Fabian H. Leendertz

Helmholtz Institute for One Health · Department Epidemiology and Ecology of Emerging Diseases

Background/Objectives: Antibiotic-resistant bacteria pose a significant global public health threat that demands serious attention. The proliferation of antimicrobial resistance (AMR) is primarily attributed to the overuse of antibiotics in humans, livestock, and the agro-industry. However, it is worth noting that antibiotic-resistant genes (ARGs)...

An older wild female chimpanzee ( Pan troglodytes ) was found dead with a large calcium oxalate stone in the renal pelvis. Histopathological changes included glomerulosclerosis, interstitial nephritis and fibrosis, focal mineralization, and medial hypertrophy. Urinary albumin‐creatinine‐ratio showed increased values from 15 months before death. Cau...

Background Campylobacter spp. is a significant etiological agent of bacterial gastroenteritis globally. In Burkina Faso (BFA), the actual impact of this pathogen on gastroenteritis is considerably underestimated, primarily due to inadequate surveillance systems. Objectives This study aimed to investigate the proportion of Campylobacter species res...

Bombali virus (BOMV) is a novel Orthoebolavirus that has been detected in free-tailed bats in Sierra Leone, Guinea, Kenya, and Mozambique. We screened our collection of 349 free-tailed bat lungs collected in Côte d’Ivoire and Tanzania for BOMV RNA and tested 228 bat blood samples for BOMV antibodies. We did not detect BOMV-specific antibodies but f...

Background Viral gastrointestinal infections remain a major public health concern in developing countries. In Burkina Faso, there are very limited updated data on the circulating viruses and their genetic diversity. Objectives This study investigates the detection rates and characteristics of rotavirus A (RVA), norovirus (NoV), sapovirus (SaV) and...

Long-term observations of wildlife are key to understanding the ecological foundations of disease emergence. They provide unique opportunities to detect pathogens with zoonotic potential that could threaten human health but also pose a threat for the animals. [Image: see text]

Bacillus cereus biovar anthracis ( Bcbva ) is an atypical anthrax-causing bacterium, inflicting wildlife fatalities across African rainforest ecosystems. The pathogen’s virulence in one of our closest living relatives, the chimpanzee, together with human serological evidence, suggests Bcbva is zoonotic. While classical B. anthracis -induced anthrax...

Bacillus cereus biovar anthracis ( Bcbva ) is an atypical anthrax-causing bacterium, inflicting wildlife fatalities across African rainforest ecosystems. The pathogen’s virulence in one of our closest living relatives, the chimpanzee, together with human serological evidence, suggests Bcbva is zoonotic. While classical B. anthracis -induced anthrax...

Nematodes belonging to the genus Oesophagostomum frequently infect wild chimpanzees ( Pan troglodytes ) across widely separated field sites. Nodular lesions (granulomas) containing Oesophagostomum are commonly seen in the abdomen of infected chimpanzees post‐mortem. At Taï National Park, Côte d'Ivoire, previous studies have identified larvae of a v...

Background Exposure to antibiotics has been shown to be one of the drivers of antimicrobial resistance (AMR) and is critical to address when planning and implementing strategies for combatting AMR. However, data on antibiotic use in sub-Saharan Africa are still limited. Using hospital-based surveillance data from the African Network for Improved Di...

Background The coronavirus pandemic again highlighted the need for robust health care facility infection prevention and control (IPC) programmes. WHO guidelines on the core components (CCs) of IPC programmes provides guidance for facilities, but their implementation can be difficult to achieve in resource-limited settings. We aimed to gather eviden...

To decipher the evolution of the hominoid brain and its functions, it is essential to conduct comparative studies in primates, including our closest living relatives. However, strong ethical concerns preclude in vivo neuroimaging of great apes. We propose a responsible and multidisciplinary alternative approach that links behavior to brain anatomy...

Fine-scale knowledge of the changes in composition and function of the human gut microbiome compared that of our closest relatives is critical for understanding the evolutionary processes underlying its developmental trajectory. To infer taxonomic and functional changes in the gut microbiome across hominids at different timescales, we perform high-...

Objectives Healthcare workers (HCWs) are on the frontline of combating COVID-19, hence are at elevated risk of contracting an infection with SARS-CoV-2. The present study aims to measure the impact of SARS-CoV-2 on HCWs in central sub-Saharan Africa. Setting A cross-sectional serological study was conducted at six urban and five rural hospitals du...

Bacillus cereus biovar anthracis (Bcbva) is an atypical anthrax-causing bacterium, inflicting wildlife fatalities across African rainforest ecosystems. The pathogen's virulence in one of our closest living relatives, the chimpanzee, together with human serological evidence, suggests Bcbva is zoonotic. While classical B. anthracis-induced anthrax ha...

Advances in viral discovery techniques have led to the identification of numerous novel viruses in human samples. However, the low prevalence of certain viruses in humans raises doubts about their association with our species. To ascertain the authenticity of a virus as a genuine human-infecting agent, it can be useful to investigate the diversific...

West Nile virus (WNV), a mosquito-borne flavivirus, is endemic to South Africa. However, its contribution to acute febrile and neurological disease in hospitalized patients in South Africa is unknown. This study examined two patient cohorts for WNV using molecular testing and IgM serology with confirmation of serological results by viral neutraliza...

Background The coronavirus pandemic again highlighted the need for robust health care facility infection prevention and control (IPC) programmes. WHO guidelines on the core components (CCs) of IPC programmes provides guidance for facilities, but their implementation can be difficult to achieve in resource-limited settings. We aimed to gather eviden...

Terrestrial vertebrates are threatened by anthropogenic activities around the world. The rapid biodiversity loss that ensues is most intense in the tropics and affects ecosystem functions, such as seed dispersal, or may facilitate pathogen transmission. Monitoring vertebrate distributions is essential for understanding changes in biodiversity and e...

The metabarcoding of vertebrate DNA found in invertebrate-derived DNA (iDNA) has proven a powerful tool for monitoring biodiversity. To date, iDNA has primarily been used to detect the presence/absence of particular taxa using metabarcoding, though recent efforts demonstrated the potential utility of these data for estimating relative animal abunda...

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with increased transmissibility, virulence and immune escape abilities have heavily altered the COVID-19 pandemic’s course. Deciphering local and global transmission patterns of those variants is thus key in building a profound understanding of the virus’ spread around the globe....

Metabarcoding of invertebrate-derived DNA (iDNA) is increasingly used to describe vertebrate diversity in terrestrial ecosystems. Fly iDNA has also shown potential as a tool for detecting pathogens. Combining these approaches makes fly iDNA a promis-ing tool for understanding the ecology and distribution of novel pathogens or emerg-ing infectious d...

Characterizing trajectories of the composition and function of hominid gut microbiota across diverse environments and host species can help reveal specific properties of the human microbiota, with possible implications for host evolution and health. Using shotgun metagenomic sequencing, we investigated taxonomic and functional diversity in the gut...

The selection pressures that drove dramatic encephalisation processes through the mammal lineage remain elusive, as does knowledge of brain structure reorganisation through this process. In particular, considerable structural brain changes are present across the primate lineage, culminating in the complex human brain that allows for unique behaviou...

Flies form high-density associations with human settlements and groups of nonhuman primates and are implicated in transmitting pathogens. We investigate the movement of nonhuman primate-associated flies across landscapes surrounding Kibale National Park, Uganda, using a mark-recapture experiment. Flies were marked in nine nonhuman primate groups at...

The close phylogenetic relationship between humans and nonhuman primates (hereafter primates), coupled with mounting anthropogenic impacts, such as habitat change, wildmeat hunting, pet-keeping, and tourism, increases disease risks for primates and humans by facilitating zoonotic pathogen exchange and altering host-pathogen interactions. Infectious...

Background: After its initial detection in Wuhan, China, in December 2019, SARS-CoV-2 has spread rapidly, causing successive epidemic waves worldwide. This study aims to provide a genomic epidemiology of SARS-CoV-2 in Burkina Faso. Methods: Three hundred and seventy-seven SARS-CoV-2 genomes obtained from PCR-positive nasopharyngeal samples (PCR...

Background: After its initial detection in Wuhan, China, in December 2019, SARS-CoV-2 has spread rapidly, causing successive epidemic waves worldwide. This study aims to provide a genomic epidemiology of SARS-CoV-2 in Burkina Faso. Methods: Three hundred and seventy-seven SARS-CoV-2 genomes obtained from PCR-positive nasopharyngeal samples (PCR cyc...

A novel hantavirus, named Kiwira virus, was molecularly detected in six Angolan free-tailed bats (Mops condylurus, family Molossidae) captured in Tanzania and in one free-tailed bat in the Democratic Republic of Congo. Hantavirus RNA was found in different organs, with the highest loads in the spleen. Nucleotide sequences of large parts of the geno...

Background Reports on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread across Africa have varied, including among healthcare workers (HCWs). This study assessed the comparative SARS-CoV-2 burden and associated risk factors among HCWs in three African countries. Methods A multicentre study was conducted at regional healthcare fac...

The emergence of infectious diseases, such as COVID‐19, impacts livelihood strategies and conservation tools reliant on human‐wildlife interactions, such as wildlife‐based tourism and research. This is particularly relevant to great ape conservation, as humans and great apes are susceptible to being infected by similar pathogens. Evidence‐based str...

Flies are implicated in carrying and mechanically transmitting many primate pathogens. We investigated how fly associations vary across six monkey species (Cercopithecus ascanius, Cercopithecus mitis, Colobus guereza, Lophocebus albigena, Papio anubis, and Piliocolobus tephrosceles) and whether monkey group size impacts fly densities. Fly densities...

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...

The human parasite Plasmodium malariae has relatives infecting African apes (Plasmodium rodhaini) and New World monkeys (Plasmodium brasilianum), but its origins remain unknown. Using a novel approach to characterise P. malariae-related sequences in wild and captive African apes, we found that this group comprises three distinct lineages, one of wh...

Human respiratory pathogens have repeatedly caused lethal outbreaks in wild great apes across Africa, leading to population declines. Nonetheless, our knowledge of potential genomic changes associated with pathogen introduction and spread at the human‐great ape interface remains sparse. Here, we made use of target enrichment coupled with next gener...

Decades after its discovery in East Africa, Zika virus (ZIKV) emerged in Brazil in 2013 and infected millions of people during intense urban transmission. Whether vertebrates other than humans are involved in ZIKV transmission cycles remained unclear. Here, we investigate the role of different animals as ZIKV reservoirs by testing 1723 sera of pets...

Background In sub-Saharan Africa, acute respiratory infections (ARI), acute gastrointestinal infections (GI) and acute febrile disease of unknown cause (AFDUC) have a large disease burden, especially among children, while respective aetiologies often remain unresolved. The need for robust infectious disease surveillance to detect emerging pathogens...

Agroforest mosaics represent one of the most extensive human-impacted terrestrial systems worldwide and play an increasingly critical role in wildlife conservation. In such dynamic shared landscapes, coexistence can be compromised if people view wildlife as a source of infectious disease. A cross-disciplinary One Health knowledge base can help to i...

Humans are considered as the main host for Mycobacterium leprae1, the aetiological agent of leprosy, but spillover has occurred to other mammals that are now maintenance hosts, such as nine-banded armadillos and red squirrels2,3. Although naturally acquired leprosy has also been described in captive nonhuman primates4–7, the exact origins of infect...

Distinct SARS-CoV-2 lineages, discovered through various genomic surveillance initiatives, have emerged during the pandemic following unprecedented reductions in worldwide human mobility. We here describe a SARS-CoV-2 lineage - designated B.1.620 - discovered in Lithuania and carrying many mutations and deletions in the spike protein shared with wi...

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...

Authors of the March WHO report into how COVID-19 emerged warn that further delay makes crucial inquiry biologically difficult

Background: On October, 2020, after the first wave of COVID-19, only 8290 confirmed cases were reported in Kinshasa, Democratic Republic of the Congo, but the real prevalence remains unknown. To guide public health policies, we aimed to describe the prevalence of SARS-CoV-2 IgG antibodies in the general population in Kinshasa. Methods: We conduc...

Background: Blood cultures (BC) have a high clinical relevance and are a priority specimen for surveillance of antimicrobial resistance. Manual BC are still most frequently used in resource-limited settings. Data on automated BC performance in Africa are scarce. We implemented automated BC at a surveillance site of the African Network for improved...

The 1918 influenza pandemic was the deadliest respiratory pandemic of the 20th century and determined the genomic make-up of subsequent human influenza A viruses (IAV). Here, we analyze the first 1918 IAV genomes from Europe and from the first, milder wave of the pandemic. 1918 IAV genomic diversity is consistent with local transmission and frequen...

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...

Many high-income countries have met the SARS-CoV-2 pandemic with overwhelming sequencing resources and have identified numerous distinct lineages, including some with notably altered biology. Over a year into the pandemic following unprecedented reductions in worldwide human mobility, distinct introduced lineages of SARS-CoV-2 without sequenced ant...

SARS-CoV-2 variants of concern (VOC) and variants of interest (VOI) are heavily altering the COVID-19 pandemic's course due to their increased transmissibility, virulence and immune escape abilities. Data on their spread in western sub-Saharan Africa is however still scarce. We therefore sequenced viral genomes from SARS-CoV-2 cases identified in c...

Objective Haemorrhoidal disease (HEM) affects a large and silently suffering fraction of the population but its aetiology, including suspected genetic predisposition, is poorly understood. We report the first genome-wide association study (GWAS) meta-analysis to identify genetic risk factors for HEM to date. Design We conducted a GWAS meta-analysi...

Significance Mammals harbor diverse communities of gut microbes. The assembly and evolution of the bacterial components of these communities are influenced by host evolutionary histories and social behavior. Little is known about the ecological and evolutionary origins of the phages infecting these bacteria. We explore drivers of phage community as...

We determined near complete and complete monkeypox virus genomes in a shrew ( Crocidura littoralis ), two squirrels ( Funisciurus anerythrus, Funisciurus bayonii ), and produced shorter sequences from two rats ( Stochomys longicaudatus, Cricetomys sp. 2) originating from the Democratic Republic of the Congo. This suggests that a number of rodents b...

We determined a near complete and complete monkeypox virus (Mpox) genome in an elephant shrew ( Petrodromus tetradactylus ), a squirrel ( Funisciurus bayonii ), and produced shorter sequencesobtained from two rats ( Stochomys longicaudatus, Cricetomys sp. 2 ) originating from the Democratic Republic of the Congo. We also ran a series of molecular c...

Viruses closely related to human pathogens can reveal the origins of human infectious diseases. Human herpes simplexvirus type 1 (HSV-1) and type 2 (HSV-2) are hypothesized to have arisen via host-virus co-divergence and cross-species transmission. We report the discovery of novel herpes simplexviruses during a large-scale screening of fecal sample...

Over the last two decades, the viromes of our closest relatives, the African great apes (AGA), have been intensively studied. Comparative approaches have unveiled diverse evolutionary patterns, highlighting both stable host-virus associations over extended evolutionary timescales and much more recent viral emergence events. In this chapter, we summ...

Hemorrhoidal disease (HEM) affects a large fraction of the population but its etiology including suspected genetic predisposition is poorly understood. We conducted a GWAS meta-analysis of 218,920 HEM patients and 725,213 controls of European ancestry, demonstrating modest heritability and genetic correlation with several other diseases from the ga...

Humans are considered the main host for Mycobacterium leprae , the aetiologic agent of leprosy, but spill-over to other mammals such as nine-banded armadillos and red squirrels occurs. Although naturally acquired leprosy has also been described in captive nonhuman primates, the exact origins of infection remain unclear. Here, we report on leprosy-l...

Many non-human primate species in sub-Saharan Africa are infected with Treponema pallidum subsp. pertenue, the bacterium causing yaws in humans. In humans, yaws is often characterized by lesions of the extremities and face, while T. pal-lidum subsp. pallidum causes venereal syphilis and is typically characterized by primary lesions on the genital,...

It has been a long time since the world has experienced a pandemic with such a rapid devastating impact as the current COVID-19 pandemic. The causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is unusual in that it appears capable of infecting many different mammal species. As a significant proportion of people worldwide...

The multimammate mouse (Mastomys natalensis; M. natalensis) serves as the main reservoir for the zoonotic arenavirus Lassa virus (LASV), and this has led to considerable investigation into the distribution of LASV and other related arena-viruses in this host species. In contrast to the situation with arenaviruses, the presence of other viruses in M...

In mammals, the excretion of cortisol can provide energy toward restoring homeostasis and is a major component of the stress response. However, chronically elevated cortisol levels also have suppressive effects on immune function. As mounting an immune response is energetically costly, sick individuals may conserve energy by exhibiting certain sick...

After the 2017 Ebola virus (EBOV) outbreak in Likati, a district in northern Democratic Republic of the Congo, we sampled small mammals from the location where the primary case-patient presumably acquired infection. None tested positive for EBOV RNA or antibodies against EBOV, highlighting the ongoing challenge in detecting animal reservoirs for EB...

Older origins of measles virus Animal domestication by humans is thought to have given many pathogens an opportunity to invade a new host, and measles is one example of this. However, there is controversy about when measles emerged in humans, because the historical descriptions of measles are relatively recent (late ninth century CE). The controver...

Yaws-like lesions are widely reported in wild African great apes, yet the causative agent has not been confirmed in affected animals. We describe yaws-like lesions in a wild chimpanzee in Guinea for which we demonstrate infection with Treponema pallidum subsp. pertenue. Assessing the conservation implications of this pathogen requires further resea...