Reemergence of Sylvatic Dengue Virus Serotype 2 in Kedougou, Senegal, 2020.

In 2020, a sylvatic dengue virus serotype 2 infection outbreak resulted in 59 confirmed dengue cases in Kedougou, Senegal, suggesting those strains might not require adaptation to reemerge into urban transmission cycles. Large-scale genomic surveillance and updated molecular diagnostic tools are needed to effectively prevent dengue virus infections in Senegal.

Serosurvey of Chikungunya Virus in Old World Fruit Bats, Senegal, 2020-2022.

We conducted a cross-sectional serosurvey for chikungunya virus (CHIKV) exposure in fruit bats in Senegal during 2020-2023. We found that 13.3% (89/671) of bats had CHIKV IgG; highest prevalence was in Eidolon helvum (18.3%, 15/82) and Epomophorus gambianus (13.7%, 63/461) bats. Our results suggest these bats are naturally exposed to CHIKV.

Case Management of Imported Crimean-Congo Hemorrhagic Fever, Senegal, July 2023.

We report an imported Crimean-Congo hemorrhagic fever case in Senegal. The patient received PCR confirmation of virus infection 10 days after symptom onset. We identified 46 patient contacts in Senegal; 87.7% were healthcare professionals. Strengthening border crossing and community surveillance systems can help reduce the risks of infectious disease transmission.

Real-Time Enterovirus D68 Outbreak Detection through Hospital Surveillance of Severe Acute Respiratory Infection, Senegal, 2023.

In December 2023, we observed through hospital-based surveillance a severe outbreak of enterovirus D68 infection in pediatric inpatients in Dakar, Senegal. Molecular characterization revealed that subclade B3, the dominant lineage in outbreaks worldwide, was responsible for the outbreak. Enhanced surveillance in inpatient settings, including among patients with neurologic illnesses, is needed.

Investigating linkage to care following community-based screening for hepatitis B virus in rural Senegal: A mixed methods study.

This paper investigates linkage to care following community-based screening for hepatitis B virus (HBV) in rural Senegal. HBV-positive participants who completed a biological and clinical examination to assess liver disease and treatment eligibility were referred to a regional hospital (if eligible for treatment), invited to join the Sen-B research cohort study (adults with detectable viral load) or referred to their local health centre (all others). Logistic regressions were conducted to investigate factors associated with (i) uptake of the scheduled post-screening examination, and (ii) HBV management initiation. Obstacles to HBV management were identified using thematic analysis of in-depth patient interviews. Of the 206 HBV-positive participants, 163 (79.1%) underwent the examination; 47 of the 163 (28.8%) initiated HBV management. Women, people not migrating for >6 months/year, individuals living in households with more agricultural and monetary resources, with other HBV-positive participants, and beneficiaries of the national cash transfer program, were all more likely to undergo the examination. The likelihood of joining the Sen-B cohort increased with household monetary resources, but decreased with agricultural resources. Initiation of HBV management in local health centre was higher among participants with a non-agricultural economic activity. Individuals reported wariness and confusion about HBV management content and rationale at various stages of the care continuum, in particular with respect to venous blood sampling and management without treatment. In conclusion, HBV community-based test-and-treat strategies are feasible, but early loss to follow-up must be addressed through simplified, affordable management and community support and sensitization.

Evidence of Plasmodium vivax circulation in western and eastern regions of Senegal: implications for malaria control.

BACKGROUND: Malaria elimination in Senegal requires accurate diagnosis of all Plasmodium species. Plasmodium falciparum is the most prevalent species in Senegal, although Plasmodium malariae, Plasmodium ovale, and recently Plasmodium vivax have also been reported. Nonetheless, most malaria control tools, such as Histidine Rich Protein 2 rapid diagnosis test (PfHRP2-RDT,) can only diagnose P. falciparum. Thus, PfHRP2-RDT misses non-falciparum species and P. falciparum infections that fall below the limit of detection. These limitations can be addressed using highly sensitive Next Generation Sequencing (NGS). This study assesses the burden of the four different Plasmodium species in western and eastern regions of Senegal using targeted PCR amplicon sequencing. METHODS: Three thousand samples from symptomatic and asymptomatic individuals in 2021 from three sites in Senegal (Sessene, Diourbel region; Parcelles Assainies, Kaolack region; Gabou, Tambacounda region) were collected. All samples were tested using PfHRP2-RDT and photoinduced electron transfer polymerase chain reaction (PET-PCR), which detects all Plasmodium species. Targeted sequencing of the nuclear 18S rRNA and the mitochondrial cytochrome B genes was performed on PET-PCR positive samples. RESULTS: Malaria prevalence by PfHRP2-RDT showed 9.4% (94/1000) and 0.2% (2/1000) in Diourbel (DBL) and Kaolack (KL), respectively. In Tambacounda (TAM) patients who had malaria symptoms and had a negative PfHRP2-RDT were enrolled. The PET-PCR had a positivity rate of 23.5% (295/1255) overall. The PET-PCR positivity rate was 37.6%, 12.3%, and 22.8% in Diourbel, Kaolack, and Tambacounda, respectively. Successful sequencing of 121/295 positive samples detected P. falciparum (93%), P. vivax (2.6%), P. malariae (4.4%), and P. ovale wallikeri (0.9%). Plasmodium vivax was co-identified with P. falciparum in thirteen samples. Sequencing also detected two PfHRP2-RDT-negative mono-infections of P. vivax in Tambacounda and Kaolack. CONCLUSION: The findings demonstrate the circulation of P. vivax in western and eastern Senegal, highlighting the need for improved malaria control strategies and accurate diagnostic tools to better understand the prevalence of non-falciparum species countrywide.

Implementing long-acting injectable antiretroviral treatments in Senegal: issues, challenges and conditions for introducing them. Qualitative study with healthcare providers and patients.

Long-acting injectable antiretroviral therapy (LAI-ART) can offer people living with HIV (PLWH) a promising alternative to daily oral therapy. This article highlights the issues, challenges and conditions related to introducing LAI-ART into the social lives of PLWH and HIV-care practices in Senegal. Semi-structured interviews were conducted with 42 PLWH in two hospital care units in Dakar and with 13 healthcare providers and 6 peer educators. Interviews were transcribed, thematically coded and analysed using a cross-sectional approach. We found three key issues. First, simplifying living with HIV: PLWH respondents perceive LAI-ART as an opportunity to ease the burden associated with taking tablets. This enthusiasm may however be qualified by an ambivalent relationship with injections and is subject to certain conditions. Second, certain constraints linked to the medicalisation of care are to be anticipated, including the obligation to go to the hospital every two months for injections. These findings foreshadow the new management work for medical follow-up expected to fall on PLWH and caregivers. Third, the challenges of introducing LAI-ART in Senegal are to ensure adequate organisation of care and supply and sustainability of the program. These results clarify how to implement programs to introduce LAI-ART into real life in the West African context.

Prevalence and associated factors of schistosomiasis among pregnant women in northern Senegal.

BACKGROUND: Schistosomiasis remains a public health concern worldwide. It is responsible for more than 240 million cases in 78 countries, 40 million of whom are women of childbearing age. In the Senegal River basin, both Schistosoma haematobium and Schistosoma mansoni are very prevalent in school-age children. However, there is a lack of information on the burden of schistosomiasis in pregnant women, which can cause complications in the pregnancy outcome. This study aimed to determine the prevalence and associated factors of schistosomiasis in pregnant women. METHODS: We conducted a prospective cross-sectional study of pregnant women attending antenatal clinics at the health center of the Senegalese Sugar Company and at the hospital of Richard Toll between August and December 2021. The urine and stool samples collected were examined using microscopy techniques and quantitative polymerase chain reaction (qPCR) to detect the presence of S. haematobium and S. mansoni. The urines were previously tested using urine reagent strips to detect hematuria and proteinuria. Socio-demographical, clinical, and diagnostically data were recorded by the midwife and the gynaecologist. The data were analyzed using a logistic regression model. RESULTS: Among the 298 women examined for the infection by microscopic, 65 (21.81%) were infected with urogenital schistosomiasis, 10 (3.36%) with intestinal schistosomiasis, and 4 (1.34%) were co-infected with both types of schistosomiasis. Out of the 288 samples tested by qPCR, 146 (48.99%) were positive for S. haematobium, 49 (35.51%) for S. mansoni and 22 (15.94%) for both species (co-infection). Pregnant women having microscopic haematuria and proteinuria were significantly more infected (p < 0.05). CONCLUSION: This study has revealed a high prevalence of schistosomiasis in pregnant women in Senegal. The qPCR allowed us to detect more cases compared to the microscopy. There is a need to conduct more studies to understand the real burden of the disease and to set up a surveillance system to prevent pregnancy-related complications.

Spatial and Socioeconomic Inequalities in Cesarean Section Deliveries in Urban Settings in Dakar, Senegal.

As part of an initiative aimed at reducing maternal and child mortality, Senegal implemented a policy of free Cesarean section (C-section) since 2005. Despite the implementation, C-section rates have remained low and significant large disparities in access, particularly in major cities such as Dakar. This paper aims to assess C-section rates and examines socioeconomic inequalities in C-section use in the Dakar region between 2005 and 2019. This study incorporates data from various sources, including the health routine data within District Health Information Software 2 (DHIS2) platform, government statistics on slum areas, and data from Demographic and Health Surveys (DHS). A geospatial analysis was conducted to identify locations of Comprehensive emergency obstetric and Newborn Care (CEmONC) services using the Direction des Travaux Géographiques et Cartographiques (DTGC) databases and satellite imagery from the Google Earth platform. The analytical approach encompassed univariate, bivariate, and multivariate analyses. The C-section rate fluctuated over the years, increasing from 11.1% in 2005 to 16.4% in 2011, declined to 9.8% in 2014, and then raised to 13.3% in 2019. The wealth tertile demonstrated a positive correlation with C-sections in urban areas of the Dakar region. Geospatial analyses revealed that women residing in slum areas were less likely to undergo C-section deliveries. These findings underscore the importance of public health policies extending beyond merely providing free C-section delivery services. Strategies that improve equitable access to C-section delivery services for women across all socioeconomic strata are needed, particularly targeting the poor women and those in urban slums.

Advancing access to care: An assessment of the prehospital system in Senegal.

BACKGROUND: Most low- and middle-income countries do not have a mature prehospital system limiting access to definitive care. This study sought to describe the current state of the prehospital system in Senegal and offer recommendations aimed at improving system capacity and population access to definitive care. METHODS: Structured interviews were conducted with key informants in various regions throughout the country using qualitative and quantitative techniques. A standardized questionnaire was generated using needs assessment forms and system frameworks. Descriptive statistics were performed for quantitative data analysis, and qualitative data was consolidated and presented using ATLAS.ti. RESULTS: Two (20%) of the studied regions, Dakar and Saint-Louis, had a mature prehospital system in place, including dispatch centers and teams of trained personnel utilizing equipped ambulances. 80% of the studied regions lacked an established prehospital system. The vast majority of the population relied on the fire department for transport to a healthcare facility. The ambulances in rural regions were not part of a formal prehospital system, were not equipped with life-support supplies, and were limited to inter-facility transfers. CONCLUSIONS: While Dakar and Saint-Louis have mature prehospital systems, the rest of the country is served by the fire department. There are significant opportunities to further strengthen the prehospital system in rural Senegal by training the fire department in basic life support and first aid, maintaining cost efficiency, and building on existing national resources. This has the potential to significantly improve access to definitive care and outcomes of emergent illness in the Senegalese community.

A typology of social network interactions in sub-Saharan Africa: Evidence from a rural population in Senegal.

Social isolation/marginalization in sub-Saharan Africa is under-researched, despite increasing evidence of weakening traditional community-based social support. This paper aims to develop a typology of social networks capable of accounting for social marginalization in a rural community in Western Senegal and to describe the socio-demographic characteristics of network profiles. Building on prior qualitative work, we carry out a latent profile analysis using a unique and extensive social network data set, identifying four different network profiles: Locally integrated, Constrained relationships, Locally marginalized, and Local elites. This paper provides the first empirically supported classification of social integration and marginalization in social networks in rural sub-Saharan Africa. In doing so, it can serve as a reference for future research seeking to understand both the broader scope of social integration and marginalization and the consequences of differential access to social capital through social networks on access to health resources and well-being.

[Epidemiological and anatomopathological profile of endometriosis in Dakar: retrospective study over a period of 20 years]. / Aspects épidémiologique et anatomopathologique des endométrioses à Dakar : étude rétrospective sur une période de 20 ans.

INTRODUCTION: Endometriosis is a gynecological pathology defined by the presence and abnormal development of endometrial tissue outside the uterine cavity. Our objective was to draw up an epidemiological profile and to describe the anatomical clinical forms of endometriosis in Dakar. PATIENTS AND METHODS: This is a retrospective study of all cases of external and internal endometriosis diagnosed in an anatomy and pathology laboratory in Dakar over a period of twenty (20) years. The study parameters were collected from anonymous data sheets. Data entry and analysis were performed using version 22 of the EPI INFO and SPSS software. RESULTS: Our study involved 104 female patients. The mean age was 47.3±10.0. Among the patients with an adenomyosis condition, the mean age was 49.8 years. Patients with an external endometriosis condition had a mean age of 37.6 years. The location of the endometriosis was statistically correlated with the age of patients and with parity. Anatomically and pathologically, the surgical specimen 89.4% (n=93) was the main type of sampling that was found. The uterine body was the main location of the pathology, with 78.9% (n=82), followed by the umbilical location with 9.6% (n=10). Leiomyomas 44.07% (n=26) were the main associated lesions. CONCLUSION: Endometriosis is a gynecological pathology that is unfortunately not well known, and which is under diagnosed in Senegal.

Three-arm clinical trial of improved flour targeting intestinal microbiota (MALINEA).

The main objective of this project was to compare in the field conditions two strategies of re-nutrition of children with moderate acute malnutrition (MAM) aged from 6 to 24 months, targeting the microbiota in comparison with a standard regimen. A three-arm, open-label, pragmatic randomised trial was conducted in four countries (Niger, CAR, Senegal and Madagascar). Children received for 12 weeks either fortified blended flour (FBF control) = arm 1, or FBF + azithromycin (oral suspension of 20 mg/kg/day daily given with a syringe) for the first 3 days at inclusion = arm 2 or mix FBF with inulin/fructo-oligosaccharides (6 g/day if age ≥12 months and 4 g if age <12 months) = arm 3. For each arm, children aged from 6 to 11 months received 100 g x 2 per day of flours and those aged from 12 to 24 months received 100 g × 3 per day of FBF. The primary endpoint was nutritional recovery, defined by reaching a weight-for-height z-score (WHZ) ≥ -1.5 within 12 weeks. Overall, 881 children were randomised (297, 290 and 294 in arm 1, arm 2 and arm 3, respectively). Three hundred and forty-four children were males (39%) and median/mean age were 14.6/14.4 months (SD = 4.9, IQR = 10.5-18.4). At inclusion, the three arms were comparable for all criteria, but differences were observed between countries. Overall, 44% (390/881) of the children recovered at week 12 from MAM, with no significant difference between the three arms (41.4%, 45.5% and 45.9%, in arm 1, arm 2 and arm 3, respectively, p = 0.47). This study did not support the true advantages of adding a prebiotic or antibiotic to flour. When using a threshold of WHZ ≥ -2 as an exploratory endpoint, significant differences were observed between the three arms, with higher success rates in arms with antibiotics or prebiotics compared to the control arm (66.9%, 66.0% and 55.2%, respectively, p = 0.005).

Development and validation of a tool to assess underlying factors of iron-rich food consumption among pregnant women.

Anaemia among pregnant women remains a public health concern globally. One major cause of this persistent problem is iron deficiency, which may be the result of limited iron intake in the diet. Using the extended version of the theory of planned behaviour (eTPB), this study aims to develop and validate a questionnaire assessing psychosocial and environmental factors that could influence the consumption of iron-rich foods (IRFs) among Senegalese pregnant women. A three-step procedure was used. Six focus group discussions (FGDs) were held with 10 pregnant women each from a different region to identify salient beliefs related to each of the four constructs of the eTPB using a structured guide. Information from FGDs was used to develop a questionnaire, which was administered to the first group (n = 200) of pregnant women. Principal component analyses and exploratory factorial analyses were performed on the first set of data to identify latent factors for each construct namely the attitude, subjective norm and perceived behavioural control. A revised and shorter version of the questionnaire was administered to a second sample of pregnant women (n = 226) and confirmatory factorial analyses were conducted using this second set of data. Hancock and Muller's H reliability index was computed on the final model. The final questionnaire included 44 items. Most criteria for fit indices were met and H values were satisfactory. This study proposes a tool that could be used to explore determinants of the consumption of IRF among pregnant women. Further validation is still warranted in other contexts.

New Genotype of Coxiella burnetii Causing Epizootic Q Fever Outbreak in Rodents, Northern Senegal.

In Senegal, Coxiella burnetii, which causes Q fever, has often been identified in ticks and humans near livestock, which are considered to be reservoirs and main sources of infection. We describe the emergence of C. burnetii in rodents, not previously known to carry this pathogen, and describe 2 new genotypes.

Shifting Patterns of Influenza Circulation during the COVID-19 Pandemic, Senegal.

Historically low levels of seasonal influenza circulation were reported during the first years of the COVID-19 pandemic and were mainly attributed to implementation of nonpharmaceutical interventions. In tropical regions, influenza's seasonality differs largely, and data on this topic are scarce. We analyzed data from Senegal's sentinel syndromic surveillance network before and after the start of the COVID-19 pandemic to assess changes in influenza circulation. We found that influenza shows year-round circulation in Senegal and has 2 distinct epidemic peaks: during January-March and during the rainy season in August-October. During 2021-2022, the expected January-March influenza peak completely disappeared, corresponding to periods of active SARS-CoV-2 circulation. We noted an unexpected influenza epidemic peak during May-July 2022. The observed reciprocal circulation of SARS-CoV-2 and influenza suggests that factors such as viral interference might be at play and should be further investigated in tropical settings.

Molecular characterization of circulating Dengue virus 2 during an outbreak in Northern Senegal's Saint-Louis region in 2018.

Globally, 390 million people are at risk of dengue infection and over the past 50 years, the virus incidence increased thirty-fold. In Senegal, an unprecedented occurrence of outbreaks and sporadic cases have been noticed since 2017. In October 2018, an outbreak of Dengue virus 2 (DENV-2) was reported in the north of Senegal affecting multiple areas including Saint-Louis, Richard Toll, and Rosso which are located at the border with Mauritania. Of these 173 blood specimen samples collected from patients, 27 were positive for dengue by quantitative reverse transcription PCR (qRT-PCR), and eight were serologically confirmed to be positive for DENV immunoglobulin M (IgM). Serotyping using qRT-PCR reveals that isolates were positive for DENV-2. A subset of DENV-2 positive samples was selected and subjected to whole-genome sequencing followed by phylogenetic analysis. Analysis of six nearly complete genome sequences revealed that the isolates belong to the cosmopolitan genotype and are closely related to the Mauritanian strains detected between 2017 and 2018 and those detected in many West African countries such as Burkina Faso or Cote d'Ivoire. Our results suggest a transboundary circulation of the DENV-2 cosmopolitan genotype between Senegal and Mauritania and call for a need for coordinated surveillance of arboviruses between these two countries. Interestingly, a high level of homology between West African isolates highlights endemicity and calls for the set-up of subregional viral genomic surveillance which will lead to a better understanding of viral dynamics, transmission, and spread across Africa.

Exclusive Breastfeeding Measured by Deuterium-Oxide Turnover Method is Associated with Motor Development in Rural Senegalese Infants.

BACKGROUND: The findings on the relationship between breastfeeding and children's motor development are very poor, particularly in low and middle income countries, because of the use of inadequate measures of breastfeeding practices. OBJECTIVES: To assess the relationship between exclusive breastfeeding, measured by the deuterium-oxide turnover method (DTM), and the acquisition of motor development in a cohort of Senegalese children. METHODS: One hundred forty mother-infant (4-5 mo) pairs were recruited and monitored up to 18 mo. Breast milk intake and breastfeeding practices were measured by DTM. Six stages of motor development were assessed: "sitting without support," "hands-and-knees crawling," "standing with assistance," "walking with assistance," "standing alone," and "walking alone." Acquisition age of motor milestones between exclusively breastfed (EBF) and not exclusively breastfed (non-EBF) infants was compared using Student's and Wilcoxon's tests. Mixed linear regression, adjusted with confounding factors, was used to determine the association between EBF and motor development. RESULTS: Overall, 32.9% of infants were EBF at the enrollment at 4-5 mo of age. Breast milk intake of EBF infants was significantly higher than that of non-EBF infants (1039 ± 193 g/d compared with 915 ± 211 g/d; P < 0.01). At 4-5 mo of age, only "sitting without support" (67.4% compared with 47.9%, P = 0.02) and "hands-and-knees crawling" (17.4% compared with 4.3%, P = 0.01) were completed significantly in the EBF group. At 18 mo, all children had completed all 6 motor developmental milestones. However, their acquisition age was significantly earlier in the EBF group after adjustment. Non-EBF infants had a delay of 0.4 to 0.5 mo on the acquisition of the first 5 stages compared to EBF infants. For "walking alone," no difference was found after adjustment. CONCLUSIONS: Motor skill acquisition is earlier in EBF infants compared to non-EBF infants. This finding highlights the need to strengthen the advocacy for EBF up to 6 mo.

Design, development and usability of an educational AI chatbot for People with Haemophilia in Senegal.

INTRODUCTION: Gaps in the disease knowledge of People with Haemophilia (PWH) in Senegal are important barriers to the effective management of haemophilia. Digital health systems for chronic diseases in low- and middle-income countries are suggested to improve education and self-management. Artificial Intelligence (AI) chatbots could improve knowledge and support symptom monitoring. AIM: Development process and usability testing of an AI chatbot to assess its future adoption in Senegal. METHODS: An AI chatbot prototype was designed based on a multilingual conversational engine using Natural Language Processing. A sequential mixed method was used including a co-creative design process with a task force made up of PWH and medical doctors. Usability was assessed through the System Usability Scale (SUS) questionnaire. RESULTS: An AI chatbot in French and Wolof, named Saytù Hemophilie, was developed for Android and Apple iOS devices. It was assessed as a very usable system with a SUS score of 81.7, above average. 42% would prefer to use the Wolof version even if they were very satisfied with the French version. The level of Wolof in the app did not always correspond to users' levels. Participants praised its accessibility and reliability, and its ability to enhance self-learning. CONCLUSIONS: Findings suggest that a culturally adapted digital conversational agent is likely to be used by PWH in Senegal and their families to improve education and self-management of haemophilia. Relevance and impact are foreseen for other communities in Africa and beyond.

Bartonella raoultii sp. nov., isolated from infected rodents (Mastomys erythroleucus) in Senegal.

Bartonella species are involved in various human diseases, causing a range of clinical manifestations; animals are considered as the main reservoirs, transmitting diverse species of Bartonella through direct contact and haematophagous insects. Here, we characterize a new species, Bartonella raoultii sp. nov., within the genus Bartonella, using a taxonogenomic polyphasic approach. Strain 094T (= CSUR B1097T=DSM 28004T), isolated from the blood of an infected rodent (Mastomys erythroleucus) in Senegal, is an aerobic and rod-shaped bacterium. The annotated non-contiguous genome sequence is 1 952322 bp long and contains 37.2 mol% G+C content, 1686 protein-coding genes and 50 RNA genes, including seven rRNA genes.