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Viruses Jun 2021There is a growing number of perinatally HIV-1-infected children worldwide who must maintain life-long ART. In early life, HIV-1 infection is established in an... (Review)
Review
There is a growing number of perinatally HIV-1-infected children worldwide who must maintain life-long ART. In early life, HIV-1 infection is established in an immunologically inexperienced environment in which maternal ART and immune dynamics during pregnancy play a role in reservoir establishment. Children that initiated early antiretroviral therapy (ART) and maintained long-term suppression of viremia have smaller and less diverse HIV reservoirs than adults, although their proviral landscape during ART is reported to be similar to that of adults. The ability of these early infected cells to persist long-term through clonal expansion poses a major barrier to finding a cure. Furthermore, the effects of life-long HIV persistence and ART are yet to be understood, but growing evidence suggests that these individuals are at an increased risk for developing non-AIDS-related comorbidities, which underscores the need for an HIV cure.
Topics: Anti-Retroviral Agents; Antiretroviral Therapy, Highly Active; Child; DNA, Viral; Disease Reservoirs; Female; HIV Infections; HIV-1; Humans; Infectious Disease Transmission, Vertical; Pregnancy; Proviruses; Viral Load; Viremia
PubMed: 34204740
DOI: 10.3390/v13061134 -
Proceedings of the National Academy of... Apr 2022SignificanceThe clear need to mitigate zoonotic risk has fueled increased viral discovery in specific reservoir host taxa. We show that a combination of viral and...
SignificanceThe clear need to mitigate zoonotic risk has fueled increased viral discovery in specific reservoir host taxa. We show that a combination of viral and reservoir traits can predict zoonotic virus virulence and transmissibility in humans, supporting the hypothesis that bats harbor exceptionally virulent zoonoses. However, pandemic prevention requires thinking beyond zoonotic capacity, virulence, and transmissibility to consider collective "burden" on human health. For this, viral discovery targeting specific reservoirs may be inefficient as death burden correlates with viral, not reservoir, traits, and depends on context-specific epidemiological dynamics across and beyond the human-animal interface. These findings suggest that longitudinal studies of viral dynamics in reservoir and spillover host populations may offer the most effective strategy for mitigating zoonotic risk.
Topics: Animals; Chiroptera; Disease Reservoirs; Virulence; Viruses; Zoonoses
PubMed: 35349342
DOI: 10.1073/pnas.2113628119 -
Philosophical Transactions of the Royal... Sep 2019The risk of zoonotic spillover from reservoir hosts, such as wildlife or domestic livestock, to people is shaped by the spatial and temporal distribution of infection in... (Review)
Review
The risk of zoonotic spillover from reservoir hosts, such as wildlife or domestic livestock, to people is shaped by the spatial and temporal distribution of infection in reservoir populations. Quantifying these distributions is a key challenge in epidemiology and disease ecology that requires researchers to make trade-offs between the extent and intensity of spatial versus temporal sampling. We discuss sampling methods that strengthen the reliability and validity of inferences about the dynamics of zoonotic pathogens in wildlife hosts. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.
Topics: Animals; Animals, Wild; Disease Reservoirs; Epidemiological Monitoring; Population Surveillance; Reproducibility of Results; Zoonoses
PubMed: 31401966
DOI: 10.1098/rstb.2018.0336 -
Current Opinion in Plant Biology Aug 2020Understanding the ecological and evolutionary processes underlying the emergence of infectious disease is critically important in guiding prevention, management and... (Review)
Review
Understanding the ecological and evolutionary processes underlying the emergence of infectious disease is critically important in guiding prevention, management and breeding strategies. Novel pathogen lineages may arise within agricultural environments, wild hosts or from non-host associated disease reservoirs. Although the source of most disease outbreaks remains unknown, environmental and zoonotic origins are frequently identified in mammalian pathosystems and expanded sampling of plant pathosystems reveals important links with wild populations. This review describes key ecological and evolutionary processes underlying disease emergence, with particular emphasis on shifts from wild reservoirs to cultivated hosts and genetic mechanisms driving host adaption subsequent to emergence.
Topics: Agriculture; Animals; Biological Evolution; Disease Reservoirs; Plant Diseases
PubMed: 32712539
DOI: 10.1016/j.pbi.2020.06.003 -
International Journal of Environmental... Dec 2015Given the relatively recent recognition of Lyme disease (LD) by CDC in 1990 as a nationally notifiable infectious condition, the rise of reported human cases every year... (Review)
Review
Given the relatively recent recognition of Lyme disease (LD) by CDC in 1990 as a nationally notifiable infectious condition, the rise of reported human cases every year argues for a better understanding of its geographic scope. The aim of this inquiry was to explore research conducted on spatiotemporal patterns of Lyme disease in order to identify strategies for implementing vector and reservoir-targeted interventions. The focus of this review is on the use of GIS-based methods to study populations of the reservoir hosts, vectors and humans in addition to the spatiotemporal interactions between these populations. New GIS-based studies are monitoring occurrence at the macro-level, and helping pinpoint areas of occurrence at the micro-level, where spread within populations of reservoir hosts, clusters of infected ticks and tick to human transmission may be better understood.
Topics: Animals; Disease Reservoirs; Ecosystem; Geographic Information Systems; Geographic Mapping; Humans; Lyme Disease; Maps as Topic; Remote Sensing Technology; Ticks
PubMed: 26633445
DOI: 10.3390/ijerph121214971 -
Journal of Neurovirology Jun 2015HIV-1 replication in the central nervous system (CNS) is typically limited by the availability of target cells. HIV-1 variants that are transmitted and dominate the... (Review)
Review
HIV-1 replication in the central nervous system (CNS) is typically limited by the availability of target cells. HIV-1 variants that are transmitted and dominate the early stages of infection almost exclusively use the CCR5 coreceptor and are well adapted to entering, and thus infecting, cells expressing high CD4 densities similar to those found on CD4+ T cells. While the "immune privileged" CNS is largely devoid of CD4+ T cells, macrophage and microglia are abundant throughout the CNS. These cells likely express CD4 densities that are too low to facilitate efficient entry or allow sustained replication by most HIV-1 isolates. Examination of CNS viral populations reveals that late in disease the CNS of some individuals contains HIV-1 lineages that have evolved the ability to enter cells expressing low levels of CD4 and are well-adapted to entering macrophages. These macrophage-tropic (M-tropic) viruses are able to maintain sustained replication in the CNS for many generations, and their presence is associated with severe neurocognitive impairment. Whether conditions such as pleocytosis are necessary for macrophage-tropic viruses to emerge in the CNS is unknown, and extensive examinations of macrophage-tropic variants have not revealed a genetic signature of this phenotype. It is clear, however, that macrophage tropism is rare among HIV-1 isolates and is not transmitted, but is important due to its pathogenic effects on hosts. Prior to the evolution of macrophage-tropic variants, the viruses that are predominately infecting T cells (R5 T cell-tropic) may infect macrophages at a low level and inefficiently, but this could contribute to the reservoir.
Topics: Brain; Central Nervous System; Disease Reservoirs; HIV Infections; HIV-1; Humans; Macrophages; Microglia; Virus Latency
PubMed: 25236812
DOI: 10.1007/s13365-014-0287-x -
Parasitology Apr 2018Leptospirosis is a zoonotic bacterial disease of global importance. A large spectrum of asymptomatic animal hosts can carry the infection and contribute to the burden of... (Review)
Review
Leptospirosis is a zoonotic bacterial disease of global importance. A large spectrum of asymptomatic animal hosts can carry the infection and contribute to the burden of human disease. Environmental sources of human contamination also point to the importance of a hydrotelluric reservoir. Leptospirosis can be caused by as many as 15 different pathogenic or intermediate Leptospira species. However, classification of these bacteria remains complicated through the use of both serological and genetic classification systems that show poor correlation. With the advent of molecular techniques, DNA-based barcoding offers a conceptual framework that can be used for leptospirosis surveillance as well as source tracking. In this review, we summarize some of the current techniques, highlight significant successes and weaknesses and point to the future opportunities and challenges to successfully establish a widely applicable barcoding scheme for Leptospira.
Topics: Animals; DNA Barcoding, Taxonomic; Disease Reservoirs; Environmental Microbiology; Genotyping Techniques; Humans; Leptospira; Leptospirosis; Phylogeny; Zoonoses
PubMed: 28716157
DOI: 10.1017/S0031182017001147 -
Viruses May 2021The persistence of HIV-1 viral reservoirs in the brain, despite treatment with combination antiretroviral therapy (cART), remains a critical roadblock for the...
The persistence of HIV-1 viral reservoirs in the brain, despite treatment with combination antiretroviral therapy (cART), remains a critical roadblock for the development of a novel cure strategy for HIV-1. To enhance our understanding of viral reservoirs, two complementary studies were conducted to (1) evaluate the HIV-1 mRNA distribution pattern and major cell type expressing HIV-1 mRNA in the HIV-1 transgenic (Tg) rat, and (2) validate our findings by developing and critically testing a novel biological system to model active HIV-1 infection in the rat. First, a restricted, region-specific HIV-1 mRNA distribution pattern was observed in the HIV-1 Tg rat. Microglia were the predominant cell type expressing HIV-1 mRNA in the HIV-1 Tg rat. Second, we developed and critically tested a novel biological system to model key aspects of HIV-1 by infusing F344/N control rats with chimeric HIV (EcoHIV). In vitro, primary cultured microglia were treated with EcoHIV revealing prominent expression within 24 h of infection. In vivo, EcoHIV expression was observed seven days after stereotaxic injections. Following EcoHIV infection, microglia were the major cell type expressing HIV-1 mRNA, results that are consistent with observations in the HIV-1 Tg rat. Within eight weeks of infection, EcoHIV rats exhibited neurocognitive impairments and synaptic dysfunction, which may result from activation of the NogoA-NgR3/PirB-RhoA signaling pathway and/or neuroinflammation. Collectively, these studies enhance our understanding of HIV-1 viral reservoirs in the brain and offer a novel biological system to model HIV-associated neurocognitive disorders and associated comorbidities (i.e., drug abuse) in rats.
Topics: Animals; Cells, Cultured; Disease Models, Animal; Disease Reservoirs; Female; HIV-1; Male; Microglia; Neurocognitive Disorders; Neuroinflammatory Diseases; RNA, Viral; Rats; Rats, Inbred F344; Rats, Transgenic
PubMed: 34067600
DOI: 10.3390/v13050924 -
Current HIV/AIDS Reports Feb 2019In addition to preventive protocols and antiretroviral therapy, HIV-1 eradication has been considered as an additional strategy to help fight the AIDS epidemic. With the... (Review)
Review
PURPOSE OF REVIEW
In addition to preventive protocols and antiretroviral therapy, HIV-1 eradication has been considered as an additional strategy to help fight the AIDS epidemic. With the support of multiple funding agencies, research groups worldwide have been developing protocols to achieve either a sterilizing or a functional cure for HIV-infection.
RECENT FINDINGS
Most of the studies focus on the elimination or suppression of circulating CD4+ T cells, the best characterized HIV-1 latent reservoir. The role of the central nervous system (CNS) as a latent reservoir is still controversial. Although brain macrophages and astrocytes are susceptible to HIV-1 infection, it has not been ascertained whether the CNS carries latent HIV-1 during cART and, if so, whether the virus can be reactivated and spread to other compartments after ART interruption. Here, we examine the implications of HIV-1 eradication strategies on the CNS, regardless of whether it is a true latent reservoir and, if so, whether it is present in all patients.
Topics: Astrocytes; Brain; CD4-Positive T-Lymphocytes; Disease Eradication; Disease Reservoirs; HIV Infections; HIV-1; Humans; Macrophages; Virus Latency
PubMed: 30734905
DOI: 10.1007/s11904-019-00428-7 -
Chemotherapy 2021Viruses arise through cross-species transmission and can cause potentially fatal diseases in humans. This is the case of the severe acute respiratory syndrome... (Review)
Review
Viruses arise through cross-species transmission and can cause potentially fatal diseases in humans. This is the case of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which recently appeared in Wuhan, China, and rapidly spread worldwide, causing the outbreak of coronavirus disease 2019 (COVID-19) and posing a global health emergency. Sequence analysis and epidemiological investigations suggest that the most likely original source of SARS-CoV-2 is a spillover from an animal reservoir, probably bats, that infected humans either directly or through intermediate animal hosts. The role of animals as reservoirs and natural hosts in SARS-CoV-2 has to be explored, and animal models for COVID-19 are needed as well to be evaluated for countermeasures against SARS-CoV-2 infection. Experimental cells, tissues, and animal models that are currently being used and developed in COVID-19 research will be presented.
Topics: Animals; COVID-19; Communicable Disease Control; Disease Reservoirs; Disease Transmission, Infectious; Disease Vectors; Humans; Models, Theoretical; SARS-CoV-2
PubMed: 33774628
DOI: 10.1159/000515341