Zoonotic Epidemics Research Articles

The Trans-zoonotic Virome interface: Measures to balance, control and treat epidemics

The global virome: The viruses have a global distribution, phylogenetic diversity and host specificity. They are obligate intracellular parasites with single- or double-stranded DNA or RNA genomes, and afflict bacteria, plants, animals and human population. The viral infection begins when surface proteins bind to receptor proteins on the host cell surface, followed by internalisation, replication and lysis. Further, trans-species interactions of viruses with bacteria, small eukaryotes and host are associated with various zoonotic viral diseases and disease progression. Virome interface and transmission: The cross-species transmission from their natural reservoir, usually mammalian or avian, hosts to infect human-being is a rare probability, but occurs leading to the zoonotic human viral infection. The factors like increased human settlements and encroachments, expanded travel and trade networks, altered wildlife and livestock practices, modernised and mass-farming practices, compromised ecosystems and habitat destruction, and global climate change have impact on the interactions between virome and its hosts and other species and act as drivers of trans-species viral spill-over and human transmission. Zoonotic viral diseases and epidemics: The zoonotic viruses have caused various deadly pandemics in human history. They can be further characterized as either newly emerging or re-emerging infectious diseases, caused by pathogens that historically have infected the same host species, but continue to appear in new locations or in drug-resistant forms, or reappear after apparent control or elimination. The prevalence of zoonoses underlines importance of the animal–human–ecosystem interface in disease transmission. The present COVID-19 infection has certain distinct features which suppress the host immune response and promote the disease potential. Treatment for epidemics like covid-19: It appears that certain nutraceuticals may provide relief in clinical symptoms to patients infected with encapsulated RNA viruses such as influenza and coronavirus. These nutraceuticals appear to reduce the inflammation in the lungs and help to boost type 1 interferon response to these viral infections. The human intestinal microbiota acting in tandem with the host’s defence and immune system, is vital for homeostasis and preservation of health. The integrity and balanced activity of the gut microbes is responsible for the protection from disease states including viral infections. Certain probiotics may help in improving the sensitivity and effectivity of immune system against viral infections. Currently, antiviral therapy is available only for a limited number of zoonotic viral infections. Because viruses are intracellular parasites, antiviral drugs are not able to deactivate or destroy the virus but can reduce the viral load by inhibiting replication and facilitating the host’s innate immune mechanisms to neutralize the virus. Conclusion: Lessons from recent viral epidemics - Considering that certain nutraceuticals have demonstrated antiviral effects in both clinical and animal studies, further studies are required to establish their therapeutic efficacy. The components of nutraceuticals such as luteolin, apigenin, quercetin and chlorogenic acid may be useful for developing a combo-therapy. The use of probiotics to enhance immunity and immune response against viral infections is a novel possibility. The available antiviral therapy is inefficient in deactivating or destroying the infecting viruses, may help in reducing the viral load by inhibiting replication. The novel efficient antiviral agents are being explored.

Comparative Transcriptome Analysis of Artificially Induced Rough-Mutant Brucella Strain RM57 and Its Parent Strain Brucella melitensis M1981.

Brucellosis is one of the most common zoonotic epidemics with a serious threat to public health and livestock development in many countries across the world. Vaccination is a key control strategy toward preventing brucellosis in high-prevalence regions. Recently, a rough-type Brucella melitensis mutant strain (RM57) induced from a B. melitensis strain M1981 showed protective effects in guinea pigs indicating that it is a good vaccine candidate. In this study, stress response assays were performed to reveal the mechanisms underlying virulence attenuation of RM57. In addition, a genome-wide transcriptome profile of RM57 was analyzed relative to the parent strain M1981 in order to reveal genetic factors controlling the phenotypes. Our results indicated a similar sensitivity to various stress conditions in RM57 owing to a lack of significant differences from its parent strain. Transcriptome analysis showed that a total of 1,205 genes were differentially expressed between RM57 and M1981 with gene ontology terms revealing that these genes are involved in energy production and conversion, translation, ribosomal structure, and biogenesis. Pathway enrichment analysis revealed that genes involved in oxidative phosphorylation, ribosome, nitrogen metabolism, tyrosine metabolism, and two-component system were significantly affected. As a result of these differences at the molecular level, the function of type IV secretion system in RM57 was found to be affected leading to reduced virulence of the RM57 mutant strain in both macrophage and mice infection models.

Towards an Alternative Black Death Narrative for Ireland: Ecological and Socio-Economic Divides on the Medieval European Frontier

Studies over the last couple of decades of human zoonotic (animal reservoir initiated) epidemics reveal that vulnerability-factors for such epidemics include high population densities, human-induced changes in the biological makeup of ecological systems, and the distinct human interactions within these new ecosystems, intensive farming practices, malnutrition, and prior ill-health. The recent DNA evidence of Yersinia pestis, known to be responsible for the bubonic plague, forces a re-evaluation of basic assumptions of the Black Death that almost all historical narratives have made. A monomorphic pathogen, Y. pestis, has been remarkable in how little it has changed since the Black Death, and there is no evidence to show that the 14th-century plague was more virulent or contagious than modern outbreaks.Contemporary medieval documentation reveals a perception that the Gaelic-Irish were not suffering from the Black Death as much as the colonists. However, if the genetic disposition between the national groups was a significant factor, then why is there no noteworthy difference noted in subsequent epidemics? This paper uses vulnerability factors for a zoonotic epidemic to assess regional ecological risk in Gaelic and colonial Ireland. Since the ecological change of the period has been largely attributed to human activity, socio-economic and knowledge systems and institutions role in promoting certain activity that altered the landscape is an important part of this inquiry. Pollen evidence is used in conjunction with historic and archaeological data to note regional differences, and to document how they became especially apparent during the Bruce Invasion of 1315–1318. The evidence suggests that vulnerability to epidemic disease was greater in the south-east and midlands of Ireland than in northern parts of the island, and that this paved the way for contrasting responses to the Black Death.

Innovative Preventive and Resilience Approaches Against Aedes-linked Vector-borne Arboviral Diseases Threat and Epidemics Burden in Gulf Council Countries.

Facing the local and imported borderless Aedes-linked vector-borne viral diseases threat and epidemics burden, the Health Committee of the Gulf Cooperation Council (GCC), including the Saudi Arabian government, announced that all Gulf countries are still free from the threat of a Zika virus epidemic. This article provides a vision of integrated eco-friendly and sustainable behavioral communication change (BCC), biological control preparedness and resilience approaches, and innovations implementation in Saudi Arabia and GCC for the purpose of controlling the threat of Aedes-linked vector-borne viral diseases. Implementing innovative Aedes-linked arboviral preventive and resilient control measures is pivotal in improving community-based surveillance-response systems, BCC multidisciplinary and empowerment methods, and in enhancing community social mobilization and risk communication strategies. Moreover, boosting social, cultural and ecological preparedness, and prompt management approaches are necessary against the threat of local and global zoonotic epidemics and pandemics. Nurturing evidence and proven tick or mosquito vector populations' reduction, planned urbanization, climate change and waste management systems, and implementing data sharing and tailored mitigation solutions are crucial against the persisting Aedes competence and the public health threat of dengue, MERS-CoV, and influenza outbreaks. Sustained investment and ample financial allocation are needed to improve Muslim pilgrimage (Hajj and Umrah mass gathering) including point of entry screening and treatment, community-based education and awareness campaigns, and increasing mosquito vector viral pathogens surveillance interventions. Increasing evidence-based population participation and resilient emergency community preparedness and rapid response programs integration are critical to reduce mosquito breeding sites, dengue, and other arboviral infections.

Anthropogenic global defaunation and its consequences for planetary health

The Convention on Biological Diversity has set the 20 Aichi targets for biodiversity by 2020. However, almost all indicators of the Aichi targets show negative trends. Anthropogenic pressure (human appropriation of biological productivity), biodiversity (Living Planet Index), biodiversity benefits (domesticated breeds, Red List of pollinators) show decline with negative consequences on resources and ecosystem services. Many academic studies and reports conducted by international organizations stressed that biodiversity loss is affecting ecosystem resilience but also health and well-being. However, we still lack a framework that could link socio-economics, ecosystems, biodiversity and health. The social-ecology approach links ecological and biological metabolism with social metabolism, where social systems are seen as hybrid systems between cultures, socio-economics (exchanges and flows) and environments (metabolic exchanges). Human societies can then be characterized by stocks and flows that involve: population and its demography, biophysical stocks and trade/production, land and its biological productivity. An important parameter is HANPP (Human Appropriation of the Net Primary Productivity). HANPP has doubled in the 20th century and scenarios suggest that this appropriation will continue to increase considerably in the coming decades. HANPP is an appropriate indicator for research into the impact of human intervention on biodiversity and can link human appropriation of environmental metabolism with ecological theories on biodiversity, like the species-energy hypothesis. We used the conceptual framework of social-ecology that links “drivers” (food consumption, energy), “pressures” (land use, HANPP), “states” (biodiversity change), “impacts” (reduction of the quality of ecosystem services) and “responses” (governance, land planning, conservation). This conceptual framework makes it possible to address the link between biodiversity and health. We tested this social-ecology framework using several databases at the nation level. We confirmed the species-energy hypothesis by showing a positive correlation between HANPP and declining biodiversity. The hypothesis of a reduction in ecosystem services for the regulation of infectious diseases appears also to be confirmed with an increase in zoonotic disease epidemics with the increase in HANPP at the world nation level. The incorporation of health components in social-ecology might provide governance tools for global biodiversity conservation and planetary health.

Transcriptome analysis of gene expression profiling of infected macrophages between Brucella suis 1330 and live attenuated vaccine strain S2 displays mechanistic implication for regulation of virulence

Brucellosis is one of the most common zoonotic epidemics worldwide. Vaccination against brucellosis is an important control strategy to prevent the disease in many high-prevalence regions. At present, Brucella vaccine strain S2 is the most widely used vaccine in China. To uncover the mechanisms underlying virulence attenuation of S2, in this study we characterized the transcriptional profile of S2 and 1330 infected macrophages by transcriptome analysis. The results revealed that expressions of 440 genes were significantly different between macrophages infected by 1330 and S2. Data analysis showed that in the gene ontology term, the different expressed genes involved in innate immune response, phagoctyosis, recognition, and inflammatory response were significantly enriched. Pathway enrichment analysis indicated that the genes involved in transcriptional misregulation in cancer, staphylococcus aureus infection pathways and NF-kappa B signaling pathway were significantly affected. To reveal the molecular mechanisms related to different expression profiles of infected macrophages, the transcription levels of the different genes between the two bacterial genomes were detected. In total, the transcription of 29 different genes was significantly changed in either culture medium or infected microphages. The results of this study can be conducive to the promotion of better understanding of the related mechanisms underlying virulence attenuation of S2 and interactions between host cells and Brucella strains.

TRANSBOUNDARY DISEASES AND WILDLIFE MANAGEMENT: AN OVERVIEW

Wildlife is the fauna and flora that are out of the control of man, although over the years common usage, public perceptions and history have practically defined wildlife as undomesticated free ranging terrestrial vertebrates which include reptiles, amphibians, birds, mammals excluding fishes. Wildlife play important roles in the epidemiology of emerging and re-emerging diseases either as vectors such as in rabies, primary target of disease such as in botulism and reservoirs such as in tularemia, Ebola virus disease (EVD), Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) . These diseases usually transcend national and regional borders causing high mortalities and morbidities. The transboundary nature of such epidemics and the collaborative efforts in combating the scourge was investigated using published literature. Wildlife has been incriminated in the occurrence and spread of various diseases many of which led to loss of lives and have the potentials of being pandemic. Diseases were promptly controlled in cases where collaborative efforts were applied in the management. Since the world is now a single global village, advanced collaborative strategic guidelines should be established for implementation and prevention of future pathogenic zoonosis within states, regions, continents and globally. Transboundary public health education of the citizenry will be of immense importance in the control and prevention of these diseases. Sustainable development goals (SDGS), poverty alleviation, enhanced culture and eco-tourism may not be realizable in the face of ignorance and disease. Highly pathogenic emerging and re-emerging zoonotic diseases and epidemics involving wildlife have grave consequences on national, regional, continental and world economies. These could however be prevented and controlled through multifaceted collaborative efforts and cooperation transcending geographical borders so that the planet can be rescued from the raging scourge of disease.

Zoonotic Epidemic of Sporotrichosis: Cat to Human Transmission

Most of the 51 species embedded in the genus Sporothrix are nonpathogenic environmental fungi that are closely related to decaying wood, plants, and soil. However, members of the Sporothrix schenckii complex are highly successful mammal pathogens, including S. brasiliensis, S. schenckii sensu stricto (s. str.), S. globosa, and S. luriei, the causative agents of human and animal sporotrichosis [1]. Their key to success during mammal infection lies at least in part with their ability to change from a mycelial saprophytic lifestyle at 25°C in the environment to a parasitic yeast cell at an elevated temperature (35°C–37°C), such as those developed by warm-blooded hosts [2]. Typically, infection develops after traumatic inoculation of contaminated soil, plants, and organic matter into skin or mucosa. Alternatively, infection may occur during the animal transmission (cat–cat or cat–dog) and zoonotic transmission (cat–human), which has been mostly associated with scratches or bites from infected cats [2]. In Brazil, S. brasiliensis is repeatedly associated with feline infection and has consistently shown higher virulence during epizootics, as well as in murine models of sporotrichosis. A hallmark of S. brasiliensis infection is its tendency to escalate to outbreaks or epidemics among cats with high potential for zoonotic transmission. Sporotrichosis is an emergent disease and, over the past two decades, the incidence of zoonotic sporotrichosis has been on the rise, particularly in Brazil. Judging from the epizootic and zoonotic epidemics taking place in Rio de Janeiro, Brazil, tackling sporotrichosis requires the engagement of animal and human health policies to reduce the transmission chain of Sporothrix.

Deletion of the Small RNA Chaperone Protein Hfq down Regulates Genes Related to Virulence and Confers Protection against Wild-Type Brucella Challenge in Mice.

Brucellosis is one of the most common zoonotic epidemics worldwide. Brucella, the etiological pathogen of brucellosis, has unique virulence characteristics, including the ability to survive within the host cell. Hfq is a bacterial chaperone protein that is involved in the survival of the pathogen under stress conditions. Moreover, hfq affects the expression of a large number of target genes. In the present study, we characterized the expression and regulatory patterns of the target genes of Hfq during brucellosis. The results revealed that hfq expression is highly induced in macrophages at the early infection stage and at the late stage of mouse infection. Several genes related to virulence, including omp25, omp31, vjbR, htrA, gntR, and dnaK, were found to be regulated by hfq during infection in BALB/c mice. Gene expression and cytokine secretion analysis revealed that an hfq-deletion mutant induced different cytokine profiles compared with that induced by 16M. Infection with the hfq-deletion mutant induced protective immune responses against 16M challenge. Together, these results suggest that hfq is induced during infection and its deletion results in significant attenuation which affects the host immune response caused by Brucella infection. By regulating genes related to virulence, hfq promotes the virulence of Brucella. The unique characteristics of the hfq-deletion mutant, including its decreased virulence and the ability to induce protective immune response upon infection, suggest that it represents an attractive candidate for the design of a live attenuated vaccine against Brucella.

Dacryocystitis due toSporothrix brasiliensis: a case report of a successful clinical and serological outcome with low-dose potassium iodide treatment and oculoplastic surgery

Sporothrix brasiliensis is the main species of the S.schenckii complex implicated in the zoonotic epidemics of sporotrichosis in Rio de Janeiro, Brazil. Epidemiological features have been already described, such as zoonotic transmission by cats and increased frequency of atypical clinical aspects. The involvement of the face by contact with cats is common in childhood; as a result, ophthalmic manifestations have increased. We report a case of acute dacryocystitis in a 9-year-old girl. A calmodulin-based molecular phylogeny was used to identify the agent as S.brasiliensis. This is a rare type of presentation, usually complicated with nasolacrimal duct occlusion. The patient was cured without sequelae after treatment with a low dose of saturated solution of potassium iodide and decompressive oculoplastic surgery. Therapeutic options and considerations of aetiological agents and serology are discussed.

Enhancing epidemiological analysis of intercontinental dispersion of H5N1 viral strains by migratory waterfowl using phylogeography.

BackgroundIntercontinental migratory waterfowl are the primary vectors for dispersion of H5N1 viruses and have been implicated in several zoonotic epidemics and pandemics. Recent investigations have established that with a single mutation, the virus gains the ability to transmit between humans. Consequently, there is a heightened urgency to identify innovative approaches to proactively mitigate emergent epidemics. Accordingly, a novel methodology combining temporo-geospatial epidemiology and phylogeographic analysis of viral strains is proposed to identify critical epicenters and epidemic pathways along with high risk candidate regions for increased surveillance.ResultsEpidemiological analysis was used to identify 91,245 candidate global infection transmission pathways between 22 high risk waterfowl species. Dominant infection pathways (25,625 and 54,500 in summering and wintering zones) were identified through annotation using phylogeographical data computed from the phylogram of 2417 H5N1 HA isolates (from GISAID EpiFlu database). Annotation of infection pathways in turn delineated 23 influential clades out of 130 clades in the phylogram.ConclusionsThe phylogeographic analyses provides strong cross-validation of epidemic pathways and identifies the dominant pathways for use in other epidemiological and prophylactic studies. The temporo-geospatial characteristics of infection transmission provides corroborating, but novel evidence for rapid genesis of H5N1 lineages in S.E. Asia. The proposed method pinpoints several regions, particularly in the southern hemisphere, as candidates for increased surveillance.

Using multitype branching processes to quantify statistics of disease outbreaks in zoonotic epidemics.

Branching processes have served as a model for chemical reactions, biological growth processes, and contagion (of disease, information, or fads). Through this connection, these seemingly different physical processes share some common universalities that can be elucidated by analyzing the underlying branching process. In this work we focus on coupled branching processes as a model of infectious diseases spreading from one population to another. An exceedingly important example of such coupled outbreaks are zoonotic infections that spill over from animal populations to humans. We derive several statistical quantities characterizing the first spillover event from animals to humans, including the probability of spillover, the first passage time distribution for human infection, and disease prevalence in the animal population at spillover. Large stochastic fluctuations in those quantities can make inference of the state of the system at the time of spillover difficult. Focusing on outbreaks in the human population, we then characterize the critical threshold for a large outbreak, the distribution of outbreak sizes, and associated scaling laws. These all show a strong dependence on the basic reproduction number in the animal population and indicate the existence of a novel multicritical point with altered scaling behavior. The coupling of animal and human infection dynamics has crucial implications, most importantly allowing for the possibility of large human outbreaks even when human-to-human transmission is subcritical.

Institutional frameworks for management of epizoonotic emergencies in six countries in the Eastern Africa region: a situational analysis.

The Eastern Africa region is a hot-spot for epidemics of emerging zoonotic diseases ('epizoonotics'). However, the region's capacity for response to epidemics of zoonotic origin has not been documented. This paper presents a multi-country situational analysis on the institutional frameworks for management of zoonotic epidemics in the Eastern Africa region. A multi-country assessment of 6 country teams was conducted (Uganda, Kenya, Tanzania, Ethiopia, DRC and Rwanda). It involved a review of records and interviews with key informants from agencies with a stake in the management of zoonotic and disasters in general in the respective countries. Qualitative data were analyzed for key emerging themes. There are many socio-cultural risk factors to epidemic prone zoonotic diseases in the region. Countries have varying levels of preparedness for zoonotic emergencies. All 6 countries have a framework for disaster management. However, technical response to epidemics is managed by the line sectors, with limited Inter-sectoral collaboration. Some sectors were disproportionately more prepared than others. Surveillance systems are mostly passive and inadequate for early detection. All 6 countries have built reasonable capacity to respond to avian influenza, but not other zoonotic emergencies. Most countries lack personnel at the operational levels, and veterinary public health services are ill-facilitated. There is need to strengthen veterinary public health services at all levels, but with a 'one health' approach. There is also need to establish 'risk-based surveillance' hot spots for zoonotic epidemics and to build community resilience 'epizoonotic' diseases.

Amplification of Emerging Viruses in a Bat Colony

Bats host noteworthy viral pathogens, including coronaviruses, astroviruses, and adenoviruses. Knowledge on the ecology of reservoir-borne viruses is critical for preventive approaches against zoonotic epidemics. We studied a maternity colony of Myotis myotis bats in the attic of a private house in a suburban neighborhood in Rhineland-Palatinate, Germany, during 2008, 2009, and 2010. One coronavirus, 6 astroviruses, and 1 novel adenovirus were identified and monitored quantitatively. Strong and specific amplification of RNA viruses, but not of DNA viruses, occurred during colony formation and after parturition. The breeding success of the colony was significantly better in 2010 than in 2008, in spite of stronger amplification of coronaviruses and astroviruses in 2010, suggesting that these viruses had little pathogenic influence on bats. However, the general correlation of virus and bat population dynamics suggests that bats control infections similar to other mammals and that they may well experience epidemics of viruses under certain circumstances.

Zoonotic viral diseases and the frontier of early diagnosis, control and prevention

Public awareness of the human health risks of zoonotic infections has grown in recent years. Currently, concern of H5N1 flu transmission from migratory bird populations has increased with foci of fatal human cases. This comes on the heels of other major zoonotic viral epidemics in the last decade. These include other acute emerging or re-emerging viral diseases such as severe acute respiratory syndrome (SARS), West-Nile virus, Ebola virus, monkeypox, as well as the more inapparent insidious slow viral and prion diseases. Virus infections with zoonotic potential can become serious killers once they are able to establish the necessary adaptations for efficient human-to-human transmission under circumstances sufficient to reach epidemic proportions. The monitoring and early diagnosis of these potential risks are overlapping frontiers of human and veterinary medicine. Here, current viral zoonotics and evolving threats are reviewed.

Emerging zoonotic epidemics in the interconnected global community

The rate at which epidemics of zoonotic disease in humans have surfaced over the past 25 years has shaken – some would say shattered – the assumption that zoonotic diseases...

New partnerships between animal health services and public health agencies

As Veterinary Services and animal health organisations attempt to respond to a new era of emerging and re-emerging zoonotic diseases, their ability and skill in forming new strategic partnerships will be paramount. While these new partnerships are likely to include many relationships outside traditional Veterinary Services and animal agriculture, none will become more important than the formation of new animal health and public health partnerships. Episodes of emerging zoonoses are being increasingly recognised around the world and the confluence of people, animals and animal products today is unprecedented. Concurrently, a wide array of complex factors are also converging that will not only ensure the continuous emergence of zoonoses, but are also likely to drive the further increase and expansion of these diseases. This article discusses the need for the creation of more effective and co-operative partnerships in the face of new microbial threats, the complexity of both the formation and expansion of zoonoses, and the collective abilities of both human and animal health services to respond to them. Lessons learned from recent zoonotic epidemics supportthe need for co-ordinated research, interdisciplinary centres, integrated surveillance systems, response systems and infrastructures, and workforce development strategies. While there are some excellent examples of collaborative animal and public health relationships, there is no question that more and stronger partnerships among national and international organisations, both academic and private, will be necessary to meet the future challenges of emerging zoonoses and to manage their profound implications.