Alpha Kabinet KEITA

Université Gamal Abdel Nasser de Conakry

Tropheryma whipplei is known as the cause of Whipple's disease, but it is also an emerging pathogen, detected in stool, that causes various chronic localized infections without histological digestive involvement and is associated with acute infections, including gastroenteritis and bacteremia. We conducted a study in 2008 and 2009 using 497 non-dia...

Background With the increasing frequency and impact of Ebola virus disease (EVD) outbreaks illustrated by recent epidemics, good knowledge on extent of viral persistance or RNA detection in body fluids from survivors is urgently needed. Methods Ebola viral RNA shedding was studied with molecular assays in semen (n=1,368), urine (n=1,875), cervico-...

Zoonoses can constitute a threat for public health that can have a global importance, as seen with the current COVID-19 pandemic of severe acute respiratory syndrome coronavirus (SARS-CoV2). Bats have been recognized as an important reservoir of zoonotic coronaviruses (CoVs). In West Africa, where there is a high diversity of bat species, little is...

The progression of the SARS-CoV-2 pandemic in Africa has so far been heterogeneous and the full impact is not yet well understood. Here, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations predomina...

Seven years after the declaration of the first epidemic of Ebola virus disease in Guinea, the country faced a new outbreak—between 14 February and 19 June 2021—near the epicentre of the previous epidemic1,2. Here we use next-generation sequencing to generate complete or near-complete genomes of Zaire ebolavirus from samples obtained from 12 differe...

Background Several variants of SARS-CoV-2 have a demonstrated impact on public health, including high and increased transmissibility, severity of infection, and immune escape. Therefore, this study aimed to determine the SARS-CoV-2 lineages and better characterize the dynamics of the pandemic during the different waves in Guinea. Methods Whole gen...

In Guinea, genomic surveillance has been established to generate sequences and identify locally circulating SARS-CoV-2 variants. This study aims to describe the distribution, genetic diversity, evolution, and origin of SARS-CoV-2 lineages circulating in Guinea during the COVID-19 pandemic. We performed a migration analysis by selecting all sequence...

Background: In December 2019, the world experienced one of the significant health crises of the 21 st century with the emergence and rapid spread of the potentially fatal 2019 coronavirus (COVID-19). In this context, sentinel surveillance of SARS-CoV-2 variants was conducted in Conakry. Here we report the first data on reproduction numbers and risk...

Background The arboviruses continue to be a threat to public health and socioeconomic development in sub-Saharan Africa (SSA). Seroprevalence surveys can be used as a population surveillance strategy for arboviruses in the absence of treatment and vaccines for most arboviruses, guiding the public health interventions. The objective of this study wa...

Background This study aimed to demonstrate that the genomic material of SARS-CoV-2 can be isolated from strips of COVID-19 rapid diagnostic test cassettes. Method It was a prospective cross-sectional study involving patients admitted to treatment centers and sampling sites in the city of Conakry, Guinea. A total of 121 patients were double sampled...

Objectives: This study aimed to investigate the prevalence of orthoebolavirus antibodies in Madina Oula, a non-epidemic rural area in Guinea, in 2022. Methods: A cross-sectional study conducted from March 14 to April 3, 2022, involved recording household and socio-demographic characteristics, lifestyle data, and collecting dried blood spots (DBS)...

Background The escalating risk and contemporary occurrences of arbovirus infections prompt a critical inquiry into the ability of nations to execute efficient surveillance systems capable to detect, prevent and respond to arbovirus outbreaks. Healthcare workers (HCWs) are the major actors in the surveillance of infectious diseases with epidemic pot...

The seroprevalence to orthoebolaviruses was studied in 9594 bats (5972 frugivorous and 3622 insectivorous) from Cameroon, the Democratic Republic of Congo (DRC) and Guinea, with a Luminex-based serological assay including recombinant antigens of four orthoebolavirus species. Seroprevalence is expressed as a range according to different cut-off calc...

We investigated factors which might influence the circulation of ebolaviruses in fruit bats in Guinea in order to better understand their role in the ecology of ebolaviruses and evaluate risks of spill-over to other animals or humans. We performed serological tests on populations of 4 bat species (Eidolon helvum, Hypsignathus monstrosus, Lissonycte...

Background Several variants of SARS-CoV-2 have a demonstrated impact on public health, including high and increased transmissibility, severity of infection and immune escape. Therefore, this study aimed to describe the genetic modifications and distribution of SARS-CoV-2 lineages and better characterize the dynamics of the pandemic during the diffe...

Background We aimed to estimate the SARS-CoV-2 seroprevalence among the general population in Conakry, Guinea and Yaounde, Cameroon after the COVID-19 Omicron wave. Methods We conducted population-based age-stratified seroprevalence surveys in Conakry, Guinea and Yaounde, Cameroon (May and June 2022). We collected demographic, epidemiologic inform...

Bats are at the origin of human coronaviruses, either directly or via an intermediate host. We tested swabs from 4597 bats (897 from the Democratic Republic of Congo (DRC), 2191 from Cameroon and 1509 from Guinea) with a broadly reactive PCR in the RdRp region. Coronaviruses were detected in 903 (19.6%) bats and in all species, with more than 25 in...

RESUME: La Guinée et la République Démocratique du Congo (RDC) sont deux pays confrontés à des maladies zoonotiques (ré)émergentes, lesquelles représentent de graves menaces pour la santé publique et pour l'économie. Cela renforce l'importance de mettre l'accent sur les approches interdisciplinaires pour la prévention, la détection et l'atténuation...

We conducted three successive seroprevalence surveys, three months apart, using a multistage cluster sampling to measure the extent and dynamics of the SARS-CoV-2 epidemic in Conakry, the capital city of Guinea. Seroprevalence increased from 17.3% (95% CI: 12.4-23.8) in December 2020 during the first survey (S1) to 28.9% (95% CI: 25.6-32.4%) in Mar...

Data regarding the prevalence and consequences of self-medication during the COVID-19 pandemic in Africa are very limited. The study aimed to explore the frequency and risk factors of self-medication against COVID-19 by health personnel in this study. This cross-sectional study took place in June 2021, in Conakry, in the all three national hospital...

Acetaminophen is a well-known as analgesic and antipyretic drug. It is considered to be safe when administered within its therapeutic range. However, in cases of intoxication, hepatotoxicity can occur. This was a cross-sectional study including persons who went to a pharmacy of Conakry to buy acetaminophen without a prescription. Data were collecte...

Investment in Africa over the past year with regards to SARS-CoV-2 genotyping has led to a massive increase in the number of sequences, exceeding 100,000 genomes generated to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence within their own borders, coupled with a decrease in sequ...

Background: Emergence of mosquito-borne arboviruses has caused significant public health burden. The life cycle of arboviruses comprises sylvatic and urban cycles, including a wildlife reservoir, a human host, and an arthropod vector. However, many questions remain on the sylvatic cycles of arboviruses. In this study, we investigate the prevalence...

We conducted three successive seroprevalence surveys, three months apart, using a multistage cluster sampling to measure the extent and dynamics of the SARS-CoV-2 epidemic in Conakry, the capital city of Guinea. Seroprevalence increased from 17.3% (95% CI: 12.4-23.8) in December 2020 during the first survey (S1) to 28.9% (95% CI: 25.6-32.4%) in Mar...

The progression of the SARS-CoV-2 pandemic in Africa has so far been heterogeneous and the full impact is not yet well understood. Here, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations predominantl...

Background The viral load has become an indispensable tool in evaluating antiretroviral therapy (ART) in people living with HIV / AIDS. This study aimed to assess virological suppression among in people living with HIV / AIDS on antiretroviral therapy in Guinea.Methods This was a descriptive cross-sectional study of more than three years that invol...

Background Insufficient long-term data are available on antibody kinetics in survivors of Ebola virus disease (EVD). Likewise, few studies, with very small sample sizes, have investigated cross-reactions between Ebolavirus spp. In this study, we aimed to assess the humoral antibody response and its determinants in survivors of EVD and assess cross-...

Background: The Expanded Program on Immunisation has made it possible to prevent more than 3 million deaths in children under 5 years. The objectives of this study were to estimate the vaccination coverage of children from 0 to 59 months and identify factors associated with incomplete vaccination coverage. Methods: A cross-sectional study was carr...

The progression of the SARS-CoV-2 pandemic in Africa has so far been heterogeneous and the full impact is not yet well understood. Here, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations, predominant...

Background: Longitudinal analyses are needed to better understand long-term Ebola virus disease (EVD) sequelae. We aimed to estimate the prevalence, incidence and duration of sequelae and identify risk factors associated with symptom occurrence among EVD survivors in Guinea. Methods: We followed 802 EVD survivors over 48 months and recorded clin...

On January 30, 2020, the World Health Organization designated the outbreak as a Public Health Emergency of International Scope (USPPI). The purpose of this study was to assess the knowledge, attitudes and practices of medical personnel on the prevention of Covid-2019. A cross-sectional study among front-line health workers in the health facilities...

Long-term follow up studies from Ebola virus disease (EVD) survivors (EBOV_S) are lacking. Here, we evaluate immune and gene expression profiles in 35 Guinean EBOV_S from the last West African outbreak, a median of 23 months (IQR [18–25]) after discharge from treatment center. Compared with healthy donors, EBOV_S exhibit increases of blood markers...

The ebola epidemic that raged in West Africa between 2013 and 2016 was the largest since the discovery of the virus in 1976. During this epidemic, more than 11,000 cases were notified with a lethality of over 67%. Several means of transmission have been described. The great difficulty noted during the epidemic was the estimation of the number of as...

Background The tremendous size of the 2013-2016 West African outbreak of Ebola virus disease (EVD) resulted in a sizeable population of survivors, many reporting short-term sequelae such as arthralgia and myalgia. Objectives We aimed to report a detailed and long-term description of patients’ musculoskeletal (MS) symptoms. Methods We performed a...

The current outbreak occurring in the Congo highlights the continuous challenge that the continent of Africa faces with Ebola outbreaks. Since the first recorded Ebola outbreak occurred simultaneously in Democratic Republic of Congo (DRC) and in Sudan in 1976, there have been 27 recorded outbreaks in Africa by country with the most severe occurring...

Emerging infectious diseases appear recurrently and represent a threat to global health security. Africa is particularly exposed to the risks of infectious epidemics, due to both the number of circulating infectious agents, especially in wildlife, and the social and environmental factors that promote their epidemic spread. Ebola outbreaks in West A...

Clinical follow-up of Ebola virus disease (EVD) survivors revealed a persistence of clinical symptoms and higher risk of mortality. Long-term analyses of the immune and inflammatory profiles of EVD survivors are currently lacking. Here, we evaluate immune profile status and gene expression profiles in 35 Guinean EVD survivors (EBOV_S) from the last...

Background The prevalence of Ebola virus infection among people who have been in contact with patients with Ebola virus disease remains unclear, but is essential to understand the dynamics of transmission. This study aimed to identify risk factors for seropositivity and to estimate the prevalence of Ebola virus infection in unvaccinated contact per...

Background: The prevalence of Ebola virus infection among people who have been in contact with patients with Ebola virus disease remains unclear, but is essential to understand the dynamics of transmission. This study aimed to identify risk factors for seropositivity and to estimate the prevalence of Ebola virus infection in unvaccinated contact p...

Bats are considered a reservoir species for Ebola viruses, but non-human primates (NHP) have represented a source of infection in several outbreaks in humans. Here we report serological screening of blood or fecal samples from monkeys (n=2,322) and apes (n=2,327). Thirty-six NHP species from Cameroon, Democratic Republic of Congo and Ivory Coast we...

Les maladies infectieuses émergentes sont récurrentes et représentent un enjeu de sécurité sanitaire planétaire. Le continent africain est particulièrement exposé aux risques infectieux épidémiques à cause du nombre d'agents infectieux qui y circulent, en particulier dans la faune, mais aussi de par des facteurs sociaux et environnementaux qui favo...

To clarify the role of bats in the ecology of Ebola viruses, we assessed the prevalence of Ebola virus antibodies in a large-scale sample of bats collected during 2015-2017 from countries in Africa that have had previous Ebola outbreaks (Guinea, the Democratic Republic of the Congo) or are at high risk for outbreaks (Cameroon). We analyzed 4,022 bl...

Questions remain as whether an unnoticed Ebola outbreak has occurred in Guinea before the 2014-2016 epidemic. To address this, we used a highly sensitive and specific Luminex-based assay for Ebola virus (EBOV) antibody detection to screen blood samples collected in the framework of the Demographic Health Survey performed in 2012 in Guinea. One samp...

Questions remain as to whether an unnoticed Ebola outbreak occurred in Guinea before the 2014-2016 epidemic. To address this, we used a highly sensitive and specific Luminex-based assay for Ebola virus (EBOV) antibody detection to screen blood samples collected in the framework of the Demographic Health Survey performed in 2012 in Guinea. One sampl...

Skin infections are common in sub-Saharan Africa, including chronic wounds. This study aimed to assess the presence of several microorganisms in skin specimens from patients with chronic wounds and healthy people in Maferinyah (Republic of Guinea). Eighty-four skin samples from the wounds of 20 patients (42 edge swabs and 42 center swabs) and twent...

This study modeled the presence of Ebola virus RNA in the semen of male Ebola survivors participating in the Postebogui study in Guinea. The median time of reverse-transcription polymerase chain reaction negativity was 46.4 days after symptom onset (95% confidence interval, 11-82.6). The results emphasize the importance of the World Health Organiza...

Background: The high number of survivors from the 2013-16 west African outbreak of Ebola virus disease (EVD) has raised several new issues: long-term clinical complications, psychosocial consequences, risks of EVD reactivation, and secondary transmission due to viral persistence in body fluids. We aimed to assess long-term clinical, psychosocial,...

The recent Ebola virus outbreak in West Africa illustrates clearly the need for additional studies in humans and animals to elucidate the ecology of Ebola viruses. Here we developed a serological assay based on the Luminex technology. Nine recombinant proteins representing different viral regions (NP, VP40 and GP) from four of the five EBV lineages...

The bacterium Tropheryma whipplei, which causes Whipple disease in humans, is commonly detected in the feces of persons in Africa. It is also associated with acute infections. We investigated the role of T. whipplei in febrile patients from 2 rural villages in Senegal. During June 2010-March 2012, we collected whole-blood finger-prick samples from...

Introduction: Nosocomial infections can be prevented by applying simple hygiene rules. However, they have not been sufficiently studied in the Republic of Guinea. For this purpose, we conducted a one-day study in the Conakry University Hospital surgery wards and intensive care units. Methods: Fourteen units (12 surgical wards and 2 intensive care u...

Malaria is considered to be the most common etiology of fever in sub-Saharan Africa while bacteremias exist but are under assessed. This study aimed to assess bacteremias and malaria in children from urban and rural areas in Gabon. DNA extracts from blood samples of 410 febrile and 60 afebrile children were analyzed using quantitative polymerase ch...

Les infections nosocomiales sont évitables par l’hygiène. Elles ne sont pas suffisamment étudiées et documentées en Guinée. C’est dans ce but que nous avons réalisé dans les services de chirurgie et de réanimation du CHU de Conakry une étude « un jour donné ». Quatorze services (12 de chirurgie et 02 de réanimation) ont participé à l’étude. Au tota...

Strain FF2T was isolated from the blood sample of a 35 year-old febrile Senegalese male, in Dielmo, Senegal. This strain exhibited a 97.47% 16S rRNA sequence identity with Diaminobutyricimonas aerilata. The score from MALDI-TOF-MS does not allow any identification. Using a polyphasic study made of phenotypic and genomic analyses, strain FF2T was Gr...

T he detection of Plasmodium spp. by the molecular analysis of human feces was reported to be comparable to detection in the blood. We believe that for epidemiological studies using molecular tools, it would be simpler to use feces, which are easier to obtain and require no training for their collection. Our aim was to evaluate the usefulness of fe...

T ropheryma whipplei, which causes Whipple's disease (WD), is detected with variable prevalence in human stool and saliva. We investigate the epidemiological factors which influence the bacterium natural history. For this purpose, molecular and/ or serological studies was performed in entire population of 2 villages in Senegal (Dielmo and Ndiop), i...

The detection of Plasmodium spp. by the molecular analysis of human feces was reported to be comparable to detection in the blood. We believe that for epidemiological studies using molecular tools, it would be simpler to use feces, which are easier to obtain and require no training for their collection. Our aim was to evaluate the usefulness of fec...

Tropheryma whipplei is a bacterium commonly found in feces of young children in Africa, but with no data from Asia. We estimated the prevalence of T. whipplei carriage in feces of children in Lao PDR (Laos). Using specific quantitative real-time PCR, followed by genotyping for each positive specimen, we estimated the prevalence of T. whipplei in 11...

Background: Tropheryma whipplei, the agent of Whipple’s disease, was still recently considered as a rare bacterium causing a rare chronic disease, mainly in white male of 50 year-old. In fact, T. whipplei is highly frequent in rural Senegal with a prevalence reaching 75% in feces of children of less than 5 year-old. Preliminary data suggested also...

RESUME Objectif : Evaluer le taux de létalité du paludisme grave chez les enfants hospitalisés et d'en identifier les facteurs associés en république de Guinée. Méthodes : Nous avons mené une étude d'observation rétrospective des dossiers d'hospitalisation pour paludisme grave (critères OMS 2000) en 2008 des enfants âgés de < 15 ans dans les servic...

Tropheryma whipplei, which causes Whipple’s disease (WD), is detected with variable prevalence in stool and saliva samples. Here, to investigate the epidemiological factors which influences the natural history of the bacterium; we performed molecular and/or serological studies in entire population of 2 villages in Senegal (Dielmo and Ndiop) in home...