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.

[Water, sanitation and diarrheal risk in Nouakchott Urban Community, Mauritania]. / Eau potable, assainissement et risque de maladies diarrhéiques dans la Communauté Urbaine de Nouakchott, Mauritanie.

INTRODUCTION: Drinking water and sanitation are two factors of inter-linked inextricably public health especially in the city of Nouakchott where the low availability of these services leads to a multitude of use and hygiene practices involving a complex socio-ecological system with an increased risk of waterborne diseases transmission (diarrhea, cholera, etc.). METHODS: Thus, this contribution analyzes the impact of socio-ecological system on the development of diarrheal diseases by using socio-environmental and epidemiological data from various sources (national surveys and registries consultation). RESULTS: Overall, the results show that only 25.6% of households have access to drinking water sources while 69.8% of the populations dispose improved latrines. Hence, the weakness in environmental sanitation conditions explains the level of diarrheal morbidity averring 12.8% at the urban level, with an unequal spatial distribution showing less affected communes such as Tevragh Zeina (9.1%) and municipalities more affected like Sebkha (19.1%). The distribution according to the age categories shows that children under 5 years are the most affected with 51.7% followed by people aged over 14 with 34.2%. The correlation analysis between socio-economic, environmental and epidemiological variables reveals a number of significant associations: untreated water consumption and diarrhea (R = 0.429); collection of wastewater and occurrence of diarrhea ; existence of improved latrine and reduction of diarrheal risk (R = 0.402). DISCUSSION: Therefore, exposure to diarrheal diseases through the prism of water and sanitation is a real public health problem that requires a systemic and integrated approach to improving environmental health.

Heat waves and health risks in the northern part of Senegal: analysing the distribution of temperature-related diseases and associated risk factors.

The Sahelian zone of Senegal experienced heat waves in the previous decades, such as 2013, 2016 and 2018 that were characterised by temperatures exceeding 45°C for up to 3 successive days. The health impacts of these heat waves are not yet analysed in Senegal although their negative effects have been shown in many countries. This study analyses the health impacts of observed extreme temperatures in the Sahelian zone of the country, focusing on morbidity and mortality by combining data from station observation, climate model projections, and household survey to investigate heat wave detection, occurrence of climate-sensitive diseases and risk factors for exposure. To do this, a set of climatic (temperatures) and health (morbidity, mortality) data were collected for the months of April, May and June from 2009 to 2019. These data have been completed with 1246 households' surveys on risk factor exposure. Statistical methods were used to carry out univariate and bivariate analyses while cartographic techniques allowed mapping of the main climatic and health indicators. The results show an increase in temperatures compared to seasonal normal for the 1971-2000 reference period with threshold exceedances of the 90th percentiles (42°C) for the maxima and (27°C) the minima and higher temperatures during the months of May and June. From health perspective, it was noted an increase in cases of consultation in health facilities as well as a rise in declared morbidity by households especially in the departments of Kanel (17.7%), Ranérou (16.1 %), Matam (13.7%) and Bakel (13.7%). The heat waves of May 2013 were also associated with cases of death with a reported mortality (observed by medical staff) of 12.4% unequally distributed according to the departments with a higher number of deaths in Matam (25, 2%) and in Bakel (23.5%) than in Podor (8.4%) and Kanel (0.8%). The morbidity and mortality distribution according to gender shows that women (57%) were more affected than men (43%). These health risks have been associated with a number of factors including age, access to drinkable water, type of fuel, type of housing and construction materials, existence of fan and an air conditioner, and health history.The heat wave recurrence has led to a frequency in certain diseases sensitive to rising temperatures, which is increasingly a public health issue in the Sahelian zone of Senegal.

[Health care utilization in Nouakchott (Mauritania): spatial inequalities or social sluggishness?]. / Recours aux soins et utilisation des services de santé à Nouakchott (Mauritanie) : inégalités spatiales ou pesanteurs sociales ?

In African cities where environmental, social and economic problems facilitate the development of urban pathology, inadequate or ineffective health facilities raise the question of access to quality care, especially for slum dwellers. The city of Nouakchott marked by a multifaceted urban crisis is an illustration of this troubling situation. To analyse the spatial organisation and functioning of the healthcare system by assessing the use of health services, we studied this utilisation in August 2004 in three areas of the city by a cross-sectional survey of 836 households. The results show that therapeutic itineraries are as diverse as health care provision is varied. About 50.8 % of those seeking health care reported using modern services (public health clinics, private clinics, private doctors or nurses) for the most common diseases (acute respiratory infection and diarrhea) in their community, but this rate varied significantly by disease, social category and neighborhood. Thus, this mediocre level of utilisation of public health clinics is due to the poor quality of care provided. Moreover, healthcare services are often used only in case of severe or worsening illness, with signs (e.g., cough and persistent fever, or weight loss) seen to suggest more serious diseases, such as tuberculosis, meningitis or severe malaria. Geographic accessibility of health services was relatively good (70 %). It was the economic, socio-cultural, organizational and functional factors that appeared to determine the choice to use modern health care. The slackening of socio-cultural and organizational constraints and adaptation to economic ones should help to improve health policies and foster a functioning healthcare system.

Knowledge and practices of mothers and caregivers on diarrhoeal management among under 5-year-old children in a medium-size town of Senegal.

In 2016, about one out of 10 children in sub-Saharan Africa died due to diarrhoea, causing an estimated burden of 25 million disability-adjusted life years. A prominent cause of death is dehydration linked to lack of knowledge and adequate management of diarrhoeal episodes. This study assessed knowledge and practices of mothers and caregivers on diarrhoeal management among under 5-year-old children in a medium-size town of Senegal. A cross-sectional survey was carried out between September and October 2016 in four zones of Mbour, located in the south-western part of Senegal. Mothers and caregivers of children under the age of 5 years were interviewed to determine their levels of knowledge and management practice of diarrhoea. The association between diarrhoea and source of care was determined using logistic regression analyses. In total, 367 mothers and caregivers who reported a diarrhoeal episode in at least one of their children under 5 years of age were included. Slightly less than a quarter (23.2%, 95% confidence interval (CI) 18.9-27.8%) of respondents had good management practice of diarrhoea, while 40.0% (95% CI: 34.5-45.6%) had high level of knowledge about diarrhoea. Mothers and caregivers having sought care from public health facilities had two and four times higher odds of good knowledge and good management practices of diarrhoea, respectively, compared to those seeking no care outside the home or from traditional healers. The weakness regarding knowledge and quality management practice, particularly the poor use of internationally recommended treatment of childhood diarrhoea among mothers and caregivers, confirms the low coverage of oral rehydration salt and zinc and lack of sensitization about diarrhoea. We conclude that diarrhoea management practices in this part of Senegal do not correspond with international recommendations, even when mothers and caregivers visit government health facilities. There is a need to develop and implement communication strategies for health care providers' and the mothers and caregivers in order to facilitate sustainable positive change in the management of childhood diarrhoea at the community level. Moreover, mothers, caregivers and health care providers need specific training on the current guidelines for diarrhoea management.

No barrier breakdown between human and cattle schistosome species in the Senegal River Basin in the face of hybridisation.

Schistosomiasis is widely distributed along the Senegal River Basin (SRB), affecting both the human population and their livestock. Damming of the Senegal River for irrigation purposes in the 1980s induced ecological changes that resulted in a large outbreak of Schistosoma mansoni, followed a few years later by an increase and spread of Schistosoma haematobium infections. The presence of hybrid crosses between the human and cattle schistosomes, S. haematobium and Schistosoma bovis, respectively, is adding complexity to the disease epidemiology in this area, and questions the strength of the species boundary between these two species. This study aimed to investigate the epidemiology of S. haematobium, S. bovis and their hybrids along the Senegal River basin using both microsatellite genetic markers and analysis of mitochondrial and nuclear DNA markers. Human schistosome populations with a S. haematobium cox1 mtDNA profile and those with a S. bovis cox1 mtDNA profile (the so-called hybrids) appear to belong to a single randomly mating population, strongly differentiated from the pure S. bovis found in cattle. These results suggest that, in northern Senegal, a strong species boundary persists between human and cattle schistosome species and there is no prolific admixing of the populations. In addition, we found that in the SRB S. haematobium was spatially more differentiated in comparison to S. mansoni. This may be related either to the presence and susceptibility of the intermediate snail hosts, or to the colonisation history of the parasite.

Risk factors for schistosomiasis in an urban area in northern Côte d'Ivoire.

BACKGROUND: Schistosomiasis is a water-based disease transmitted by trematodes belonging to the genus Schistosoma. The aim of this study was to assess the relationship between the prevalence of schistosomiasis and access to water, sanitation and hygiene (WASH) and environmental and socioeconomic factors in the city of Korhogo, northern Côte d'Ivoire. METHODS: A cross-sectional study including 728 randomly selected households was conducted in Korhogo in March 2015. The heads of the households were interviewed about access to WASH and environmental and socioeconomic factors. All children abed between 5 and 15 years living in the households were selected to provide stool and urine samples for parasitological diagnosis of Schistosoma mansoni and Schistosoma haematobium infection. The relationship between infection with S. mansoni and potential risk factors was analysed by a mixed logistic regression model with 'household' as a random factor. Likelihood ratio tests were used to identify factors that were significantly associated with a Schistosoma spp. infection. RESULTS: The overall prevalence of schistosomiasis among school-aged children in Korhogo was 1.9% (45/2341) composed of 0.3% (3/1248) S. haematobium and 3.5% (42/1202) S. mansoni. Due to the low prevalence of S. haematobium infection, risk factor analysis was limited to S. mansoni. Boys were 7.8 times more likely to be infected with S. mansoni than girls. Children between 10 and 15 years of age were 3.8 times more likely to be infected than their younger counterparts aged 5-10 years. Moreover, living in a house further away from a water access point (odds ratio [OR] = 0.29, 95% confidence interval [CI]: 0.13-0.70) and abstaining from swimming in open freshwater bodies (OR = 0.16, 95% CI: 0.04-0.56) were significantly associated with decreased odds of S. mansoni infection. The socioeconomic status did not appear to influence the prevalence of S. mansoni. CONCLUSIONS: A strategy to reduce the incidence of schistosomiasis should focus on health education to change the behaviour of populations at risk and encourage communities to improve sanitation and infrastructure in order to reduce contact with surface water.

Impact of climate variability on the transmission risk of malaria in northern Côte d'Ivoire.

Since the 1970s, the northern part of Côte d'Ivoire has experienced considerable fluctuation in its meteorology including a general decrease of rainfall and increase of temperature from 1970 to 2000, a slight increase of rainfall since 2000, a severe drought in 2004-2005 and flooding in 2006-2007. Such changing climate patterns might affect the transmission of malaria. The purpose of this study was to analyze climate and environmental parameters associated with malaria transmission in Korhogo, a city in northern Côte d'Ivoire. All data were collected over a 10-year period (2004-2013). Rainfall, temperature and Normalized Difference Vegetation Index (NDVI) were the climate and environmental variables considered. Association between these variables and clinical malaria data was determined, using negative binomial regression models. From 2004 to 2013, there was an increase in the annual average precipitation (1100.3-1376.5 mm) and the average temperature (27.2°C-27.5°C). The NDVI decreased from 0.42 to 0.40. We observed a strong seasonality in these climatic variables, which resembled the seasonality in clinical malaria. An incremental increase of 10 mm of monthly precipitation was, on average, associated with a 1% (95% Confidence interval (CI): 0.7 to 1.2%) and a 1.2% (95% CI: 0.9 to 1.5%) increase in the number of clinical malaria episodes one and two months later respectively. A 1°C increase in average monthly temperature was, on average, associated with a decline of a 3.5% (95% CI: 0.1 to 6.7%) in clinical malaria episodes. A 0.1 unit increase in monthly NDVI was associated with a 7.3% (95% CI: 0.8 to 14.1%) increase in the monthly malaria count. There was a similar increase for the preceding-month lag (6.7% (95% CI: 2.3% to 11.2%)). The study results can be used to establish a malaria early warning system in Korhogo to prepare for outbreaks of malaria, which would increase community resilience no matter the magnitude and pattern of climate change.

Urbanisation and its effect on risk factors associated with childhood diarrhoea in Mbour, Senegal: A visualisation.

Rapid urbanisation, particularly in secondary cities in Africa, brings along specific challenges for global health, including the prevention and control of infectious diseases such as diarrhoea. Our purpose was to visualise urbanisation trends and its effect on risk factors associated with childhood diarrhoea, e.g. water supply, sanitation, wastewater and solid waste management in Mbour, a secondary city in south-western Senegal. Our visualisation is facilitated by epidemiological and geographical surveys carried out in 2016. A deeper spatial and visual understanding of the urbanisation trends and the disparities of diarrhoea-associated risk factors might lead to the implementation of suitable health interventions and preventive measures. Our visualisation is aimed to serve as a basis for discussion and as a decision support tool for policymakers, municipal officials and local communities to prioritise interventions related to water, sanitation and waste management with a view to reduce the environmental and health risks in the rapidly growing city of Mbour, which is set as an example for other similar secondary cities across low- and middle-income countries in Africa.

Prevalence of diarrhoea and risk factors among children under five years old in Mbour, Senegal: a cross-sectional study.

BACKGROUND: Diarrhoeal diseases remain an important cause of mortality and morbidity among children, particularly in low- and middle-income countries. In Senegal, diarrhoea is responsible for 15% of all deaths in children under the age of five and is the third leading cause of childhood deaths. For targeted planning and implementation of prevention strategies, a context-specific understanding of the determinants of diarrhoeal diseases is needed. The aim of this study was to identify risk factors of diarrhoeal diseases in children under the age of five in Mbour, Senegal. METHODS: Between February and March 2014, a cross-sectional survey was conducted in four zones of Mbour to estimate the burden of diarrhoeal diseases (i.e. diarrhoea episodes in the 2 weeks preceding the survey) and associated risk factors. The zones covered urban central, peri-central, north peripheral and south peripheral areas. Overall, 596 households were surveyed by a questionnaire, yielding information on sociodemographic, environmental and hygiene behavioural factors. Univariable and multivariable logistic regression analyses were used to identify risk factors associated with the occurrence of diarrhoea. RESULTS: The reported prevalence of diarrhoea among children under the age of five during the 2 weeks preceding the survey was 26%. Without adjustment, the highest diarrhoea prevalence rates were observed in the peri-central (44.8%) and urban central zones (36.3%). Multivariable regression revealed significant associations between diarrhoeal diseases and unemployment of mothers (adjusted odds ratio [aOR] = 1.62, 95% confidence interval [CI]: 1.18-2.23), use of open bags for storing household waste (aOR = 1.75, 95% CI: 1.00-3.02), evacuation of household waste in public streets (aOR = 2.07, 95% CI: 1.20-3.55), no treatment of stored drinking water (aOR = 1.69, 95% CI: 1.11-2.56) and use of shared toilets (aOR = 1.69, 95% CI: 1.11-2.56). CONCLUSION: We found a high prevalence of diarrhoea in children under the age of five in Mbour, with the highest prevalence occurring in the central and peri-central areas. These findings underscore the need for public health interventions to alleviate the burden of diarrhoea among vulnerable groups. Promotion of solid waste disposal and reduction of wastewater exposure should be implemented without delay.

Association between Childhood Diarrhoeal Incidence and Climatic Factors in Urban and Rural Settings in the Health District of Mbour, Senegal.

We assessed the association between childhood diarrhoeal incidence and climatic factors in rural and urban settings in the health district of Mbour in western Senegal. We used monthly diarrhoeal case records among children under five years registered in 24 health facilities over a four-year period (2011-2014). Climatic data (i.e., daily temperature, night temperature and rainfall) for the same four-year period were obtained. We performed a negative binomial regression model to establish the relationship between monthly diarrhoeal incidence and climatic factors of the same and the previous month. There were two annual peaks in diarrhoeal incidence: one during the cold dry season and one during the rainy season. We observed a positive association between diarrhoeal incidence and high average temperature of 36 °C and above and high cumulative monthly rainfall at 57 mm and above. The association between diarrhoeal incidence and temperature was stronger in rural compared to urban settings, while higher rainfall was associated with higher diarrhoeal incidence in the urban settings. Concluding, this study identified significant health-climate interactions and calls for effective preventive measures in the health district of Mbour. Particular attention should be paid to urban settings where diarrhoea was most common in order to reduce the high incidence in the context of climatic variability, which is expected to increase in urban areas in the face of global warming.

Comparison of Malaria Simulations Driven by Meteorological Observations and Reanalysis Products in Senegal.

The analysis of the spatial and temporal variability of climate parameters is crucial to study the impact of climate-sensitive vector-borne diseases such as malaria. The use of malaria models is an alternative way of producing potential malaria historical data for Senegal due to the lack of reliable observations for malaria outbreaks over a long time period. Consequently, here we use the Liverpool Malaria Model (LMM), driven by different climatic datasets, in order to study and validate simulated malaria parameters over Senegal. The findings confirm that the risk of malaria transmission is mainly linked to climate variables such as rainfall and temperature as well as specific landscape characteristics. For the whole of Senegal, a lag of two months is generally observed between the peak of rainfall in August and the maximum number of reported malaria cases in October. The malaria transmission season usually takes place from September to November, corresponding to the second peak of temperature occurring in October. Observed malaria data from the Programme National de Lutte contre le Paludisme (PNLP, National Malaria control Programme in Senegal) and outputs from the meteorological data used in this study were compared. The malaria model outputs present some consistencies with observed malaria dynamics over Senegal, and further allow the exploration of simulations performed with reanalysis data sets over a longer time period. The simulated malaria risk significantly decreased during the 1970s and 1980s over Senegal. This result is consistent with the observed decrease of malaria vectors and malaria cases reported by field entomologists and clinicians in the literature. The main differences between model outputs and observations regard amplitude, but can be related not only to reanalysis deficiencies but also to other environmental and socio-economic factors that are not included in this mechanistic malaria model framework. The present study can be considered as a validation of the reliability of reanalysis to be used as inputs for the calculation of malaria parameters in the Sahel using dynamical malaria models.

Reconstructing Colonization Dynamics of the Human Parasite Schistosoma mansoni following Anthropogenic Environmental Changes in Northwest Senegal.

BACKGROUND: Anthropogenic environmental changes may lead to ecosystem destabilization and the unintentional colonization of new habitats by parasite populations. A remarkable example is the outbreak of intestinal schistosomiasis in Northwest Senegal following the construction of two dams in the '80s. While many studies have investigated the epidemiological, immunological and geographical patterns of Schistosoma mansoni infections in this region, little is known about its colonization history. METHODOLOGY/PRINCIPAL FINDINGS: Parasites were collected at several time points after the disease outbreak and genotyped using a 420 bp fragment of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) and nine nuclear DNA microsatellite markers. Phylogeographic and population genetic analyses revealed the presence of (i) many genetically different haplotypes at the non-recombining mitochondrial marker and (ii) one homogenous S. mansoni genetic group at the recombining microsatellite markers. These results suggest that the S. mansoni population in Northwest Senegal was triggered by intraspecific hybridization (i.e. admixture) between parasites that were introduced from different regions. This would comply with the extensive immigration of infected seasonal agricultural workers from neighboring regions in Senegal, Mauritania and Mali. The spatial and temporal stability of the established S. mansoni population suggests a swift local adaptation of the parasite to the local intermediate snail host Biomphalaria pfeifferi at the onset of the epidemic. CONCLUSIONS/SIGNIFICANCE: Our results show that S. mansoni parasites are very successful in colonizing new areas without significant loss of genetic diversity. Maintaining high levels of diversity guarantees the adaptive potential of these parasites to cope with selective pressures such as drug treatment, which might complicate efforts to control the disease.

Water quality and health in a Sahelian semi-arid urban context: an integrated geographical approach in Nouakchott, Mauritania.

Access to sufficient quantities of safe drinking water is a human right. Moreover, access to clean water is of public health relevance, particularly in semi-arid and Sahelian cities due to the risks of water contamination and transmission of water-borne diseases. We conducted a study in Nouakchott, the capital of Mauritania, to deepen the understanding of diarrhoeal incidence in space and time. We used an integrated geographical approach, combining socio-environmental, microbiological and epidemiological data from various sources, including spatially explicit surveys, laboratory analysis of water samples and reported diarrhoeal episodes. A geospatial technique was applied to determine the environmental and microbiological risk factors that govern diarrhoeal transmission. Statistical and cartographic analyses revealed concentration of unimproved sources of drinking water in the most densely populated areas of the city, coupled with a daily water allocation below the recommended standard of 20 l per person. Bacteriological analysis indicated that 93% of the non-piped water sources supplied at water points were contaminated with 10-80 coliform bacteria per 100 ml. Diarrhoea was the second most important disease reported at health centres, accounting for 12.8% of health care service consultations on average. Diarrhoeal episodes were concentrated in municipalities with the largest number of contaminated water sources. Environmental factors (e.g. lack of improved water sources) and bacteriological aspects (e.g. water contamination with coliform bacteria) are the main drivers explaining the spatio-temporal distribution of diarrhoea. We conclude that integrating environmental, microbiological and epidemiological variables with statistical regression models facilitates risk profiling of diarrhoeal diseases. Modes of water supply and water contamination were the main drivers of diarrhoea in this semi-arid urban context of Nouakchott, and hence require a strategy to improve water quality at the various levels of the supply chain.

Absence of dry season Plasmodium parasitaemia, but high rates of reported acute respiratory infection and diarrhoea in preschool-aged children in Kaédi, southern Mauritania.

BACKGROUND: The epidemiology of malaria in the Senegal River Gorgol valley, southern Mauritania, requires particular attention in the face of ongoing and predicted environmental and climate changes. While "malaria cases" are reported in health facilities throughout the year, past and current climatic and ecological conditions do not favour transmission in the dry season (lack of rainfall and very high temperatures). Moreover, entomological investigations in neighbouring regions point to an absence of malaria transmission in mosquito vectors in the dry season. Because the clinical signs of malaria are non-specific and overlap with those of other diseases (e.g. acute respiratory infections and diarrhoea), new research is needed to better understand malaria transmission patterns in this region to improve adaptive, preventive and curative measures. METHODS: We conducted a multipurpose cross-sectional survey in the city of Kaédi in April 2011 (dry season), assessing three major disease patterns, including malaria. Plasmodium spp. parasite rates were tested among children aged 6-59 months who were recruited from a random selection of households using a rapid diagnostic test and microscopic examination of Giemsa-stained thick and thin blood films. Acute respiratory infection and diarrhoea were the two other diseases investigated, administering a parental questionnaire to determine the reported prevalence among participating children. FINDINGS: No Plasmodium infection was found in any of the 371 surveyed preschool-aged children using two different diagnostic methods. Acute respiratory infections and diarrhoea were reported in 43.4% and 35.0% of the participants, respectively. About two thirds of the children with acute respiratory infections and diarrhoea required medical follow-up by a health worker. CONCLUSIONS: Malaria was absent in the present dry season survey in the capital of the Gorgol valley of Mauritania, while acute respiratory infections and diarrhea were highly prevalent. Surveys should be repeated towards the end of rainy season, which will enhance our understanding of the potential changes in malaria transmission in a region known as 'hot spot' of predicted climate change.