Naturally acquired simian retrovirus infections in central African hunters

Prioritization of zoonoses of wildlife origin for multisectoral one health collaboration in Guyana, 2022

Background

The human population in Guyana, located on the South American continent, is vulnerable to zoonotic diseases due to an appreciable reliance on Neotropical wildlife as a food source and for trade. An existing suboptimal health surveillance system may affect the effective monitoring of important zoonotic diseases. To effectively address this deficit, a One Health zoonotic disease prioritization workshop was conducted to identify nationally significant zoonoses.

Methods

Prioritization of zoonotic diseases was conducted for the first time in Guyana & Caribbean region using literature review, prioritization criteria and a risk prioritization tool in combination with a consultative One Health workshop. This involved multisectoral experts from varied disciplines of social, human, animal, and environmental health to prioritize zoonotic diseases using a modified semi-quantitative One Health Zoonotic Disease Prioritization (OHZDP) tool. The inclusion and exclusion criteria were applied to pathogen hazards in existence among wildlife in Guyana during the hazard identification phase.

Results

In total, fifty zoonoses were chosen for prioritization. Based on their weighted score, prioritized diseases were ranked in order of relative importance using a one-to-five selection scale. In Guyana, this zoonotic disease prioritization method is the first significant step toward bringing together specialists from the fields of human, animal, and environmental health. Following discussion of the OHZDP Tool output among disease experts, a final zoonotic disease list, including tuberculosis, leptospirosis, gastroenteritis, rabies, coronavirus, orthopoxvirus, viral hemorrhagic fevers, and hepatitis were identified as the top eight priority zoonoses in Guyana.

Conclusions

This represents the first prioritization of nationally significant zoonotic diseases in Guyana and the English-speaking Caribbean. This One Health strategy to prioritize these eight zoonoses of wildlife origin is a step that will support future tracking and monitoring for disease prevalence among humans and wildlife and can be used as a decision-making guide for policymakers and stakeholders in Guyana.

A systematic mapping review of links between handling wild meat and zoonotic diseases

1.Hunting, trade, and consumption of wildlife present a serious threat to global public health as it places humans in close contact with zoonotic pathogens.2.We systematically mapped the literature on wild meat handling and zoonotic disease transmission (1996-2022) using the online database Web of Science and Google search engine and identified 6229 articles out of which 253 were finally selected for use in our mapping review; 51 of these provided specific information regarding transmission risks.3.The reviewed studies reported 43 zoonotic pathogens (17 bacteria, 15 viruses, and 11 parasites) that could pose a potential risk to human health.4.Sixteen hygienic and sanitary behaviours were described in the reviewed studies. Disease surveillance was the most frequent. Most of the surveillance studies were carried out in Europe and were less common in the tropics.5.To inform policy and practical actions effectively, it is imperative to broaden our understanding of how various mitigation behaviours can be employed to minimize the risk of transmission.

Zoonoses in a changing world

Animals are continuously exposed to pathogens but rarely get infected, because pathogens must overcome barriers to establish successful infections. Ongoing planetary changes affect factors relevant for such infections, such as pathogen pressure and pathogen exposure. The replacement of wildlife with domestic animals shrinks the original host reservoirs, whereas expanding agricultural frontiers lead to increased contact between natural and altered ecosystems, increasing pathogen exposure and reducing the area where the original hosts can live. Climate change alters species' distributions and phenology, pathogens included, resulting in exposure to pathogens that have colonized or recolonized new areas. Globalization leads to unwilling movement of and exposure to pathogens. Because people and domestic animals are overdominant planetwide, there is increased selective pressure for pathogens to infect them. Nature conservation measures can slow down but not fully prevent spillovers. Additional and enhanced surveillance methods in potential spillover hotspots should improve early detection and allow swifter responses to emerging outbreaks.

Viruses in saliva from sanctuary chimpanzees (Pan troglodytes) in Republic of Congo and Uganda

Pathogen surveillance for great ape health monitoring has typically been performed on non-invasive samples, primarily feces, in wild apes and blood in sanctuary-housed apes. However, many important primate pathogens, including known zoonoses, are shed in saliva and transmitted via oral fluids. Using metagenomic methods, we identified viruses in saliva samples from 46 wild-born, sanctuary-housed chimpanzees at two African sanctuaries in Republic of Congo and Uganda. In total, we identified 20 viruses. All but one, an unclassified CRESS DNA virus, are classified in five families: Circoviridae, Herpesviridae, Papillomaviridae, Picobirnaviridae, and Retroviridae. Overall, viral prevalence ranged from 4.2% to 87.5%. Many of these viruses are ubiquitous in primates and known to replicate in the oral cavity (simian foamy viruses, Retroviridae; a cytomegalovirus and lymphocryptovirus; Herpesviridae; and alpha and gamma papillomaviruses, Papillomaviridae). None of the viruses identified have been shown to cause disease in chimpanzees or, to our knowledge, in humans. These data suggest that the risk of zoonotic viral disease from chimpanzee oral fluids in sanctuaries may be lower than commonly assumed.

Weaponising microbes for peace

There is much human disadvantage and unmet need in the world, including deficits in basic resources and services considered to be human rights, such as drinking water, sanitation and hygiene, healthy nutrition, access to basic healthcare, and a clean environment. Furthermore, there are substantive asymmetries in the distribution of key resources among peoples. These deficits and asymmetries can lead to local and regional crises among peoples competing for limited resources, which, in turn, can become sources of discontent and conflict. Such conflicts have the potential to escalate into regional wars and even lead to global instability. Ergo: in addition to moral and ethical imperatives to level up, to ensure that all peoples have basic resources and services essential for healthy living and to reduce inequalities, all nations have a self-interest to pursue with determination all available avenues to promote peace through reducing sources of conflicts in the world. Microorganisms and pertinent microbial technologies have unique and exceptional abilities to provide, or contribute to the provision of, basic resources and services that are lacking in many parts of the world, and thereby address key deficits that might constitute sources of conflict. However, the deployment of such technologies to this end is seriously underexploited. Here, we highlight some of the key available and emerging technologies that demand greater consideration and exploitation in endeavours to eliminate unnecessary deprivations, enable healthy lives of all and remove preventable grounds for competition over limited resources that can escalate into conflicts in the world. We exhort central actors: microbiologists, funding agencies and philanthropic organisations, politicians worldwide and international governmental and non-governmental organisations, to engage - in full partnership - with all relevant stakeholders, to 'weaponise' microbes and microbial technologies to fight resource deficits and asymmetries, in particular among the most vulnerable populations, and thereby create humanitarian conditions more conducive to harmony and peace.

Interventions to Reduce Risk for Pathogen Spillover and Early Disease Spread to Prevent Outbreaks, Epidemics, and Pandemics

The pathogens that cause most emerging infectious diseases in humans originate in animals, particularly wildlife, and then spill over into humans. The accelerating frequency with which humans and domestic animals encounter wildlife because of activities such as land-use change, animal husbandry, and markets and trade in live wildlife has created growing opportunities for pathogen spillover. The risk of pathogen spillover and early disease spread among domestic animals and humans, however, can be reduced by stopping the clearing and degradation of tropical and subtropical forests, improving health and economic security of communities living in emerging infectious disease hotspots, enhancing biosecurity in animal husbandry, shutting down or strictly regulating wildlife markets and trade, and expanding pathogen surveillance. We summarize expert opinions on how to implement these goals to prevent outbreaks, epidemics, and pandemics.

Bacteriophages diversity in India's major river Ganga: a repository to regulate pathogenic bacteria in the aquatic environment

Bacteriophages are key viruses that can kill thousands of harmful microbes generally present at polluted sites. Such bacteriophages are abundantly present in the river Ganga, where millions of people in India and abroad drink its water and take baths every day for spiritual reasons. Besides bacteriophages, several pathogenic and zoonotic microbes are present in the river Ganga. It is interesting to study the diversity and abundance of bacteria and their respective phages present in polluted or non-polluted sites. Thus, the metagenomics study was carried out at the most polluted sites of river Ganga near Kanpur and non-polluted sites at Farakka, which harbors several harmful bacteria and their phages. The results revealed a significantly higher percentage of Microviridae phage family, ssDNA viruses, and Mimiviridae virus family near Kanpur than Farakka. In addition, compared to Kanpur, Farakka has a more significant percentage of Myoviridae, an unidentified phage family, and Retroviridae viral families. Despite heavy drainage of untreated and contaminated effluents from the leather industry, pesticide industry, paper mills, metropolitan cities, and other sources, the vast number of said phages kills several harmful pathogenic microbes in polluted sites to maintain the Ganga water's healing power or natural sterility. In a polluted aquatic environment, the varieties of bacteriophages were identified in the Ganga and their interaction with the microbial host. The taxonomic diversity of several bacteriophages found in pathogenic host systems was investigated to get exceptional knowledge of these small viruses in the aquatic environment.

Breaking barriers: Scientific contributions in virology from women in low- and middle-income countries

The advancement of science has been a collective effort and benefits from a diversity of views and gender representation. However, support for and recognition of women in science is often insufficient. Despite historically being marginalized by the scientific community, research by women has advanced the field of virology, from the discovery of rotavirus and isolation of human immunodeficiency virus (HIV) to a vaccine for polio and the initial description of a virus’ ability to cause cancer. Although women in science, technology, engineering, and mathematics (STEM) fields are continuing to share their diverse wealth of knowledge and innovation, even today many are under-recognized and under-supported in low- and middle-income countries (LMICs). This review will highlight women in virology from LMICs in Africa, Asia, and Latin America where the barriers to scientific education and achievement for women can be far greater than in high income countries. Despite these barriers, the women we profile below have made important contributions to translational virology. We hope this review will contribute to the global expansion of efforts to provide improved access to and retention in scientific careers for women.

Understanding Factors that Shape Exposure to Zoonotic and Food-Borne Diseases Across Wild Meat Trade Chains

The rise of zoonotic disease-related public health crises has sparked calls for policy action, including calls to close wildlife markets. Yet, these calls often reflect limited understanding of where, precisely, exposure to risk occurs along wildlife and wild meat trade chains. They also threaten to negatively impact food security and livelihoods. From a public health perspective, it is important to understand the practices that shape food safety all along the trade chain, resulting in meat that is either safe to eat or managed as a potential vector of pathogens. This article uses ethnographic methods to examine the steps that lead a wild animal from the forest to the plate of an urban consumer in Yangambi and Kisangani in the Democratic Republic of Congo (DRC). Focusing on hunters, village-level consumers, transporters, market traders and urban consumers, we highlight specific practices that expose different actors involved in the trade chain to wild meat related health risks, including exposure to food borne illnesses from contaminated meat and zoonotic pathogens through direct contact with wild animals, and the local practices in place to reduce the same. We discuss interventions that could help prevent and mitigate zoonotic and food borne disease risks associated with wild meat trade chains.

A strategy to assess spillover risk of bat SARS-related coronaviruses in Southeast Asia

Emerging diseases caused by coronaviruses of likely bat origin (e.g., SARS, MERS, SADS, COVID-19) have disrupted global health and economies for two decades. Evidence suggests that some bat SARS-related coronaviruses (SARSr-CoVs) could infect people directly, and that their spillover is more frequent than previously recognized. Each zoonotic spillover of a novel virus represents an opportunity for evolutionary adaptation and further spread; therefore, quantifying the extent of this spillover may help target prevention programs. We derive current range distributions for known bat SARSr-CoV hosts and quantify their overlap with human populations. We then use probabilistic risk assessment and data on human-bat contact, human viral seroprevalence, and antibody duration to estimate that a median of 66,280 people (95% CI: 65,351–67,131) are infected with SARSr-CoVs annually in Southeast Asia. These data on the geography and scale of spillover can be used to target surveillance and prevention programs for potential future bat-CoV emergence.

Coronaviruses may spill over from bats to humans. This study uses epidemiological data, species distribution models, and probabilistic risk assessment to map overlap among people and SARSr-CoV bat hosts and estimate how many people are infected with bat-origin SARSr-CoVs in Southeast Asia annually.

Human-mediated impacts on biodiversity and the consequences for zoonotic disease spillover

Human-mediated changes to natural ecosystems have consequences for both ecosystem and human health. Historically, efforts to preserve or restore 'biodiversity' can seem to be in opposition to human interests. However, the integration of biodiversity conservation and public health has gained significant traction in recent years, and new efforts to identify solutions that benefit both environmental and human health are ongoing. At the forefront of these efforts is an attempt to clarify ways in which biodiversity conservation can help reduce the risk of zoonotic spillover of pathogens from wild animals, sparking epidemics and pandemics in humans and livestock. However, our understanding of the mechanisms by which biodiversity change influences the spillover process is incomplete, limiting the application of integrated strategies aimed at achieving positive outcomes for both conservation and disease management. Here, we review the literature, considering a broad scope of biodiversity dimensions, to identify cases where zoonotic pathogen spillover is mechanistically linked to changes in biodiversity. By reframing the discussion around biodiversity and disease using mechanistic evidence - while encompassing multiple aspects of biodiversity including functional diversity, landscape diversity, phenological diversity, and interaction diversity - we work toward general principles that can guide future research and more effectively integrate the related goals of biodiversity conservation and spillover prevention. We conclude by summarizing how these principles could be used to integrate the goal of spillover prevention into ongoing biodiversity conservation initiatives.

Gastro-intestinal parasites of sympatric red panda and livestock in protected areas of Nepal

Background

Disease transmission among humans, domestic animals and wildlife can have profound consequences in human health, wildlife conservation and maintenance of biodiversity. The issue of disease transmission can be particularly important for threatened wildlife species, yet such information remains scarce due to logistic constraints and government regulation on animal handlings. The red panda (Ailurus fulgens) is one of the globally threatened species challenged with habitat fragmentation and human disturbance. In Nepal, livestock grazing is recognised as one of the major threats to the red panda.

Aim

We aimed to provide the first empirical data on gastro‐intestinal parasites for sympatric livestock and red panda from two geographically isolated regions in Nepal.

Methods

In this study, we systematically sampled, and examined the faecal of livestock and red panda in two separate protected areas to provide the first empirical data on their gastro‐intestinal parasite, including the prevalence, parasite richness and load.

Results

We documented 11 parasite taxa (7 nematodes, 2 cestodes, 1 trematode and 1 coccidian), of which 8 are shared by both livestock and red panda. Furthermore, parasite prevalence, parasite load and parasite richness were generally higher in the livestock than the red panda.

Conclusion

The data provided from this systematic survey on parasites of sympatric livestock and red panda in wild raises the concern about the potential role of livestock mediating disease dynamics in the red panda. Our study suggests that cross‐transmission of parasites between livestock and red panda are likely, and the livestock may be a competent agent bringing disease to both red panda and human. Therefore, managing human‐livestock‐wildlife contact to reduce disease risk to all groups should be a key component in conservation planning of protected areas.

A strategy to assess spillover risk of bat SARS-related coronaviruses in Southeast Asia

Emerging diseases caused by coronaviruses of likely bat origin (e.g. SARS, MERS, SADS and COVID-19) have disrupted global health and economies for two decades. Evidence suggests that some bat SARS-related coronaviruses (SARSr-CoVs) could infect people directly, and that their spillover is more frequent than previously recognized. Each zoonotic spillover of a novel virus represents an opportunity for evolutionary adaptation and further spread; therefore, quantifying the extent of this "hidden" spillover may help target prevention programs. We derive biologically realistic range distributions for known bat SARSr-CoV hosts and quantify their overlap with human populations. We then use probabilistic risk assessment and data on human-bat contact, human SARSr-CoV seroprevalence, and antibody duration to estimate that ∼400,000 people (median: ∼50,000) are infected with SARSr-CoVs annually in South and Southeast Asia. These data on the geography and scale of spillover can be used to target surveillance and prevention programs for potential future bat-CoV emergence.

No need to beat around the bushmeat-The role of wildlife trade and conservation initiatives in the emergence of zoonotic diseases

Wildlife species constitute a vast and uncharted reservoir of zoonotic pathogens that can pose a severe threat to global human health. Zoonoses have become increasingly impactful over the past decades, and the expanding trade in wildlife is unarguably among the most significant risk factors for their emergence. Despite several warnings from the academic community about the spillover risks associated with wildlife trade, the ongoing COVID-19 pandemic underlines that current policies on the wildlife industry are deficient. Conservation initiatives, rather than practices that attempt to eradicate zoonotic pathogens or the wild species that harbour them, could play a vital role in preventing the emergence of life-threatening zoonoses. This review explores how wildlife conservation initiatives could effectively reduce the risk of new zoonotic diseases emerging from the wildlife trade by integrating existing literature on zoonotic diseases and risk factors associated with wildlife trade. Conservation should mainly aim at reducing human-wildlife interactions in the wildlife trade by protecting wildlife habitats and providing local communities with alternative protein sources. In addition, conservation should focus on regulating the legal wildlife trade and education about disease transfer and safer hunting and butchering methods. By uniting efforts for wildlife protection and universal concern for preventing zoonotic epidemics, conservation initiatives have the potential to safeguard both biodiversity, animal welfare, and global human health security.

Transmission of infectious viruses in the natural setting at human-animal interface

Most viral pathogens causing epidemics and pandemics are zoonotic, emerging from wildlife reservoirs like SARS CoV2 causing the global Covid-19 pandemic, although animal origin of this virus remains a mystery. Cross-species transmission of pathogens from animals to humans is known as zoonosis. However, pathogens are also transmitted from humans to animals in regions where there is a close interaction between animals and humans by 'reverse transmission' (anthroponosis). Molecular evidence for the transmission of two zoonotic RNA viruses at the human-monkey interface in Rajasthan forests is presented here: a) the apathogenic Simian Foamy Viruses (SFV), and b): Influenza A viruses (IAV)-like virus, etiologic agent for human flu infecting wild Indian rhesus monkeys inhabiting Rajasthan forests. The data provide critical information on ecology and evolution of viruses of Public Health relevance. During replication, viral genomes mutate along the transmission route to adapt to the new hosts, generating new variants that are likely to have properties different from the founder viruses. Wild Indian monkeys are under-sampled for monitoring infectious diseases mainly because of the difficulties with sample collection. Monkeys are perceived as religious icons by the Hindus in India. It is extremely difficult to obtain permission from the Forest and Wildlife Department government authorities to collect wild simian blood samples for surveillance of infectious diseases caused by viral pathogens. Reducing animal-human contact and affordable vaccination are two relevant anti-viral strategies to counteract the spread of infectious zoonotic pathogens. Genbank Accession numbers: Indian SFVmac: ADN94420, IAV like virus: MZ298601.

Illegal Wildlife Trade and Emerging Infectious Diseases: Pervasive Impacts to Species, Ecosystems and Human Health

Simple Summary

Wildlife is trafficked illegally across the globe every day. The illegal wildlife trade (IWT) creates opportunity for emerging infectious disease (EID) events to occur. EIDs are a major threat to wildlife, ecosystems, and public health. This study addresses the lack of comprehensive review of pathogens identified in IWT and highlights the expansion of literature on this subject over the past 30 years. We reviewed 82 scientific papers and conference proceedings from 1990 to 2020. Trends in EIDs identified in IWT have significantly increased over the past decade. Cases covered 240 pathogens across all taxa. Approximately 60% of the pathogens identified were zoonotic (transmissible between animals and humans) and threaten public health. Based on our findings, we recommend further research is needed to monitor and prevent the IWT.

Abstract

Emerging infectious disease (EID) events can be traced to anthropogenic factors, including the movement of wildlife through legal and illegal trade. This paper focuses on the link between illegal wildlife trade (IWT) and infectious disease pathogens. A literature review through Web of Science and relevant conference proceedings from 1990 to 2020 resulted in documenting 82 papers and 240 identified pathogen cases. Over 60% of the findings referred to pathogens with known zoonotic potential and five cases directly referenced zoonotic spillover events. The diversity of pathogens by taxa included 44 different pathogens in birds, 47 in mammals, 16 in reptiles, two in amphibians, two in fish, and one in invertebrates. This is the highest diversity of pathogen types in reported literature related to IWT. However, it is likely not a fully representative sample due to needed augmentation of surveillance and monitoring of IWT and more frequent pathogen testing on recovered shipments. The emergence of infectious disease through human globalization has resulted in several pandemics in the last decade including SARS, MERS, avian influenza H1N1,and Ebola. We detailed the growing body of literature on this topic since 2008 and highlight the need to detect, document, and prevent spillovers from high-risk human activities, such as IWT.

Foamy Viruses, Bet, and APOBEC3 Restriction

Non-human primates (NHP) are an important source of viruses that can spillover to humans and, after adaptation, spread through the host population. Whereas HIV-1 and HTLV-1 emerged as retroviral pathogens in humans, a unique class of retroviruses called foamy viruses (FV) with zoonotic potential are occasionally detected in bushmeat hunters or zookeepers. Various FVs are endemic in numerous mammalian natural hosts, such as primates, felines, bovines, and equines, and other animals, but not in humans. They are apathogenic, and significant differences exist between the viral life cycles of FV and other retroviruses. Importantly, FVs replicate in the presence of many well-defined retroviral restriction factors such as TRIM5α, BST2 (Tetherin), MX2, and APOBEC3 (A3). While the interaction of A3s with HIV-1 is well studied, the escape mechanisms of FVs from restriction by A3 is much less explored. Here we review the current knowledge of FV biology, host restriction factors, and FV-host interactions with an emphasis on the consequences of FV regulatory protein Bet binding to A3s and outline crucial open questions for future studies.

Hunting and consumption of rodents by children in the Lassa fever endemic area of Faranah, Guinea

As a consequence of the Ebola outbreak, human-animal contact has gained importance for zoonotic transmission surveillance. In Faranah (Upper Guinea), daily life is intertwined with rodents, such as the Natal multimammate mouse, Mastomys natalensis; a reservoir for Lassa virus (LASV). However, this contact is rarely perceived as a health risk by residents, although Lassa fever (LF) is known to be endemic to this region. Conversely, these observations remain a great concern for global health agendas. Drawing on ethnographic research involving interviews, focus group discussions, participant observations, and informal discussions over four months, we first identified factors that motivated children to hunt and consume rodents in Faranah villages, and thereafter, explored the knowledge of LF infection in children and their parents. Furthermore, we studied two dimensions of human-rodent encounters: 1) space-time of interaction and 2) factors that allowed the interaction to occur and their materiality. This approach allowed us to contextualize child-rodent contacts beyond domestic limits in the fallow fields, swamps, and at other times for this practice. A close look at these encounters provided information on rodent trapping, killing, and manipulation of cooking techniques and the risk these activities posed for the primary transmission of LASV. This research facilitated the understanding of children's exposure to M. natalensis during hunting sessions and the importance of rodent hunting, which is a part of their boyish identity in rural areas. Determination of when, where, why, and how children, rodents, and environments interacted allowed us to understand the exposures and risks important for human and animal surveillance programs in the Lassa-endemic region.

Taking a lesson from the COVID-19 pandemic: Preventing the future outbreaks of viral zoonoses through a multi-faceted approach

The pandemic of the novel coronavirus disease 2019 (COVID-19) has caused a significant burden to healthcare systems, economic crisis, and public fears. It is also a lesson to be learned and a call-to-action to minimize the risk of future viral pandemics and their associated challenges. The present paper outlines selected measures (i.e., monitoring and identification of novel viral agents in animals, limitations to wildlife trade, decreasing hunting activities, changes to mink farming and meat production), the implementation of which would decrease such a risk. The role of viral surveillance systems and research exploring the virus strains associated with different animal hosts is emphasized along with the need for stricter wild trade regulations and changes to hunting activities. Finally, the paper suggests modifications to the meat production system, particularly through the introduction of cultured meat that would not only decrease the risk of exposure to novel human viral pathogens but also strengthen food security and decrease the environmental impacts of food production.

Biodiversity loss and COVID-19 pandemic: The role of bats in the origin and the spreading of the disease

The loss of biodiversity in the ecosystems has created the general conditions that have favored and, in fact, made possible, the insurgence of the COVID-19 pandemic. A lot of factors have contributed to it: deforestation, changes in forest habitats, poorly regulated agricultural surfaces, mismanaged urban growth. They have altered the composition of wildlife communities, greatly increased the contacts of humans with wildlife, and altered niches that harbor pathogens, increasing their chances to come in contact with humans. Among the wildlife, bats have adapted easily to anthropized environments such as houses, barns, cultivated fields, orchards, where they found the suitable ecosystem to prosper. Bats are major hosts for αCoV and βCoV: evolution has shaped their peculiar physiology and their immune system in a way that makes them resistant to viral pathogens that would instead successfully attack other species, including humans. In time, the coronaviruses that bats host as reservoirs have undergone recombination and other modifications that have increased their ability for inter-species transmission: one modification of particular importance has been the development of the ability to use ACE2 as a receptor in host cells. This particular development in CoVs has been responsible for the serious outbreaks in the last two decades, and for the present COVID-19 pandemic.

Human T-cell lymphotropic virus type 1 transmission dynamics in rural villages in the Democratic Republic of the Congo with high nonhuman primate exposure

The Democratic Republic of the Congo (DRC) has a history of nonhuman primate (NHP) consumption and exposure to simian retroviruses yet little is known about the extent of zoonotic simian retroviral infections in DRC. We examined the prevalence of human T-lymphotropic viruses (HTLV), a retrovirus group of simian origin, in a large population of persons with frequent NHP exposures and a history of simian foamy virus infection. We screened plasma from 3,051 persons living in rural villages in central DRC using HTLV EIA and western blot (WB). PCR amplification of HTLV tax and LTR sequences from buffy coat DNA was used to confirm infection and to measure proviral loads (pVLs). We used phylogenetic analyses of LTR sequences to infer evolutionary histories and potential transmission clusters. Questionnaire data was analyzed in conjunction with serological and molecular data. A relatively high proportion of the study population (5.4%, n = 165) were WB seropositive: 128 HTLV-1-like, 3 HTLV-2-like, and 34 HTLV-positive but untypeable profiles. 85 persons had HTLV indeterminate WB profiles. HTLV seroreactivity was higher in females, wives, heads of households, and increased with age. HTLV-1 LTR sequences from 109 persons clustered strongly with HTLV-1 and STLV-1 subtype B from humans and simians from DRC, with most sequences more closely related to STLV-1 from Allenopithecus nigroviridis (Allen's swamp monkey). While 18 potential transmission clusters were identified, most were in different households, villages, and health zones. Three HTLV-1-infected persons were co-infected with simian foamy virus. The mean and median percentage of HTLV-1 pVLs were 5.72% and 1.53%, respectively, but were not associated with age, NHP exposure, village, or gender. We document high HTLV prevalence in DRC likely originating from STLV-1. We demonstrate regional spread of HTLV-1 in DRC with pVLs reported to be associated with HTLV disease, supporting local and national public health measures to prevent spread and morbidity.

An Ethnographic Approach to Characterizing Potential Pathways of Zoonotic Disease Transmission from Wild Meat in Guyana

The hunting, butchery, and consumption of wild meat is an important interface for zoonotic disease transmission. Despite this, few researchers have used ethnography to understand the sociocultural factors that may increase zoonotic disease transmission from hunting, particularly in Amazonia. Here, we use ethnographic methods consisting of structured, semi-structured and unstructured interviews, and participant observation to address questions pertaining to wild meat consumption, pathways of zoonotic disease transmission, food security, and the cultural identity of indigenous Waiwai in the Konashen Community Owned Conservation Area, Guyana. Our data revealed that the majority of Waiwai eat wild meat two to three times/week and 60% of respondents reported butchery-related injuries. However, semi-structured and unstructured interviews, and participant observation data indicate that the Waiwai do not perceive most cuts from butchery as injuries, despite being a potential route of pathogen exposure. Additionally, participant observation revealed that hunting is integral to Waiwai identity and the Waiwai exhibit a cultural aversion to domestic meats. These findings provide valuable insights into the interplay of hunting and wild meat consumption and disease in Amazonia and demonstrate how an ethnographic approach provides the contextual data necessary for identifying potential pathways of zoonotic transmission from wild meat.

Addressing the illegal wildlife trade in the European Union as a public health issue to draw decision makers attention

The European Union is one of the most important markets for the trafficking of endangered species and a major transit point for illegal wildlife trade. The latter is not only one of the most important anthropogenic drivers of biodiversity loss, it also represents a growing risk for public health. Indeed, wildlife trade exposes humans to a plethora of severe emerging infectious diseases, some of which have contributed to the most dramatic global pandemics humankind has endured. Illegal wildlife trade is often considered as a problem of developing countries but it is first and foremost an international global business with a trade flow from developing to developed countries. The devastating effects of the ongoing SARS-CoV-2 outbreak should thus be an unassailable argument for European decision makers to change paradigm. Rather than deploying efforts and money to combat novel pathogens, mitigating the risk of spreading emerging infectious diseases should be addressed and be part of any sustainable socioeconomic development plan. Stricter control procedures at borders and policies should be enforced. Additionally, strengthening research in wildlife forensic science and developing a network of forensic laboratories should be the cornerstone of the European Union plan to tackle the illegal wildlife trade. Such proactive approach, that should further figure in the EU-Wildlife Action Plan, could produce a win-win situation: the curb of illegal wildlife trade would subsequently diminish the likelihood of importing new zoonotic diseases in the European Union.

Extracellular vesicles in virus infection and pathogenesis

Viruses are obligate intracellular parasites that usurp cellular signaling networks to promote pathogen spread and disease progression. Signaling through extracellular vesicles (EVs) is an emerging field of study in the virus-host interaction network. EVs relay information both locally and distally through incorporated contents, typically without tripping innate immune sensors. Therefore, this extracellular signaling axis presents itself as a tantalizing target for promoting a favorable niche for the pathogen(s) takeover of the host, particularly for chronic infections. From the incorporation of virus-encoded molecules such as micro RNAs and proteins/enzymes to the envelopment of entire infectious particles, evolutionary distinct viruses have shown a remarkable ability to converge on this means of communication. In this review, we will cover the recent advances in this field and explore how EV can be used as potential biomarkers for chronic, persistent, or latent virus infections.

A systemic approach to assess the potential and risks of wildlife culling for infectious disease control

The maintenance of infectious diseases requires a sufficient number of susceptible hosts. Host culling is a potential control strategy for animal diseases. However, the reduction in biodiversity and increasing public concerns regarding the involved ethical issues have progressively challenged the use of wildlife culling. Here, we assess the potential of wildlife culling as an epidemiologically sound management tool, by examining the host ecology, pathogen characteristics, eco-sociological contexts, and field work constraints. We also discuss alternative solutions and make recommendations for the appropriate implementation of culling for disease control.

ACE2 and TMPRSS2 variation in savanna monkeys (Chlorocebus spp.): Potential risk for zoonotic/anthroponotic transmission of SARS-CoV-2 and a potential model for functional studies

The COVID-19 pandemic, caused by the coronavirus SARS-CoV-2, has devastated health infrastructure around the world. Both ACE2 (an entry receptor) and TMPRSS2 (used by the virus for spike protein priming) are key proteins to SARS-CoV-2 cell entry, enabling progression to COVID-19 in humans. Comparative genomic research into critical ACE2 binding sites, associated with the spike receptor binding domain, has suggested that African and Asian primates may also be susceptible to disease from SARS-CoV-2 infection. Savanna monkeys (Chlorocebus spp.) are a widespread non-human primate with well-established potential as a bi-directional zoonotic/anthroponotic agent due to high levels of human interaction throughout their range in sub-Saharan Africa and the Caribbean. To characterize potential functional variation in savanna monkey ACE2 and TMPRSS2, we inspected recently published genomic data from 245 savanna monkeys, including 163 wild monkeys from Africa and the Caribbean and 82 captive monkeys from the Vervet Research Colony (VRC). We found several missense variants. One missense variant in ACE2 (X:14,077,550; Asp30Gly), common in Ch. sabaeus, causes a change in amino acid residue that has been inferred to reduce binding efficiency of SARS-CoV-2, suggesting potentially reduced susceptibility. The remaining populations appear as susceptible as humans, based on these criteria for receptor usage. All missense variants observed in wild Ch. sabaeus populations are also present in the VRC, along with two splice acceptor variants (at X:14,065,076) not observed in the wild sample that are potentially disruptive to ACE2 function. The presence of these variants in the VRC suggests a promising model for SARS-CoV-2 infection and vaccine and therapy development. In keeping with a One Health approach, characterizing actual susceptibility and potential for bi-directional zoonotic/anthroponotic transfer in savanna monkey populations may be an important consideration for controlling COVID-19 epidemics in communities with frequent human/non-human primate interactions that, in many cases, may have limited health infrastructure.

Systematic Review of Important Viral Diseases in Africa in Light of the 'One Health' Concept

Emerging and re-emerging viral diseases are of great public health concern. The recent emergence of Severe Acute Respiratory Syndrome (SARS) related coronavirus (SARS-CoV-2) in December 2019 in China, which causes COVID-19 disease in humans, and its current spread to several countries, leading to the first pandemic in history to be caused by a coronavirus, highlights the significance of zoonotic viral diseases. Rift Valley fever, rabies, West Nile, chikungunya, dengue, yellow fever, Crimean-Congo hemorrhagic fever, Ebola, and influenza viruses among many other viruses have been reported from different African countries. The paucity of information, lack of knowledge, limited resources, and climate change, coupled with cultural traditions make the African continent a hotspot for vector-borne and zoonotic viral diseases, which may spread globally. Currently, there is no information available on the status of virus diseases in Africa. This systematic review highlights the available information about viral diseases, including zoonotic and vector-borne diseases, reported in Africa. The findings will help us understand the trend of emerging and re-emerging virus diseases within the African continent. The findings recommend active surveillance of viral diseases and strict implementation of One Health measures in Africa to improve human public health and reduce the possibility of potential pandemics due to zoonotic viruses.

Monkeypox Rash Severity and Animal Exposures in the Democratic Republic of the Congo

Experimental studies have suggested a larger inoculum of monkeypox virus may be associated with increased rash severity; however, little data are available on the relationship between specific animal exposures and rash severity in endemic regions. Using cross-sectional data from an active surveillance program conducted between 2005 and 2007 in the Sankuru Province of the Democratic Republic of the Congo, we explored the possible relationship between rash severity and exposures to rodents and non-human primates among confirmed MPX cases. Among the 223 PCR-confirmed MPX cases identified during active surveillance, the majority of cases (n = 149) presented with mild rash (5-100 lesions) and 33% had a more serious presentation (> 100 lesions). No association between exposure to rodents and rash severity was found in the multivariable analysis. Those that self-reported hunting NHP 3 weeks prior to onset of MPX symptoms had 2.78 times the odds of severe rash than those that did not report such exposure (95% CI: 1.18, 6.58). This study provides a preliminary step in understanding the association between animal exposure and rash severity and demonstrates correlation with exposure to NHPs and human MPX presentation. Additional research exploring the relationship between rash severity and NHPs is warranted.

Infection with Foamy Virus in Wild Ruminants-Evidence for a New Virus Reservoir?

Foamy viruses (FVs) are widely distributed and infect many animal species including non-human primates, horses, cattle, and cats. Several reports also suggest that other species can be FV hosts. Since most of such studies involved livestock or companion animals, we aimed to test blood samples from wild ruminants for the presence of FV-specific antibodies and, subsequently, genetic material. Out of 269 serum samples tested by ELISA with the bovine foamy virus (BFV) Gag and Bet antigens, 23 sera showed increased reactivity to at least one of them. High reactive sera represented 30% of bison samples and 7.5% of deer specimens. Eleven of the ELISA-positives were also strongly positive in immunoblot analyses. The peripheral blood DNA of seroreactive animals was tested by semi-nested PCR. The specific 275 bp fragment of the pol gene was amplified only in one sample collected from a red deer and the analysis of its sequence showed the highest homology for European BFV isolates. Such results may suggest the existence of a new FV reservoir in bison as well as in deer populations. Whether the origin of such infections stems from a new FV or is the result of BFV inter-species transmission remains to be clarified.

Human Viruses: Emergence and Evolution

Many new viruses have emerged in the last five decades. These newer genetically active agents have a major impact on the public health systems worldwide. Most emerging infections appear to be caused by pathogens already present in the environment, brought out of obscurity or given a selective advantage by changing conditions and afforded an opportunity to infect new host populations. Also on rare occasions, a new variant may evolve and cause a new disease. Altered virus transmission because of deforestation and environment change, ecological changes and agricultural development, commerce, technology, microbial adaptation and change, breakdown of public health measures, and deficiencies in public health infrastructure are the reasons for emergence and reemergence of infectious diseases in general and viral infections in particular.

Specific factors precipitating disease emergence can be identified in virtually all cases. Moreover, these factors are increasing in prevalence. This increase, together with the ongoing evolution of viral and microbial variants and selection for drug resistance, suggests that infections will continue to emerge and probably increase and emphasize the urgent need for effective surveillance and control. These viruses are rich source of emerging diseases due to the introduction of infections from other species in the zoonotic pool. In the near future, there is an urgent need to monitor collaboration between human–animal interface so that public health risks can be understood. A number of activities increase microbial traffic from animals to humans or disseminate microbes from isolated groups into new populations and as a result promote emergence and epidemics. In some cases, including many of the most novel infections, the agents are zoonotic crossing from their natural hosts into the human population because of many similarities. Vector-borne diseases also have a natural advantage of dissemination.

Bovine Foamy Virus: Shared and Unique Molecular Features In Vitro and In Vivo

The retroviral subfamily of Spumaretrovirinae consists of five genera of foamy (spuma) viruses (FVs) that are endemic in some mammalian hosts [1]. Closely related species may be susceptible to the same or highly related FVs. FVs are not known to induce overt disease and thus do not pose medical problems to humans and livestock or companion animals. A robust lab animal model is not available or is a lab animal a natural host of a FV. Due to this, research is limited and often focused on the simian FVs with their well-established zoonotic potential. The authors of this review and their groups have conducted several studies on bovine FV (BFV) in the past with the intention of (i) exploring the risk of zoonotic infection via beef and raw cattle products, (ii) studying a co-factorial role of BFV in different cattle diseases with unclear etiology, (iii) exploring unique features of FV molecular biology and replication strategies in non-simian FVs, and (iv) conducting animal studies and functional virology in BFV-infected calves as a model for corresponding studies in primates or small lab animals. These studies gained new insights into FV-host interactions, mechanisms of gene expression, and transcriptional regulation, including miRNA biology, host-directed restriction of FV replication, spread and distribution in the infected animal, and at the population level. The current review attempts to summarize these findings in BFV and tries to connect them to findings from other FVs.

Infectious Disease Risk Across the Growing Human-Non Human Primate Interface: A Review of the Evidence

Most of the human pandemics reported to date can be classified as zoonoses. Among these, there is a long history of infectious diseases that have spread from non-human primates (NHP) to humans. For millennia, indigenous groups that depend on wildlife for their survival were exposed to the risk of NHP pathogens' transmission through animal hunting and wild meat consumption. Usually, exposure is of no consequence or is limited to mild infections. In rare situations, it can be more severe or even become a real public health concern. Since the emergence of acquired immune deficiency syndrome (AIDS), nobody can ignore that an emerging infectious diseases (EID) might spread from NHP into the human population. In large parts of Central Africa and Asia, wildlife remains the primary source of meat and income for millions of people living in rural areas. However, in the past few decades the risk of exposure to an NHP pathogen has taken on a new dimension. Unprecedented breaking down of natural barriers between NHP and humans has increased exposure to health risks for a much larger population, including people living in urban areas. There are several reasons for this: (i) due to road development and massive destruction of ecosystems for agricultural needs, wildlife and humans come into contact more frequently; (ii) due to ecological awareness, many long distance travelers are in search of wildlife discovery, with a particular fascination for African great apes; (iii) due to the attraction for ancient temples and mystical practices, others travelers visit Asian places colonized by NHP. In each case, there is a risk of pathogen transmission through a bite or another route of infection. Beside the individual risk of contracting a pathogen, there is also the possibility of starting a new pandemic. This article reviews the known cases of NHP pathogens' transmission to humans whether they are hunters, travelers, ecotourists, veterinarians, or scientists working on NHP. Although pathogen transmission is supposed to be a rare outcome, Rabies virus, Herpes B virus, Monkeypox virus, Ebola virus, or Yellow fever virus infections are of greater concern and require quick countermeasures from public health professionals.

Simian Foamy Viruses in Central and South America: A New World of Discovery

Foamy viruses (FVs) are the only exogenous retrovirus to date known to infect neotropical primates (NPs). In the last decade, an increasing number of strains have been completely or partially sequenced, and molecular evolution analyses have identified an ancient co-speciation with their hosts. In this review, the improvement of diagnostic techniques that allowed the determination of a more accurate prevalence of simian FVs (SFVs) in captive and free-living NPs is discussed. Determination of DNA viral load in American primates indicates that oral tissues are the viral replicative site and that buccal swab collection can be an alternative to diagnose SFV infection in NPs. Finally, the transmission potential of NP SFVs to primate workers in zoos and primate centers of the Americas is examined.

Cross-species pathogen spillover across ecosystem boundaries: mechanisms and theory

Pathogen spillover between different host species is the trigger for many infectious disease outbreaks and emergence events, and ecosystem boundary areas have been suggested as spatial hotspots of spillover. This hypothesis is largely based on suspected higher rates of zoonotic disease spillover and emergence in fragmented landscapes and other areas where humans live in close vicinity to wildlife. For example, Ebola virus outbreaks have been linked to contacts between humans and infected wildlife at the rural-forest border, and spillover of yellow fever via mosquito vectors happens at the interface between forest and human settlements. Because spillover involves complex interactions between multiple species and is difficult to observe directly, empirical studies are scarce, particularly those that quantify underlying mechanisms. In this review, we identify and explore potential ecological mechanisms affecting spillover of pathogens (and parasites in general) at ecosystem boundaries. We borrow the concept of 'permeability' from animal movement ecology as a measure of the likelihood that hosts and parasites are present in an ecosystem boundary region. We then discuss how different mechanisms operating at the levels of organisms and ecosystems might affect permeability and spillover. This review is a step towards developing a general theory of cross-species parasite spillover across ecosystem boundaries with the eventual aim of improving predictions of spillover risk in heterogeneous landscapes. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.

Simian Foamy Virus Co-Infections

Foamy viruses (FVs), also known as spumaretroviruses, are complex retroviruses that are seemingly nonpathogenic in natural hosts. In natural hosts, which include felines, bovines, and nonhuman primates (NHPs), a large percentage of adults are infected with FVs. For this reason, the effect of FVs on infections with other viruses (co-infections) cannot be easily studied in natural populations. Most of what is known about interactions between FVs and other viruses is based on studies of NHPs in artificial settings such as research facilities. In these settings, there is some indication that FVs can exacerbate infections with lentiviruses such as simian immunodeficiency virus (SIV). Nonhuman primate (NHP) simian FVs (SFVs) have been shown to infect people without any apparent pathogenicity. Humans zoonotically infected with simian foamy virus (SFV) are often co-infected with other viruses. Thus, it is important to know whether SFV co-infections affect human disease.

Clinical Signs and Blood Test Results Among Humans Infected With Zoonotic Simian Foamy Virus: A Case-Control Study

Background

A spillover of simian foamy virus (SFV) to humans, following bites from infected nonhuman primates (NHPs), is ongoing in exposed populations. These retroviruses establish persistent infections of unknown physiological consequences to the human host.

Methods

We performed a case-control study to compare 24 Cameroonian hunters infected with gorilla SFV and 24 controls matched for age and ethnicity. A complete physical examination and blood test were performed for all participants. Logistic regression and Wilcoxon signed rank tests were used to compare cases and controls.

Results

The cases had significantly lower levels of hemoglobin than the controls (median, 12.7 vs 14.4 g/dL; P = .01). Basophil levels were also significantly lower in cases than controls, with no differences for other leukocyte subsets. Cases had significantly higher urea, creatinine, protein, creatinine phosphokinase, and lactate dehydrogenase levels and lower bilirubin levels than controls. Cases and controls had similar frequencies of general, cutaneous, gastrointestinal, neurological, and cardiorespiratory signs.

Conclusions

The first case-control study of apparently healthy SFV-infected Cameroonian hunters showed the presence of hematological abnormalities. A thorough clinical and laboratory workup is now needed to establish the medical relevance of these observations because more than half of cases had mild or moderate anemia.

Clinical Trials Registration

NCT03225794.

Human-animal interactions and bat coronavirus spillover potential among rural residents in Southern China

Human interaction with animals has been implicated as a primary risk factor for several high impact zoonoses, including many bat-origin viral diseases. However the animal-to-human spillover events that lead to emerging diseases are rarely observed or clinically examined, and the link between specific interactions and spillover risk is poorly understood. To investigate this phenomenon, we conducted biological-behavioral surveillance among rural residents in Yunnan, Guangxi, and Guangdong districts of Southern China, where we have identified a number of SARS-related coronaviruses in bats. Serum samples were tested for four bat-borne coronaviruses using newly developed enzyme-linked immunosorbent assays (ELISA). Survey data were used to characterize associations between human-animal contact and bat coronavirus spillover risk. A total of 1,596 residents were enrolled in the study from 2015 to 2017. Nine participants (0.6%) tested positive for bat coronaviruses. 265 (17%) participants reported severe acute respiratory infections (SARI) and/or influenza-like illness (ILI) symptoms in the past year, which were associated with poultry, carnivore, rodent/shrew, or bat contact, with variability by family income and district of residence. This study provides serological evidence of bat coronavirus spillover in rural communities in Southern China. The low seroprevalence observed in this study suggests that bat coronavirus spillover is a rare event. Nonetheless, this study highlights associations between human-animal interaction and zoonotic spillover risk. These findings can be used to support targeted biological behavioral surveillance in high-risk geographic areas in order to reduce the risk of zoonotic disease emergence.

Toward a quantification of risks at the nexus of conservation and health: The case of bushmeat markets in Lao PDR

Trade of bushmeat and other wildlife for human consumption presents a unique set of challenges to policy-makers who are confronted with multiple trade-offs between conservation, food security, food safety, culture and tradition. In the face of these complex issues, risk assessments supported by quantitative information would facilitate evidence-based decision making. We propose a conceptual model for disease transmission risk analysis, inclusive of these multiple other facets. To quantify several processes included in this conceptual model we conducted questionnaire surveys with wildlife consumers and vendors in semi-urban centers in Lao People's Democratic Republic (Lao PDR, Laos) and direct observations of consumer behaviors. Direct observation of market stalls indicated an estimated average of 10 kg bushmeat biomass per stall per hour. The socio-demographic data suggested that consumption of bushmeat in urban areas was not for subsistence but rather driven by dietary preference and tradition. Consumer behavioral observations indicated that each animal receives an average of 7 contacts per hour. We provide other key parameters to estimate the risk of disease transmission from bushmeat consumption and illustrate their use in assessing the total public health and socio-economic impact of bushmeat consumption. Pursuing integrative approaches to the study of bushmeat consumption is essential to develop effective and balanced policies that support conservation, public health, and rural development goals.

Molecular Analysis of the Complete Genome of a Simian Foamy Virus Infecting Hylobates pileatus (pileated gibbon) Reveals Ancient Co-Evolution with Lesser Apes

Foamy viruses (FVs) are complex retroviruses present in many mammals, including nonhuman primates, where they are called simian foamy viruses (SFVs). SFVs can zoonotically infect humans, but very few complete SFV genomes are available, hampering the design of diagnostic assays. Gibbons are lesser apes widespread across Southeast Asia that can be infected with SFV, but only two partial SFV sequences are currently available. We used a metagenomics approach with next-generation sequencing of nucleic acid extracted from the cell culture of a blood specimen from a lesser ape, the pileated gibbon (Hylobates pileatus), to obtain the complete SFVhpi_SAM106 genome. We used Bayesian analysis to co-infer phylogenetic relationships and divergence dates. SFVhpi_SAM106 is ancestral to other ape SFVs with a divergence date of ~20.6 million years ago, reflecting ancient co-evolution of the host and SFVhpi_SAM106. Analysis of the complete SFVhpi_SAM106 genome shows that it has the same genetic architecture as other SFVs but has the longest recorded genome (13,885-nt) due to a longer long terminal repeat region (2,071 bp). The complete sequence of the SFVhpi_SAM106 genome fills an important knowledge gap in SFV genetics and will facilitate future studies of FV infection, transmission, and evolutionary history.

Serologic Evidence of Ebolavirus Infection in a Population With No History of Outbreaks in the Democratic Republic of the Congo

Background

Previous studies suggest that cases of Ebola virus disease (EVD) may go unreported because they are asymptomatic or unrecognized, but evidence is limited by study designs and sample size.

Methods

A large population-based survey was conducted (n = 3415) to assess animal exposures and behaviors associated with Ebolavirus antibody prevalence in rural Kasai Oriental province of the Democratic Republic of Congo (DRC). Fourteen villages were randomly selected and all healthy individuals ≥1 year of age were eligible.

Results

Overall, 11% of subjects tested positive for Zaire Ebolavirus (EBOV) immunoglobulin G antibodies. Odds of seropositivity were higher for study participants older than 15 years of age and for males. Those residing in Kole (closer to the outbreak site) tested positive at a rate 1.6× higher than Lomela, with seropositivity peaking at a site located between Kole and Lomela. Multivariate analyses of behaviors and animal exposures showed that visits to the forest or hunting and exposure to rodents or duikers predicted a higher likelihood of EBOV seropositivity.

Conclusions

These results provide serologic evidence of Ebolavirus exposure in a population residing in non-EBOV outbreak locations in the DRC and define statistically significant activities and animal exposures that associate with EBOV seropositivity.

Clinical and Molecular Features of Feline Foamy Virus and Feline Leukemia Virus Co-Infection in Naturally-Infected Cats

Feline foamy virus (FFV) and feline leukemia virus (FeLV) belong to the Retroviridae family. While disease has not been reported for FFV infection, FeLV infection can cause anemia and immunosuppression (progressive infection). Co-infection with FFV/FeLV allows evaluation of the pathogenic potential and epidemiology of FFV infection in cats with FeLV pathology. Blood and buccal swab samples from 81 cats were collected in Rio de Janeiro. Plasma was serologically tested for FeLV. DNA extracted from peripheral blood mononuclear cells and buccal swabs was used to PCR detect FFV and FeLV. A qPCR was developed to detect and measure FFV proviral loads (pVLs) in cats. FeLV qPCR was performed using previous methods. The median log10 pVL of FFV mono-infected individuals was lower than found in FFV/FeLV co-infected cats in buccal swabs (p = 0.003). We found 78% of cats had detectable buccal FFV DNA in FFV mono-infected and FFV co-infected FeLV-progressive cats, while in FeLV-regressive cats (those without signs of disease) 22% of cats had detectable buccal FFV DNA (p = 0.004). Our results suggest that regressive FeLV infection may reduce FFV saliva transmission, the main mode of FV transmission. We did not find evidence of differences in pathogenicity in FFV mono- and -dually infected cats. In summary, we show that FVs may interact with FeLV within the same host. Our study supports the utility of cats naturally co-infected with retroviruses as a model to investigate the impact of FV on immunocompromised mammalian hosts.

Potent neutralizing antibodies in humans infected with zoonotic simian foamy viruses target conserved epitopes located in the dimorphic domain of the surface envelope protein

Human diseases of zoonotic origin are a major public health problem. Simian foamy viruses (SFVs) are complex retroviruses which are currently spilling over to humans. Replication-competent SFVs persist over the lifetime of their human hosts, without spreading to secondary hosts, suggesting the presence of efficient immune control. Accordingly, we aimed to perform an in-depth characterization of neutralizing antibodies raised by humans infected with a zoonotic SFV. We quantified the neutralizing capacity of plasma samples from 58 SFV-infected hunters against primary zoonotic gorilla and chimpanzee SFV strains, and laboratory-adapted chimpanzee SFV. The genotype of the strain infecting each hunter was identified by direct sequencing of the env gene amplified from the buffy coat with genotype-specific primers. Foamy virus vector particles (FVV) enveloped by wild-type and chimeric gorilla SFV were used to map the envelope region targeted by antibodies. Here, we showed high titers of neutralizing antibodies in the plasma of most SFV-infected individuals. Neutralizing antibodies target the dimorphic portion of the envelope protein surface domain. Epitopes recognized by neutralizing antibodies have been conserved during the cospeciation of SFV with their nonhuman primate host. Greater neutralization breadth in plasma samples of SFV-infected humans was statistically associated with smaller SFV-related hematological changes. The neutralization patterns provide evidence for persistent expression of viral proteins and a high prevalence of coinfection. In conclusion, neutralizing antibodies raised against zoonotic SFV target immunodominant and conserved epitopes located in the receptor binding domain. These properties support their potential role in restricting the spread of SFV in the human population.

MONKEY BITES AND INJURIES IN THE ZAGREB ANTIRABIES CLINIC IN 2014

SUMMARY – Travelling around the world and visiting distant places and countries (especially national parks, parks of nature, natural resorts, etc.) sometimes may result in animal bites and injuries from the species which are not usually represented as the source of human rabies cases, such as monkeys. In the last ten to fifteen years, monkey bites and injuries present an unpleasant experience and cause a lot of problems for travelers and tourists when travelling to India, Thailand, Indonesia or Bali because they have to seek a medical facility for wound treatment, tetanus prophylaxis, antimicrobial therapy and rabies postexposure prophylaxis (PEP). In 2014, 706 persons were registered at the Zagreb Antirabies Clinic as having sustained bites by various animals, ten of them reported to have been bitten or injured by monkeys. Nine of them sustained injuries during their travel to India, Thailand, Indonesia and Bali. All injuries occurred when they wanted to pet or tried to feed monkeys, or refused to give them food. Most of the monkeys were macaques, capuchins, or of unknown type. Only one monkey bite recorded in the city of Zagreb occurred in the Zagreb ZOO while a professional animal handler was feeding a capuchin monkey in the cage. He did not receive rabies PEP, but instead, the capuchin monkey was put under veterinary supervision. All other patients started with PEP in the countries where the injuries occurred and continued/completed it at the Zagreb Antirabies Clinic. They received antirabies vaccine only (PVRV, RABIPUR) upon 5-dose regimen (Essen scheme) and 2-1-1 (Zagreb scheme) regimen. None of them contracted rabies. After many years, monkeys were the animal species immediately following dogs and cats in the official report of the Zagreb Antirabies Clinic, which was quite surprising. Usually, monkey bites and injuries do not present a serious problem in daily routine because they occur sporadically.

Spumaretroviruses: Updated taxonomy and nomenclature

Spumaretroviruses, commonly referred to as foamy viruses, are complex retroviruses belonging to the subfamily Spumaretrovirinae, family Retroviridae, which naturally infect a variety of animals including nonhuman primates (NHPs). Additionally, cross-species transmissions of simian foamy viruses (SFVs) to humans have occurred following exposure to tissues of infected NHPs. Recent research has led to the identification of previously unknown exogenous foamy viruses, and to the discovery of endogenous spumaretrovirus sequences in a variety of host genomes. Here, we describe an updated spumaretrovirus taxonomy that has been recently accepted by the International Committee on Taxonomy of Viruses (ICTV) Executive Committee, and describe a virus nomenclature that is generally consistent with that used for other retroviruses, such as lentiviruses and deltaretroviruses. This taxonomy can be applied to distinguish different, but closely related, primate (e.g., human, ape, simian) foamy viruses as well as those from other hosts. This proposal accounts for host-virus co-speciation and cross-species transmission.

Nef Secretion into Extracellular Vesicles or Exosomes Is Conserved across Human and Simian Immunodeficiency Viruses

Extracellular vesicles (EVs) or exosomes have been implicated in the pathophysiology of infections and cancer. The negative regulatory factor (Nef) encoded by simian immunodeficiency virus (SIV) and human immunodeficiency virus (HIV) plays a critical role in the progression to AIDS and impairs endosomal trafficking. Whether HIV-1 Nef can be loaded into EVs has been the subject of controversy, and nothing is known about the connection between SIV Nef and EVs. We find that both SIV and HIV-1 Nef proteins are present in affinity-purified EVs derived from cultured cells, as well as in EVs from SIV-infected macaques. Nef-positive EVs were functional, i.e., capable of membrane fusion and depositing their content into recipient cells. The EVs were able to transfer Nef into recipient cells. This suggests that Nef readily enters the exosome biogenesis pathway, whereas HIV virions are assembled at the plasma membrane. It suggests a novel mechanism by which lentiviruses can influence uninfected and uninfectable, i.e., CD4-negative, cells.IMPORTANCE Extracellular vesicles (EVs) transfer biologically active materials from one cell to another, either within the adjacent microenvironment or further removed. EVs also package viral RNAs, microRNAs, and proteins, which contributes to the pathophysiology of infection. In this report, we show that both human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) incorporate the virus-encoded Nef protein into EVs, including EVs circulating in the blood of SIV-infected macaques and that this presents a novel mechanism of Nef transfer to naive and even otherwise non-infectable cells. Nef is dispensable for viral replication but essential for AIDS progression in vivo Demonstrating that Nef incorporation into EVs is conserved across species implicates EVs as novel mediators of the pathophysiology of HIV. It could help explain the biological effects that HIV has on CD4-negative cells and EVs could become biomarkers of disease progression.

Foamy virus zoonotic infections

BACKGROUND

Foamy viruses (FV) are ancient complex retroviruses that differ from orthoretroviruses such as human immunodeficiency virus (HIV) and murine leukemia virus (MLV) and comprise a distinct subfamily of retroviruses, the Spumaretrovirinae. FV are ubiquitous in their natural hosts, which include cows, cats, and nonhuman primates (NHP). FV are transmitted mainly through saliva and appear nonpathogenic by themselves, but they may increase morbidity of other pathogens in coinfections.

CONCLUSIONS

This review summarizes and discusses what is known about FV infection of natural hosts. It also emphasizes what is known about FV zoonotic infections A large number of studies have revealed that the FV of NHP, simian foamy viruses (SFV), are transmitted to humans who interact with infected NHP. SFV from a variety of NHP establish persistent infection in humans, while bovine foamy virus and feline foamy virus rarely or never do. The possibility of FV recombination and mutation leading to pathogenesis is considered. Since humans can be infected by SFV, a seemingly nonpathogenic virus, there is interest in using SFV vectors for human gene therapy. In this regard, detailed understanding of zoonotic SFV infection is highly relevant.

Zoonotic infection of Brazilian primate workers with New World simian foamy virus

Simian foamy viruses (SFVs) are retroviruses present in nearly all nonhuman primates (NHPs), including Old World primates (OWP) and New World primates (NWP). While all confirmed human infections with SFV are from zoonotic transmissions originating from OWP, little is known about the zoonotic transmission potential of NWP SFV. We conducted a longitudinal, prospective study of 56 workers occupationally exposed to NWP in Brazil. Plasma from these workers was tested using Western blot (WB) assays containing NWP SFV antigens. Genomic DNA from blood and buccal swabs was analyzed for the presence of proviral SFV sequences by three nested PCR tests and a new quantitative PCR assay. Exposure histories were obtained and analyzed for associations with possible SFV infection. Ten persons (18%) tested seropositive and two persons were seroindeterminate (3.6%) for NWP SFV. Six persons had seroreactivity over 2–3 years suggestive of persistent infection. All SFV NWP WB-positive workers reported at least one incident involving NWP, including six reporting NWP bites. NWP SFV viral DNA was not detected in the blood or buccal swabs from all 12 NWP SFV seroreactive workers. We also found evidence of SFV seroreversion in three workers suggestive of possible clearance of infection. Our findings suggest that NWP SFV can be transmitted to occupationally-exposed humans and can elicit specific humoral immune responses but infection remains well-controlled resulting in latent infection and may occasionally clear.