Refugee women's and providers' perceptions of person-centered maternity care: a qualitative study in two refugee camps in Chad.

BACKGROUND: Globally, mistreatment of women during labor and delivery is a common human rights violation. Person-centered maternity care (PCMC), a critical component of quality of care, is respectful and responsive to an individual's needs and preferences. Factors related to poor PCMC are often exacerbated in humanitarian settings. METHODS: We conducted a qualitative study to understand Sudanese refugee women's experiences, including their perceptions of quality of care, during labor and delivery at the maternities in two refugee camps in eastern Chad, as well as maternity health workers' perceptions of PCMC and how they could be better supported to provide this. In-depth interviews were conducted individually with 22 women who delivered in the camp maternities and five trained midwives working in the two maternities; and in six dyads with a total of 11 Sudanese refugee traditional birth attendants and one assistant midwife. In addition, facility assessments were conducted at each maternity to determine their capacity to provide PCMC. RESULTS: Overall, women reported positive experiences in the camp maternities during labor and delivery. Providers overwhelmingly defined respectful care as patient-centered and respect as being something fundamental to their role as health workers. While very few reported incidents of disrespect between providers and patients in the maternity, resource constraints, including overwork of the providers and overcrowding, resulted in some women feeling neglected. CONCLUSIONS: Despite providers' commitment to offering person-centered care and women's generally positive experiences in this study, one of few that explored PCMC in a refugee camp, conflict and displacement exacerbates the conditions that contribute to mistreatment during labor and delivery. Good PCMC requires organizational emphasis and support, including adequate working conditions and ensuring suitable resources so health workers can effectively perform.

Community-based symptom reporting among agro-pastoralists and their livestock in Chad in a One Health approach.

One Health Syndromic Surveillance has a high potential for detecting early epidemiological events in remote and hard-to-reach populations. Chadian pastoralists living close to their animals and being socio-economically unprivileged have an increased risk for zoonosis exposure. Engaging communities in disease surveillance could also strengthen preparedness capacities for outbreaks in rural Chad. This study describes a retrospective cross-sectional survey that collected data on clinical symptoms reported in people and livestock in Chadian agro-pastoral communities. In January-February 2018, interviews were conducted in rural households living in nomadic camps or settled villages in the Yao and Danamadji health districts. The questionnaire covered demographic data and symptoms reported in humans and animals for the hot, wet, and cold seasons over the last 12 months. Incidence rates of human and animal symptoms were comparatively analyzed at the household level. Ninety-two households with a homogeneous socio-demographic distribution were included. We observed cough and diarrhea as the most frequent symptoms reported simultaneously in humans and animals. In all species, the incidence rate of cough was significantly higher during the cold season, and diarrhea tended to occur more frequently during the wet season. However, the incidence rate of cough and diarrhea in animals did not predict the incidence rate of these symptoms in humans. Overall, the variations in reported symptoms were consistent with known seasonal, regional, and sociological influences on endemic diseases. Our retrospective study demonstrated the feasibility of collecting relevant health data in humans and animals in remote regions with low access to health services by actively involving community members. This encourages establishing real-time community-based syndromic surveillance in areas such as rural Chad.

Malaria infection and predictor factors among Chadian nomads' children.

BACKGROUND: In Chad, malaria remains a significant public health concern, particularly among nomadic populations. Geographical factors and the mobility of human populations have shown to be associated with the diversity of Plasmodium species. The study aims to describe the malaria prevalence among nomadic children and to investigate its associated factors. METHODS: A cross-sectional study was conducted in February and October 2021 among nomadic communities in Chad. Blood sample were collected and tested from 187 Arab, Fulani and Dazagada nomadic children aged 3-59 months using malaria rapid diagnostic test (RDT). A structured electronic questionnaire was administered to their parents to collect information about the socio­economic data. Malaria testing results were categorized according to the SD BIOLINE Malaria Ag Pf/Pan RDT procedures. Logistic regression analysis was used to determine key risk factors explaining the prevalence of malaria. STATA version IC 13 was used for statistical analysis. RESULTS: The overall malaria prevalence in nomadic children was 24.60%, with 65.20% being Plasmodium falciparum species and 34.8% mixed species. Boys were twice as likely (COR = 1.83; 95% CI, 0.92-3.62; p = 0.083) to have malaria than girls. Children whose parents used to seek traditional drugs were five times more likely (AOR = 5.59; 95% CI, 1.40-22.30, p = 0.015) to have malaria than children whose parents used to seek health facilities. Children whose parents reported spending the last night under a mosquito net were one-fifth as likely (AOR = 0.17; 95% CI, 0.03-0.90, p = 0.037) to have malaria compared to children whose parents did not used a mosquito net. Furthermore, Daza children were seventeen times (1/0.06) less likely (AOR = 0.06; 95% CI, 0.01-0.70, p = 0.024) to have malaria than Fulani children and children from households piped water as the main source were seven times more likely (AOR = 7.05; 95% CI, 1.69-29.45; p = 0.007) to have malaria than those using surface water. CONCLUSIONS: Malaria remains a significant public health issue in the nomadic communities of Chad. Community education and sensitization programs within nomad communities are recommended to raise awareness about malaria transmission and control methods, particularly among those living in remote rural areas. The National Malaria Control Program (NMCP) should increase both the coverage and use of long-lasting insecticidal nets (LLINs) and seasonal malaria chemoprevention (SMC) in addition to promoting treatment-seeking behaviors in nomadic communities.

Limited impact of vector control on the population genetic structure of Glossina fuscipes fuscipes from the sleeping sickness focus of Maro, Chad.

Tsetse flies (genus Glossina) transmit deadly trypanosomes to human populations and domestic animals in sub-Saharan Africa. Some foci of Human African Trypanosomiasis due to Trypanosoma brucei gambiense (g-HAT) persist in southern Chad, where a program of tsetse control was implemented against the local vector Glossina fuscipes fuscipes in 2018 in Maro. We analyzed the population genetics of G. f. fuscipes from the Maro focus before control (T0), one year (T1), and 18 months (T2) after the beginning of control efforts. Most flies captured displayed a local genetic profile (local survivors), but a few flies displayed outlier genotypes. Moreover, disturbance of isolation by distance signature (increase of genetic distance with geographic distance) and effective population size estimates, absence of any genetic signature of a bottleneck, and an increase of genetic diversity between T0 and T2 strongly suggest gene flows from various origins, and a limited impact of the vector control efforts on this tsetse population. Continuous control and surveillance of g-HAT transmission is thus recommended in Maro. Particular attention will need to be paid to the border with the Central African Republic, a country where the entomological and epidemiological status of g-HAT is unknown.

Title: Impact limité de la lutte antivectorielle sur la structure des populations de Glossina fuscipes fuscipes dans le foyer de la maladie du sommeil de Maro, Tchad. Abstract: Les mouches tsé-tsé (genre Glossina) transmettent des trypanosomes mortels aux populations humaines ainsi qu'aux animaux domestiques en Afrique sub-saharienne. Certains foyers de la trypanosomiase humaine Africaine due à Trypanosoma brucei gambiense (THA-g) persistent au sud du Tchad, où un programme de lutte antivectorielle a été mis en place contre le vecteur local de la maladie, Glossina fuscipes fuscipes, en particulier à Maro en 2018. Nous avons analysé la structure génétique des populations de G. f. fuscipes de ce foyer à T0 (avant lutte), une année après le début de la lutte (T1), et 18 mois après (T2). La plupart des mouches capturées après le début de la lutte ont montré un profil génétique local (survivants locaux), mais quelques-unes d'entre elles présentaient des génotypes d'individus atypiques. Par ailleurs, la présence de perturbations des signatures d'isolement par la distance (augmentation de la distance génétique avec la distance géographique), l'absence de signature génétique d'un goulot d'étranglement, et un accroissement de la diversité génétique entre T0 et T2 sont des arguments forts en faveur de la recolonisation de la zone par des mouches d'origines variées, tout en témoignant des effets limités de la campagne de lutte dans ce foyer. Ces résultats conduisent à recommander une lutte et une surveillance continues dans le foyer de Maro. Une attention particulière devra par ailleurs être prêtée à l'autre côté de la rive, située côté République Centre Africaine, dont le statut épidémiologique reste inconnu concernant les tsé-tsé et la THA-g.

Assessment of current water, sanitation, and hygiene (WASH) practices in the third and ninth districts of N'Djamena, Chad.

Access to safe drinking water, sanitation, and hygiene in Chad's cities, especially N'Djamena, is a persistent and significant challenge. This study aimed to assess current practices in water, sanitation, and hygiene in N'Djamena's third and ninth districts. We surveyed 395 households, conducted water source identification, and analyzed seven water samples at the National Water Laboratory. Temperature, ammonium, total coliforms, and aerobic flora values exceeded World Health Organization (WHO) guidelines. Ammonium and temperature averaged 0.7 mg/L and 30.1-31.93 °C, respectively. Bacterial contamination (>100 MPN/100 mL) exceeded the WHO's 0 MPN/100 mL guidelines, rendering the water unfit for consumption. Survey results indicate that 78.7% use hand pumps, 21.1% have tap water access, and 0.2% rely on rivers for water. Regarding toilets, 92.8% have traditional models, 2.9% have modern facilities, and 4.3% practice open defecation. 95% dispose of untreated wastewater into nature, with only 5% using septic tanks. For solid waste, 72% use illegal dumpsites, 18% rely on public services, and 10% burn waste. Finally, 95.5% of households wash their hands with clean water and soap after using the toilet. It is crucial to treat drinking water and implement proper hygiene and sanitation measures to safeguard the population's health in the studied area.

A Review on Medicinal and Ethnomedicinal Uses, Biological Features, and Phytochemical Constituents of Sesbania sesban L. Merr., A Nitrogen-Fixing Plant Native to the Republic of Chad.

This study reports on a literature review of the leguminous tree Sesbania sesban (L.) Merr which is found in the N'djamena region, the Republic of Chad. The study focused on S. sesban's medicinal and ethnomedicinal uses, biological features, and phytochemical constituents to assist in future evaluations. A literature review was conducted using academic websites, such as Science Direct and Springer, online international plant databases, and data from national herbaria. S. sesban is a perennial shrub or tree that measures 3-4 m in height. This species is becoming rare in N'djamena but can be found in the rainy season, while in winter, it occurs mainly in ponds (called the Chadian dialect "Bouta") and on the shores of the Chari and Logone rivers. The local inhabitants in Chad use the species as medicine, livestock feed, and fuelwood and for improving soil fertility and repelling desert encroachment. Traditional healers use its leaves to treat breast cancer and edema. S. sesban is an essential species native to the Republic of Chad that needs conservation and valorization. Viewing its importance and rarity in N'djamena , a strategy for replanting the species in gardens, homes, and fields around N'djamena and other regions of Chad is recommended.

Predicting the potential impact of scaling up four pneumonia interventions on under-five pneumonia mortality: A prospective Lives Saved Tool (LiST) analysis for Bangladesh, Chad, and Ethiopia.

Background: Pneumonia remains the leading cause of mortality in under-five children outside the neonatal period. Progress has slowed down in the last decade, necessitating increased efforts to scale up effective pneumonia interventions. Methods: We used the Lives Saved Tool (LiST), a modelling software for child mortality in low- and middle-income settings, to prospectively analyse the potential impact of upscaling pneumonia interventions in Bangladesh, Chad, and Ethiopia from 2023 to 2030. We included Haemophilus influenzae type B (Hib) vaccination, pneumococcal conjugate vaccine (PCV), oral antibiotics, pulse oximetry, and oxygen as pneumonia interventions in our analysis. Outcomes of interest were the number of pneumonia deaths averted, the proportion of deaths averted by intervention, and changes in the under-five mortality rate. Findings: We found that 19 775 lives of children under-five could be saved in Bangladesh, 76 470 in Chad, and 97 343 in Ethiopia by scaling intervention coverages to ≥90% by 2030. Our estimated reductions in pneumonia deaths among children under five range from 44.61% to 57.91% in the respective countries. Increased coverage of oral antibiotics, pulse oximetry, and oxygen show similar effects in all three countries, averting between 18.80% and 23.65% of expected pneumonia deaths. Scaling-up PCV has a prominent effect, especially in Chad, where it could avert 14.04% of expected pneumonia deaths. Under-five mortality could be reduced by 1.42 per 1000 live births in Bangladesh, 22.52 per 1000 live births in Chad, and 5.48 per 1000 live births in Ethiopia. Conclusions: This analysis shows the high impact of upscaling pneumonia interventions. The lack of data regarding coverage indicators is a barrier for further research, policy, and implementation, all requiring increased attention.

Contextual factors for understanding the heterogeneity of outcomes of a policy of exemption from payment for care in Chad / Les facteurs contextuels pour comprendre l'hétérogénéité des résultats d'une politique d'exemption du paiement des soins au Tchad

Chad has one of the highest maternal and infant mortality rates in the world. Efforts to reduce these rates have led to the introduction of fee exemption and community involvement initiatives to further encourage the use of health services. Despite the introduction of these initiatives, inequalities in access to and use of health facilities persist. The aim of this study is to understand why and how the same action, implemented in a quasi-homogeneous way, produced contrasting results in different health centers. A multiple, contrasting case study was used to analyze the outcomes of pediatrics consultations and deliveries in four health centers in the Bénoye and Beinamar districts. Data were collected through individual interviews (n=26) and focus groups (n=22) with women beneficiaries, community health workers, and health care providers. The qualitative software QDA Miner was used to process the data. The study revealed that the organizational and managerial capacities of the providers and community actors would explain the heterogeneity of the results observed. Contextual factors such as the remoteness of services or the impassability and dangerousness of roads accentuated the disparities in the results observed. The results of this study show that human and contextual factors would explain the heterogeneity of the observed effects.

Le Tchad a l'un des taux de mortalité maternelle et infantile les plus élevés au monde. Les efforts visant à réduire ces taux ont conduit à la mise en place d'une politique d'exemption du paiement des soins, associée à l'implication des communautés pour encourager l'utilisation des services. Malgré l'introduction de cette initiative, des inégalités dans l'accès et l'utilisation des établissements de santé persistent. L'objectif de cette étude est de comprendre pourquoi et comment cette politique d'exemption, mise en œuvre de manière quasi homogène, a donné des résultats contrastés dans plusieurs centres de santé. Une étude de cas multiples contrastés a été utilisée pour analyser les résultats des consultations pédiatriques et des accouchements dans quatre centres de santé des districts de Bénoye et Beinamar. Les données ont été recueillies lors des entretiens individuels (n=26) et des groupes de discussion (n=22) auprès des femmes bénéficiaires, des agents de santé communautaire et des prestataires de soins. Le logiciel QDA Miner a été utilisé pour traiter les données. L'étude a révélé que les capacités organisationnelles et managériales des prestataires et des acteurs communautaires expliqueraient l'hétérogénéité des résultats observés. Des facteurs contextuels tels que l'éloignement des services ou l'impraticabilité et la dangerosité des routes ont accentué les disparités des résultats observés. Dans la mise en place des politiques de santé, il est important de tenir compte des facteurs humains et contextuels, car ils participent à l'explication de l'hétérogénéité des effets observés et renforcent la pertinence de ce type d'études.

Epidemiology of group A rotavirus in children under five years of age with gastroenteritis in N'Djamena, Chad.

BACKGROUND: Group A Rotaviruses (RVA) is one of the most common causes of severe diarrhoea in infants and children under 5 years of age. Unlike many countries in the world where RVA surveillance/control is active, in Chad , there is currently no applied RVA immunization program and surveillance strategy. The present study aims to determine the prevalence and associated risk factors of RVA gastroenteritis among children under five years of age in N'Djamena. METHOD: This study comprised two parts: (1) A cross-sectional study carried in four hospitals in N'Djamena between August and November 2019, to determine infection risk factors and evidence of RVA infection among children aged five and below, consulted or hospitalized for diarrhea. An ELISA based RVA VP6 protein detection was used to determine RVA infection prevalence. Infection results and sociodemographic data were statistically analysed to determine RVA infection risk factors. (2) A retrospective study that consisted of analysing the records of stool examinations of the period from January 2016 to December 2018, to determine the prevalence of infectious gastroenteritis among the target population. RESULTS: For the cross-sectional study, RVA infection prevalence was 12.76% (18/141) with males (61.11%) being more affected (sex ratio: 1.57). Children below 12 months were the most affected age group (44.44%) and 44.4% were malnourished. The mean Vesikari score shows that 38.8% of children have a high severity level and 41.1% have a moderate level. For the retrospective study, 2,592 cases of gastroenteritis hospitalization were analysed; 980 out of 2,592 cases (37.81%) of hospitalization due to diarrhoea were due to diarrhoeagenic pathogens including Emtamoeba hystolitica, Gardia lamblia, Trichomonas hominis, Hymenolepis nana, Escherichia coli, Shigella spp, Proteus mirabilis, and Klebsiella oxytoca. Cases of diarrhoea with negative pathogen search were 1,612 cases (62.19%). The diarrhoea peak was observed during the dry seasons, and the age group under 11 months was the most affected was (57.3%). CONCLUSION: This study describes the evidence of RVA infection among diarrhoeic children below five years of age in N'Djamena, thus indicates a serious health burden. Malnourishment younger age was the higher risk factor. Further studies are needed to determine the circulating strains prior to considering introduction of RVA vaccine and setup a routine rotavirus surveillance in Chad.

Presence of neutralizing SARS-CoV-2 antibodies in asymptomatic population of N'Djamena, Chad.

INTRODUCTION: Neutralizing antibodies (NAbs) are an important specific defence against viral infections, as these antibodies bind to specific receptor(s) and block the viral entry. NAbs assessments are therefore useful in determining individual or herd immunity to SARS-CoV-2. This study aims to deepen the investigation by assessing the positivity rate of neutralizing anti-spike antibodies to understand the real protection of the studied population against SARS-CoV-2. METHODS: This study involved 260 plasma samples from a larger cohort of 2,700 asymptomatic volunteer donors, enrolled between August and October 2021 in health facilities of N'Djamena. In this study four different kits and techniques including the pseudotype assay have been used and compared with detect the SARS-CoV-2 antibodies. Pseudotyped vesicular stomatitis virus (VSV), was used both the identify and measure the NAbs that to evaluate the performance of two cheaper and easy to use commercial kits, specific for the detection of receptor-binding domain antibodies (anti-RBD) against the SARS-CoV-2 spike protein. RESULTS: The VSV spike neutralization assay showed that 59.0% (n = 59) samples were positive for NAbs with titers ranging from 1:10 to 1:4800. While 23 out the 41 negative NAbs samples were detected positive using anti-RBD (Abbott) test. Furthermore, a direct and significant strong correlation was found between NAbs and anti-RBD, specifically with Abbott kit. Taken together, the Roche and Abbott methods indicated agreement at the high concentrations of antibodies with the VSV-pseudovirus method. Abbott and Roche indicated a good sensitivity, but the Abbott system test appeared to have better specificity than the Roche test. CONCLUSION: Our findings indicated a high presence of NAbs against SARS-CoV-2 spike protein among asymptomatic individuals in N'Djamena. This could be one of the reasons for the low severity of Covid-19 observed in this area, given the key role of NAbs in blocking SARS-CoV-2 infection.

Assessing the Effects of One-Time Praziquantel Treatment on Urogenital Lesions Detected by Ultrasound in Schistosoma haematobium-Infected Individuals in Chad.

The objective was to determine the impact of a single dose of praziquantel on urogenital lesions caused by Schistosoma haematobium. Ultrasound (US) was performed on three age groups of subjects with a positive test for hematuria, with the first examination performed in November 2017 and a follow-up visit 7 months later. None of the subjects had previously received treatment. The participants were categorized into three distinct age groups: group 1 = 1-15 years, group 2 = 15-30 years, and group 3 = ≥ 30 years. A total of 250 people from these three groups underwent screening: 99 in group 1, 90 in group 2, and 61 in group 3, among whom 131 (52.4%) had at least one detectable lesion of the urogenital tract on US. Follow-up US after 7 months was possible in 60%, 67%, and 77% of the respective groups (with lesions). The anomalies disappeared in 80% of individuals in group 1, 76% of those in group 2, and 65% in group 3. With the exception of calcifications, most visible anomalies had been resolved. The total number of anomalies is low. Severe obstructive uropathy was not detected. We can conclude that single treatment with praziquantel is able to cure visible anomalies, with the exception of calcifications. The low rate of anomalies, compared with levels in the literature, is speculated to be due to undetected death by obstructive uropathy caused by S. haematobium. This requires further investigation.

Impact of COVID-19 Pandemic on the Clinical Follow-Up of Patients Living with HIV in Chad: A Retrospective Monocentric Investigation.

The impact of the coronavirus disease 2019 (COVID-19) pandemic on the clinical follow-up of people living with HIV (PLWH) remains poorly documented in Sahelian Africa. We conducted a monocentric retrospective investigation of the outcomes (loss to follow-up [LTFU], transferred, or dead) among a cohort of PLWH receiving antiretroviral treatment (ART) in N'djamena, Chad (December 2019-December 2022). The incidence of LTFU was found to be higher in 2020 than in 2022 (P > 10-4), with increases of incidence of LTFU in the first trimester of 2020 before identified severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection cases in Chad. The all-cause mortality was low and did not appear to be influenced by SARS-CoV-2 infection waves. Our data reveal a concerning trend of significantly increased LTFU among PLWH receiving ART during the COVID-19 pandemic. Our findings indicate that it is crucial to provide accurate information to ensure the continuity of care for PLWH during a sanitary crisis in Sahelian Africa.

Women's autonomy and fertility in Chad.

Chad's total fertility rate (TFR) is 6.4 children per woman, compared with no more than 5.5 in neighbouring countries: Cameroon and the Central African Republic. Scientific research on the determinants of fertility in Chad should therefore be carried out in order to show decision-makers how they can strengthen their actions in this area. This is the aim of this study, which focuses on the influence of women's autonomy on fertility in Chad. Analyses of data from the Multiple Indicator and Demographic and Health Survey (DHS/MICS) conducted in Chad in 2014/2015 and a qualitative survey conducted in the same country in 2020 show, among other things, that 1) in socio-cultural groups characterised by strong gender inequalities, women's autonomy is positively associated with their desired fertility; 2) in these and other groups characterised by less gender inequality, women's autonomy is negatively associated with their actual fertility, all things being equal; 3) the hypotheses explaining this relationship differ across sociocultural groups: In highly gender- inegalitarian groups, the frequent death of children leads couples in which women have either little or no autonomy to compensate with high fertility, whereas in less gender- inegalitarian groups, the negative association between women's autonomy and fertility is due to late union formation, union dissolution, the fertility-reducing effects of breastfeeding and modern contraception, and other intermediate fertility variables not considered here. These findings highlight both the importance of designing development programmes in Chad that focus on women's empowerment and the need for such programmes to take sufficient account of the socio-cultural contexts in which the populations concerned live.

Au Tchad, l'Indice Synthétique de Fécondité (ISF) est de 6,4 enfants par femme, alors que chez ses voisins, comme le Cameroun et la RCA, il ne dépasse pas 5,5. Il est alors très important de réaliser des recherches scientifiques sur les déterminants de la fécondité dans le premier pays, afin de montrer à ses décideurs comment ils devraient renforcer leurs actions dans ce domaine. La recherche réalisée ici en est un exemple et porte spécifiquement sur l'influence de l'autonomie de la femme sur sa fécondité dans ce pays. Les analyses des données de l'Enquête Démographique et de Santé et à Indicateurs Multiples (EDS/MICS) qui y a été menée en 2014/2015, et de celles de l'enquête qualitative, menée dans le même pays en 2020, ont, entre autres, révélé, ce qui suit : 1) dans les groupes socioculturels très inégalitaires en matière de genre, l'autonomie de la femme est positivement associée à sa fécondité désirée ; 2) dans ces groupes et dans ceux moins inégalitaires, toutes choses égales par ailleurs, l'autonomie de la femme est associée négativement à sa fécondité effective ; 3) les hypothèses d'explication de cette relation varie selon les groupes socioculturels : dans les premiers, les décès fréquents d'enfants entraînent les couples où les femmes ont une autonomie nulle ou faible à les compenser par une fécondité élevée ; dans les derniers, ce sont les entrées tardives en union, les ruptures d'unions, les effets réducteurs d'allaitement et de la contraception moderne et d'autres variables intermédiaires de la fécondité, non prises en compte, qui justifient pourquoi l'autonomie de la femme y est négativement associée à sa fécondité. Les résultats de cette étude témoignent non seulement de la pertinence des programmes de développement focalisés dans ce pays sur l'autonomisation de la femme, mais aussi du fait que pour être efficaces ces programmes devraient prendre suffisamment en compte les contextes dans lesquels vivent les populations concernées.

Investigation of optimized observation periods for estimating a representative home range of free-roaming domestic dogs.

Free-roaming domestic dogs (FRDD), as vectors of zoonotic diseases, are of high relevance for public health. Understanding roaming patterns of dogs can help to design disease control programs and disease transmission simulation models. Studies on GPS tracking of dogs report stark differences in recording periods. So far, there is no accepted number of days required to capture a representative home range (HR) of FRDD. The objective of this study was to evaluate changes in HR size and shape over time of FRDD living in Chad, Guatemala, Indonesia and Uganda and identify the period required to capture stable HR values. Dogs were collared with GPS units, leading to a total of 46 datasets with, at least, 19 recorded days. For each animal and recorded day, HR sizes were estimated using the Biased Random Bridge method and percentages of daily change in size and shape calculated and taken as metrics. The analysis revealed that the required number of days differed substantially between individuals, isopleths, and countries, with the extended HR (95% isopleth value) requiring a longer recording period. To reach a stable HR size and shape values for 75% of the dogs, 26 and 21 days, respectively, were sufficient. However, certain dogs required more extended observational periods.

Community Clustering of Food Insecurity and Malnutrition Associated With Systemic Drivers in Chad.

BACKGROUND: Chad suffers from protracted hunger, facing high food insecurity (Integrated Food Security Phase Classification 3 and above), and acute malnutrition levels that surpass the emergency threshold (15% global acute malnutrition) yearly. The Food Security Sector, with European Union support, leads an inclusive effort to increase synergy between humanitarian, development, and peace-building actors to understand and address drivers of hunger. OBJECTIVE: To understand the spatial distribution of child wasting and household food insecurity and systemic drivers (conflict, livelihoods, vegetation, cultural norms) as well as better understand the relationship between child wasting and household food insecurity in Kanem and Bahr el Ghazal (BeG) region, Chad, with the goal of improving nexus programming and targeting. METHODS: A cross-sectional randomized cluster survey was conducted in August 2021 in Kanem and BeG across 86 villages, reaching 7002 households and 6136 children. Data were collected on child anthropometry, household food security, and livelihoods. Using mixed methods, primary data were triangulated with secondary geospatial data on vegetation index and conflicts as well as qualitative interviews with local actors. Analysis was conducted using comparison tests, linear and logistic crude, and adjusted models, as well as looking at the design effect as a measure of clustering of outcomes at the community level. RESULTS: The geospatial distribution of hunger indicators shows child wasting and food insecurity are highly clustered. However, communities with a high prevalence of child wasting were not those with the highest levels of food insecurity, indicating different pathways. Clustering of food insecurity and child wasting is due to basic drivers of conflict, health, and seasonal access to natural resources. CONCLUSIONS: The high levels of food insecurity and child wasting are each concentrated in specific survey clusters and are not necessarily connected. They result from different causal pathways at the community level linked to the systemic drivers of the rule of access to natural resources, environmental seasonality, and livelihoods. This suggests a greater need for an integrated humanitarian, development, and peace-building interventions to address the persistent high prevalence of food insecurity and child wasting. It also suggests that these community-level and systemic drivers require greater consideration from the start in research design and data collection.

Plain language titleUnderstanding Linkages Between Household Food Insecurity, Child Malnutrition, and Their Respective Clustered Drivers in ChadPlain language summaryChad experiences emergency levels of household food insecurity and child malnutrition. To address this issue, the United Nations Food and Agricultural Organization has undertaken a collaborative effort to enhance cooperation among humanitarian, development, and peace-building actors. The objective of this study was to examine how child malnutrition, food insecurity, and their drivers cluster across communities in Kanem and Bahr El Ghazal to improve response planning and targeting. The study collected data in August 2021 on malnutrition, food security, livelihoods, vegetation, and conflict and carried out interviews with local informants. In total, the research covers 86 villages, 7,002 households, and 6,136 children. The research shows that the 2 measures of hunger, child malnutrition and food insecurity, are highly clustered, affecting some communities more than others. However, villages with a high prevalence of child acute malnutrition did not have the highest levels of food insecurity, suggesting different community-level drivers. The clustering of food insecurity and malnutrition at the village level was linked to the diversity of livelihoods, the experience of conflict, health, and seasonal limitations in accessing natural resources. These findings are crucial for informing the targeting and design of integrated humanitarian, development, and peace programs. Taking a systemic approach and fostering strong coordination across interventions to address the drivers of food insecurity and malnutrition holds great potential for tackling hunger in Chad.

The Complexity of the Seasonality of Nutritional Status: Two Annul Peaks in Child Wasting in Eastern Chad.

BACKGROUND: Understanding seasonal patterns in nutritional status is critical for achieving and tracking global nutrition goals. However, the majority of nutrition seasonality research design draws on 2 or 3 within-year time points based on existing assumptions of seasonality, missing a more nuanced pattern. OBJECTIVE: We aimed to identify the intra-year variability of childhood wasting, severe wasting, and weight-for-height z-scores (WHZ) in a dryland single wet-season context and illustrate an analytical approach for improving analysis of the seasonality of nutritional status. METHODS: To quantify the intra-year variability in nutritional status, we use data from a 23-month panel study (May 2018 to March 2020) following 231 children (6-59 months of age) in eastern Chad. We apply a mixed-effects harmonic regression with child- and village-level fixed effects on the odds of being wasted, severely wasted, and on WHZ, testing for multiple and nonsymmetrical seasonal peaks, adjusted for child sex and age. We triangulate our findings using climate data on temperature, vegetation, and precipitation. RESULTS: We identify 2 annual peaks of wasting and severe wasting. Wasting peaks at 14.7% (confidence interval [CI], 11.8-18.2) at the end of the dry season, while the smaller peak corresponds to the start of the harvest period at 13.4% (CI, 10.7-16.6). The odds of being wasted decline during the rainy season to 11.8% (CI, 9.4-14.7), with the lowest prevalence of 8.8% (CI, 6.9-11.1) occurring during the start of the dry season. In addition, a 1°C monthly increase in temperature is significantly associated with a 5% (CI, 1.4-8.7) and 12% (CI, 3.0-20.3) increase in the odds that a child is wasted and severely wasted, respectively. CONCLUSIONS: Intra-year variability of child wasting is far more complex and nuanced than identified by the literature, with 2 peaks, as opposed to 1, likely corresponding to different seasonal drivers, such as food insecurity, disease, water contamination, and care practices at different times of year. Better seasonality analysis can go a long way in improving the timing and content of programming with the goal of reducing child wasting.

Plain language titleTwo Seasonal Peaks of Acute Malnutrition in ChadPlain language summaryUnderstanding seasonal patterns in nutrition is crucial for achieving and monitoring global nutrition goals. However, most research on nutrition seasonality relies on only a few time points within a year, which oversimplifies the true pattern. In our study conducted in Chad, a dryland environment with a single rainy season, we examined various indicators of acute malnutrition, including severe acute malnutrition. We analyzed 23 months of data from 231 children aged 6 to 59 months, considering factors such as sex, age, monthly rainfall, temperature, and vegetation. Our findings revealed 2 peaks of acute malnutrition, challenging the prevailing notion of a single peak identified in existing literature. The first, larger peak occurred at the onset of the rainy season, followed by a decline and then a second peak just before the harvest period. This pattern aligned with temperature variations rather than rainfall. The complex and nuanced seasonal patterns we observed suggest that different factors such as food insecurity, disease, water contamination, and care practices may contribute to acute malnutrition at different times of the year. Improved analysis of seasonality can significantly enhance the timing and effectiveness of interventions aimed at reducing child wasting.

Molecular detection of Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts in wild population of tsetse flies collected in Cameroon, Chad and Nigeria.

BACKGROUND: Tsetse flies are cyclical vectors of African trypanosomiasis (AT). The flies have established symbiotic associations with different bacteria that influence certain aspects of their physiology. Vector competence of tsetse flies for different trypanosome species is highly variable and is suggested to be affected by bacterial endosymbionts amongst other factors. Symbiotic interactions may provide an avenue for AT control. The current study provided prevalence of three tsetse symbionts in Glossina species from Cameroon, Chad and Nigeria. RESULTS: Tsetse flies were collected and dissected from five different locations. DNA was extracted and polymerase chain reaction used to detect presence of Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts, using species specific primers. A total of 848 tsetse samples were analysed: Glossina morsitans submorsitans (47.52%), Glossina palpalis palpalis (37.26%), Glossina fuscipes fuscipes (9.08%) and Glossina tachinoides (6.13%). Only 95 (11.20%) were infected with at least one of the three symbionts. Among infected flies, six (6.31%) had Wolbachia and Spiroplasma mixed infection. The overall symbiont prevalence was 0.88, 3.66 and 11.00% respectively, for Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts. Prevalence varied between countries and tsetse fly species. Neither Spiroplasma species nor S. glossinidius were detected in samples from Cameroon and Nigeria respectively. CONCLUSION: The present study revealed, for the first time, presence of Spiroplasma species infections in tsetse fly populations in Chad and Nigeria. These findings provide useful information on repertoire of bacterial flora of tsetse flies and incite more investigations to understand their implication in the vector competence of tsetse flies.

Trends and Determinants of Children's Wasting and Women's Thinness in Chad, 2015 to 2021.

BACKGROUND: Cross-sectional surveys using the Standardized Monitoring and Assessment of Relief and Transitions methodology have been conducted annually in Chad since 2015 to evaluate population-level nutritional status. OBJECTIVE: This analysis characterizes national and subnational trends in child wasting and women's thinness from 2015 to 2021 in Chad and identifies risk factors during the COVID-19 pandemic. METHODS: Annual survey data with 12,000 to 15,000 households were included. Wasting was estimated for children 6 to 59 months using the WHO child growth standards, and among women 15 to 49 years, thinness was defined as mid-upper arm circumference <23 cm. Trends were stratified by agroecological zone, and chi-square tests used to assess statistical significance. Simple and multivariate logistic regression models were conducted for 2020 and 2021 to identify risk factors of wasting and thinness. RESULTS: About 11,958 to 17,897 children and 9883 to 15,535 women contributed values each year. National wasting and thinness rates did not significantly decrease over the 7-year period (wasting: 14.1% to 12.1%, P = .43; thinness: 15.2% to 13.4%, P = .51) and wasting rose from 2020 to 2021. The Saharan and Sahelian zones had consistently higher rates compared to the Sudanian zone. Younger age, male sex, inadequate infant and young child feeding practices, and poorer household socio-economic factors were associated with greater odds of child wasting. For women, younger age, lack of nutrition knowledge, and poorer household socio-economic factors increased the odds of thinness. CONCLUSIONS: Undernutrition in Chad has not improved since 2015, and the COVID-19 pandemic likely exacerbated the crisis among children nationally and among women subnationally. Multisectoral approaches and regional targeting of interventions are recommended.

Therapeutic efficacy of artesunate-amodiaquine and artemether-lumefantrine for the treatment of uncomplicated falciparum malaria in Chad: clinical and genetic surveillance.

BACKGROUND: Artesunate-amodiaquine (AS-AQ) and artemether-lumefantrine (AL) are the currently recommended first-and second-line therapies for uncomplicated Plasmodium falciparum infections in Chad. This study assessed the efficacy of these artemisinin-based combinations, proportion of day 3 positive patients, proportions of molecular markers associated with P. falciparum resistance to anti-malarial drugs and variable performance of HRP2-based malaria rapid diagnostic tests (RDTs). METHODS: A single-arm prospective study assessing the efficacy of AS-AQ and AL at three sites (Doba, Kelo and Koyom) was conducted between November 2020 to January 2021. Febrile children aged 6 to 59 months with confirmed uncomplicated P. falciparum infection were enrolled sequentially first to AS-AQ and then AL at each site and followed up for 28 days. The primary endpoint was PCR-adjusted adequate clinical and parasitological response (ACPR). Samples collected on day 0 were analysed for mutations in pfkelch13, pfcrt, pfmdr-1, pfdhfr, pfdhps genes and deletions in pfhrp2/pfhrp3 genes. RESULTS: By the end of 28-day follow-up, per-protocol PCR corrected ACPR of 97.8% (CI 95% 88.2-100) in Kelo and 100% in Doba and Kayoma were observed among AL treated patients. For ASAQ, 100% ACPR was found in all sites. All, but one patient, did not have parasites detected on day 3. Out of the 215 day 0 samples, 96.7% showed pfkelch13 wild type allele. Seven isolates carried nonsynonymous mutations not known to be associated artemisinin partial resistance (ART-R). Most of samples had a pfcrt wild type allele (79% to 89%). The most prevalent pfmdr-1 allele detected was the single mutant 184F (51.2%). For pfdhfr and pfdhps mutations, the quintuple mutant allele N51I/C59R/S108N + G437A/540E responsible for SP treatment failures in adults and children was not detected. Single deletion in the pfhrp2 and pfhrp3 gene were detected in 10/215 (4.7%) and 2/215 (0.9%), respectively. Dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, were observed in 5/215 (2.3%) isolates. CONCLUSION: The results of this study confirm that AS-AQ and AL treatments are highly efficacious in study areas in Chad. The absence of known pfkelch13 mutations in the study sites and the high parasite clearance rate at day 3 suggest the absence of ART-R. The absence of pfdhfr/pfdhps quintuple or sextuple (quintuple + 581G) mutant supports the continued use of SP for IPTp during pregnancy. The presence of parasites with dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, warrants the continued surveillance. Trial registration ACTRN12622001476729.