mortality due to severe malaria remains high in developing countries despite improvements in malaria management and a better understanding of its pathophysiology. To address the lack of epidemiological studies on severe malaria in Gabon, this study describes the epidemiological aspects of severe malaria in rural, semi-rural, and urban areas of southeast Gabon. Methods Demographic, clinical, and laboratory data for children and adolescents aged 0–18 years were collected in 2019 from hospital records at three health facilities in southeastern Gabon. The patients included in the study were positive for P falciparum malaria diagnosed by microscopy with at least one of the malaria severity criteria. Results Severe malaria accounted for 18.8% (667/3552) of malaria cases. Children aged 0–5 years accounted for 71.8% (479/667) of all severe malaria cases. Adolescents over 15 years of age were the least affected by severe malaria with 4.2% (28/667). Across the study, severe anemia (49.0%, 327/667), convulsions (43.0%, 287/667), respiratory distress (5.1%, 34/667), and altered consciousness (4.8%, 32/667) were the most frequent clinical signs of severe malaria in children. Franceville was the locality most affected by severe malaria with 49.2% (328/667), followed by Koulamoutou with 42.0% (280/667) and Lastourville with 8.8% (59/667). Convulsions (50.6%, 166/328) and coma (6.1%, 20/328) were more frequent in children living in urban areas. In contrast, severe anemia (56.7%, 186/339) and jaundice (6.8%, 23/339) were more common in children living in semi-rural areas. Conclusion Severe malaria is more prevalent in urban areas in regions with a high malaria transmission intensity. However, in this study, the epidemiological characteristics of severe malaria were similar in the three settings (urban, rural, and semi-rural areas) despite different levels of urbanization. Nevertheless, the various signs of severity were more frequent in Franceville, an urban area. Children under 5 years of age remain the most vulnerable age group.

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