Epidemiology and Molecular Analyses of Influenza B Viruses in Senegal from 2010 to 2019.

Influenza virus types A and B are responsible for acute viral infections that affect annually 1 billion people, with 290,000 to 650,000 deaths worldwide. In this study, we investigated the circulation of influenza B viruses over a 10-year period (2010-2019). Specimens from patients suspected of influenza infection were collected. Influenza detection was performed following RNA extraction and real-time RT-PCR. Genes coding for hemagglutinin (HA) and neuraminidase (NA) of influenza B viruses were partially sequenced, and phylogenetic analyses were carried out subsequently. During the study period, we received and tested a total of 15,156 specimens. Influenza B virus was detected in 1322 (8.7%) specimens. The mean age of influenza B positive patients was 10.9 years. When compared to reference viruses, HA genes from Senegalese circulating viruses showed deletions in the HA1 region. Phylogenetic analysis highlighted the co-circulation of B/Victoria and B/Yamagata lineage viruses with reassortant viruses. We also noted a clear seasonal pattern of circulation of influenza B viruses in Senegal.

[Smoking in People Living with HIV (PLHA) and followed up in the Outpatient Department of the Hospital Fann of Dakar]. / Le tabagisme chez les patients vivant avec le VIH (PvVIH) suivis au Centre de Traitement Ambulatoire de l'Hôpital Fann de Dakar.

INTRODUCTION: PLHA who smoke have twice the never-smoker mortality rate and have an increased risk of developing non-AIDS diseases. The prevalence of tobacco smoking is higher among PLHA than in the general population. The purpose of this study was to assess the prevalence of smoking among PLHA, to describe the clinical and spirometric features of smokers and ex-smokers and to assess their knowledge and attitudes toward smoking. METHODS: We conducted a cross-sectional, descriptive and analytical study among PLHA followed up in the Outpatient Department of the National University Hospital Center of Fann from 15 July to 15 December 2015. RESULTS: Three hundred (300) PLHA were included in the study. Sex ratio was 0.8. Out of the study population, 15% were smokers and 23.7% were ex-smokers. The average age of patients was 44.38±9.55 years. The quasi-totality of the smokers (91.1%) had already started smoking before the detection of the serological status and 35.6% of them had increased tobacco use after. Respiratory symptoms among smokers were dominated by respiratory distress (64.4%). Smokers who underwent spirometry had obstructive ventilatory impairment not improved by beta-2-mimetic agents (67%) and restrictive disease (28.1%). Out of ex-smokers, 40.8% reported that their serological status was the reason for smoking cessation. CONCLUSION: People may begin or increase smoking after knowledge of serological status. In PLHA, smoking causes cardiovascular and respiratory diseases as well as complications.

Mitochondrial DNA Mutations and Rheumatic Heart Diseases.

Acute rheumatic fever (ARF) is an autoimmune disease affecting the heart-valve endocardium in its final stage. Although rare in developing countries, ARF persists in third-world countries, particularly Senegal, where rheumatic heart diseases (RHDs) are the most common pediatric cardiovascular pathology. This study aimed to investigate mutations in MT-CYB in ARF and RHD in Senegalese patients. MT-CYB was amplified from blood samples from ARF patients at the Clinical of Thoracic and Cardiovascular Surgery of Fann National University Hospital Centre, Dakar, Senegal (control group, healthy individuals) and sequenced. More than half of the MT-CYB mutations (58.23%) were heteroplasmic. Transitions (61.67%) were more frequent than transversions (38.33%), and non-synonymous substitutions represented 38.33% of mutations. Unoperated RHD patients harbored frequent MT-CYB polymorphisms (7.14 ± 14.70 mutations per sample) and accounted for 72.73% of mutations. Paradoxically, subjects undergoing valvular replacement harbored infrequent polymorphisms (1.39 ± 2.97 mutations per patient) and lacked 36 mutations present in unoperated subjects. A genetic differentiation was observed between these two populations, and the mutations in operated subjects were neutral, while those in unoperated subjects were under positive selection. These results indicate a narrow link (perhaps even causal) between MT-CYB mutations and ARF and its complications (i.e., RHDs) and that these mutations are largely deleterious.

Somatic Mitochondrial Mutations in Oral Cavity Cancers among Senegalese Patients.

Background: Somatic mutations affecting the mitochondrial DNA (mtDNA) have been frequently observed in human cancers and proposed as important oncological biomarkers. However, the exact mtDNA mutations that is responsible for the pathogenesis of cancer remains unclear. The aim of this study was to investigate somatic mutations in the MT-CYB and D-Loop regions of mitochondrial DNA (mtDNA) in oral cavity cancers from Senegalese patients. Methods: MT-CYB and the D-Loop of mtDNA derived from 45 oral cavity cancer tissues and 21 control blood samples were assessed by PCR and sequencing. The sequences of MT-CYB and the D-Loop from cancerous tissues were compared with control sequences, and sequence differences were recognized as somatic mutations. Results: Overall, 389 somatic mtDNA mutations were identified, most of which (79.43%) were located in the D-Loop region. The majority of base substitution mutations were G-to-A (63.93%) and T-to-C (16.39%) transitions. In the protein-coding MT-CYB gene, 29 missense mutations were observed. The pathogenic mutation load of MT-CYB was 3.11%. Pathogenic mutations were carried by 25% of patients. pArg76Pro (pArg282Pro in rCRS) was novel and was the most common pathogenic mutation observed. Conclusion: These results strongly indicate that mtDNA mutations are a potential marker of oral cavity cancer.

[Radiological features of microscopy-positive pulmonary tuberculosis in patients in the Pneumology Department at the National University Hospital, Fann, Dakar (Sénégal)]. / Particularités radiologiques de la tuberculose pulmonaire à microscopie positive au Service de Pneumologie du Centre Hospitalier National Universitaire de FANN (CHNUF), Dakar (Sénégal).

This study aimed to determine the radiological features of microscopy-positive pulmonary tuberculosis (TB). We conducted a retrospective study, analyzing radiographical imaging of patients with microscopy-positive pulmonary tuberculosis between 15 November 2015 and 15 March 2016. The medical records of 66 patients meeting the inclusion criteria were selected, 81.8% of which belonged to men. The average age of patients was 37.5 ± 14.9 years. Patients had variable parenchymal lesions dominated by infiltrated lesions in 84.8% (CI 95%; 73.9-92.4%) of cases, followed by alveolar syndrome in 68.2% (CI95%; 55.5-79.1%) of cases. Lesions were extensive in 71.2% (CI 95%; 58.7-81.7%) of cases and bilateral in 45.4% (CI 95%; 31.1-58.1%) of cases. These radiological abnormalities occurred in 52.2% (CI 95%; 36.9 - 67.1%) of cases in undernourished patients. In 22.7% (CI 95%; 13.3-34.7%) of cases, these lesions were secondary to an episode of pulmonary tuberculosis; 34.8% (IC95; 23.5 - 47.5%) of patients were regular tobacco smokers consuming, on average, 17 tobacco packs per year (±11.3). TB recurrences were more frequent in patients with a history of smoking versus non-smokers (26.1% versus 20.9%, p < 0.42 respectively). HIV-1 serology test was positive in 7.6% of cases. This study highlights the importance of suspecting pulmonary tuberculosis in young undernourished patients, having a history of smoking, with infiltrated lesions associated or not with cavitary lesions on radiographic examination and living in TB epidemic area.