[Contribution of cardiac CT in the management of congenital heart disease : experience of the Abidjan cardiology institute in 27 cases]. / Apport du scanner cardiaque dans la prise en charge des cardiopathies congénitales : expérience de l'institut de cardiologie d'Abidjan à propos de 27 cas.

INTRODUCTION AND OBJECTIVES: In contrast to developed countries, cardiac CT is not widely used in West Africa for the assessment of congenital heart disease, and has only recently been introduced in Côte d'Ivoire. The lack of data prompted this study, the aim of which was to describe our experience of the contribution of CT to the management of congenital heart disease in the Ivorian cardiology setting. PATIENTS AND METHOD: This was a prospective study which took place in the pediatric cardiology department over a period of 9 months (September 2022 to June 2023) which included all patients with congenital heart disease explored by echocardiography and cardiac scan. RESULTS: The average age was 5.7 ± 4.7 years with extremes of 5 months and 16 years. We noted a female predominance with a sex ratio of 0.52. The main heart diseases were: tetralogy of Fallot (37.1%), followed by pulmonary atresia with open septum (18.52%). The assessment of the anatomy of the pulmonary arteries (81.48%), the search for aortopulmonary collaterals (59.63%) and finally the assessment of the anatomy of the aorta (18.52%) were the main indications. The practice of cardiac CT scanning has enabled better accuracy in the diagnosis and management of congenital heart disease in several cases: an interruption of the aortic arch was found in 1 case initially suspected of hypoplasia of the aortic arch, three cases of partial abnormal pulmonary venous return and one case of total abnormal pulmonary venous return. Also, agenesis of the left pulmonary artery with birth anomaly of the right coronary artery in the assessment of tetralogy of Fallot was found in 1 case. The CT scan made it possible to specify the exact topography of the aortopulmonary collaterals in four cases of pulmonary atresia with an open septum. CONCLUSION: CT has enabled better visualization of the arterial and venous pulmonary tree, identification and exact localization of aorto-pulmonary collaterals, precise description of the three-dimensional anatomy of the coronary arteries, and better precision of congenital anomalies of the aorta.

Wolbachia and Asaia Distribution among Different Mosquito Vectors Is Affected by Tissue Localization and Host Species.

Microbial communities play an important role in the fitness of mosquito hosts. However, the factors shaping microbial communities in wild populations, with regard to interactions among microbial species, are still largely unknown. Previous research has demonstrated that two of the most studied mosquito symbionts, the bacteria Wolbachia and Asaia, seem to compete or not compete, depending on the genetic background of the reference mosquito host. The large diversity of Wolbachia-Asaia strain combinations that infect natural populations of mosquitoes may offer a relevant opportunity to select suitable phenotypes for the suppression of pathogen transmission and for the manipulation of host reproduction. We surveyed Wolbachia and Asaia in 44 mosquito populations belonging to 11 different species of the genera Anopheles, Aedes, and Culex using qualitative PCR. Through quantitative PCR, the amounts of both bacteria were assessed in different mosquito organs, and through metagenomics, we determined the microbiota compositions in some selected mosquito populations. We show that variation in microbial community structure is likely associated with the species/strain of mosquito, its geographical position, and tissue localization. Together, our results shed light on the interactions among different bacterial species in the microbial communities of mosquito vectors, and this can aid the development and/or improvement of methods for symbiotic control of insect vectors.

Innovative blood transfusion strategies to address global blood deserts: a consensus statement from the Blood Delivery via Emerging Strategies for Emergency Remote Transfusion (Blood DESERT) Coalition.

In rural settings worldwide, many people live in effective blood deserts without access to any blood transfusion. The traditional system of blood banking is logistically complex and expensive for many resource-restricted settings and demands innovative and multidisciplinary solutions. 17 international experts in medicine, industry, and policy participated in an exploratory process with a 2-day hybrid seminar centred on three promising innovative strategies for blood transfusions in blood deserts: civilian walking blood banks, intraoperative autotransfusion, and drone-based blood delivery. Participant working groups conducted literature reviews and interviews to develop three white papers focused on the current state and knowledge gaps of each innovation. Seminar discussion focused on defining blood deserts and developing innovation-specific implementation agendas with key research and policy priorities for future work. Moving forward, advocates should prioritise the identification of blood deserts and address the context-specific challenges for these innovations to alleviate the ongoing crisis in blood deserts.

Promoting responsive care and early learning practices in Northern Ghana: results from a counselling intervention within nutrition and health services.

OBJECTIVE: This study assesses change in caregiver practices after integrating responsive care and early learning (RCEL) in nutrition and health services and community platforms in northern Ghana. DESIGN: We trained health facility workers and community health volunteers to deliver RCEL counselling to caregivers of children under 2 years of age through existing health facilities and community groups. We assessed changes in caregivers' RCEL practices before and after the intervention with a household questionnaire and caregiver-child observations. SETTING: The study took place in Sagnarigu, Gushegu, Wa East and Mamprugu-Moagduri districts from April 2022 to March 2023. Study sites included seventy-nine child welfare clinics (CWC) at Ghana Health Service facilities and eighty village savings and loan association (VSLA) groups. PARTICIPANTS: We enrolled 211 adult caregivers in the study sites who had children 0-23 months at baseline and were enrolled in a CWC or a VSLA. RESULTS: We observed improvements in RCEL and infant and young child feeding practices, opportunities for early learning (e.g. access to books and playthings) in the home environment and reductions in parental stress. CONCLUSIONS: This study demonstrates the effectiveness of integrating RCEL content into existing nutrition and health services. The findings can be used to develop, enhance and advocate for policies integrating RCEL into existing services and platforms in Ghana. Future research may explore the relationship between positive changes in caregiver behaviour and improvements in child development outcomes as well as strategies for enhancing paternal engagement in care practices, improving child supervision and ensuring an enabling environment.

Gene-to-gene coordinated regulation of transcription and alternative splicing by 3D chromatin remodeling upon NF-κB activation.

The NF-κB protein p65/RelA plays a pivotal role in coordinating gene expression in response to diverse stimuli, including viral infections. At the chromatin level, p65/RelA regulates gene transcription and alternative splicing through promoter enrichment and genomic exon occupancy, respectively. The intricate ways in which p65/RelA simultaneously governs these functions across various genes remain to be fully elucidated. In this study, we employed the HTLV-1 Tax oncoprotein, a potent activator of NF-κB, to investigate its influence on the three-dimensional organization of the genome, a key factor in gene regulation. We discovered that Tax restructures the 3D genomic landscape, bringing together genes based on their regulation and splicing patterns. Notably, we found that the Tax-induced gene-gene contact between the two master genes NFKBIA and RELA is associated with their respective changes in gene expression and alternative splicing. Through dCas9-mediated approaches, we demonstrated that NFKBIA-RELA interaction is required for alternative splicing regulation and is caused by an intragenic enrichment of p65/RelA on RELA. Our findings shed light on new regulatory mechanisms upon HTLV-1 Tax and underscore the integral role of p65/RelA in coordinated regulation of NF-κB-responsive genes at both transcriptional and splicing levels in the context of the 3D genome.

The NF-κB pathway is essential for coordinating gene expression in response to various stimuli, including viral infections. Most studies have focused on the role of NF-κB in transcriptional regulation. In the present study, the impact of the potent NF-κB activator HTLV-1 Tax oncoprotein on the three-dimensional organization of the genome was investigated. Tax-mediated NF-κB activation was found to restructure the 3D genomic landscape in cells and to bring genes together in multigene complexes that are coordinately regulated either transcriptionally or through alternative splicing by NF-κB. Induced coordinate changes in transcription and alternative splicing included the two master genes of NF-κB pathway NFKBIA and RELA. The findings have significant implications for understanding cell fate determination and disease development associated with HTLV-1 infection, as well as chronic NF-κB activation in various human inflammatory diseases and cancer.

Diverse novel Wolbachia bacteria strains and genera-specific co-infections with Asaia bacteria in Culicine mosquitoes from ecologically diverse regions of Cameroon.

Background: The endosymbiotic bacterium Wolbachia infects numerous species of insects and Wolbachia transinfection of Aedes mosquito species is now being used for biocontrol programs as Wolbachia strains can both inhibit arboviruses and invade wild mosquito populations. The discovery of novel, resident Wolbachia strains in mosquito species warrants further investigation as potential candidate strains for biocontrol strategies. Methods: We obtained mosquito specimens from diverse Culicine mosquitoes from Cameroon including ecologically diverse locations in the Central and West Regions. Wolbachia prevalence rates were assessed in addition to the environmentally acquired bacterial species Asaia in major Culicine genera. PCR-based methods were also used with phylogenetic analysis to confirm identities of host mosquito species and Wolbachia strains were classified using multi-locus sequence typing (MLST). Results: We report high Wolbachia prevalence rates for Culicine species, including in a large cohort of Aedes africanus collected from west Cameroon in which 100% of mono-specific pools were infected. Furthermore, co-infections with Asaia bacteria were observed across multiple genera, demonstrating that these two bacteria can co-exist in wild mosquito populations.  Wolbachia strain MLST and phylogenetic analysis provided evidence for diverse Wolbachia strains in 13 different mosquito species across seven different genera.  Full or partial MLST profiles were generated from resident Wolbachia strains in six Culex species ( quinquefasciatus, watti, cinerus, nigripalpus, perexiguus and rima), two Aedes species (africanus and denderensis) and in Mansonia uniformis, Catageiomyia argenteopunctata, Lutzia tigripes, Eretmapodites chrysogaster and Uranotaenia bilineata. Conclusions: Our study provides further evidence that Wolbachia is widespread within wild mosquito populations of diverse Culicine species and provides further candidate strains that could be investigated as future options for Wolbachia-based biocontrol to inhibit arbovirus transmission.

Assessment of the impact of the biological larvicide VectoMax G: Combination of Bacillus thuringiensis and Lysinibacillus sphaericus on non-target aquatic organisms in Yaoundé-Cameroon.

There has been a renewed interest for larviciding during the recent decade. Although biological larvicides are considered not to be harmful to non-target organisms, there is still not sufficient data on the effect of new long-lasting larvicide formulations such as VectoMax G combining Bacillus thuringiensis israelensis and Lysinibacullus sphaericus on the environment especially on non-target organisms. The present study aimed to assess the possible influence of VectoMax G on the diversity and abundance of the aquatic fauna cohabiting with mosquito larvae in breeding habitats during a larviciding trial in the city of Yaoundé. Twelve districts of the city of Yaoundé divided into 6 intervention and 6 control sites were chosen for the study. In each district 4 semi-permanent or permanent aquatic habitats were followed. VectoMax G application was done once every two weeks during 6 months and aquatic organisms were collected 48 h after each treatment. All collected organisms were brought to the laboratory for identification. Physico-chemical parameters were recorded as well. A high diversity of the zooplankton was recorded in the intervention areas with 28 species collected against 14 species in the control areas. Cladocerans were the most represented group in both sites while Ostracods were found only in control sites. A total of 19 macro-invertebrates species were recorded in the control areas vs 16 species in the intervention areas. Gasteropods were the most represented groups of macro-invertebrates. Vertebrates such as larvivorous fishes and amphibians larvae were also found in approximately similar densities in both sites. The study indicated no significant influence of larviciding with VectoMax G on the diversity and abundance of the non-target aquatic fauna in the city of Yaoundé.

A homozygous mutation in the human selenocysteine tRNA gene impairs UGA recoding activity and selenoproteome regulation by selenium.

The selenocysteine (Sec) tRNA (tRNA[Ser]Sec) governs Sec insertion into selenoproteins by the recoding of a UGA codon, typically used as a stop codon. A homozygous point mutation (C65G) in the human tRNA[Ser]Sec acceptor arm has been reported by two independent groups and was associated with symptoms such as thyroid dysfunction and low blood selenium levels; however, the extent of altered selenoprotein synthesis resulting from this mutation has yet to be comprehensively investigated. In this study, we used CRISPR/Cas9 technology to engineer homozygous and heterozygous mutant human cells, which we then compared with the parental cell lines. This C65G mutation affected many aspects of tRNA[Ser]Sec integrity and activity. Firstly, the expression level of tRNA[Ser]Sec was significantly reduced due to an altered recruitment of RNA polymerase III at the promoter. Secondly, selenoprotein expression was strongly altered, but, more surprisingly, it was no longer sensitive to selenium supplementation. Mass spectrometry analyses revealed a tRNA isoform with unmodified wobble nucleotide U34 in mutant cells that correlated with reduced UGA recoding activities. Overall, this study demonstrates the pleiotropic effect of a single C65G mutation on both tRNA phenotype and selenoproteome expression.

The Cascade of Care for Hepatitis C Treatment in Rwanda: A Retrospective Cohort Study of the 2017-2019 Mass Screening and Treatment Campaign.

Access to hepatitis C (HCV) testing and treatment is still limited globally. To address this, the Government of Rwanda launched a voluntary mass screening and treatment campaign in 2017. We studied the progression of patients through the cascade of HCV care during this campaign. We conducted a retrospective cohort study and included all patients screened at 46 hospitals between April 2017 and October 2019. We used hierarchical logistic regression to assess factors associated with HCV positivity, gaps in care, and treatment failure. A total of 860,801 people attended the mass screening during the study period. Some 5.7% tested positive for anti-HCV, and 2.9% were confirmed positive. Of those who were confirmed positive, 52% initiated treatment, and 72% of those initiated treatment, completed treatment and returned for assessment 12 weeks afterward. The cure rate was 88%. HCV positivity was associated with age, socio-economic status, sex, marital status, and HIV coinfection. Treatment failure was associated with cirrhosis, baseline viral load, and a family history of HCV. Our results suggest that future HCV screening and testing interventions in Rwanda and other similar settings should target high-risk groups. High dropout rates suggest that more effort should be put into patient follow-up to increase adherence to care.

High prevalence of asymptomatic Plasmodium falciparum malaria in Makenene, a locality in the forest-savannah transition zone, Centre Region of Cameroon.

Malaria transmission and prevalence is still not well documented across Cameroon particularly in medium-sized cities or localities representing high transit zone. Different risk factors could be associated with persistence malaria transmission such as population movement from high to low transmission settings. A cross-sectional community-based study was carried out to determine malaria prevalence and risk factors in Makenene, a small city in a forest-savannah which is a crossroads between different parts of the country where travellers usually stop-over day and night to rest. Using malaria diagnostic test (mRDTs from SD-BIOLINE) and microscopy (thin and thick blood smears), 406 participants from 237 households were tested for malaria infection. The prevalence of malaria was high irrespective of the detection method: mRDT (41.87%) or microscopy (38.42%). At household level, 46.41% of households had at least one case of malaria with an average of 1.41 infected individuals per household. Parasite density was also high with the majority of infected individuals (64.74%) bearing more than 500 parasites/µl. Only Plasmodium falciparum was found. The chances of being infected with malaria parasites was almost the same for all participants irrespective of the sleeping behavior, bednet usage, house type and environmental factors. The study supports high malaria transmission in the locality and the need for additional studies on vectors bionomics and transmission patterns.

Aedes Mosquito Surveillance Using Ovitraps, Sweep Nets, and Biogent Traps in the City of Yaoundé, Cameroon.

Arbovirus diseases represent a significant public health problem in Cameroon and vector surveillance is a key component of prevention strategies. However, there is still not enough evidence of the efficacy of different sampling methods used to monitor Aedes mosquito population dynamic in different epidemiological settings. The present study provides data on the evaluation of ovitraps and different adult sampling methods in the city of Yaoundé and its close vicinity. Entomological surveys were carried out from February 2020 to March 2021 in two urban (Obili, Mvan), two peri-urban (Simbock, Ahala), and two rural (Lendom, Elig-essomballa) sites in the city of Yaoundé. The efficacy of three sampling methods, namely ovitraps, Biogent Sentinel trap, and sweep nets, was evaluated. Different ovitrap indices were used to assess the infestation levels across study sites; a general linear model was used to determine if there are statistical differences between positive ovitraps across ecological zones. A total of 16,264 Aedes mosquitoes were collected during entomological surveys. Ovitraps provided the highest mosquito abundance (15,323; 91.14%) and the highest species diversity. Of the five Aedes species collected, Aedes albopictus (59.74%) was the most commonly recorded in both urban and rural settings. Different Aedes species were collected in the same ovitrap. The ovitrap positivity index was high in all sites and varied from 58.3% in Obili in the urban area to 86.08% in Lendom in the rural area. The egg density index varied from 6.42 in Mvan (urban site) to 13.70 in Lendom (rural area). Adult sampling methods recorded mostly Aedes albopictus. The present study supports high infestation of Aedes species in the city of Yaoundé. Ovitraps were highly efficient in detecting Aedes distribution across study sites. The situation calls for regular surveillance and control of Aedes population to prevent sudden occurrence of outbreaks.

Population knowledge, attitudes and practices towards malaria prevention in the locality of Makenene, Centre-Cameroon.

BACKGROUND: To contribute to the mission of the National Malaria Control Programme (NMCP) and guide future interventions in Cameroon in general, and in Makenene in particular, this study assessed the knowledge, attitudes and practices of the population of Makenene towards the fight against malaria. METHODS: Using a semi-structured questionnaire, a descriptive cross-sectional household community survey was carried out in randomly selected households in Makenene, a locality situated between forest and savannah ecotypes. RESULTS: Out of the 413 households surveyed, all (100%) claimed to have heard of malaria with over 94% (n = 391) associating disease transmission with mosquito bites. The main mosquito control tools used in the area were mosquito nets (92.25%). The majority of participants had good knowledge (55.93%; n = 231), good practices (71.67%, n = 296) but moderate attitudes (47.94%; n = 198) towards malaria control and fight. Good knowledge and practices were recorded mostly in educated persons including public servants and students. Good attitudes were adopted mostly by public servants and students of secondary and higher levels of education. CONCLUSION: In Makenene, the population exhibits good knowledge and practices towards malaria and its control. However, despite high LLINs ownership and use, people still complain about malaria in the area. Control tools should be monitored, repaired or replaced when necessary to support the achievement of the NMCP mission.

Epidemiology of sexually transmitted infections: trends among patients screened for sexually transmitted infections in rwandan health facilities 2014-2020.

BACKGROUND: Sexually Transmitted Infections (STIs) are of great global health concern. Currently, there are limited epidemiological data characterizing STIs in the general population in Rwanda. We assessed the national and regional epidemiology of STIs in Rwanda from 2014-2020 among patients syndromically screened for STIs in all health facilities in Rwanda. METHODS: This is a retrospective analysis of the trend of STIs epidemiology among screened patients at all health facilities in Rwanda using data from the Health Management Information System (HMIS) reporting. Adult patients (15 years and over) screened for STIs between July 2014 and June 2020 were included in the analysis. Outcomes of interest were the number of individuals screened for STIs and individuals diagnosed with at least one STI with a syndromic approach only or plus a test together. RESULTS: Overall, the number of individuals screened for STIs over the study period was 5.3 million (M) in 2014-2015, 6.6 M in 2015-2016, 6.3 M in 2016-2017, 6.7 M in 2017-2018, 6.2 M in 2018-2019, and 4.9 M in 2019-2020. There was a modest increase in the number of individuals diagnosed and treated for STIs from 139,357 in 2014-15 to 202,294 (45% increase) in 2019-2020. At the national level, the prevalence of STI syndromes amongst individuals screened at health facilities in Rwanda varied between 2.37% to 4.16% during the study period. Among the provinces, Kigali city had the highest prevalence for the whole 6 years ranging from 3.46% (95%CI: 3.41, 3.51) in 2014-2015 to 8.23% (95%CI: 8.15, 8.31) in 2019-2020. CONCLUSION: From 2014 to 2020, the number of patients screened for STI syndromes in Rwanda varied between 4.9 M and 6.7 M. However, the prevalence of STIs among screened patients increased considerably over time, which could be associated with public awareness and improved data recording. The highest prevalence of all STIs was observed in urban areas and near borders, and private clinics reported more cases, suggesting the need to improve awareness in these settings and increase confidentiality and trust in public health clinics.

Impact of COVID-19 pandemic on HCV care cascade in Rwanda: Ecological study from July 2019 to June 2021.

Content available: Author Interview and Audio Recording.

Efficacy of Trapping Methods in the Collection of Eretmapodites (Diptera: Culicidae) Mosquitoes in an Afrotropical Rainforest Region, South western Cameroon.

Very little data exist on the biology of an afrotropical rainforest mosquito Eretmapodites (Er.) in a world undergoing dramatic changes due to deforestation. The aim was to assess the efficacy of different trapping methods in the collection of Er. mosquito in forested area. This was a longitudinal study involving collection of mosquitoes for over two years. Multiple collection methods (grouped into two categories), were used; i) net baited and un-baited traps to collect adults, ii) techniques that target immature stages subsequently reared to adults. All males were identified by genitalia dissection. Five thousand seven hundred and four mosquitoes representing 11 genera among which 2,334 Er. were identified. Mosquito abundance was highest in the net traps (n = 1276 (56.4%)) and sweep nets (n = 393(17.4%)) respectively. The abundance was highest in green colored net traps (435(34.09%)) with significant value of χ2= 40.000, P < 0.001 and in pigeons baited traps (473 (37.06%)) with significant value of χ2= 42.000, P = 0.003. The diversity ranges from H' = 2.65; DS = 0.84; SR = 24; ACE = 24.77 in sweep net to H' = 0; DS = 0; SR = 1; ACE = 1 in rock pool among males mosquitoes. While for females, H = 1.14; DS = 0.71; SR = 5; ACE = 5.16, in sweep net to H = 0; DS = 0; SR = 1; ACE = 1 in rock pool, tarpaulin, resting cage. Net traps, bamboo pot, and sweep netting are efficient in collecting high abundance of forest mosquitoes in the Talanagaye rainforest.

Effect of unmanned aerial vehicle (drone) delivery on blood product delivery time and wastage in Rwanda: a retrospective, cross-sectional study and time series analysis.

BACKGROUND: The accessibility of blood and blood products remains challenging in many countries because of the complex supply chain of short lifetime products, timely access, and demand fluctuation at the hospital level. In an effort to improve availability and delivery times, Rwanda launched the use of drones to deliver blood products to remote health facilities. We evaluated the effect of this intervention on blood product delivery times and wastage. METHODS: We studied data from 20 health facilities between Jan 1, 2015, and Dec 31, 2019, in Rwanda. First, we did a cross-sectional comparison of data on emergency delivery times from the drone operator collected between March 17, 2017, and Dec 31, 2019, with two sources of estimated driving times (Regional Centre for Blood Transfusion estimates and Google Maps). Second, we used interrupted time series analysis and monthly administrative data to assess changes in blood product expirations after the commencement of drone deliveries. FINDINGS: Between March 17, 2017, and Dec 31, 2019, 12 733 blood product orders were delivered by drones. 5517 (43%) of 12 733 were emergency orders. The mean drone delivery time was 49·6 min (95% CI 49·1 to 50·2), which was 79 min faster than existing road delivery methods based on estimated driving times (p<0·0001) and 98 min faster based on Google Maps estimates (p<0·0001). The decrease in mean delivery time ranged from 3 min to 211 min depending on the distance to the facility and road quality. We also found a decrease of 7·1 blood unit expirations per month after the start of drone delivery (95% CI -11·8 to -2·4), which translated to a 67% reduction at 12 months. INTERPRETATION: We found that drone delivery led to faster delivery times and less blood component wastage in health facilities. Future studies should investigate if these improvements are cost-effective, and whether drone delivery might be effective for other pharmaceutical and health supplies that cannot be easily stored at remote facilities. FUNDING: Canadian Institutes for Health Research.

Wolbachia Detection in Field-Collected Mosquitoes from Cameroon.

Wolbachia spp., known to be maternally inherited intracellular bacteria, are widespread among arthropods, including mosquitoes. Our study assessed the presence and prevalence of Wolbachia infection in wild mosquitoes collected in Cameroon, using the combination of 23s rRNA Anaplasmatacea and 16s rRNA Wolbachia genes. Mosquitoes that were positive for Wolbachia were sequenced for subsequent phylogenetic analysis. Out of a total of 1740 individual mosquitoes belonging to 22 species and five genera screened, 33 mosquitoes (1.87%) belonging to eight species (namely, Aedes albopictus, A. contigus, Culex quinquefasciatus, C. perfuscus, C. wigglesworthi, C. duttoni, Anopheles paludis and Coquillettidia sp.) were found to be positive for Wolbachia infections. Wolbachia spp. were absent in A. gambiae and A. aegypti, the main vectors of malaria and dengue, respectively. Phylogenetic analysis of the 16S RNA sequences showed they belong mainly to two distinct subgroups (A and B). This study reports the presence of Wolbachia in about eight species of mosquitoes in Cameroon and suggests that future characterisation of the strains is needed.

An update on the mosquito fauna and mosquito-borne diseases distribution in Cameroon.

The expansion of mosquito-borne diseases such as dengue, yellow fever, and chikungunya in the past 15 years has ignited the need for active surveillance of common and neglected mosquito-borne infectious diseases. The surveillance should be designed to detect diseases and to provide relevant field-based data for developing and implementing effective control measures to prevent outbreaks before significant public health consequences can occur. Mosquitoes are important vectors of human and animal pathogens, and knowledge on their biodiversity and distribution in the Afrotropical region is needed for the development of evidence-based vector control strategies. Following a comprehensive literature search, an inventory of the diversity and distribution of mosquitoes as well as the different mosquito-borne diseases found in Cameroon was made. A total of 290 publications/reports and the mosquito catalogue website were consulted for the review. To date, about 307 species, four subspecies and one putative new species of Culicidae, comprising 60 species and one putative new species of Anopheles, 67 species and two subspecies of Culex, 77 species and one subspecies of Aedes, 31 species and one subspecies of Eretmapodites, two Mansonia, eight Coquillettidia, and 62 species with unknown medical and veterinary importance (Toxorhynchites, Uranotaenia, Mimomyia, Malaya, Hodgesia, Ficalbia, Orthopodomyia, Aedeomyia, and Culiseta and Lutzia) have been collected in Cameroon. Multiple mosquito species implicated in the transmission of pathogens within Anopheles, Culex, Aedes, Eretmapodites, Mansonia, and Coquillettidia have been reported in Cameroon. Furthermore, the presence of 26 human and zoonotic arboviral diseases, one helminthic disease, and two protozoal diseases has been reported. Information on the bionomics, taxonomy, and distribution of mosquito species will be useful for the development of integrated vector management programmes for the surveillance and elimination of mosquito-borne diseases in Cameroon.

Aedes Mosquito Distribution along a Transect from Rural to Urban Settings in Yaoundé, Cameroon.

INTRODUCTION: The surveillance of mosquito vectors is important for the control of arboviruses diseases worldwide. Detailed information on the bionomics and distribution of their main vectors, Aedes aegypti and Aedes albopictus, is essential for assessing disease transmission risk and for better planning of control interventions. METHODS: Entomological surveys were carried out from November 2019 to November 2020 in six localities of Yaoundé city following a transect from urban to rural settings: two urban (Obili, Mvan), two peri-urban (Simbock, Ahala) and two rural areas (Lendom, Elig-essomballa)-during rainy and dry seasons. All water containers were inspected. Aedes mosquito abundance, species distribution and seasonal distribution patterns were compared using generalized linear models. Stegomyia indexes were estimated to determine the risk of arbovirus transmission. RESULTS: A total of 6332 mosquitoes larvae were collected (2342 in urban areas, 1694 in peri-urban areas and 2296 in rural sites). Aedes species recorded included Ae. albopictus, Ae. aegytpi, Ae. simpsoni and Aedes spp. High mosquito abundance was registered in the rainy season (4706) compared to the dry season (1626) (p < 0.0001). Ae. albopictus was the most abundant Aedes species in urban (96.89%) and peri-urban (95.09%) sites whereas Ae. aegypti was more prevalent in rural sites (68.56%) (p < 0.0001). Both species were found together in 71 larval habitats. Ae. albopictus was mostly found in discarded tires (42.51%), whereas Ae. aegypti was more prevalent in plastic containers used for storing water (65.87%). The majority of Aedes mosquitoes' breeding places were situated close to human dwellings (0-10 m). CONCLUSION: Uncontrolled urbanization seems to greatly favour the presence of Aedes mosquito species around human dwellings in Yaoundé. Controlling Aedes mosquito distribution is becoming urgent to reduce the risk of arbovirus outbreaks in the city of Yaoundé.