Host phylogenetic distance drives trends in virus virulence and transmissibility across the animal–human interface

Historically, efforts to assess ‘zoonotic risk’ have focused mainly on quantifying the potential for cross-species emergence of viruses from animal hosts. However, viruses clearly differ in relative burden, both in terms of morbidity and mortality (virulence) incurred and the capacity for sustained human-to-human transmission. Extending previously published databases, we delineated host and viral traits predictive of human mortality associated with viral spillover, viral capacity to transmit between humans following spillover and the probability of a given virus being zoonotic. We demonstrate that increasing host phylogenetic distance from humans positively correlates with human mortality but negatively correlates with human transmissibility, suggesting that the virulence induced by viruses emerging from hosts at high phylogenetic distance may limit capacity for human transmission. Our key result is that hosts most closely related to humans harbour zoonoses of lower impact in terms of morbidity and mortality, while the most distantly related hosts—in particular, order Chiroptera (bats)—harbour highly virulent zoonoses with a lower capacity for endemic establishment in human hosts. As a whole, our results emphasize the importance of understanding how zoonoses manifest in the human population and also highlight potential risks associated with multi-host transmission chains in spillover. This article is part of the theme issue ‘Dynamic and integrative approaches to understanding pathogen spillover’.

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Zoonotic Potential of Influenza A Viruses: A Comprehensive Overview

Viruses ◽

10.3390/v10090497 ◽

2018 ◽

Vol 10 (9) ◽

pp. 497 ◽

Cited By ~ 50

Author(s):

Ahmed Mostafa ◽

Elsayed Abdelwhab ◽

Thomas Mettenleiter ◽

Stephan Pleschka

Keyword(s):

Genetic Diversity ◽

Global Health ◽

Influenza A ◽

Viral Evolution ◽

Zoonotic Potential ◽

Influenza A Viruses ◽

Comprehensive Overview ◽

High Genetic Diversity ◽

Human Interface ◽

Animal Hosts

Influenza A viruses (IAVs) possess a great zoonotic potential as they are able to infect different avian and mammalian animal hosts, from which they can be transmitted to humans. This is based on the ability of IAV to gradually change their genome by mutation or even reassemble their genome segments during co-infection of the host cell with different IAV strains, resulting in a high genetic diversity. Variants of circulating or newly emerging IAVs continue to trigger global health threats annually for both humans and animals. Here, we provide an introduction on IAVs, highlighting the mechanisms of viral evolution, the host spectrum, and the animal/human interface. Pathogenicity determinants of IAVs in mammals, with special emphasis on newly emerging IAVs with pandemic potential, are discussed. Finally, an overview is provided on various approaches for the prevention of human IAV infections.

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Pathology of Coronavirus Infections: A Review of Lesions in Animals in the One-Health Perspective

Animals ◽

10.3390/ani10122377 ◽

2020 ◽

Vol 10 (12) ◽

pp. 2377

Author(s):

Valentina Zappulli ◽

Silvia Ferro ◽

Federico Bonsembiante ◽

Ginevra Brocca ◽

Alessandro Calore ◽

...

Keyword(s):

Public Health ◽

One Health ◽

Preventive Measures ◽

Tissue Injury ◽

Wild Animals ◽

Zoonotic Risk ◽

Health Concept ◽

Animal Hosts ◽

The One ◽

Human Infections

Coronaviruses (CoVs) are worldwide distributed RNA-viruses affecting several species, including humans, and causing a broad spectrum of diseases. Historically, they have not been considered a severe threat to public health until two outbreaks of COVs-related atypical human pneumonia derived from animal hosts appeared in 2002 and in 2012. The concern related to CoVs infection dramatically rose after the COVID-19 global outbreak, for which a spill-over from wild animals is also most likely. In light of this CoV zoonotic risk, and their ability to adapt to new species and dramatically spread, it appears pivotal to understand the pathophysiology and mechanisms of tissue injury of known CoVs within the “One-Health” concept. This review specifically describes all CoVs diseases in animals, schematically representing the tissue damage and summarizing the major lesions in an attempt to compare and put them in relation, also with human infections. Some information on pathogenesis and genetic diversity is also included. Investigating the lesions and distribution of CoVs can be crucial to understand and monitor the evolution of these viruses as well as of other pathogens and to further deepen the pathogenesis and transmission of this disease to help public health preventive measures and therapies.

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Morbidity due to Schistosoma mansoni - Entamoeba histolytica coinfection in hamsters (Mesocricetus auratus)

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/s0037-86822007000200005 ◽

2007 ◽

Vol 40 (2) ◽

pp. 170-174 ◽

Cited By ~ 1

Author(s):

Silvio Santana Dolabella ◽

Paulo Marcos Zech Coelho ◽

Izabela Torquetti Borçari ◽

Nelson Azevedo Santos Teixeira Mello ◽

Zilton de Araújo Andrade ◽

...

Keyword(s):

Portal Vein ◽

Schistosoma Mansoni ◽

Entamoeba Histolytica ◽

Mesocricetus Auratus ◽

Morbidity And Mortality ◽

Single Infection ◽

Morphological Findings ◽

Highly Virulent

Data on Schistosoma mansoni-Entamoeba histolytica coinfection are scarce in the literature. In the present study, hamsters that had been infected for 70 days with Schistosoma mansoni (LE strain) were inoculated via the portal vein with two strains of trophozoites of Entamoeba histolytica: ICB-EGG (highly virulent) and ICB-RPS (non-virulent). The most evident result of coinfection was increased morbidity and mortality, in comparison with either of the infections alone. Histologically, there were no evident signs of interaction between these two infections. The morphological findings of schistosomal granuloma and amoebic abscesses in the liver were similar to those seen in the respective single-infection controls. However, there was severe wasting of the animals with both infections and greater numbers of amoebic lesions in their livers. The results obtained indicated that schistosomiasis aggravates the course of amoebiasis in hamsters.

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Controlling emerging zoonoses at the animal-human interface

One Health Outlook ◽

10.1186/s42522-020-00024-5 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

Riley O. Mummah ◽

Nicole A. Hoff ◽

Anne W. Rimoin ◽

James O. Lloyd-Smith

Keyword(s):

Disease Control ◽

Resource Constraints ◽

Relative Effectiveness ◽

Emerging Pathogens ◽

Modeling Framework ◽

Control Policies ◽

Human Interface ◽

Animal Hosts ◽

And Control ◽

Animal Reservoirs

Abstract Background For many emerging or re-emerging pathogens, cases in humans arise from a mixture of introductions (via zoonotic spillover from animal reservoirs or geographic spillover from endemic regions) and secondary human-to-human transmission. Interventions aiming to reduce incidence of these infections can be focused on preventing spillover or reducing human-to-human transmission, or sometimes both at once, and typically are governed by resource constraints that require policymakers to make choices. Despite increasing emphasis on using mathematical models to inform disease control policies, little attention has been paid to guiding rational disease control at the animal-human interface. Methods We introduce a modeling framework to analyze the impacts of different disease control policies, focusing on pathogens exhibiting subcritical transmission among humans (i.e. pathogens that cannot establish sustained human-to-human transmission). We quantify the relative effectiveness of measures to reduce spillover (e.g. reducing contact with animal hosts), human-to-human transmission (e.g. case isolation), or both at once (e.g. vaccination), across a range of epidemiological contexts. Results We provide guidelines for choosing which mode of control to prioritize in different epidemiological scenarios and considering different levels of resource and relative costs. We contextualize our analysis with current zoonotic pathogens and other subcritical pathogens, such as post-elimination measles, and control policies that have been applied. Conclusions Our work provides a model-based, theoretical foundation to understand and guide policy for subcritical zoonoses, integrating across disciplinary and species boundaries in a manner consistent with One Health principles.

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Serologic Evidence of Occupational Exposure to Avian Influenza Viruses at the Wildfowl/Poultry/Human Interface

Microorganisms ◽

10.3390/microorganisms9102153 ◽

2021 ◽

Vol 9 (10) ◽

pp. 2153

Author(s):

Maria Alessandra De Marco ◽

Mauro Delogu ◽

Marzia Facchini ◽

Livia Di Trani ◽

Arianna Boni ◽

...

Keyword(s):

Avian Influenza ◽

Influenza Viruses ◽

Confirmatory Test ◽

Avian Influenza Viruses ◽

Serum Samples ◽

Human Interface ◽

Zoonotic Risk ◽

Exposed Workers ◽

Occupationally Exposed ◽

Human Sera

Ecological interactions between wild aquatic birds and outdoor-housed poultry can enhance spillover events of avian influenza viruses (AIVs) from wild reservoirs to domestic birds, thus increasing the related zoonotic risk to occupationally exposed workers. To assess serological evidence of AIV infection in workers operating in Northern Italy at the wildfowl/poultry interface or directly exposed to wildfowl, serum samples were collected between April 2005 and November 2006 from 57 bird-exposed workers (BEWs) and from 7 unexposed controls (Cs), planning three sample collections from each individual. Concurrently, AIV surveillance of 3587 reared birds identified 4 AIVs belonging to H10N7, H4N6 and H2N2 subtypes while serological analysis by hemagglutination inhibition (HI) assay showed recent infections caused by H1, H2, H4, H6, H10, H11, H12, and H13 subtypes. Human sera were analyzed for specific antibodies against AIVs belonging to antigenic subtypes from H1 to H14 by using HI and virus microneutralization (MN) assays as a screening and a confirmatory test, respectively. Overall, antibodies specific to AIV-H3, AIV-H6, AIV-H8, and AIV-H9 were found in three poultry workers (PWs) and seropositivity to AIV-11, AIV-H13—still detectable in October 2017—in one wildlife professional (WP). Furthermore, seropositivity to AIV-H2, accounting for previous exposure to the “extinct” H2N2 human influenza viruses, was found in both BEWs and Cs groups. These data further emphasize the occupational risk posed by zoonotic AIV strains and show the possible occurrence of long-lived antibody-based immunity following AIV infections in humans.

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Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to animals: an updated review

Journal of Translational Medicine ◽

10.1186/s12967-020-02534-2 ◽

2020 ◽

Vol 18 (1) ◽

Cited By ~ 6

Author(s):

Sina Salajegheh Tazerji ◽

Phelipe Magalhães Duarte ◽

Parastoo Rahimi ◽

Fatemeh Shahabinejad ◽

Santosh Dhakal ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Preventive Measures ◽

Phylogenetic Analyses ◽

First Century ◽

Future Research ◽

World Population ◽

Human Interface ◽

The Past ◽

Pet Owners ◽

Animal Hosts

Abstract COVID-19 caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in Wuhan (Hubei province, China) during late 2019. It has spread across the globe affecting nearly 21 million people with a toll of 0.75 million deaths and restricting the movement of most of the world population during the past 6 months. COVID-19 became the leading health, economic, and humanitarian challenge of the twenty-first century. In addition to the considerable COVID-19 cases, hospitalizations, and deaths in humans, several cases of SARS-CoV-2 infections in animal hosts (dog, cat, tiger, lion, and mink) have been reported. Thus, the concern of pet owners is increasing. Moreover, the dynamics of the disease requires further explanation, mainly concerning the transmission of the virus from humans to animals and vice versa. Therefore, this study aimed to gather information about the reported cases of COVID-19 transmission in animals through a literary review of works published in scientific journals and perform genomic and phylogenetic analyses of SARS-CoV-2 isolated from animal hosts. Although many instances of transmission of the SARS-CoV-2 have been reported, caution and further studies are necessary to avoid the occurrence of maltreatment in animals, and to achieve a better understanding of the dynamics of the disease in the environment, humans, and animals. Future research in the animal–human interface can help formulate and implement preventive measures to combat the further transmission of COVID-19.

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Bats host the most virulent—but not the most dangerous—zoonotic viruses

10.1101/2021.07.25.453574 ◽

2021 ◽

Author(s):

Sarah Guth ◽

Nardus Mollentze ◽

Katia Renault ◽

Daniel Streicker ◽

Elisa Visher ◽

...

Keyword(s):

Case Fatality ◽

Human Case ◽

Host Population ◽

Reservoir Host ◽

Human Populations ◽

Animal Reservoir ◽

Human Mortality ◽

Zoonotic Viruses ◽

Zoonotic Risk ◽

Context Specific

Identifying virus characteristics associated with the largest public health impacts on human populations is critical to informing zoonotic risk assessments and surveillance strategies. Efforts to assess "zoonotic risk" often use trait-based analyses to identify which viral and reservoir host groups are most likely to source zoonoses but have not fully addressed how and why the impacts of zoonotic viruses vary in terms of disease severity ('virulence'), capacity to spread within human populations ('transmissibility'), or total human mortality ('death burden'). We analyzed trends in human case fatality rates, transmission capacities, and total death burdens across a comprehensive dataset of mammalian and avian zoonotic viruses. Bats harbor the most virulent zoonotic viruses even when compared to birds, which alongside bats, have been hypothesized to be "special" zoonotic reservoirs due to molecular adaptations that support the physiology of flight. Reservoir host groups more closely related to humans—in particular, Primates—harbor less virulent, but more highly transmissible viruses. Importantly, disproportionately high human death burden, arguably the most important metric of zoonotic risk, is not associated with any animal reservoir, including bats. Our data demonstrate that mechanisms driving death burdens are diverse and often contradict trait-based predictions. Ultimately, total human mortality is dependent on context-specific epidemiological dynamics, which are shaped by a combination of viral traits and conditions in the animal host population and across and beyond the human-animal interface. Understanding the conditions that predict high zoonotic burden in humans will require longitudinal studies of epidemiological dynamics in wildlife and human populations.

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Strain typing and characterization of virulence genes in clinicalStaphylococcus aureusisolates from Kenya

10.1101/390955 ◽

2018 ◽

Author(s):

Cecilia Kyany’a ◽

Justin Nyasinga ◽

Daniel Matano ◽

Valerie Oundo ◽

Simon Wacira ◽

...

Keyword(s):

Virulence Genes ◽

Illumina Miseq ◽

Strain Typing ◽

Toxin Genes ◽

Severe Infections ◽

Potential Risks ◽

Hospital Acquired ◽

Spa Types ◽

Highly Virulent

AbstractStaphylococcusaureusstrain typing is an important surveillance tool as particular strains have been associated with virulence and community and hospital acquired MRSA outbreaks globally. This study sought to determine the circulating strain types ofS.aureusin Kenya and establish the virulence genes among the strains. ClinicalS.aureusisolates from 3 hospitals in Kenya were sequenced on the Illumina Miseq and genomes assembled and annotated on PATRIC. Results demonstrated great diversity among the isolates with identification of 6 distinct CC (8,22,15,80,121,152), 8 ST types (8, 15, 22,80,121,152,241, 1633) and 8 spa types (t005, t037, t064, t084, t233, t2029, t272,t355). Novel STs (4705, 4707) and a novel spa type (t17826) were identified. The most prominent clonal complex was CC 152 comprised of only MSSA. A majority of MRSA isolates (3/4) typed to ST 241, CC8. One MRSA isolate typed to a novel ST 4705. All isolates were screened for a panel of 56 known virulence genes (19 adhesins, 9 hemolysins, 5 immune evasion proteins, 6 exo-enzymes and 19 toxins). 9 toxin genes were detected among the isolates with CC8 isolates having the highest numbers of toxin genes. An MSSA isolate (CC8) from a severe burn infection had the highest number of toxin genes (5). All MRSA isolates (CC8) had only 2 toxins, SEK and SEQ, whereas a majority of the MSSA isolates either had 0 or ≥2 toxins. SEK+SEQ and TSST-1+SEB+SEL toxin combinations were observed among patients whose disease resulted in hospitalization, an indicator of severe infections. This study confirms the highly heterogeneousS.aureuspopulation in Kenya. MSSA appear to have the potential of accumulating more toxin genes than MRSA. This co-occurrence of major toxin genes, some associated with MRSA, highlights the potential risks of outbreaks of highly virulent MRSA infections which would pose treatment challenges.

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