Publications by authors named "Brian R Amman"

Article Synopsis
  • This chapter outlines the various procedures involved in studying experimental infections of Egyptian rousette bats with the Marburg virus.
  • It covers topics like planning and preparation for studies, the importance of personal protective equipment, and the overall methodologies used in these experiments.
  • The chapter concludes with a focus on specific techniques for serial sampling and sacrifice within the context of the research studies.
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  • The Sosuga virus (SOSV) is a rare paramyxovirus linked to human illness, first identified in 2012 in an individual from South Sudan and Uganda.
  • Ecological studies revealed that the Egyptian rousette bat (ERB) is the only bat species consistently testing positive for SOSV, indicating it serves as a competent host for the virus.
  • Recent surveillance in Sierra Leone identified SOSV RNA in ERBs, suggesting that the virus has expanded its range from East Africa to West Africa, potentially affecting ERB populations across sub-Saharan Africa.
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Bats are increasingly recognized as reservoirs of emerging zoonotic pathogens. Egyptian rousette bats (ERBs) are the known reservoir of Marburg virus (MARV), a filovirus that causes deadly Marburg virus disease (MVD) in humans. However, ERBs harbor MARV asymptomatically, likely due to a coadapted and specific host immunity-pathogen relationship.

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Several filoviruses, including Marburg virus (MARV), cause severe disease in humans and nonhuman primates (NHPs). However, the Egyptian rousette bat (ERB, ), the only known MARV reservoir, shows no overt illness upon natural or experimental infection, which, like other bat hosts of zoonoses, is due to well-adapted, likely species-specific immune features. Despite advances in understanding reservoir immune responses to filoviruses, ERB peripheral blood responses to MARV and how they compare to those of diseased filovirus-infected spillover hosts remain ill-defined.

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Marburg virus disease, caused by Marburg and Ravn orthomarburgviruses, emerges sporadically in sub-Saharan Africa and is often fatal in humans. The natural reservoir is the Egyptian rousette bat (ERB), which sheds virus in saliva, urine, and feces. Frugivorous ERBs discard test-bitten and partially eaten fruit, potentially leaving infectious virus behind that could be consumed by other susceptible animals or humans.

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Background: The human-pathogenic Kasokero virus (KASV) circulates in an enzootic transmission cycle between Egyptian rousette bats (ERBs; Rousettus aegyptiacus) and their argasid tick ectoparasites, Ornithodoros (Reticulinasus) faini. Although tick salivary gland components have been shown to potentiate virus infection in vertebrate non-reservoirs (i.e.

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Article Synopsis
  • Egyptian rousette bats (ERBs) are linked to several bunyaviruses, particularly Kasokero virus (KASV), which was first recognized in Uganda in 1977.
  • In a study, researchers examined tissue samples from KASV-infected ERBs to analyze liver damage, immune responses, and virus clearance, finding significant liver lesions but no clinical disease.
  • KASV primarily replicated in the liver and was mostly cleared from both the liver and spleen by 6 days post-infection, indicating that ERBs can effectively manage KASV without severe health consequences.
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From July−November 2020, mink (Neogale vison) on 12 Utah farms experienced an increase in mortality rates due to confirmed SARS-CoV-2 infection. We conducted epidemiologic investigations on six farms to identify the source of virus introduction, track cross-species transmission, and assess viral evolution. Interviews were conducted and specimens were collected from persons living or working on participating farms and from multiple animal species.

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Article Synopsis
  • Researchers investigated whether bats in Uganda could be reservoirs for the o'nyong-nyong virus (ONNV) and chikungunya virus (CHIKV) through blood samples.
  • They tested 652 serum samples from six bat species and found that 13.2% of Egyptian rousettes and 8% of little free-tailed bats had antibodies to ONNV.
  • Although interepidemic circulation of ONNV and CHIKV was suggested, the inconsistent presence of antibodies indicates that Egyptian rousette bats are unlikely to be the main reservoirs for these viruses.
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  • The Kasokero virus (KASV) has been isolated from Egyptian rousette bats and ticks, indicating a possible cycle of transmission between these species.
  • A study inoculated these bats to evaluate their potential as reservoirs for KASV, showing high virus replication without apparent illness.
  • Results suggest ERBs are competent reservoirs for KASV and may transmit the virus to other bats and potentially humans through contact with their excretions.
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Zoonotic transmission of SARS-CoV-2 from infected humans to other animals has been documented around the world, most notably in mink farming operations in Europe and the United States. Outbreaks of SARS-CoV-2 on Utah mink farms began in late July 2020 and resulted in high mink mortality. An investigation of these outbreaks revealed active and past SARS-CoV-2 infections in free-roaming and in feral cats living on or near several mink farms.

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Ecological and experimental infection studies have identified Egyptian rousette bats (ERBs; : family Pteropodidae) as a reservoir host for the zoonotic rubula-like paramyxovirus Sosuga virus (SOSV). A serial sacrifice study of colony-bred ERBs inoculated with wild-type, recombinant SOSV identified small intestines and salivary gland as major sites of viral replication. In the current study, archived formalin-fixed paraffin-embedded (FFPE) tissues from the serial sacrifice study were analyzed in depth-histologically and immunohistochemically, for SOSV, mononuclear phagocytes and T cells.

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Background: In June 2019, the Bolivian Ministry of Health reported a cluster of cases of hemorrhagic fever that started in the municipality of Caranavi and expanded to La Paz. The cause of these cases was unknown.

Methods: We obtained samples for next-generation sequencing and virus isolation.

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Article Synopsis
  • - The study analyzed 72 mink affected by SARS-CoV-2 outbreaks on US farms, discovering respiratory damage similar to that seen in humans with COVID-19, including bronchiolitis in 74% of mink found dead.
  • - Testing methods showed that conventional reverse transcription-PCR (cRT-PCR) was more effective at detecting SARS-CoV-2 in upper respiratory tract tissues than in lung specimens, indicating the virus primarily affects the nasal area.
  • - The presence of the viral receptor ACE2 was noted in the nasal epithelium, suggesting that mink could serve as a useful model for studying SARS-CoV-2 infection and its effects in humans.
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Article Synopsis
  • Marburg virus (MARV) is mainly found in sub-Saharan Africa and is often deadly in humans, with Egyptian rousette bats being its natural carriers.
  • These bats spread the virus through their saliva and urine while foraging for fruit, which can be accidentally consumed by other animals or humans.
  • The study detected MARV RNA on discarded fruit and showed that the virus could survive for up to 6 hours on commonly cultivated fruit types in the region.
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Article Synopsis
  • In summer 2020, SARS-CoV-2 was discovered on mink farms in Utah, prompting a One Health initiative to determine the outbreak's scope by sampling various animals around the farms.
  • Of 365 animals tested, 72% were found to have at least one type of coronavirus, with specific findings including 127 alphacoronaviruses and 74 cases of SARS-CoV-2 in mink.
  • The study indicates a concerningly high prevalence of coronaviruses among animals on mink farms, suggesting these locations could be significant sources for future cross-species viral transmission and new pandemic risks.
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  • Serological cross-reactivity among flaviviruses makes it difficult to determine prior infections in animals in areas with multiple circulating strains.
  • The study hypothesized that subgenomic flavivirus RNA (sfRNA) could indicate Zika virus (ZIKV) infection because it persists in tissues, confirmed by detecting sfRNA in Jamaican fruit bats while NS5 was not present.
  • In a broader application with 198 bat samples from Uganda, sfRNA was detected in four bats from three species, marking the first discovery of ZIKV RNA in East African bats and supporting the use of sfRNA for identifying past flavivirus infections.
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Article Synopsis
  • The Kasokero virus (KASV) was first discovered in 1977 in bats in Uganda and is linked to both mild and severe illnesses in humans.
  • Despite being part of a group of viruses usually transmitted by ticks or vertebrates, a tick vector for KASV was not identified until recent studies.
  • Testing 786 tick pools from bat habitats revealed KASV RNA in several pools, suggesting KASV is spread between O. (R.) faini ticks and R. aegyptiacus bats, with potential risks for human transmission.
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Article Synopsis
  • Marburg virus (MARV) is highly virulent in primates, causing severe disease through immune suppression and inflammation, while causing little harm to its reservoir host, the Egyptian rousette bat (ERB).
  • Research using ERBs infected with a bat strain of MARV reveals that they activate antiviral genes but do not significantly induce proinflammatory genes, contrasting with immune responses seen in primates.
  • These findings provide evidence that the ERB's immune tolerance allows it to host MARV asymptomatically and offer insights into how different hosts respond to pathogens, which could inform future antiviral therapies.
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  • The COVID-19 pandemic reveals significant public health and economic issues stemming from viruses spilling over from wildlife, particularly focusing on the impact of SARS-CoV-2.
  • There's a growing concern about the potential for humans to infect wildlife, especially free-ranging bats, which might become new reservoirs for the virus, complicating public health efforts.
  • A review indicates that over 40 species of North American bats could be vulnerable to SARS-CoV-2, emphasizing the need for a unified approach to human and wildlife health during this pandemic.
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In August 2012, a wildlife biologist became severely ill after becoming infected with a novel paramyxovirus, termed Sosuga virus. In the weeks prior to illness, the patient worked with multiple species of bats in South Sudan and Uganda, including Egyptian rousette bats (ERBs: Rousettus aegyptiacus). A follow-up study of Ugandan bats found multiple wild-caught ERBs to test positive for SOSV in liver and spleen.

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Marburg virus (MARV) causes sporadic outbreaks of severe Marburg virus disease (MVD). Most MVD outbreaks originated in East Africa and field studies in East Africa, South Africa, Zambia, and Gabon identified the Egyptian rousette bat (ERB; Rousettus aegyptiacus) as a natural reservoir. However, the largest recorded MVD outbreak with the highest case-fatality ratio happened in 2005 in Angola, where direct spillover from bats was not  shown.

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Dysregulated and maladaptive immune responses are at the forefront of human diseases caused by infection with zoonotic viral hemorrhagic fever viruses. Elucidating mechanisms of how the natural animal reservoirs of these viruses coexist with these agents without overt disease, while permitting sufficient replication to allow for transmission and maintenance in a population, is important for understanding the viral ecology and spillover to humans. The Egyptian rousette bat (ERB) has been identified as a reservoir for Marburg virus (MARV), a filovirus and the etiological agent of the highly lethal Marburg virus disease.

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With the exception of Reston and Bombali viruses, the marburgviruses and ebolaviruses (family Filoviridae) cause outbreaks of viral hemorrhagic fever in sub-Saharan Africa. The Egyptian rousette bat (ERB) is a natural reservoir host for the marburgviruses and evidence suggests that bats are also natural reservoirs for the ebolaviruses. Although the search for the natural reservoirs of the ebolaviruses has largely involved serosurveillance of the bat population, there are no validated serological assays to screen bat sera for ebolavirus-specific IgG antibodies.

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Egyptian rousette bats () are natural reservoir hosts of Marburg virus (MARV), and Ravn virus (RAVV; collectively called marburgviruses) and have been linked to human cases of Marburg virus disease (MVD). We investigated the clinical and pathologic effects of experimental MARV infection in Egyptian rousettes through a serial euthanasia study and found clear evidence of mild but transient disease. Three groups of nine, captive-born, juvenile male bats were inoculated subcutaneously with 10,000 TCID of Marburg virus strain Uganda 371Bat2007, a minimally passaged virus originally isolated from a wild Egyptian rousette.

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