Aurel Holzschuh

• Doctor of Philosophy
• Postdoctoral Researcher at Swiss Tropical and Public Health Institute

The evolution of genetic diversity and population structure of Plasmodium vivax as malaria elimination approaches remains unclear. This study analyzed the genetic variation and molecular epidemiology of P. vivax from Yala Province in southern Thailand, an area in the pre-elimination phase. Seventy P. vivax isolates, collected between 2017 and 2020,...

This protocol outlines a multiplexed nanopore amplicon sequencing (AmpSeq) panel targeting six highly diverse P. falciparum microhaplotype loci. For a detailed explanation of the data analysis, please refer to our pre-print and github repository. An example workflow of the bioinformatics pipeline and haplotype inference code used in the pre-print c...

Wolbachia is a widespread bacterial endosymbiont in arthropods known for its ability to manipulate host reproduction through cytoplasmic incompatibility (CI), thereby promoting its spread. However, Wolbachia harbors an array of mobile genetic elements (MGEs) that can rapidly alter its genomic structure and content, including the cif loci responsibl...

Background The assessment of antimalarial drug efficacy against Plasmodium falciparum requires PCR correction to distinguish recrudescence from new infections by comparing parasite genotypes before treatment and in recurrent infections. Nanopore sequencing offers a low-cost, portable, scalable, and rapid alternative to traditional methods, supporti...

Background Zanzibar has made significant progress in malaria control reaching a population prevalence of around 1% with program-led interventions. Nevertheless, malaria infections persist in people with no recent travel history implying locally acquired infections. Understanding risk factors of local transmission is crucial to refine elimination st...

Malaria cases are frequently recorded in the Ethiopian highlands even at altitudes above 2000 m. The epidemiology of malaria in the Ethiopian highlands, and, in particular, the role of importation by human migration from the highly endemic lowlands is not well understood. We sequenced 187 Plasmodium falciparum samples from two sites in the Ethiopia...

Genomic epidemiology holds promise for malaria control and elimination efforts, for example by informing on Plasmodium falciparum genetic diversity and prevalence of mutations conferring anti-malarial drug resistance. Limited sequencing infrastructure in many malaria-endemic areas prevents the rapid generation of genomic data. To address these issu...

Background Zanzibar has made substantial progress in malaria control with vector control, improved diagnosis, and artemisinin-based combination therapy. Parasite prevalence in the population has remained around 1% but imported infections from mainland Tanzania contribute to sustained local transmission. Understanding travel patterns between mainlan...

Zanzibar has made significant progress toward malaria elimination, but recent stagnation requires novel approaches. We developed a highly multiplexed droplet digital PCR (ddPCR)-based amplicon sequencing method targeting 35 microhaplotypes and drug-resistance loci, and successfully sequenced 290 samples from five districts covering both main island...

Malaria cases are frequently recorded in the Ethiopian highlands even at altitudes above 2,000 m. The epidemiology of malaria in the Ethiopian highlands, and in particular the role of importation by human migration from the highly endemic lowlands is not well understood. We characterized the parasite population structure and genetic relatedness by...

Background Zanzibar has made substantial progress in malaria control with the scaling-up of vector control, improved diagnosis, and artemisinin-based combination therapy. Parasite prevalence in the population has remained around 1% but imported infections from mainland Tanzania contribute to sustained local transmission. Understanding travel patter...

Over the past 15 years, Zanzibar has made great strides toward malaria elimination; yet progress has stalled. Parasite genetic data of Plasmodium falciparum may inform strategies for malaria elimination by helping to identify contributory factors to parasite persistence. Here we elucidate fine-scale parasite population structure and infer relatedne...

Background Co-infection of the four major species of human malaria parasite Plasmodium falciparum (Pf), P. vivax (Pv), P. malariae (Pm), and P. ovale sp. (Po) is regularly observed, but there is limited understanding of between-species interactions. In particular, little is known about the effects of multiple Plasmodium species co-infections on gam...

Rapid diagnostic tests (RDTs) are a key tool for the diagnosis of malaria infections among clinical and subclinical individuals. Low-density infections, and deletions of the P. falciparum hrp2/3 genes (encoding the HRP2 and HRP3 proteins detected by many RDTs) present challenges for RDT-based diagnosis. The novel Rapigen Biocredit three-band Plasmo...

Most rapid diagnostic tests for Plasmodium falciparum malaria target the Histidine-Rich Proteins 2 and 3 (HRP2, HRP3). Deletions of the hrp2 and hrp3 genes result in false negative tests and are a threat for malaria control. A novel assay for molecular surveillance of hrp2/hrp3 deletions was developed based on droplet digital PCR (ddPCR). The assay...

Rapid diagnostic tests (RDTs) are a key tool for the diagnosis of malaria infections among febrile and subclinical individuals. Low-density infections, and deletions of the P. falciparum hrp2 / 3 genes (encoding for the HRP2 and HRP3 proteins detected by many RDTs) present challenges for RDT-based diagnosis. The novel Rapigen Biocredit three-band P...

Background Molecular and genomic surveillance is becoming increasingly used to track malaria control and elimination efforts. Blood samples can be collected as whole blood and stored at − 20 °C until DNA extraction, or as dried blood spots (DBS), circumventing the need for a cold chain. Despite the wide use of either method, systematic comparisons...

Background: The most commonly used Plasmodium falciparum rapid diagnostic tests target the Histidine-Rich Proteins 2 and 3 (HRP2, HRP3). An increasing number of countries report parasites that carry hpr2 and/or hrp3 gene deletions, resulting in false negative test results. Molecular surveillance of hrp2 and hrp3 deletions is crucial but adequate pr...

Background 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 and around homes of passively detected cases (index households), which has been evaluated in a number of settings with disparate results. Method...

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. Molecular monitoring of residual malaria infections usually requires a large study size, therefore sampling and diagnostic processes need to be econom...

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. Molecular monitoring of residual malaria infections usually requires a large study size, therefore sampling and diagnostic processes need to be economic...

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. Molecular monitoring of residual malaria infections usually requires a large study size, therefore sampling and diagnostic processes need to be economic...

Background: A novel ultra-sensitive malaria RDT (us-RDT) has been developed for improved active P.falciparum case detection. The utility of this us-RDT in clinical diagnosis and fever management has not been evaluated to date. Methods: Diagnostic performance of us-RDT was compared retrospectively to conventional RDT (co-RDT) in 3000 children and...