Last data update: May 13, 2024. (Total: 46773 publications since 2009)
Records 1-7 (of 7 Records) |
Query Trace: Fischer RJ[original query] |
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Surface-aerosol stability and pathogenicity of diverse MERS-CoV strains from 2012 - 2018 (preprint)
van Doremalen N , Letko M , Fischer RJ , Bushmaker T , Yinda CK , Schulz J , Seifert SN , Kim NJ , Hemida MG , Kayali G , Park WB , Perera RA , Tamin A , Thornburg NJ , Tong S , Queen K , van Kerkhove MD , Choi YK , Oh MD , Assiri AM , Peiris M , Gerber SI , Munster VJ . bioRxiv 2021 Middle East Respiratory Syndrome coronavirus (MERS-CoV) is a coronavirus that infects both humans and dromedary camels and is responsible for an ongoing outbreak of severe respiratory illness in humans in the Middle East. While some mutations found in camel-derived MERS-CoV strains have been characterized, the majority of natural variation found across MERS-CoV isolates remains unstudied. Here we report on the environmental stability, replication kinetics and pathogenicity of several diverse isolates of MERS-CoV as well as SARS-CoV-2 to serve as a basis of comparison with other stability studies. While most of the MERS-CoV isolates exhibited similar stability and pathogenicity in our experiments, the camel derived isolate, C/KSA/13, exhibited reduced surface stability while another camel isolate, C/BF/15, had reduced pathogenicity in a small animal model. These results suggest that while betacoronaviruses may have similar environmental stability profiles, individual variation can influence this phenotype, underscoring the importance of continual, global viral surveillance. |
Surface‒Aerosol Stability and Pathogenicity of Diverse Middle East Respiratory Syndrome Coronavirus Strains, 2012‒2018.
van Doremalen N , Letko M , Fischer RJ , Bushmaker T , Schulz J , Yinda CK , Seifert SN , Kim NJ , Hemida MG , Kayali G , Park WB , Perera Rapm , Tamin A , Thornburg NJ , Tong S , Queen K , van Kerkhove MD , Choi YK , Oh MD , Assiri AM , Peiris M , Gerber SI , Munster VJ . Emerg Infect Dis 2021 27 (12) 3052-3062 Middle East respiratory syndrome coronavirus (MERS-CoV) infects humans and dromedary camels and is responsible for an ongoing outbreak of severe respiratory illness in humans in the Middle East. Although some mutations found in camel-derived MERS-CoV strains have been characterized, most natural variation found across MERS-CoV isolates remains unstudied. We report on the environmental stability, replication kinetics, and pathogenicity of several diverse isolates of MERS-CoV, as well as isolates of severe acute respiratory syndrome coronavirus 2, to serve as a basis of comparison with other stability studies. Although most MERS-CoV isolates had similar stability and pathogenicity in our experiments, the camel-derived isolate C/KSA/13 had reduced surface stability, and another camel isolate, C/BF/15, had reduced pathogenicity in a small animal model. These results suggest that although betacoronaviruses might have similar environmental stability profiles, individual variation can influence this phenotype, underscoring the need for continual global viral surveillance. |
Host associations and genomic diversity of Borrelia hermsii in an endemic focus of tick-borne relapsing fever in western North America.
Johnson TL , Fischer RJ , Raffel SJ , Schwan TG . Parasit Vectors 2016 9 (1) 575 BACKGROUND: An unrecognized focus of tick-borne relapsing fever caused by Borrelia hermsii was identified in 2002 when five people became infected on Wild Horse Island in Flathead Lake, Montana. The terrestrial small mammal community on the island is composed primarily of pine squirrels (Tamiasciurus hudsonicus) and deer mice (Peromyscus maniculatus), neither of which was known as a natural host for the spirochete. Thus a 3-year study was performed to identify small mammals as hosts for B. hermsii. METHODS: Small mammals were captured alive on two island and three mainland sites, blood samples were collected and examined for spirochetes, and serological tests performed to detect anti-B. hermsii antibodies. Ornithodoros hermsi ticks were collected and fed on laboratory mice to assess infection. Genomic DNA samples from spirochetes isolated from infected mammals and ticks were analyzed by multilocus sequence typing. RESULTS: Eighteen pine squirrels and one deer mouse had detectable spirochetemias when captured, from which 12 isolates of B. hermsii were established. Most pine squirrels were seropositive, and the five species of sciurids combined had a significantly higher prevalence of seropositive animals than did the other six small mammal species captured. The greater diversity of small mammals on the mainland in contrast to the islands demonstrated that other species in addition to pine squirrels were also involved in the maintenance of B. hermsii at Flathead Lake. Ornithodoros hermsi ticks produced an additional 12 isolates of B. hermsii and multilocus sequence typing identified both genomic groups of B. hermsii described previously, and identified a new genomic subdivision. Experimental infections of deer mice with two strains of B. hermsii demonstrated that these animals were susceptible to infection with spirochetes belonging to Genomic Group II but not Genomic Group I. CONCLUSIONS: Pine squirrels are the primary hosts for the maintenance of B. hermsii on the islands in Flathead Lake, however serological evidence showed that numerous additional species are also involved on the mainland. Future studies testing the susceptibility of several small mammal species to infection with different genetic types of B. hermsii will help define their role as hosts in this and other endemic foci. |
Plasmodium Parasitemia Associated With Increased Survival in Ebola Virus-Infected Patients.
Rosenke K , Adjemian J , Munster VJ , Marzi A , Falzarano D , Onyango CO , Ochieng M , Juma B , Fischer RJ , Prescott JB , Safronetz D , Omballa V , Owuor C , Hoenen T , Groseth A , Martellaro C , van Doremalen N , Zemtsova G , Self J , Bushmaker T , McNally K , Rowe T , Emery SL , Feldmann F , Williamson BN , Best SM , Nyenswah TG , Grolla A , Strong JE , Kobinger G , Bolay FK , Zoon KC , Stassijns J , Giuliani R , de Smet M , Nichol ST , Fields B , Sprecher A , Massaquoi M , Feldmann H , de Wit E . Clin Infect Dis 2016 63 (8) 1026-33 BACKGROUND: The ongoing Ebola outbreak in West Africa has resulted in 28 646 suspected, probable, and confirmed Ebola virus infections. Nevertheless, malaria remains a large public health burden in the region affected by the outbreak. A joint Centers for Disease Control and Prevention/National Institutes of Health diagnostic laboratory was established in Monrovia, Liberia, in August 2014, to provide laboratory diagnostics for Ebola virus. METHODS: All blood samples from suspected Ebola virus-infected patients admitted to the Medecins Sans Frontieres ELWA3 Ebola treatment unit in Monrovia were tested by quantitative real-time polymerase chain reaction for the presence of Ebola virus and Plasmodium species RNA. Clinical outcome in laboratory-confirmed Ebola virus-infected patients was analyzed as a function of age, sex, Ebola viremia, and Plasmodium species parasitemia. RESULTS: The case fatality rate of 1182 patients with laboratory-confirmed Ebola virus infections was 52%. The probability of surviving decreased with increasing age and decreased with increasing Ebola viral load. Ebola virus-infected patients were 20% more likely to survive when Plasmodium species parasitemia was detected, even after controlling for Ebola viral load and age; those with the highest levels of parasitemia had a survival rate of 83%. This effect was independent of treatment with antimalarials, as this was provided to all patients. Moreover, treatment with antimalarials did not affect survival in the Ebola virus mouse model. CONCLUSIONS: Plasmodium species parasitemia is associated with an increase in the probability of surviving Ebola virus infection. More research is needed to understand the molecular mechanism underlying this remarkable phenomenon and translate it into treatment options for Ebola virus infection. |
Ebola laboratory response at the Eternal Love Winning Africa Campus, Monrovia, Liberia, 2014-2015
de Wit E , Rosenke K , Fischer RJ , Marzi A , Prescott J , Bushmaker T , van Doremalen N , Emery SL , Falzarano D , Feldmann F , Groseth A , Hoenen T , Juma B , McNally KL , Ochieng M , Omballa V , Onyango CO , Owuor C , Rowe T , Safronetz D , Self J , Williamson BN , Zemtsova G , Grolla A , Kobinger G , Rayfield M , Stroher U , Strong JE , Best SM , Ebihara H , Zoon KC , Nichol ST , Nyenswah TG , Bolay FK , Massaquoi M , Feldmann H , Fields B . J Infect Dis 2016 214 S169-S176 West Africa experienced the first epidemic of Ebola virus infection, with by far the greatest number of cases in Guinea, Sierra Leone, and Liberia. The unprecedented epidemic triggered an unparalleled response, including the deployment of multiple Ebola treatment units and mobile/field diagnostic laboratories. The National Institute of Allergy and Infectious Diseases and the Centers for Disease Control and Prevention deployed a joint laboratory to Monrovia, Liberia, in August 2014 to support the newly founded Ebola treatment unit at the Eternal Love Winning Africa (ELWA) campus. The laboratory operated initially out of a tent structure but quickly moved into a fixed-wall building owing to severe weather conditions, the need for increased security, and the high sample volume. Until May 2015, when the laboratory closed, the site handled close to 6000 clinical specimens for Ebola virus diagnosis and supported the medical staff in case patient management. Laboratory operation and safety, as well as Ebola virus diagnostic assays, are described and discussed; in addition, lessons learned for future deployments are reviewed. |
The merits of malaria diagnostics during an Ebola virus disease outbreak
de Wit E , Falzarano D , Onyango C , Rosenke K , Marzi A , Ochieng M , Juma B , Fischer RJ , Prescott JB , Safronetz D , Omballa V , Owuor C , Hoenen T , Groseth A , van Doremalen N , Zemtsova G , Self J , Bushmaker T , McNally K , Rowe T , Emery SL , Feldmann F , Williamson B , Nyenswah TG , Grolla A , Strong JE , Kobinger G , Stroeher U , Rayfield M , Bolay FK , Zoon KC , Stassijns J , Tampellini L , de Smet M , Nichol ST , Fields B , Sprecher A , Feldmann H , Massaquoi M , Munster VJ . Emerg Infect Dis 2016 22 (2) 323-6 Malaria is a major public health concern in the countries affected by the Ebola virus disease epidemic in West Africa. We determined the feasibility of using molecular malaria diagnostics during an Ebola virus disease outbreak and report the incidence of Plasmodium spp. parasitemia in persons with suspected Ebola virus infection. |
Nanopore Sequencing as a Rapidly Deployable Ebola Outbreak Tool.
Hoenen T , Groseth A , Rosenke K , Fischer RJ , Hoenen A , Judson SD , Martellaro C , Falzarano D , Marzi A , Squires RB , Wollenberg KR , de Wit E , Prescott J , Safronetz D , van Doremalen N , Bushmaker T , Feldmann F , McNally K , Bolay FK , Fields B , Sealy T , Rayfield M , Nichol ST , Zoon KC , Massaquoi M , Munster VJ , Feldmann H . Emerg Infect Dis 2016 22 (2) 331-4 Rapid sequencing of RNA/DNA from pathogen samples obtained during disease outbreaks provides critical scientific and public health information. However, challenges exist for exporting samples to laboratories or establishing conventional sequencers in remote outbreak regions. We successfully used a novel, pocket-sized nanopore sequencer at a field diagnostic laboratory in Liberia during the current Ebola virus outbreak. |
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