Safety and Immunogenicity of a ChAd155-Vectored Respiratory Syncytial Virus Vaccine in Infants 6-7 Months of age: A Phase 1/2 Randomized Trial.

BACKGROUND: Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infections in infants. This phase 1/2, observer-blind, randomized, controlled study assessed the safety and immunogenicity of an investigational chimpanzee-derived adenoviral vector RSV vaccine (ChAd155-RSV, expressing RSV F, N, and M2-1) in infants. METHODS: Healthy 6- to 7-month-olds were 1:1:1-randomized to receive 1 low ChAd155-RSV dose (1.5 × 1010 viral particles) followed by placebo (RSV_1D); 2 high ChAd155-RSV doses (5 × 1010 viral particles) (RSV_2D); or active comparator vaccines/placebo (comparator) on days 1 and 31. Follow-up lasted approximately 2 years. RESULTS: Two hundred one infants were vaccinated (RSV_1D: 65; RSV_2D: 71; comparator: 65); 159 were RSV-seronaive at baseline. Most solicited and unsolicited adverse events after ChAd155-RSV occurred at similar or lower rates than after active comparators. In infants who developed RSV infection, there was no evidence of vaccine-associated enhanced respiratory disease (VAERD). RSV-A neutralizing titers and RSV F-binding antibody concentrations were higher post-ChAd155-RSV than postcomparator at days 31, 61, and end of RSV season 1 (mean follow-up, 7 months). High-dose ChAd155-RSV induced stronger responses than low-dose, with further increases post-dose 2. CONCLUSIONS: ChAd155-RSV administered to 6- to 7-month-olds had a reactogenicity/safety profile like other childhood vaccines, showed no evidence of VAERD, and induced a humoral immune response. Clinical Trials Registration. NCT03636906.

Left atrial remodeling and voltage-guided ablation outcome in persistent atrial fibrillation patients according to CHA2DS2-VASc score.

BACKGROUND: CHA2DS2-VASc score-related differences have been reported in atrial fibrotic remodeling and prognosis of atrial fibrillation (AF) patients after ablation. There are currently no data on the efficacy of low voltage zone (LVZ)-guided ablation in persistent AF patients according to CHA2DS2-VASc score. We assessed in a cohort of persistent AF patients the extent of LVZ, the regional distribution of LA voltage and the outcome of LA voltage-guided substrate ablation in addition to PVI according to CHA2DS2-VASc score. METHODS: 138 consecutive persistent AF patients undergoing a first voltage-guided catheter ablation were enrolled. 58 patients with CHAD2DS2-VASc score ≥ 3 and 80 patients with CHAD2DS2-VASc score ≤ 2 were included. LA voltage maps were obtained using 3D-electroanatomical mapping system in sinus rhythm. LVZ was defined as < 0.5 mV. RESULTS: In the high CHAD2DS2-VASc score group, LA voltage was lower (1.5 [1.1-2.5] vs. 2.3 [1.5-2.8] mV, p = 0.02) and LVZs were more frequently identified (40% vs. 18%), p < 0.01). Female with CHA2DS2-VASc score ≥ 3 (p = 0.031), LA indexed volume (p = 0.009) and P-wave duration ≥ 150 ms (p = 0.001) were predictors of LVZ. After a 36-month follow-up, atrial arrhythmia-free survival was similar between the two groups (logrank test, P = 0.676). CONCLUSIONS: AF patients with CHAD2DS2-VASc score ≥ 3 display more LA substrate remodeling with lower voltage and more LVZs compared with those with CHAD2DS2-VASc score ≤ 2. Despite this atrial remodeling, they had similar and favorable 36 months results after one single procedure. Unlike male with CHAD2DS2-VASc score ≥ 3, female with CHAD2DS2-VASc score ≥ 3 was predictor of LVZ occurrence.

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.

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.

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.

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.

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.

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.

Validation of the Malay version of Epworth sleepiness scale for children and adolescents (MESS-CHAD).

BACKGROUND: Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD) is a valid and reliable eight-item self-administered questionnaire for the assessment of excessive daytime sleepiness and is commonly used to screen sleep-disordered breathing for children and adolescents. The cross-sectional study aimed to translate and cross-culturally adapt ESS-CHAD into a Malay version of Epworth Sleepiness Scale for Children and Adolescents (MESS-CHAD) for the Malaysian population, and to assess the validity and reliability of MESS-CHAD. METHODS: Forward-backward translation method was used to translate and cross-culturally adapt ESS-CHAD. Three linguistic experts and two paediatricians content validated the translated version. Face validity was conducted through audio-recorded semi-structured in-depth interviews with 14 native Malay-speaking children and adolescents followed by thematic analysis. The revised questionnaire was then proofread by a linguistic expert. A total of 40 subjects answered the MESS-CHAD twice, 2 weeks apart, for test-retest reliability and internal consistency. For criterion validity, 148 eligible subjects and their parents answered MESS-CHAD and the Malay version of Sleep-Related Breathing Disorder scale extracted from the Paediatric Sleep Questionnaire (M-PSQ:SRBD) concurrently. Variance Inflation Factor (VIF) and P values of the model's outer weight and outer loading were analysed using SmartPLS software to assess the indicator's multicollinearity and significance for formative construct validity. RESULTS: Intraclass Correlation Coefficient (ICC) ranging from 0.798 to 0.932 and Cronbach's alpha ranging from 0.813 to 0.932 confirmed good to excellent test-retest reliability and internal consistency, respectively. Spearman Correlation Coefficient value of 0.789 suggested a very strong positive correlation between MESS-CHAD and M-PSQ:SRBD. VIF ranging from 1.109 to 1.455 indicated no collinearity problem. All questionnaire items in MESS-CHAD were retained as the P value of either outer model weight or outer model loading was significant (P < 0.05). CONCLUSION: ESS-CHAD has been translated and cross-culturally adapted into Malay version for the Malaysian population, and found to be valid and reliable.

Viral Hepatitis E Outbreaks in Refugees and Internally Displaced Populations, sub-Saharan Africa, 2010-2020.

Hepatitis E virus is a common cause of acute viral hepatitis. We analyzed reports of hepatitis E outbreaks among forcibly displaced populations in sub-Saharan Africa during 2010-2020. Twelve independent outbreaks occurred, and >30,000 cases were reported. Transmission was attributed to poor sanitation and overcrowding.

Knowledge and social beliefs of malaria and prevention strategies among itinerant Nomadic Arabs, Fulanis and Dagazada groups in Chad: a mixed method study.

BACKGROUND: Nomadic populations in Chad are at increased risk of contracting malaria because of their lifestyle. Being highly mobile they are often excluded from disease control programmes, and access to preventive measures and treatment is more difficult. Effective malaria control interventions take account of local modes of transmission, patterns of care-seeking behaviour and community perceptions of cause and prevention practices. There is currently little information about malaria knowledge and perceptions among nomadic groups in Chad, or their awareness of malaria control interventions and this study sought to address this knowledge gap. METHODS: A mixed methods study, including a cross-sectional survey with men and women (n = 78) to determine the level of knowledge and use of malaria prevention strategies among Arabs, Peuls and Dagazada nomadic groups. Three focus group discussions were conducted with women to explore their representation of malaria and knowledge of preventive methods. Key informant interviews were held with leaders of nomadic groups (n = 6) to understand perception of malaria risk among itinerant communities. RESULTS: Nomads are aware of the risk of malaria, recognize the symptoms and have local explanations for the disease. Reported use of preventive interventions such as Seasonal Malaria Chemoprevention (SMC) for children and Intermittent Preventive Treatment (IPT) of malaria in pregnancy was very low. However, 42.3% of respondents reported owning at least one LLIN and 60% said they slept under an LLIN the night before the survey. In case of a malaria episode, nomads seek clinicians, informal drug sellers in the street or market for self-medication, or traditional medicine depending on their financial means. Interviews with nomad leaders and discussions with women provide key themes on: (i) social representation of malaria risk and (ii) social representation of malaria and (iii) perspectives on malaria prevention and (iv) malaria treatment practices. CONCLUSION: The nomadic groups included in this study are aware of risk of malaria and their level of exposure. Local interpretations of the cause of malaria could be addressed through tailored and appropriate health education. Except for LLINs, malaria prevention interventions are not well known or used. Financial barriers lowered access to both mosquito nets and malaria treatment. Reducing the barriers highlighted in this study will improve access to the healthcare system for nomadic groups, and increase the opportunity to create awareness of and improve uptake of SMC and IPT among women and children.

Safety and immunogenicity of ChAd63-KH vaccine in post-kala-azar dermal leishmaniasis patients in Sudan.

Post-kala-azar dermal leishmaniasis (PKDL) is a chronic, stigmatizing skin condition occurring frequently after apparent clinical cure from visceral leishmaniasis. Given an urgent need for new treatments, we conducted a phase IIa safety and immunogenicity trial of ChAd63-KH vaccine in Sudanese patients with persistent PKDL. LEISH2a (ClinicalTrials.gov: NCT02894008) was an open-label three-phase clinical trial involving sixteen adult and eight adolescent patients with persistent PKDL (median duration, 30 months; range, 6-180 months). Patients received a single intramuscular vaccination of 1 × 1010 viral particles (v.p.; adults only) or 7.5 × 1010 v.p. (adults and adolescents), with primary (safety) and secondary (clinical response and immunogenicity) endpoints evaluated over 42-120 days follow-up. AmBisome was provided to patients with significant remaining disease at their last visit. ChAd63-KH vaccine showed minimal adverse reactions in PKDL patients and induced potent innate and cell-mediated immune responses measured by whole-blood transcriptomics and ELISpot. 7/23 patients (30.4%) monitored to study completion showed >90% clinical improvement, and 5/23 (21.7%) showed partial improvement. A logistic regression model applied to blood transcriptomic data identified immune modules predictive of patients with >90% clinical improvement. A randomized controlled trial to determine whether these clinical responses were vaccine-related and whether ChAd63-KH vaccine has clinical utility is underway.

Spatial and multilevel analysis of unskilled birth attendance in Chad.

BACKGROUND: Unskilled birth attendance is a major public health concern in Sub-Saharan Africa (SSA). Existing studies are hardly focused on the socio-demographic correlates and geospatial distribution of unskilled birth attendance in Chad (a country in SSA), although the country has consistently been identified as having one of the highest prevalence of maternal and neonatal deaths in the world. This study aimed to analyse the socio-demographic correlates and geospatial distribution of unskilled birth attendance in Chad. METHODS: The study is based on the latest Demographic and Health Survey (DHS) data for Chad. A total of 10,745 women aged between 15 and 49 years were included in this study. A multilevel analysis based on logistic regression was conducted to estimate associations of respondents' socio-demographic characteristics with unskilled birth attendance. Geographic Information System (GIS) mapping tools, including Getis-Ord Gi hotspot analysis tool and geographically weighted regression (GWR) tool, were used to explore areas in Chad with a high prevalence of unskilled birth attendance. RESULTS: The findings show that unskilled birth attendance was spatially clustered in four Chad departments: Mourtcha, Dar-Tama, Assoungha, and Kimiti, with educational level, occupation, birth desire, birth order, antenatal care, and community literacy identified as the spatial predictors of unskilled birth attendance. Higher educational attainment, higher wealth status, cohabitation, lowest birth order, access to media, not desiring more births, and higher antenatal care visits were associated with lower odds of unskilled birth attendance at the individual level. On the other hand, low community literacy level was associated with higher odds of unskilled birth attendance in Chad whereas the opposite was true for urban residency. CONCLUSIONS: Unskilled birth attendance is spatially clustered in some parts of Chad, and it is associated with various disadvantaged individual and community level factors. When developing interventions for unskilled birth attendance in Chad, concerned international bodies, the Chad government, maternal health advocates, and private stakeholders should consider targeting the high-risk local areas identified in this study.

Sodalis glossinidius and Wolbachia infections in wild population of Glossina morsitans submorsitans caught in the area of Lake Iro in the south of Chad.

Investigations on the bacterial fauna and their association with trypanosome infections in tsetse fly have revealed contrasting results. This study aimed to detect Wolbachia and S. glossinidius in wild populations of G. m. submorsistans and subsequently, understand the influence that these bacteria may have on the vectorial competence of this tsetse species. Tsetse flies were captured in the area of Lake Iro in the south of Chad using biconical traps. After DNA extraction from each tsetse fly, Sodalis glossinidius and Wolbachia were detected using specific primers. Sodalis glossinidius and Wolbachia infection rates were compared and association studies involving trypanosome infections and S. glossinidius or Wolbachia were performed. From 345 G. m. submorsitans analyzed, 9.0% and 14.5% were respectively infected with S. glossinidius and Wolbachia. Only 2.31% of all tsetse flies were co-infected by the 2 bacteria. Of all trypanosome-infected flies, 7.1% and 9.8% harbored, respectively, S. glossinidius and Wolbachia. No association was observed between Wolbachia and trypanosome infections while a significant association (r = 4.992; P = 0.025) was found between S. glossinidius and the presence of trypanosomes. A significant association (r = 3.147; P = 0.043) was also observed between S. glossinidius and T. simiae; and none with T. congolense or T. godfreyi. This study revealed S. glossinidius and Wolbachia in G. m. submorsitans of the area of lake Iro. It showed that co-infections between Wolbachia and S. glossinidius are rare in wild populations of G. m. submorsitans and that the tripartite associations vary according to trypanosome species as well as symbiotic mricroorganisms.

Crisis at the intersection of four countries: healthcare access for displaced persons in the Lake Chad Basin region.

For a decade, the Lake Chad Basin (LCB) region, which is at the intersection of four countries and home to ethnic groups in Cameroon, Chad, Niger and Nigeria, has been occupied by Boko Haram. The lax borders and deprivation in the region contributed to the emergence and expansion of Boko Haram's insurgency. While much is known about the human casualties of the invasion, little is known about the accessibility of healthcare for the displaced persons. This qualitative study adopted Penchansky and Thomas' ([1981]. "The Concept of Access: Definition and Relationship to Consumer Satisfaction." Medical Care 19 (2): 127-140) theory of access as its conceptual framework (with the following components: geographical accessibility, availability, financial accessibility, acceptability and accommodation) to explore the experiences of the displaced persons in the LCB with respect to access to healthcare. One-on-one interviews (n = 51) and two focus group discussions (n = 16) were conducted with 67 refugees and internally displaced persons recruited from nine host communities in Nigeria and Cameroon, who shared their perceptions of their healthcare access. The displaced persons faced barriers to their access to the healthcare in the LCB. It was found that for each of the components of the theory of access, the study participants encountered barriers to healthcare access. For example, with regard to financial accessibility (affordability), poverty was identified as the main personal barrier to the displaced persons' healthcare access, and with regard to acceptability, it was communication that was reported to be a barrier. The limitations of the study, the recommendations for future research and the implications of the findings are discussed in detail.

Repeated-Dose Toxicity, Biodistribution, and Shedding Assessments With a ChAd155 Respiratory Syncytial Virus Vaccine Candidate Evaluated in Rabbits and Rats.

Respiratory syncytial virus (RSV) is a leading cause of acute lower respiratory tract infections (LRTI) in infants, and toddlers and vaccines are not yet available. A pediatric RSV vaccine (ChAd155-RSV) is being developed to protect infants against RSV disease. The ChAd155-RSV vaccine consists of a recombinant replication-deficient chimpanzee-derived adenovirus (ChAd) group C vector engineered to express the RSV antigens F, N, and M2-1. The local and systemic effects of three bi-weekly intramuscular injections of the ChAd155-RSV vaccine was tested in a repeated-dose toxicity study in rabbits. After three intramuscular doses, the ChAd155-RSV vaccine was considered well-tolerated. Changes due to the vaccine-elicited inflammatory reaction/immune response were observed along with transient decreases in platelet count without physiological consequences, already reported for other adenovirus-based vaccines. In addition, the biodistribution and shedding of ChAd155-RSV were also characterized in two studies in rats. The distribution and persistence of the ChAd155-RSV vaccine candidate was consistent with other similar adenovector-based vaccines, with quantifiable levels of ChAd155-RSV observed at the injection site (muscle) and the draining lymph nodes up to 69 days post administration. The shedding results demonstrated that ChAd155-RSV was generally not detectable in any secretions or excreta samples. In conclusion, the ChAd155-RSV vaccine was well-tolerated locally and systemically.

Modeling Optimal Laboratory Testing Strategies for Bacterial Meningitis Surveillance in Africa.

Since 2010, the introduction of an effective serogroup A meningococcal conjugate vaccine has led to the near-elimination of invasive Neisseria meningitidis serogroup A disease in Africa's meningitis belt. However, a significant burden of disease and epidemics due to other bacterial meningitis pathogens remain in the region. High-quality surveillance data with laboratory confirmation is important to monitor circulating bacterial meningitis pathogens and design appropriate interventions, but complete testing of all reported cases is often infeasible. Here, we use case-based surveillance data from 5 countries in the meningitis belt to determine how accurately estimates of the distribution of causative pathogens would represent the true distribution under different laboratory testing strategies. Detailed case-based surveillance data was collected by the MenAfriNet surveillance consortium in up to 3 seasons from participating districts in 5 countries. For each unique country-season pair, we simulated the accuracy of laboratory surveillance by repeatedly drawing subsets of tested cases and calculating the margin of error of the estimated proportion of cases caused by each pathogen (the greatest pathogen-specific absolute error in proportions between the subset and the full set of cases). Across the 12 country-season pairs analyzed, the 95% credible intervals around estimates of the proportion of cases caused by each pathogen had median widths of ±0.13, ±0.07, and ±0.05, respectively, when random samples of 25%, 50%, and 75% of cases were selected for testing. The level of geographic stratification in the sampling process did not meaningfully affect accuracy estimates. These findings can inform testing thresholds for laboratory surveillance programs in the meningitis belt.

Spatial and temporal dynamics of space use by free-ranging domestic dogs Canis familiaris in rural Africa.

Variation in the spatial ecology of animals influences the transmission of infections and so understanding host behavior can improve the control of diseases. Despite the global distribution of free-ranging domestic dogs Canis familiaris and their role as reservoirs for zoonotic diseases, little is known about the dynamics of their space use. We deployed GPS loggers on owned but free-ranging dogs from six villages in rural Chad, and tracked the movements of 174 individuals in the dry season and 151 in the wet season. We calculated 95% and core home ranges using auto-correlated kernel density estimates (AKDE95 and AKDEcore ), determined the degree to which their movements were predictable, and identified correlates of movement patterns. The median AKDE95 range in the dry season was 0.54 km2 and in the wet season was 0.31 km2 , while the median AKDEcore range in the dry season was 0.08 km2 and in the wet season was 0.04 km2 . Seasonal variation was, in part, related to owner activities; dogs from hunting households had ranges that were five times larger in the dry season. At least 70% of individuals were more predictably "at home" (<50 m from the household) throughout the day in the dry season, 80% of dogs demonstrated periodicity in activity levels (speed), and just over half the dogs exhibited periodicity in location (repeated space use). In the wet season, dogs mostly exhibited 24-h cycles in activity and location, with peaks at midday. In the dry season, dogs exhibited both 12- and 24-h cycles, with either a single peak at midday, or one peak between 06:00 and 12:00 and a second between 18:00 and 22:00. Strategies to control canine-mediated zoonoses can be improved by tailoring operations to the local spatial ecology of free-ranging dogs. Interventions using a door-to-door strategy in rural Chad would best conduct operations during the dry season, when access to dogs around their household more reliably exceeds 70% throughout the day. Given the importance of use in hunting for explaining variation in dog space-use, targeting approaches to disease control at the household level on the basis of owner activities offers potential to improve access to dogs.

Primary resistance to antiretroviral drugs of HIV strains in Chad: a retrospective investigation by analysis of frozen dried blood spot samples.

No data concerning antiretroviral drug's (ARV) primary resistance mutation rates in Chad are available. We retrospectively analysed frozen-stored dried blood spot samples that were collected from 48 Chadian human immunodeficiency virus (HIV)-1 seropositive patients naïve of ARV. HIV-1 protease and reverse transcriptase genes were successfully sequenced for 24 (60.0%) of the 40 patients displaying a viral load > 1000 copies/ml. Seven (29.2%) displayed mutations conferring resistance against one or more classes of ARV. We evidenced high levels of primary ARV resistance mutations in Chad, but lower than those observed in patients with failure to first-line ARV.

Factors associated with female genital mutilation among women of reproductive age and girls aged 0-14 in Chad: a mixed-effects multilevel analysis of the 2014-2015 Chad demographic and health survey data.

BACKGROUND: Chad is one of the African countries with high prevalence of female genital mutilation (FGM). The aim of this study was to examine the factors associated with FGM among women aged 15-49 and girls aged 0-14 in Chad. METHODS: Data for the study were obtained from the 2014-2015 Chad Demographic and Health Survey. FGM among women aged 15-49 and girls aged 0-14 were the outcome variables. The prevalence of FGM among women and girls were presented using percentages while a mixed-effects multilevel multivariable logistic regression analysis was carried out to assess the factors associated with FGM. The results were presented using adjusted odds ratio with associated 95% confidence intervals. RESULTS: The results indicate that more than half (50.2%) of the women and 12.9% of girls in Chad had been circumcised. Among women aged 15-49, level of education, employment status, ethnicity, religion, wealth quintile and community literacy level were significant predictors of FGM. Age, partner's level of education, marital status, employment status, ethnicity, religion and mother's FGM status were associated with FGM among girls aged 0-14. CONCLUSION: This study has identified several individual and contextual factors as predictors of FGM among women and girls in Chad. The findings imply the need to adopt strategies aimed at addressing these factors in order to help eliminate the practice of FGM. Government and non-governmental organisations in Chad need to implement policies that enhance media advocacy and community dialogue to help deal with FGM in the country.