A5060276906- Malaria Research and Control
- Mosquito-borne diseases and control
- SARS-CoV-2 and COVID-19 Research
- COVID-19 Clinical Research Studies
- SARS-CoV-2 detection and testing
- Travel-related health issues
- Vaccine Coverage and Hesitancy
- Aquaculture disease management and microbiota
- Herpesvirus Infections and Treatments
- Vibrio bacteria research studies
- COVID-19 epidemiological studies
- Hemoglobinopathies and Related Disorders
- Poxvirus research and outbreaks
- Vector-borne infectious diseases
- Molecular Biology Techniques and Applications
- Advanced biosensing and bioanalysis techniques
- Clostridium difficile and Clostridium perfringens research
- Animal Virus Infections Studies
- Bird parasitology and diseases
- Biosensors and Analytical Detection
- Influenza Virus Research Studies
- Phenothiazines and Benzothiazines Synthesis and Activities
- Personality Traits and Psychology
- Complement system in diseases
- Management and Marketing Education
Robert Koch Institute
2021-2024
MRC Unit the Gambia
2021-2022
Swiss Tropical and Public Health Institute
2014-2022
University of Basel
2014-2022
Medical Research Council
2021
London School of Hygiene & Tropical Medicine
2021
Ministry of Health and Social Welfare
2021
Ifakara Health Institute
2019-2020
Tulane University
2019-2020
Humboldt-Universität zu Berlin
2012
Background Planning and evaluating malaria control strategies relies on accurate definition of parasite prevalence in the population. A large proportion asymptomatic infections can only be identified by surveillance with molecular methods, yet these also contribute to onward transmission mosquitoes. The sensitivity detection PCR is limited abundance target sequence a DNA sample; thus, becomes imperfect at low densities. We aimed increase diagnostic targeting multi-copy genomic sequences for...
Background The undetectable hypnozoite reservoir for relapsing Plasmodium vivax and P. ovale malarias presents a major challenge malaria control elimination in endemic countries. This study aims to directly determine the contribution of relapses burden infection, illness, transmission Papua New Guinean children. Methods Findings From 17 August 2009 20 May 2010, 524 children aged 5–10 y from East Sepik Province Guinea (PNG) participated randomised double-blind placebo-controlled trial blood-...
Abstract Malaria infections occurring below the limit of detection standard diagnostics are common in all endemic settings. However, key questions remain surrounding their contribution to sustaining transmission and whether they need be detected targeted achieve malaria elimination. In this study we analyse a range datasets quantify density, detectability, course infection infectiousness subpatent infections. Asymptomatically infected individuals have lower parasite densities on average low...
Amplicon deep sequencing permits sensitive detection of minority clones and improves discriminatory power for genotyping multi-clone Plasmodium falciparum infections. New amplicon data analysis protocols are needed in epidemiological studies drug efficacy trials P. falciparum.Targeted molecular marker csp novel cpmp was conducted duplicate on mixtures parasite culture strains 37 field samples. A protocol allowing to multiplex up 384 samples a single run applied. Software "HaplotypR"...
Abstract Accurate quantification of parasite density in the human host is essential for understanding biology and pathology malaria. Semi-quantitative molecular methods are widely applied, but need an external standard curve makes it difficult to compare estimates across studies. Droplet digital PCR (ddPCR) allows direct without a curve. ddPCR was used diagnose quantify P. falciparum vivax clinical patients as well asymptomatic samples. yielded highly reproducible measurements range...
Abstract High-throughput detection of neutralizing antibodies against SARS-CoV-2 presents a valuable tool for vaccine trials or investigations population immunity. We evaluate the performance first commercial surrogate virus neutralization test (sVNT, GenScript Biotech) plaque reduction (PRNT) in convalescent and vaccinated individuals. compare it to five other ELISAs, two which are designed detect antibodies. In 491 pre-vaccination serum samples, sVNT missed 23.6% PRNT-positive samples when...
Abstract Background The coronavirus disease 2019 (COVID-19) pandemic is driven by severe acute respiratory syndrome 2 (SARS-CoV-2) infection, which has led to an enormous burden on patient morbidity and mortality. renin–angiotensin–aldosterone system (RAAS) plays a significant role in various pulmonary diseases. Since SARS-CoV-2 utilizes the angiotensin-converting enzyme (ACE)2 receptor exert its virulence pathogenicity, RAAS of particular importance COVID 19. Methods Our preliminary study...
ABSTRACT Estimation of drug efficacy in antimalarial trials requires parasite genotyping to distinguish new infections from treatment failures. When using length-polymorphic molecular markers, preferential amplification short fragments can compromise detection coinfections, potentially leading misclassification outcome. We quantified minority clone detectability and competition among msp1 , msp2 glurp amplicons mixtures Plasmodium falciparum strains investigated the impact template on...
Abstract Longitudinal tracking of individual Plasmodium falciparum strains in multi-clonal infections is essential for investigating infection dynamics malaria. The traditional genotyping techniques did not permit changes clone density during persistent natural infections. Amplicon deep sequencing (Amp-Seq) offers a tool to address this knowledge gap. sensitivity Amp-Seq relative quantification clones was investigated using three molecular markers, ama 1 -D2, ama1 -D3, and cpmp ....
Reactive case detection (RCD) is a commonly used strategy for malaria surveillance and response in elimination settings. Many approaches to RCD assume detectable infections are clustered within around homes of passively detected cases (index households), which has been evaluated number settings with disparate results. Household questionnaires diagnostic testing were conducted following investigations Zanzibar, Tanzania, including the index household up 9 additional neighboring households. Of...
ABSTRACT Plasmodium falciparum , the most deadly agent of malaria, displays a wide variety resistance mechanisms in field. The ability antimalarial compounds development to overcome these must therefore be carefully evaluated ensure uncompromised activity against real-life parasites. We report here on selection and phenotypic as well genotypic characterization panel sensitive multidrug-resistant P. strains that can used optimally identify deconvolute cross-resistance signals from an extended...
In malaria endemic populations, complex patterns of Plasmodium vivax and falciparum blood-stage infection dynamics may be observed. Genotyping samples from longitudinal cohort studies for merozoite surface protein (msp) variants increases the information available in data, allowing multiple infecting parasite clones a single individual to identified. msp genotyped two cohorts Papua New Guinea (PNG) Thailand were analysed using statistical model where times acquisition clearance each clone...
The molecular force of blood-stage infection (molFOB) is a quantitative surrogate metric for malaria transmission at population level and exposure individual level. Relationships between molFOB, parasite prevalence clinical incidence were assessed in treatment-to-reinfection cohort, where P.vivax (Pv) hypnozoites eliminated half the children by primaquine (PQ). Discounting relapses, acquired equal numbers new P. falciparum (Pf) Pv infections/year (Pf-molFOB = 0-18, Pv-molFOB 0-23) resulting...
A novel ultrasensitive malaria rapid diagnostic test (us-RDT) has been developed for improved active Plasmodium falciparum infection detection. The usefulness of this us-RDT in clinical diagnosis and fever management not evaluated.Diagnostic performance was compared retrospectively to that conventional RDT (co-RDT) 3000 children 515 adults presenting with Tanzanian outpatient clinics. parasite density measured by an qPCR (us-qPCR), the HRP2 concentration enzyme-linked immunosorbent...
Abstract The monkeypox virus (MPXV) outbreak in 2022 has renewed interest the detection of antibodies against orthopox viruses (OPXV) and MPXV, as serological methods can aid diagnostics are key to epidemiological studies. Here three complementary described with different strengths development evaluation in‐house assays: An immunofluorescence assay (IFA) for specific IgG IgM, an enzyme‐linked immunosorbent higher sample throughput studies a neutralization test detect neutralizing antibodies....
Abstract Background Molecular detection of low-density Plasmodium falciparum infections is essential for surveillance studies conducted to inform malaria control strategies in close-to-elimination settings. monitoring residual usually requires a large study size, therefore sampling and diagnostic processes need be economical optimized high-throughput. A method comparison was undertaken identify the most efficient procedure processing collections community samples with optimal test...
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is evolving differently in Africa than other regions. has lower SARS-CoV-2 transmission rates and milder clinical manifestations. Detailed epidemiologic data are needed Africa. We used publicly available to calculate infections per 1,000 persons Gambia. evaluated among 1,366 employees of the Medical Research Council Unit Gambia (MRCG), where systematic surveillance symptomatic cases contact tracing were implemented. By...
Background Co-infection of the four major species human malaria parasite Plasmodium falciparum ( Pf ), P . vivax Pv malariae Pm and ovale sp. Po ) is regularly observed, but there limited understanding between-species interactions. In particular, little known about effects multiple co-infections on gametocyte production. Methods We developed molecular assays for detecting asexual stages , This first description diagnostics gametocytes. These were implemented in a unique epidemiological...
Abstract Background Studies have shown that Omicron breakthrough infections can occur at higher SARS-CoV-2 antibody levels compared to previous variants. Estimating the magnitude of immunological protection induced from COVID-19 vaccination and infection remains important due varying local pandemic dynamics types programmes, particularly among at-risk populations such as health care workers (HCWs). We analysed a follow-up serological survey HCWs tertiary referral hospital in Germany...
Abstract Malaria risk is highly heterogeneous. Understanding village and household-level spatial heterogeneity of malaria can support a transition to spatially targeted interventions for elimination. This analysis uses data from cross-sectional prevalence surveys conducted in 2014 2016 two villages (Megiar Mirap) Papua New Guinea. Generalised additive modelling was used characterise investigate the contribution individual, household environmental-level factors. Following period declining...
SARS-CoV-2 serosurveillance is important to adapt infection control measures and estimate the degree of underreporting. Blood donor samples can be used as a proxy for healthy adult population. In repeated cross-sectional study from April 2020 2021, September April/May 2022, 13 blood establishments collected 134,510 anonymised specimens donors in 28 regions across Germany. These were tested antibodies against spike protein nucleocapsid, including neutralising capacity. Seroprevalence was...
Background Primaquine (PQ) is the only currently licensed antimalarial that prevents Plasmodium vivax (Pv) relapses. It also clears mature P. falciparum (Pf) gametocytes, thereby reducing post-treatment transmission. Randomized PQ treatment in a treatment-to-reinfection cohort Papua New Guinean children permitted study of Pv and Pf gametocyte carriage after radical cure to investigate contribution Methods Children received with Chloroquine, Artemether-Lumefantrine plus either or placebo....