Sara Eyangoh

Institut Pasteur International Network · Pasteur Center in Cameroon

The gold standard for Mycobacterium ulcerans detection is PCR due to its high accuracy in confirmation of suspected cases. But the available PCR assays are design for standard size thermocyclers which are immobile and suited for reference laboratories far away from endemic communities. This makes it a challenge to obtain immediate results for patie...

Buruli ulcer is one of the 20 neglected tropical diseases in the world. This necrotizing hypodermitis is a chronic debilitating disease caused by an environmental Mycobacterium ulcerans . At least 33 countries with tropical, subtropical and temperate climates have reported Buruli ulcer in African countries, South America and Western Pacific regions...

During the COVID 19 pandemic, round-the-clock demand for COVID -19 laboratory tests exceeded capacity, placing a significant burden on laboratory staff and infrastructure. The use of laboratory information management systems (LIMS) to streamline all phases of laboratory testing (preanalytical, analytical, and postanalytical) has become inevitable....

Background: Until 2016, microscopy was the main tool for the early detection of pulmonary tuberculosis in Cameroon, especially in remote settings. Due to the poor sensitivity of microscopy, there was a need to implement a molecular assay in order to improve tuberculosis case detection. Intervention: In 2017, tuberculosis loop-mediated isothermal a...

Introduction Yaws, caused by the bacterium Treponema pallidum subsp. pertenue, is a neglected tropical disease targeted for eradication by 2030. Improved diagnostics will be essential to meet this goal. Diagnosis of yaws has relied heavily on clinical and serological tools. However, the presence of coendemic cutaneous skin ulcer diseases, such as l...

This chapter elaborates on the microbiological confirmation of Buruli ulcer (BU) by various laboratory techniques. Recommended methods for obtaining correct samples are listed. We highlight the importance of quality assurance in BU laboratory diagnostic activities. Finally, the future of innovative tests that allow a point-of-care diagnosis is disc...

Introduction Meta-analyses conducted so far on the association between diabetes mellitus (DM) and the tuberculosis (TB) development risk did not sufficiently take confounders into account in their estimates. The objective of this systematic review was to determine whether DM is associated with an increased risk of developing TB with a sensitivity a...

We describe the coding-complete genome sequence of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strain obtained in Cameroon from a 58-year-old French patient who arrived from France on 24 February 2020. Phylogenetic analysis showed that this virus, named hCoV-19/Cameroon/1958-CMR-YAO/2020, belongs to lineage B.1.5 and is closely r...

Background Real-time PCR is recommended to detect SARS-CoV-2 infection. However, PCR availability is restricted in most countries. Rapid diagnostic tests are considered acceptable alternatives, but data are lacking on their performance. We assessed the performance of four antibody-based rapid diagnostic tests and one antigen-based rapid diagnostic...

Outbreaks of yaws-like ulcerative skin lesions in children are frequently reported in tropical and sub-tropical countries. The origin of these lesions might be primarily traumatic or infectious; in the latter case, Treponema pallidum subspecies pertenue , the yaws agent, and Haemophilus ducreyi , the agent of chancroid, are two of the pathogens com...

Background Infection with SARS-CoV-2 can lead to a detectable serological immune response even though extent of its protection is still not yet well known. We report long duration and resurgence of SARS-CoV-2 in patients with COVID-19. Methods We included a cohort of 99 participants from our non-blinded non-randomized evaluation of COVID-19 tests i...

Stool samples are alternatives to respiratory samples for bacteriological confirmation of childhood tuberculosis but require intensive laboratory processing before molecular testing to remove PCR inhibitors and debris. We aimed to develop a centrifuge-free processing method for use in resource-limited settings based on a sucrose-flotation method th...

Objectifs Cette étude avait pour objectif de déterminer la prévalence des étiologies fongiques, bactériennes et virales chez les patients séropositifs et séronégatifs au virus de l'immunodéficience humaine (VIH) souffrant d'infections des voies respiratoires basses (IVB) subissant une bronchoscopie. Matériels et Méthodes De 2017 à 2018, des patient...

Outbreaks of yaws-like ulcerative skin lesions in children are frequently reported in tropical and sub-tropical countries. The origin of these lesions might be primarily traumatic or infectious; in the latter case, Treponema pallidum subspecies pertenue, the yaws agent, and Haemophilus ducreyi, the agent of chancroid, are two pathogens commonly ass...

Background Human dietary exposure to chemicals can result in a wide range of adverse health effects. Some substances might cause non-communicable diseases, including cancer and coronary heart diseases, and could be nephrotoxic. Food is the main human exposure route for many chemicals. We aimed to assess human dietary exposure to a wide range of foo...

Mycobacterium ulcerans is the causative agent of Buruli ulcer, a neglected tropical disease found in rural areas of West and Central Africa. Despite the ongoing efforts to tackle Buruli ulcer epidemics, the environmental reservoir of its pathogen remains elusive, underscoring the need for new approaches to improving disease prevention and managemen...

For the first time, a multi-centre Total Diet Study was carried out in Benin, Cameroon, Mali and Nigeria. We collected and prepared as consumed 528 typical fatty foods from those areas and pooled these subsamples into 44 composites samples. These core foods were tested for a wide spectrum of POPs, including polychlorinated dibenzo-p-dioxins (PCDDs)...

This paper reports occurrence data related to 30 trace elements in food composite samples from a multi-regional Sub-Saharan Africa Total Diet Study. Herein, 2700 samples grouped in 225 food composite samples corresponding to 13 food groups: cereals, tubers, legumes, vegetables, fruits, nuts/seeds, meat, eggs, fish, milk/dairy, oil/fats, and beverag...

Various trapping methods and techniques developed for entomological studies are inefficient in attracting all arthropod groups. A new simple light trap, the basin light trap (BLT), to collect arthropod fauna around household in central Cameroon was thus designed. Its performance is evaluated by comparing collected data with those obtained by the Ce...

Various trapping methods and techniques developed for entomological studies are inefficient in attracting all arthropod groups. A new simple light trap, the basin light trap (BLT), to collect arthropod fauna around household in central Cameroon was thus designed. Its performance is evaluated by comparing collected data with those obtained by the Ce...

The Total Diet Study (TDS) approach provides a snapshot of the exposure of populations to food chemicals. We carried out a multi-center Total Diet Study for assessing the dietary exposure to a wide spectrum of chemical contaminants and residues in a representative sampling of the populations’ diet in Benin, Cameroon, Mali and Nigeria (2014-2018)...

Background A wide range of Nipah virus (NiV) encephalitis case fatality rates (CFR) have been reported. Data on the involvement of several potential risk factors in Nipah virus transmission remain controversial. We performed a systematic review and meta-analysis to estimate the pooled CFR of NiV encephalitis and to assess the risk factors for NiV i...

In the framework of the first regional Total Diet Study in Sub-Saharan Africa, 3696 foodstuffs, commonly consumed in Benin, Cameroon, Mali and Nigeria were purchased, prepared as consumed and pooled into 308 composite samples. Those core foods were tested for up to 470 pesticides residues by liquid and gas chromatography coupled with tandem mass sp...

As part of the first multi-centre Sub-Saharan Africa Total Diet Study, 660 typical foods from Benin, Cameroon, Mali, and Nigeria were purchased, prepared according to local consumption habits, and pooled into 55 composite samples. These core foods were tested for 15 + 1 EU priority polycyclic aromatic hydrocarbons, which were quantified by isotope...

A monkeypox virus was detected from a human clinical case in 2018 in Cameroon; a country where no human cases were reported since 1989. The virus exhibited close genetic relatedness with another monkeypox virus isolated in Nigeria during the 2017–2018 outbreak. Although our molecular findings argue in favor of an extension of the monkeypox outbreak...

The authors wish to make the following corrections to their paper [...]

We enrolled 427 human immunodeficiency virus-infected children (median age, 7.3 years), 59.2% severely immunodeficient, with suspected tuberculosis in Southeast Asian and African settings. Nontuberculous mycobacteria were isolated in 46 children (10.8%); 45.7% of isolates were Mycobacterium avium complex. Southeast Asian origin, age 5-9 years, and...

In the framework of the first multi-centre Sub-Saharan Africa Total Diet Study (SSA-TDS), 2328 commonly consumed foods were purchased, prepared as consumed and pooled into 194 composite samples of cereals, tubers, legumes, vegetables, nuts and seeds, dairy, oils, beverages and miscellaneous. Those core foods were tested for mycotoxins and other fun...

This is a descriptive study. The detailed information on TB drugs resistance cases were collected from Tuberculosis National Reference Laboratory (TB-NRL) where Drug Susceptibility Test (DST) had been performed on liquid medium using BACTEC MGIT 960. These information concern the data reported between January 2013 and December 2017. The adoption of...

Background: The most practical test for identifying tuberculosis (TB) in developing countries remains smear microscopy. However, due to its low sensitivity, a new point-of-care diagnostic method has been developed. The purpose of this study was to assess the performance of TB-Loop-mediated isothermal amplification (TB-LAMP) test on sputum samples o...

Objective: Mycobacterium tuberculosis isolates that fail to hybridize to at least one rpoB wildtype or any mutation probe on the Genotype MTBDRplus strip are assumed Rifampicin-resistant. However, the precise mutation(s) are unknown. We sought to identify the mutations in isolates with such hybridization patterns and determine if the mutations are...

Background: Tuberculosis is a major cause of morbidity and mortality in HIV-infected children, but is difficult to diagnose. We studied mortality and its determinants in antiretroviral treatment (ART)-naive HIV-infected children presenting with suspected tuberculosis. Methods: In this observational cohort study, HIV-infected children aged 13 yea...

Background Drug-resistant tuberculosis, especially multidrug-resistant tuberculosis (MDR-TB), is a major public health problem. Effective management of MDR-TB relies on accurate and rapid diagnosis. In this study, we assessed the diagnostic accuracy of the Genotype MTBDRplus assay in diagnosing MDR-TB in Cameroon, and then discuss on its utility wi...

Mycobacterium ulcerans (MU), the causative agent of Buruli ulcer, is present in a wide spectrum of environments, including terrestrial and aquatic ecosystems in tropical regions. The most promising studies on the epidemiological risk of this disease suggest that some ecological settings may favor infection of animals with MU including human. A spec...

Background Cameroon is a country where tuberculosis still remains a major public health problem. The aim of the present research was to evaluate the potential of molecular markers in predicting first-line drug resistance and to investigate the predominant genotypes representative of Mycobacterium tuberculosis strains in the Centre region of Cameroo...

Buruli ulcer (BU) is an insidious neglected tropical disease. Cases are reported around the world but the rural regions of West and Central Africa are most affected. How BU is transmitted and spreads has remained a mystery, even though the causative agent, Mycobacterium ulcerans, has been known for more than 70 years. Here, using the tools of popul...

Background . Cameroon this last decade continues to present a low contribution of M. africanum and M. bovis in human tuberculosis (TB), while M. bovis was prevalent in cattle but all these pieces of information only concerned West and Center regions. Methods . We carried out the first study in Adamaoua, one of the most rearing regions of Cameroon,...

Food consumption data of the populations of four Sub-Saharan Africa countries were derived from food expenditure data of 72.979 households. A food classification system was set up for the purpose of the study. The approach enables to take into consideration the local specificity of food consumption patterns in the completion of dietary exposure ass...

Aquatic and semi-aquatic bugs (Heteroptera) represent a remarkable diversity and a resurging interest has been given to documenting at the species level these insects inhabiting Cameroon in Central Africa due to their potential implication in the transmission of the bacterium Mycobacterium ulcerans, the causal agent of Buruli ulcer, an emerging hum...

Background: Access to laboratory diagnosis can be a challenge for individuals suspected of Buruli Ulcer (BU). Our objective was to develop a clinical score to assist clinicians working in resource-limited settings for BU diagnosis. Methododology/principal findings: Between 2011 and 2013, individuals presenting at Akonolinga District Hospital, Ca...

Background: The diagnosis of tuberculosis in human immunodeficiency virus (HIV)-infected children is challenging. We assessed the performance of alternative specimen collection methods for tuberculosis diagnosis in HIV-infected children using Xpert MTB/RIF (Xpert). Methods: HIV-infected children aged ≤13 years with suspected intrathoracic tuberc...

Buruli Ulcer is a devastating skin disease caused by the pathogen Mycobacterium ulcerans. Emergence and distribution of Buruli ulcer cases is clearly linked to aquatic ecosystems, but the specific route of transmission of M. ulcerans to humans remains unclear. Relying on the most detailed field data in space and time on M. ulcerans and Buruli ulcer...

Bovine tuberculosis is still prevalent and under-evaluated in cattle destined for human consumption in Cameroon. Potential reservoirs of the disease include livestock imported from countries endemic for bovine tuberculosis, such as Nigeria and Chad, and potential residual reservoirs in local livestock and wildlife. Few studies have been done in Cam...

To determine when risk for Buruli ulcer is highest, we examined seasonal patterns in a highly disease-endemic area of Cameroon during 2002-2012. Cases peaked in March, suggesting that risk is highest during the high rainy season. During and after this season, populations should increase protective behaviors, and case detection efforts should be int...

Technical Appendix. Additional materials, methods, and results for analysis of seasonal patterns of Buruli ulcer incidence, central Africa, 2002–2012.

Buruli ulcer, the third mycobacterial disease after tuberculosis and leprosy, is caused by the environmental mycobacterium M. ulcerans. There is at present no clear understanding of the exact mode(s) of transmission of M. ulcerans. Populations affected by Buruli ulcer are those living close to humid and swampy zones. The disease is associated with...

Host-parasite interactions are often embedded within complex host communities and can be influenced by a variety of environmental factors, such as seasonal variations in climate or abiotic conditions in water and soil, which confounds our understanding of the main drivers of many multi-host pathogens. Here, we take advantage of a combination of lar...

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Background An understanding of the factors driving the distribution of pathogens is useful in preventing disease. Often we achieve this understanding at a local microhabitat scale; however the larger scale processes are often neglected. This can result in misleading inferences about the distribution of the pathogen, inhibiting our ability to manage...

From January 2002 to May 2012, 787 new BU cases were recorded in 154 villages of the district of Akonolinga. Incidence per village ranged from 0 (n = 59 villages) to 10.4 cases/1000 person.years (py); median incidence was 0.4 cases/1,000py. Villages neighbouring the Nyong River flood plain near Akonolinga town were identified as the highest risk zo...

Background/Question/Methods Multi-host pathogens represent a current threat for public health as well as for biodiversity decline. However, the biotic and abiotic factors affecting transmission potential of such pathogens are extremely difficult to discern because of their complex transmission cycles. A striking example is the environmental patho...

Background In the 1990s, resistance rates of 15% for streptomycin-resistance and 0.6% for multidrug-resistance (MDR) were reported from the Central Region of Cameroon. This work assesses drug resistant tuberculosis in this region 12 years after reorganization of the National Tuberculosis Control Program (NTCP). Methods This cross-sectional study w...

Background: Mycobacterium ulcerans (MU) is the agent responsible for Buruli Ulcer (BU), an emerging skin disease with dramatic socioeconomic and health outcomes, especially in rural settings. BU emergence and distribution is linked to aquatic ecosystems in tropical and subtropical countries, especially to swampy and flooded areas. Aquatic animal or...

Background The potential of genetic testing to rapidly diagnose drug resistance has lead to the development of new diagnostic assays. However, prior to implementation in a given setting, the association of specific mutations with specific drug resistance phenotypes should be evaluated. The purpose of this study was to evaluate molecular markers in...

Background: Mycobacterium ulcerans (MU) is the agent responsible for Buruli Ulcer (BU), an emerging skin disease with dramatic socioeconomic and health outcomes, especially in rural settings. BU emergence and distribution is linked to aquatic ecosystems in tropical and subtropical countries, especially to swampy and flooded areas. Aquatic animal o...