The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Data Cardiomyopathy

feuille de données SPSS contenant les données brutes d'une étud

Dyslipidemia in Patients with a Cardiovascular Risk and Disease at the University Teaching Hospital of Yaoundé, Cameroon

Objective. To determine the frequency of lipid abnormalities in patients with a cardiovascular risk and disease at the University Teaching Hospital (UTH) of Yaoundé. Materials and Methods. We conducted a cross-sectional study from 1 March to 31 May 2015 at the UTH of Yaoundé. We included all patients seen in the outpatient department with a diagnosis of a cardiovascular disease or a risk factor for cardiovascular disease. Patients who accepted to participate in the study were asked to answer a questionnaire; after that a blood sample was taken for lipid profile. An informed consent was signed by all the participants and the study has received approval from the national ethic committee. Results. We recruited 264 patients of which 119 were men and 145 were women with a sex ratio of 0.82. Mean age was 61.36 years. The frequency of lipid profiles abnormalities was as follows: low HDL cholesterol (44.3%), hypertriglyceridemia (18.9%), high LDL cholesterol (3.8%), and high total cholesterol 3.4%). Hypertriglyceridemia was strongly associated with type 2 diabetes mellitus. Conclusion. Low levels of HDL cholesterol and hypertriglyceridemia are more prevalent in our study population. More studies are needed to confirm this finding in our environment

Vascular hyperreactivity in black Cameroonian hypertensive and normotensive patients: A comparative study

Introduction: Vascular hyperreactivity is a risk factor and a factor predicting hypertension (high blood pressure). Unlike other continents where several studies were carried out, it has rarely been studied in black Africa in general and in  Cameroon in particular.Methods: Vascular reactivity was measured by the cold test. Vascular  hyperreactivity was defined as an increase in blood pressure > 20 mmHg for systolic and/or > 15 mmHg for diastolic. Khi2, Man-Withney, Wilcoxon's signed ranks and logistic regression tests were used for statistical analysis.Results: A total of 31 hypertensive and 31 normotensive patients matched by age and sex participated in this study. Vascular hyperreactivity was present in 77.4%hypertensive patients and 51.6% normotensive patients. There was a significant association between vascular hyperreactivity and hypertension [OR = 3.2 (1.07 - 9.63), p = 0.034]. The median arterial pressure was higher in responders compared to non-responders in the normotensive group. Age > 45 years, female sex, obesity and family history of hypertension appeared to be associated with vascular hyperreactivity, but only in normotensive patients.Conclusion: Vascular hyperreactivity appears to be a risk factor for high blood pressure in black Cameroonians. Itappeared to be associated with low blood pressure, age, sex, obesity and family history of hypertension but this was only in the normotensive. Key words: Vascular hyperreactivity, high blood pressure, black Cameroonian, cold tes

HIV care in Cameroon: a missed opportunity to screen for high blood pressure among adults living with HIV/AIDS?

Background: Two third of the thirty-seven million people living with HIV/AIDS (PLWHA) globally live in Africa. With the advent of antiretroviral drugs, African PLWHA are living longer and are at increased risk of cardiovascular diseases including high blood pressure (HBP). In this preliminary study, we assessed how often blood pressure (BP) was measured and recorded and the prevalence of HBP in PLWHA followed at three hospitals in Cameroon.Methods: We retrospectively analysed the blood pressure measurement frequency and data of patients enrolled in the HIV care at the Limbe Regional hospital, Bamenda Regional hospital and the Jamot hospital in Yaounde from 2014 to 2017. Files of all PLWHA aged ≥21years were reviewed. Sociodemographic, laboratory and clinical data were captured. HBP was defined as systolic (and/or diastolic) blood pressure (BP)≥ 140 (90) mm Hg, or ongoing BP- lowering medications. Analysis were done using Epi info version 2.0. Statistical significance was set at p-value<0.05 at 95% confidence interval.Results: Of 991 medical files examined, 875 files (88.3%) had BP recorded at least once during the study period among which only 418 (47.8%) participants at enrolment in care. 281 (67.2%) were women, mean age was 42.6±10.6 years. The prevalence of HBP was 24.2% in 2014, dropped to 20.2% in 2015, rose to 26.3% in 2016, then dropped again to 18.9% in 2017. Compared with females, this prevalence was consistently higher among males each year.Conclusion: Less than half of PLWHA had their BP recorded at enrolment in HIV care but almost 1 of every 5 of these patients had HBP. The trend of HBP prevalence over the study period was inconsistent due to poor recording. These results warrant awareness raising for HBP screening in HIV treatment centres and further studies in larger sample with a longer follow-up period to better understand the occurrence of HBP in PLWH.Keywords: HIV/AIDS, High Blood Pressure, opportunity, trend, prevalence, Cameroo

Evaluation of pharmacological management of acute hypertensive heart failure in two Reference Hospitals of Yaoundé: a cross-sectional study

Introduction: Heart failure is a major cause of cardiovascular mortality and morbidity in sub-Saharan Africa with hypertension being one of its main drivers. We aim to assess the pharmacologic management of acute heart failure secondary to hypertensive heart disease in two reference hospitals of Yaoundé.Methods: This was a retrospective cross-sectional study spanning from January 2017 to December 2018. It was carried out in the cardiology units of the Yaoundé Central hospital and General hospital. Patients’ medical records were used for data collection. We included all patients aged 18 years or more, who were admitted for acute heart failure secondary to hypertensive heart disease and who had two-dimensional echocardiography with reduced ejection fraction and/or signs of diastolic dysfunction.Results: We found 159 patients who met the inclusion criteria. The mean age was 69.5 ± 12.9 years with a sexratio of 0.73. There was a greater proportion of patients with preserved left ventricular ejection fraction  compared to those who had mid-range or reduced left ventricular ejection fraction. Almost all 157 (98.7%) ofthe patients were treated with diuretics (loop diuretics and/or thiazides) and 15 (9.4%) with vasodilators (nitrates). Angiotensin converting enzyme inhibitors were administered to 100 (62.9%) patients and angiotensin II receptor blockers to 16 (10.1%) patients. None of them have received an inotropic agent. The inhospital dead rate was25 (15.7%) and there was no significant difference between those who received diuretics alone or in combination with vasodilators.Conclusion: Loop diuretics are the first-line drugs used for treatment of acute hypertensive heart failure in Yaoundé. Only a few patients were treated with vasodilators. More multicenter research with bigger samples sizes are needed to determine the optimal treatment for the management of acute HF in Sub-Saharan Africa. Keywords: pharmacologic management, acute heart failure, hypertensive heart disease, Yaoundé French abstract: Evaluation du traitement pharmacologique de l’insuffisance cardiaque d’origine hypertensive dans deux hôpitaux de référence de Yaoundé : une étude transversaleIntroduction. L’insuffisance cardiaque est une cause majeure de morbi-mortalité cardiovasculaire en Afrique subsaharienne dont l’hypertension artérielle constitue une des principales causes. Nous avons voulu évaluer le traitement pharmacologique de l’insuffisance cardiaque congestive due à la cardiopathie hypertensive chez des patients Camerounais. Méthodes : Il s’agissait d’une étude transversale rétrospective menée à l’hôpital central et l’hôpital général de Yaoundé sur la période allant de Janvier 2017 à Décembre 2018. Les données sociodémographiques, cliniques et thérapeutiques ont été collectées dans les dossiers médicaux des patients. Nous avons inclus des patients âgés d’au moins 18 ans, admis pour prise en charge d’une insuffisance cardiaque congestive sur cardiopathie hypertensive et ayant une échocardiographie bidimensionnelle avec une diminution de la fraction d’éjection et/ou une dysfonction diastolique. Résultats : Nous avons retrouvé des dossiers de 159 patients remplissant les critères d’inclusion. L’âge moyen des patients était de 69,5 ± 15,9 ans avec un sex-ratio de 0,73. La plus grande proportion des patients avait une fraction d’éjection préservée 72 (45,3%). La quasi-totalité des patients 157 (98,7%) était traitée avec des diurétiques (de l’anse et/ou thiazidiques) et 15 (9,4%) avec des vasodilatateurs (dérivés nitrés). Aucun patient n’avait reçu d’inotrope. Les inhibiteurs de l’enzyme de conversion ont été prescrits chez 100 (62,9%) patients et le antagoniste des récepteurs de l’angiotensine II chez 16 (10,1%) patients. La mortalité hospitalière était de 25 (15,7%) et il n’y avait aucune différence significative entre les patients traités par diurétiques seuls ou en combinaison avec les vasodilatateurs. Conclusion : Les diurétiques de l’anse représentent le traitement de première ligne de l’insuffisance cardiaque congestive à Yaoundé. Très peu de patients ont été traités avec des vasodilatateurs. Des études ultérieures multicentriques portant sur un plus grand échantillonnage sont nécessaires afin de mieux préciser le traitement optimal de prise en charge de l’insuffisance cardiaque congestive en Afrique Sub-Saharienne. Mots clés : traitement pharmacologique, insuffisance cardiaque aigue, cardiopathie hypertensive, Yaoundé

Knowledge, attitudes and practices of cardiovascular disease risk factors in in a self-selected group of adults with HIV infection in Cameroon.

Background: Human Immune-deficiency Virus (HIV) infection is a public health problem worldwide, with the greatest burden in low-income settings. Increased survival associated with the use of anti-retroviral treatment is associated with an increase in the burden of cardiovascular disease (CVD). Primordial prevention of CVD requires an adequate knowledge, attitude, and practice of the risk factors.Aim: Assess the knowledge, Attitude, and Practices (KAP) of CVD risk factors in adults with HIV infection in Cameroon.Methods: We carried out a KAP survey at the Yaounde Central Hospital. Participants were consenting adults with HIV, aged > 18 years, of both sex who received regular care at the day hospital. Each participant had a face-to-face interview with a trained investigator using a standardized questionnaire.Results: A total of 329 participants were interviewed. Their mean age was 46.6 ± 10.6 years. Ten (3%) participants had good knowledge of CVD risk factors. Higher level of education was associated with good Knowledge (OR: 3.9, [95% CI: 2 – 7.6], p<0.001). Obtaining information from the staff (OR 0.3 [95% CI: 0.2–0.6], p <0.001), and having a family history of cardiovascular diseases (OR = 0.4 [95% CI: 0.2–0.7], p = 0.004) was associated with good knowledge. 211 (64.1%) participants had inappropriate attitudes, and 40 (12.2%) participants had adequate practices. These were associated with the level of knowledge (OR = 2.0, [95% CI: 1– 3.9], p = 0.040).Conclusion: This study suggests that people with HIV in Cameroon have poor knowledge of cardiovascular risk factors, and this is associated to inadequate practices towards CVD risk factors.Key words: Knowledge, Attitudes, Practices, HIV, Cardiovascular risk factors

Clinical outcome of patients with venous thromboembolism on Rivaroxaban versus vitamin K antagonists : A preliminary report from Douala, Cameroon

Background: Direct Oral Anticoagulants (DOACs) which are increasingly used for the management of Venous Thromboembolism (VTE) have demonstrated efficacy and safety in clinical trials. However, little is known on outcomes in those managed with DOACs compared to Vitamin K Antagonists (VKAs) in routine clinical practice in Africa. In this preliminary study, we sought to compare the non-fatal clinical outcomes in VTE patients managed with Rivaroxaban versus VKAs in Douala. Materials and Methods: This preliminary study analyzed medical records of VTE patients managed with oral anticoagulants over a 3-year retrospective period in Douala General Hospital and Douala Cardiovascular Center. Outcomes of interest included bleeding, recurrent VTE and post-thrombotic syndrome. Data was analyzed using SPSS version 23. Results: Eighty-seven medical records were identified; Deep venous thrombosis (DVT) was diagnosed in 36.8% and 13.8% had both DVT and pulmonary embolism. Rivaroxaban was prescribed in 77% of cases. We included 82 medical records for the outcome analysis. Adverse clinical outcomes were recorded in 19 (23.2%) medical records amongst which 15 (78.9%) in the Rivaroxaban group. All (4 patients) who bled, 6 (66.7%) patients who had VTE recurrence and 5 (71.4%) patients with post-thrombotic syndrome were managed with Rivaroxaban, however, these were not statistically significantly different from those managed with VKAs. No predictor of clinical outcome was identified. Though more outcomes occurred within 30 days of oral anticoagulation, this was not statistically significant. Conclusion: Three-quarters of VTE patients were managed with Rivaroxaban. Although more bleeding was observed with rivaroxaban group, clinical outcomes were similar with VKA group. This seeds the idea of a prospective study in real life with a larger sample size in Africa. Keywords: Outcomes, Deep vein thrombosis, pulmonary embolism, Venous thromboembolism, Oral anticoagulation, Cameroo

Magnitude, determinants and reasons for parallel use of plants in the management of hypertension in Cameroon: a cross-sectional study

Background: Most people living in sub-Saharan Africa tend to use medicinal plants to treat various ailments including hypertension. The aim of this study was to gather data on the magnitude, determinants, and reasons for their use in the setting of hypertension in our setting.Method: We carried out a cross-sectional study in a group of patients with hypertension in Yaounde. This study was carried out between November 2016 and April 2017. In a face-to-face interview, we gathered data on socio-demography, use of medicinal plants, parts of plant used, method of preparation, and prescriber of herbal remedy.Results: Overall, 410 individuals (152 males and 258 females) participated in the study. The mean age was 66.6 ± 11.1 years. Use of medicinal plants was reported by 149 patients (36.3%, [95% CI: 32 – 41]). The most frequently used plants were Annona muricata (47.7%), Allium sativum (37.6%), and Cymbopogon citratus (37.6%). The main reason underlying the parallel use of plants was a supposed synergistic effect (34.9%). The most used parts of plants were the leaves (81.2%). Decoction was the most frequent mode of preparation (68.5%). Friends mostly recommended the herbal remedy (51.7%). No factor was associated with the parallel use of medicinal plants.Conclusion: More than one in three patients with hypertension use medicinal plants mostly as decoction of the leaves besides conventional treatment. This use was mainly supported by a supposed synergistic action.Keywords: Plants, Hypertension, Cameroo

Rationale and design of the Pan-African sudden cardiac death survey: The Pan-African SCD study

Background: The estimated rate of sudden cardiac death (SCD) in Western countries ranges from 300,000 to 400,000 annually, which represents 0.36 to 1.28 per 1 000 inhabitants in Europe and the United States. The burden of SCD in Africa is unknown. Our aim is to assess the epidemiology of SCD in Africa. Methods: The Pan-Africa SCD study is a prospective, multicentre, community-based registry monitoring all cases of cardiac arrest occurring in victims over 15 years old. We will use the definition of SCD as \u27witnessed natural death occurring within one hour of the onset of symptoms\u27 or \u27unwitnessed natural death within 24 hours of the onset of symptoms\u27. After approval from institutional boards, we will record demographic, clinical, electrocardiographic and biological variables of SCD victims (including survivors of cardiac arrest) in several African cities. All deaths occurring in residents of districts of interest will be checked for past medical history, circumstances of death, and autopsy report (if possible). We will also analyse the employment of resuscitation attempts during the time frame of sudden cardiac arrest (SCA) in various patient populations throughout African countries. Conclusion: This study will provide comprehensive, contemporary data on the epidemiology of SCD in Africa and will help in the development of strategies to prevent and manage cardiac arrest in this region of the world