Effects of biodegradation on diamondoid distribution in crude oils from the Bongor Basin,Chad

The sensitivity of biodegradation on diamondoids was investigated using a series of biodegraded oil samples from the Ronier tectonic unit of Bongor Basin,Chad.The results suggest that diamondoids,including adamantanes(As)and diamantanes(Ds),are relatively resistant to biodegradation and obvious biodegradation was observed in oils with a Peters-Moldowan(PM)biodegradation rank of 6 or more.Overall,the sensibility of biodegradation on diamondoids is generally similar to hopanes and regular steranes.As biodegradation evolves,the changes in concentration and components of diamondoids show that the biodegradation process is selective and stepwise.The significant increase of MD/MA and DMD/DMA for oils with a PM ranking 6^(+) indicates that diamantanes are generally more resistant to biodegradation than adamantanes.The similar trends of DMA/MA,EA/MA,MD/D,DMD/MD and other relevant indexes,show that higher alkylation homologs are more resistant to biodegradation.The commonly used diamondoid ratios,such as MAI,EAI,MDI and DMID-1,are obviously affected by biodegradation at the stage of high-level biodegradation,which may indicate that these ratios should be used with caution in case of severely degraded oils.

Hydrocarbon accumulation history in Lower Cretaceous in northern slope of Bongor Basin in Chad,Central Africa

Based on the analysis of the fluid inclusion homogenization temperature and apatite fission track on the northern slope zone of the Bongor Basin in Chad,this paper studied the time and stages of hydrocarbon accumulation in the study area.The results show that:(1)The brine inclusions of the samples from the Kubla and Prosopis formations in the Lower Cretaceous coexisting with the hydrocarbon generally present two sets of peak ranges of homogenization temperature,with the peak ranges of low temperature and high temperature being 75–105℃ and 115–135℃,respectively;(2)The samples from the Kubla and Prosopis formations have experienced five tectonic evolution stages,i.e.,rapid subsidence in the Early Cretaceous,tectonic inversion in the Late Cretaceous,small subsidence in the Paleogene,uplift at the turn of the Paleogene and Neogene,and subsidence since the Miocene,in which the denudation thickness of the Late Cretaceous and after the turn of the Paleogene and Neogene are~1.8 km and~0.5 km,respectively.The cumulative denudation thickness of the two periods is about 2.3 km;(3)Using the brine inclusion homogenization temperature coexisting with the hydrocarbon as the capture temperature of the hydrocarbon,and combining with the apatite fission track thermal history modeling,the result shows that the Kubla and Prosopis formations in the Lower Cretaceous on the northern slope of the Bongor Basin have the same hydrocarbon accumulation time and stages,both of which have undergone two stages of hydrocarbon charging at 80–95 Ma and 65–80 Ma.The first stage of charging corresponds to the initial migration of hydrocarbon at the end of the Early Cretaceous rapid sedimentation,while the second stage of charging is in the stage of intense tectonic inversion in the Late Cretaceous.

Genomic Profile of SARS-COV-2 Associated with COVID-19 Outbreaks in N’Djamena, Chad

Background: SARS-CoV-2 has circulated worldwide with dramatic consequences. In Chad, we have no data reported of variants. The aim of this study was to identify the SARS-CoV-2 variants that circulated during the epidemic from 2020 to 2021. Methods: This is a cross-sectional, descriptive study carried out between 2020 and 2021. Samples from patients with suspected COVID-19 were tested in five laboratories in N’Djamena. One hundred quality samples of the positives were sequenced in Kinshasa using Oxford nanopore technologies minion and the Protocol Midnight SARS-CoV2. Data were processed using Excel version 16 software. Results: Of the 100 samples sequenced, 77 (77%) produced sequences, 23 (23%) did not. The genomic profiles were wild-type Wuhan and minor mutations (19A, 19B (A), 20A (B.1, B.2), 20B (AV.1), 20D (B.1.1.1 /C.36), 20C), variant of concern Alpha (20I), variant of concern Delta (21A/J), variant of interest Eta (21D), variant of concern Omicron (21K) and unclassified variant under surveillance (B.1.640). Of these variants, the maximums were detected in patients aged 26 - 35 with 30.26% and 25.26% in 36 - 45. However, 24.67% were in travelers and 75.32% in residents, 35.06% in those vaccinated against COVID-19 and 62.33% in non-vaccinates. The estimated case-fatality rate was 2.44% (107/4374). Conclusion: This work has provided preliminary data on COVID-19 and SARS-CoV-2 variants circulating during the 2020-2021 epidemics in Chad.

Toxoplasmic Chorioretinitis: About a Case in an Immunocompetent Adult at the Renaissance University Hospital Centre (UHC) in N’Djamena (Chad) and Review of the Literature

Toxoplasmic chorioretinitis also known as ocular toxoplasmosis is a parasitic infection caused by the obligately intracellular multiplying protozoan called Toxoplasma gondii. Active toxoplasmic chorioretinitis is a rare condition in immunocompetent people. We report a case of a 47-year-old patient who received reduced right visual acuity, left hemiparesis and eye pain. Examination of the right anterior segment of the eye is unremarkable. In the fundus of the right eye, there was a focus of active toxoplasmic chorioretinitis located in the macula at 1.5 mm papillary diameter next to old scar lesions. The ophthalmological examination of the left eye was unremarkable. The paraclinical assessment carried out on the patient shows a positive Remington test on two occasions three weeks apart. The clinical outcome after initiation of treatment was favorable with a healing of the active site within four weeks.

Characterization and Assessment of the Quality of the Water and Sediments of the Islands (Moudou and Birguime) of Lake Fitri in Chad and Confirmation of the Strains Isolated by the PCR Method

The problem of access to quality water is a major challenge, as it has a major impact on the socio-economic conditions of people in developing countries. The water from the islands of Lake Fitri is one of the main sources of drinking water for the population. The aim of this study is to characterise and assess the quality of the water and sediment from the islands (Moudou and Birguime) of Lake Fitri, and to confirm the strains isolated using the PCR method. A total of fifty (50) samples of water and fifty (50) sediments from the islands of Lake Fitri were analyzed. Standard methods of microbiological and biochemical analysis of water and sediments were used. Isolated Enterobacteriaceae strains were characterized by API 20 E and API Staph galleries and Salmonella was confirmed by PCR method. Antibiotic resistance was determined using a technique recommended by the antibiogram committee of the French microbiology society (CA-SFM, 2019). The microbiological results for the water showed an abundance of total aerobic mesophilic flora (TAMF) (4.31 × 106 ± 8.05 × 105 and 5.29 × 106 ± 2.55 × 105) on the Birguime and Moudou islands successively. The microbiological results for the sediment from Birguime and Moudou islands showed an abundance of thermotolerant coliforms (E. coli) (2.05 × 105 ± 5.43 × 104 and 2.27 × 105 ± 3.49 × 104) alternately. The results obtained after incubation of the biochemical tests by the API 20E, API Staph gallery and their numerical profile proposed by the Api software confirmed the contamination. The antibiogram results showed the emergence of certain resistances to the antibiotics Tobramycin, Flucytosine, Amikacin and Teicoplani. The PCR results for Salmonella spp strains were confirmed. As a result, strict monitoring of the water on the various islands of Lake Fitri must be carried out throughout the annual cycle, by specialized personnel, to ensure proper bio-monitoring of these ecosystems.

Quantification of Total Phenols, Total Flavonoids, Total Anthocyanins and Evaluation of Antioxidant and Antiradical Activities of Detarium Senegalense Extracts from Chad

The aim of the present work is to assess the value of Detarium Senegalense by determining the content of total phenols, total flavonoids and total anthocyanins, and by evaluating the free radical scavenging activity of Detarium Senegalense extracts. For this purpose, sequential extraction using solvents of increasing polarity was essential. The various extracts obtained underwent phytochemical and biochemical analyses. Phytochemical screening revealed the presence of flavonoids, alkaloids, tannins, polyphenols, anthocyanins and steroids/terpenes. Quantitative analysis of total polyphenols, total flavonoids and total anthocyanins yielded the following results: total flavonoids (0.803 ± 0029 mg EQ/100g P for acetone extract of roots and 0.871 ± 0.401 mg EQ/100g P for methanol extract of leaves);total polyphenols (23.298 ± 12.68 mg EAG/100g P for acetone extract of roots and 24.69 ± 0.49 401 mg EAG/100g P for methanol extract of leaves);total monomeric anthocyanins (44.697 ± 0.939 mg EC3G/100g P and 16.699 ± 0.193 mg EC3G/100g P respectively for acetone and methanol extracts of stem bark). DPPH free radical scavenging activity was 1.674 ± 0.023 mg/mL for the acetone extract and 0.934 ± 0.24 mg/mL for the methanol extract of roots. .

Visceral Leishmaniasis at the National Reference University Hospital Center of N’Djamena (Chad): Epidemiological, Clinical, Diagnostic, Therapeutic and Prognostic Aspects

Introduction: leishmaniasis is a group of parasitic diseases caused by a parasite of the genus Leishmania transmitted by the bite of an infected vector called a sandfly. There are four forms. Visceral leishmaniasis is the most severe form. The aim of our work is to study the epidemiological, clinical, diagnostic, therapeutic and prognostic aspects of the disease in the Infectious Diseases Department of the Centre Hospitalier Universitaire de Référence Nationale in N'Djaména. Methodology: Patients were recruited on the basis of clinical signs suggestive of visceral leishmaniasis, i.e. prolonged fever, splenomegaly and altered general condition. Biological confirmation was performed with a rapid diagnostic test using recombinant K39 parasite antigen, which is known to have good specificity and sensitivity. Epidata version 3.1 software was used to process patient data. Results: From 05/04/21 to 15/12/23, 153 positive cases were managed. The mean age of patients was 18 years, with a sex ratio of 9.2. Of these patients, 103 (67.3%) had recently stayed at gold mining sites. Patients testing positive were treated with sodium stibogluconate combined with paromomycin for 17 days. The mortality rate was 13.2%. Conclusion: Leishmaniasis is a serious and little-known disease in Chad. In order to respond to the disease, it is necessary to reinforce the capacities of health structures and to carry out appropriate actions in the outbreaks.

Effective Strategies to Encourage the Cultivation of Sorghum and Corn in the African Sahel: An Analysis of Chad

The research explores traditional sorghum and corn cropping systems in the Guera region of the Sahel, focusing on social, economic, and ecological criteria. The region faces challenges due to its tropical climate, droughts, and land characteristics, affecting sorghum and corn cultivation. A comprehensive framework, developed in collaboration with national and international organizations, is needed to improve agricultural production in infertile land. Chad’s smallholders use a low-tech, risk-averse rainfed system, but diversified techniques and new cultivation patterns can increase profits. Modern technologies and innovations can increase diversity and create new cultivation forms, involving scientific, commercial, credit, and industrial organizations. Chad faces severe water stress and crop yield issues, with up to 95% of water resources lost due to evapotranspiration. Proper water management techniques, assisted irrigation, efficient rainwater harvesting, and effective seed selection and crop management are crucial for improving agricultural production, reducing poverty, and ensuring the survival of the region’s agricultural sector. Chemical poverty complicates crop management, but fertilizers and skips can improve soil and provide good cereals. Urea can be added to legumes to increase plant growth and nitrogen fixation, while microorganisms and mycorrhizal fungi can strengthen rhizobia and enhance plant recovery. Handling tradeoffs is crucial, as environmental shocks can lead to social consequences like hunger and unemployment. The Sahel region’s sorghum and corn plant species face food production stagnation and chronic insufficiency due to increasing population and pests. Integrated pest management strategies and market access are crucial for smallholder farmers, but quality standards are weak. Public-private partnerships can improve value chains and market linkages, leading to increased farmer income, traders’ income, and consumer prices.

Tuberculosis in the Carcinal Environment in Chad Due to the Mycobacterium Tuberculosis Circulante Complex

Tuberculosis (TB) is a serious infectious disease and its control is considered a challenge, particularly among vulnerable populations such as prisoners. The prevalence of TB in prisons is an alarming public health problem in many countries. The aim of this study is to describe the epidemiology of tuberculosis and the strategies for controlling this disease in the Chadian prison population. During the course of our study, the prevalence of tuberculosis in prisons was 9.64%. The age group between 55 years and over (43.33%) was the most represented in this study, and all patients were men with a frequency of 62.66%. The cross-tabulation of Culture_7H9G and Culture_7H9P showed that out of our total positive sample, we found a total of 87 positive strains and 63 negative strains. Our study shows that it is essential to know the prevalence of tuberculosis in all the country’s prisons. Indeed, this can serve as an indication of the need for action in prisons to reduce TB rates, in particular by improving the structure of prison environments, diagnosing new cases quickly and accurately, identifying drug-resistant strains and implementing effective, direct treatment observed in people with tuberculosis.

Knowledge and Attitudes of Nursing Staff towards Obstetric Fistula at the Abeche University Hospital, Chad

Introduction: Prevention of obstetric fistula (OF) remains a challenge in Chad where its incidence is 464 cases/year. The present study aims to determine the knowledge and attitudes of nursing staff towards obstetric fistula. Patients and Method: This was a cross-sectional, descriptive and analytical study including nursing staff at the Abéché University Hospital. The survey took place from March to May 2023 and the sampling was exhaustive. Data collection was done using a form including a questionnaire on sociodemographic parameters, knowledge and attitudes. Participation in the study was voluntary and individual. Results: Participation in the study was 76.11%. Emergency department staff were the most represented, followed by gynecology-obstetrics staff with 34.4% and 20.91% of cases respectively. Nurses represented 53.17% of participants followed by doctors (23.52%). An exact definition of obstetric fistula was reported by 7.84% of participants and it was partial in 80.39%. The level of knowledge of risk factors was considered good in 12.41%. Exact knowledge of clinical signs was reported by 74.5% of cases. Among the participants, 1.96% reported that the treatment of obstetric fistula is traditional. Knowledge about means of prevention was considered good by 13.72% (n = 21), and attitudes by 26.79%? Obstetric fistula knowledge was influenced by profession (doctor, p = 0.011) and attitudes by service (p = 0.004) and profession (doctor, p = 0.001). Conclusion: Obstetric fistula is a curable disease whose prevention remains possible and requires good knowledge of the disease and the promotion of safe motherhood. This study should serve as a basis for the establishment of the obstetric fistula module in the curriculum of healthcare personnel and the promotion of continuing training for its eradication.

Identification of Microorganisms in Poultry Farms in N’djamena and the Border Areas of Hadjer-Lamis and Chari-Baguirmi Chad

Introduction: On the outskirts of Ndjamena, semi-industrial poultry farming and traditional poultry farming are practised informally on almost all poultry farms in Chad. This type of poultry farming is faced with real health problems attributable to a lack of monitoring of the vaccination schedule, inadequate compliance with biosecurity measures and poor application of the Ichikawa rule based on the 5 M’s. Objective: The aim of this article is to identify the microorganisms responsible for contamination of poultry farms in the study area. Method: The study was carried out from 28/04/2022 to 31/01/2023 on the basis of 300 samples taken from feed, drinking water, droppings and scrapings from poultry housing surfaces in the 30 farms that served as a framework for our research. Sampling was of the simple random type, and farms were selected on the basis of the farmers’ consent. The data were recorded on pre-established survey forms. Our study was cross-sectional, descriptive and prospective. Bacteria were isolated using the reference method NF EN ISO 6579 for Salmonella spp. and cultured on the specific medium eosin methylene blue (EMB) for Escherichia coli, Pseudomonas and Citrobacter freundii. Results: The following results emerged from this study: Escherichia coli (5.33%), Pseudomonas (1.33%), Citrobacter freundii (12%) and Salmonella paratyphi (21.68%). Conclusion: Of the 300 samples analysed, 121 (40.33%) were contaminated with pathogens. This high level of contamination is a health problem. The study shows that biosecurity is less satisfactory on the farms visited. Nevertheless, farms with a very satisfactory level of biosafety ensure food safety and variety for the population.

Hydrochemical Characterisation and Assessment of the Level of Contamination of Groundwater Collected by Private Waterworks in the Town of Moundou in the South of Chad

Groundwater is the main source of drinking water for large cities in most African countries. In Moundou, for example, the conventional groundwater supply system is failing. To compensate for this state failure, the population is building boreholes and wells, most of which tap the surface water table, generally referred to as the “water table”. The aim of this study is to characterize these waters in order to assess their level of contamination and, by extension, the degree of pollution of the water table. Major elements such as: Chloride (Cl-), Sulfate (SO42-), Nitrate (NO3-), Calcium (Ca2+), magnesium (Mg2+), sodium (Na+) and potassium (K+) were analysed by Liquid Chromatography and the Bicarbonate ion (HCO3-) was determined by the titrimetric method. The methodology applied is based on a combination of hydrochemical techniques and statistical analysis (PCA and CHA). A sampling campaign was carried out during high-water periods. The results of the physico-chemical analyses show mineralization ranging from 7.29 to 3670 μS/cm, with an average of 487.44 μS/cm. The groundwater studied is generally acidic, with a pH ranging from 3.26 to 6.41. Based on their anions, they are classified into four main hydrochemical facies: chloride and sulphate facies, calcium and magnesium facies, sodium and potassium facies and bicarbonate facies. The various correlations between major ions and statistical analyses have enabled us to identify three hydrogeochemical processes involved in water mineralization. The dominant process is silicate hydrolysis, followed by cation exchange, then anthropogenic input, which influences mineralization by polluting the water.

Water Quality on the Basement Areas in Kouba-Adougoul and Its Surroundings, Guera Province, Chad

Water is an essential element for all forms of life. The quantity and quality of water are a problem in places. In Kouba Adougoul and its surroundings in south guera, water-related health problems are reported. That is why this study focuses on the quality of water in the basement areas, of Kouba Adougoul. Our objective is to contribute to a better understanding of water of human consumption in these areas for this, we carried out a physicochemical and bacteriological control on a number water point. Ten water points were collected during May 2022 for analysis. To achieve this objective, we made the in-situ analysis of physical parameters such as pH, electrical conductivity, and temperature. These measurements were made using the multi-parameter kit. The result shows that, the water temperatures vary from 24.4˚C to 27.4˚C proving that the waters are from deep depths. For the use of these waters, it is necessary to take certain precautions. The pH values varied between 6.15 and 7.78, an average of 6.77 giving some waters an aggressive character. It was low mineralized, with electrical conductivity averages ranging from 182.1 to 2100 μS/cm−1 an average of 586.36 μS/cm−1. For the chemical parameters, it is by hydrometric titration that the content of the ions was determined. The determination of the various coliforms in these waters was carried out by its various methods which led to detecting that the waters of Kouba Adougoul are turbid, and present high proportions of nitrates, iron and ammonium. The presence of pathogenic germs, such as total coliforms and thermo-tolerant coliforms in these waters, has been demonstrated. For their consumption, these waters deserve treatment beforehand. In the study area, the anthropogenic activities are considered the most serious sources of groundwater.

CHADS2评分联合白蛋白水平与老年血液透析患者预后的关系

目的本研究旨在探索CHADS2评分联合白蛋白水平与老年血液透析患者预后的关系。方法回顾性分析2018年1月—2021年10月在南京市中西医结合医院进行血液透析的老年患者,按照生存情况分为生存组和死亡组,比较2组的临床基线资料、实验室指标、CHADS2评分,采用单因素和多因素Cox分析筛选老年血液透析患者的独立危险因素,并采用受试者工作特征曲线(receiver operating characteristic curve,ROC)分析评估CHADS2评分联合白蛋白水平与老年血液透析患者预后预测效能。结果生存组血红蛋白、血清白蛋白、高密度脂蛋白比死亡组水平高(P<0.05);生存组低密度脂蛋白比死亡组水平低(P<0.05);2组血清钙、血清磷水平差异无统计学意义。生存组CHADS2评分比死亡组低(P<0.05)。单因素Cox分析结果显示年龄、合并症(高血压、糖尿病)、低密度脂蛋白升高、CHADS2评分升高是患者预后的危险因素;血红蛋白升高、血清白蛋白升高、高密度脂蛋白升高是患者预后的保护因素。多因素Cox分析结果显示CHADS2评分升高是患者预后的独立危险因素;血清白蛋白升高是患者预后的独立保护因素。ROC曲线分析结果显示CHADS2评分与血清白蛋白水平联合对患者预后的预测效能更高。结论CHADS2评分是老年血液透析患者预后的独立危险性因素,白蛋白水平是老年血液透析患者预后的独立保护性因素,两者联合可为预测患者预后情况提供有效且可靠的参考。

Gensini评分联合CHADS2评分对急性缺血性卒中患者发生急性冠状动脉综合征的预测价值

目的:分析Gensini评分联合CHADS2评分对急性缺血性卒中(AIS)患者发生急性冠状动脉综合征(ACS)的预测价值。方法:对2019年1月至2022年1月期间治疗的185例AIS患者的一般资料及临床资料进行回顾性分析,依据患者是否发生ACS分为ACS组(n=39)和对照组(n=146),比较两组患者的各项一般资料和临床资料,对差异有统计学意义的因素进一步行Logistic多因素分析,明确AIS患者发生ACS的危险因素,并分别对Gensini评分、CHADS2评分与各危险因素的关系行Pearson相关性分析,以ROC曲线分析Gensini评分联合CHADS2评分对AIS患者发生ACS的预测价值。结果:Logistic多因素分析结果显示,年龄≥65岁、合并糖尿病、左室射血分数<50%、Gensini评分≥47分、CHADS2评分≥2分为AIS患者发生ACS的危险因素(P<0.05)。Gensini评分与年龄、糖尿病、CHADS2评分呈正相关(P<0.05),与左室射血分数呈负相关(P<0.05)。CHADS2评分与年龄、糖尿病、Gensini评分呈正相关(P<0.05),与左室射血分数呈负相关(P<0.05)。ROC曲线分析结果显示,Gensini评分预测AIS患者发生ACS的敏感度和特异度分别为65.38%和71.19%,最佳截断值为50分,曲线下面积(AUC)=0.766,95%CI为0.694-0.838;CHADS2评分预测AIS患者发生ACS的敏感度和特异度分别为77.56%和75.42%,最佳截断值为2分,AUC=0.864,95%CI为0.742-0.897;Gensini评分联合CHADS2评分预测AIS患者发生ACS的敏感度和特异度分别为87.65%和84.57%,AUC=0.924,95%CI为0.812-0.934。结论:Gensini评分、CHADS2评分均为AIS患者发生ACS的危险因素,且二者联合应用对AIS患者发生ACS有较佳的预测价值。

HIV and Seroconversion among Pregnant Women at the University Hospital of Mother and Child in Chad

Background: HIV in pregnant women presented a risk of transmission to newborns. This study was to determine HIV prevalence among pregnant women in the birthing rooms and give antiretrovirals to women infected and their newborns. Methods: A preliminary study was conducted from 2013 to 2015 at the Mother and Child Hospital. Pregnant women were counseled and tested for HIV-antibody according to the national algorithm using Determine HIV 1 & 2 and Immunocomb II Bispot HIV1 & 2. The women screened HIV-negative during the prenatal consultation and who accepted a second test were screened in the birth room. The data collected were processed using the Access Microsoft office 16 and SPSS software version 18. Results: A total of 6080 pregnant women were tested before and in the birth room. Of these, 5943 (97.4%) were detected as HIV-negative and 159 (2.6%) were HIV-positive. Of the 5943 with HIV-negative status, 1333 accepted the second test in the birth room, 10 of which have become HIV-positive. The rate of seroconversions was 0.75%. Conclusion: This study determined the prevalence of HIV in pregnant women. The result reveals the importance and necessity of repeating the screening test in the birth room because of the possibility of seroconversion or new infection during pregnancy.

Different Species of Salmonella spp and Shigella spp and Their Risk of Infection in N’Djamena Chad

Introduction: Salmonella and Shigella are gram-negative bacilli that are resistant to most antibiotics and play an important role in an etiology of diarrhea disease. The aim of the study was to determine the prevalence of Salmonella spp and Shigella spp isolated from stool and blood samples in the city of N’Djamena. Materials and Method: This was a prospective study conducted in the four district hospitals of N’Djamena from 14 July 2022 to 31 December 2022. A questionnaire form was drawn up to collect the information sent to the study patients. The samples were analyzed at the CHU de la Mère et de l’Enfant, Labo-Redes laboratory according to their protocols and the standard of the antibiogram committee of the French microbiology society. Results: Of the 803 biological samples analyzed, 39 were positive for Salmonella spp and Shigella spp, including 15 for Salmonella and 24 for Shigella, giving an overall prevalence rate of 4.85%. Borehole water, uncooked food and lack of access to a latrine constitute a risk of being infected by Salmonella spp and Shigella spp species. Of the 8 antibiotics tested, Salmonella spp and Shigella spp strains showed good sensitivity to nalidixic acid (100% for Salmonella and 90 for Shigella) and to ciprofloxacin (90.9% for Salmonella and 75% for Shigella). Resistance to ampicillin was found in 81.81% of Salmonella species and 78.57% of Shigella species, as was resistance to chloramphenicol (81.81% of Salmonella species and 67.85% of Shigella species). Similarly, cleanliness of the service and equipment is an essential factor in preventing Salmonella and Shigella infections.

Study of the Germination of Scarified Seeds of Burkea africana Hook. For Its Domestication in Chad

The objective of this work was to determine new approaches that could improve the germination quality of Burkea africana seeds under reproducible conditions and by means available to farmers with a view to its propagation. The tests concerned the influence of three pre-germinative treatments. It is about the light scarification (Scl), medium scarification (Scm) and deep scarification (Scd) of seeds in order to determine some parameters of germination that are the latency time, the time of germination, the rate of germination and the speed of germination. The treated seeds were sown in transparent germinators lined with hydrophilic paper and then after the appearance of radicles, the plants were transplanted on five types of substrates (black soil, fine sand, sawdust, mixtures 1/1 of sawdust-black soil and 1/1 of sawdust-fine sand). The results obtained by the deep (Scp) and medium (Scm) scarification compared to those of the light scarification and the control, showed a clear reduction of the lag time (3 days/15 days (control). At the 5% threshold, germination times 6.27 × 10-1 (Scd) and 6.01 × 10-1 (Scm) were significantly influenced. Germination rates 4.18 × 10-1 (Scd) and 3.92 × 10-1 (Scm) are also influenced by the pretreatment. Germination rates are significantly improved (80%). Regardless of the under treatment, the substrate “sawdust and fine sand” improves the germination of scarified seeds by 14.07% more compared to the substrate “fine sand” at the 5% threshold. The mechanical scarification and the type of substrates thus influence positively and homogeneously the germination of seeds of Burkea africana. The domestication of this species is thus possible and can be considered for useful purposes.

Hepatocellular Carcinoma in Chad: A Retrospective Study of 219 Cases

Background: Although hepatocellular carcinoma was historically considered an important scourge in Middle Africa, there is no publication describing this disease in Chad. Methods: We conducted a retrospective analysis of 219 patients with hepatocellular carcinoma (HCC) attending care at the University Reference Hospital of Ndjamena between 2007 and 2016. Results: This series of HCC was characterized by a male predominance (M:F = 2.4) with a mean tumor onset at the end of the fifth decade of life (49.9 ± 14.7 years). Tumors appear on a cirrhotic liver in 70% of cases and were already multifocal at diagnosis in two thirds of the patients. Alpha-fetoprotein was above the physiological threshold (10 ng/mL) in 73.4% of cases measured and above the so-called diagnostic level (400 ng/mL) in 53.4% of patients. The principal risk factor was chronic infection with hepatitis B virus, detected in 52.6% of cases. Patients seropositive for hepatitis C virus were infrequent (8.6%) and heavy alcohol intake was even less prevalent (5.9%). Remarkably, a very large subset of patients did not present any infectious or lifestyle risk factor (43.4%). Mean AFP values or fibrosis assessment scores are usually lower in these patients than in HBV-infected ones. Conclusions: The etiological spectrum of HCC is far from being fully established in Chad. Further epidemiological research is warranted to identify risk factors involved in a large proportion of cases. Exposure to aflatoxin B1 and dysmetabolic conditions affecting the liver have to be investigated as priority.

Risk Factors of Liver Cirrhosis in Chad: Large Proportion of Cases without Clear Etiology

Background: In comparison to other forms of chronic liver diseases, cirrhosis is generally poorly studied in sub Saharan Africa. In Chad, more particularly, no data are available despite the burden of liver diseases considered as the first cause of hospitalizations in the country. Methods: We conducted a retrospective analysis of 268 patients with liver cirrhosis attending care at the University Reference Hospital between 2007 and 2016. Results: This series of liver cirrhoses was characterized by a weak mal predominance (M:F = 1.7). The age of onset occurs significantly earlier in women than in men (40.6 ± 12.0 vs. 44.4 ± 13.4, p = 0.0171). The principal risk factor was persistent infection with hepatitis B virus (49% of cases) followed distantly by infection with hepatitis C virus (13%) and excessive alcohol consumption (10%). Men were more frequently carrying HBV surface antigen than women (65.6% vs 35.9% p = 0.0019). HBV-associated liver cirrhosis was overall more severe than diseases from other causes. A large proportion of cirrhosis (30%), observed primarily in women (48.1% vs 24.1%, p = 0.0036), was considered are cryptogenic. Conclusions: The etiological spectrum of liver cirrhosis remains to be properly defined in Chad. This lack of knowledge prevents the implementation of an efficient policy of prevention. A significant effort should be secured to characterize hitherto neglected infectious, lifestyle or genetic risk factors responsible of this form of terminal disease and improve subsequently liver health of local populations.