Publications by authors named "John Klena"

Health Security is a major concern for the Democratic Republic of the Congo (DRC). It is the second largest country in Africa, borders nine other countries, has more than 80 million inhabitants, and has suffered from decades of neglect and conflicts together with multiple recurrent disease outbreaks, including Ebola.

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Background: A peri-urban outbreak of Rift Valley fever virus (RVFV) among dairy cattle from May through August 2018 in northern Tanzania was detected through testing samples from prospective livestock abortion surveillance. We sought to identify concurrent human infections, their phylogeny, and epidemiologic characteristics in a cohort of febrile patients enrolled from 2016-2019 at hospitals serving the epizootic area.

Methods: From September 2016 through May 2019, we conducted a prospective cohort study that enrolled febrile patients hospitalized at two hospitals in Moshi, Tanzania.

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Background: In September 2022, Uganda experienced an outbreak of Sudan virus disease (SVD), mainly in central Uganda. As a result of enhanced surveillance activities for Ebola disease, samples from several patients with suspected viral hemorrhagic fever (VHF) were sent to the VHF Program at Uganda Virus Research Institute (UVRI), Entebbe, Uganda, and identified with infections caused by other viral etiologies. Herein, we report the epidemiologic and laboratory findings of Crimean-Congo hemorrhagic fever (CCHF) cases that were detected during the SVD outbreak response.

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New World orthohantaviruses are rodent-borne tri-segmented viruses that cause hantavirus cardiopulmonary syndrome in humans in the Americas. Molecular diagnostics for orthohantaviruses can be improved with more sequence data. Reported here are completed genomes for Lechiguanas, Maciel, and Laguna Negra viruses.

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Background: During the 2018-20 Ebola virus disease outbreak in the Democratic Republic of the Congo, thousands of patients received unprecedented vaccination, monoclonal antibody (mAb) therapy, or both, leading to a large number of survivors. We aimed to report the clinical, virological, viral genomic, and immunological features of two previously vaccinated and mAb-treated survivors of Ebola virus disease in the Democratic Republic of the Congo who developed second episodes of disease months after initial discharge, ultimately complicated by fatal meningoencephalitis associated with viral persistence.

Methods: In this case report study, we describe the presentation, management, and subsequent investigations of two patients who developed recrudescent Ebola virus disease and subsequent fatal meningoencephalitis.

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Article Synopsis
  • * Researchers developed a simple "mix-and-read" biosensor using a split NanoLuc luciferase to detect anti-NiV antibodies in samples, validated with over 700 serum samples from Bangladesh.
  • * The new biosensor showed high sensitivity (98.6%) and specificity (100%) compared to existing tests, though it is less effective for detecting antibodies shortly after symptoms begin, making it a valuable tool for NiV surveillance and outbreak investigations.
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  • Hantavirus pulmonary syndrome (HPS) and non-HPS hantavirus infection are tracked as nationally notifiable diseases in the U.S., with diagnostics based on symptoms and lab results between 2008 and 2020.
  • A study merged epidemiological data and diagnostic lab results from the CDC to analyze the occurrence and genetic diversity of hantavirus in the U.S., revealing that the majority of cases were in western states, particularly the Four Corners region.
  • Findings highlight a seasonal spike in cases between March and August and reveal discrepancies between commercial and CDC lab tests, suggesting a need for better diagnostic tests to align results.
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Engaging communities in Ebola preparedness activities between Ebola outbreaks can not only improve community adherence to response interventions but also potentially help to improve survivorship in these communities during future Ebola outbreaks.

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  • The rVSVΔG-ZEBOV-GP vaccine has been used during Ebola outbreaks, and a study in Uganda assessed healthcare workers' knowledge, attitudes, and long-term immune responses following vaccination.
  • Out of 565 surveyed healthcare workers, only 37% reported being vaccinated, and a significant portion lacked knowledge that the vaccine only protects against Ebola.
  • Despite the general desire for booster doses, the findings highlight the need for continued education on Ebola and other viral hemorrhagic fevers, especially since the vaccine's long-term effectiveness remains uncertain.
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Background: On 20 September 2022, Uganda declared its fifth Sudan virus disease (SVD) outbreak, culminating in 142 confirmed and 22 probable cases. The reproductive rate (R) of this outbreak was 1.25.

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  • * From 1993 to 2019, researchers collected rodent samples, resulting in the sequencing of 13 new genomes, which expanded the known New World arenavirus Clade C from 11 to 24 genomes.
  • * Among these genomes, two show enough genetic variation to be classified as a new species, and the research indicates widespread circulation of Clade C in rodents, though its risk to humans is still unclear.
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Orthohantaviruses cause hantavirus cardiopulmonary syndrome; most cases occur in the southwest region of the United States. We discuss a clinical case of orthohantavirus infection in a 65-year-old woman in Michigan and the phylogeographic link of partial viral fragments from the patient and rodents captured near the presumed site of infection.

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Sporadic cases and outbreaks of Crimean-Congo hemorrhagic fever (CCHF) have been documented across Pakistan since 1976; however, data regarding the diversity of CCHF virus (CCHFV) in Pakistan is sparse. We whole-genome sequenced 36 CCHFV samples collected from persons infected in Pakistan during 2017-2020. Most CCHF cases were from Rawalpindi (n = 10), followed by Peshawar (n = 7) and Islamabad (n = 4).

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Background: The Democratic Republic of the Congo has had 15 Ebola virus disease (EVD) outbreaks, from 1976 to 2023. On June 1, 2020, the Democratic Republic of the Congo declared an outbreak of EVD in the western Équateur Province (11th outbreak), proximal to the 2018 Tumba and Bikoro outbreak and concurrent with an outbreak in the eastern Nord Kivu Province. In this Article, we assessed whether the 11th outbreak was genetically related to previous or concurrent EVD outbreaks and connected available epidemiological and genetic data to identify sources of possible zoonotic spillover, uncover additional unreported cases of nosocomial transmission, and provide a deeper investigation into the 11th outbreak.

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Hantaviruses zoonotically infect humans worldwide with pathogenic consequences and are mainly spread by rodents that shed aerosolized virus particles in urine and feces. Bioinformatics methods for hantavirus diagnostics, genomic surveillance and epidemiology are currently lacking a comprehensive approach for data sharing, integration, visualization, analytics and reporting. With the possibility of hantavirus cases going undetected and spreading over international borders, a significant reporting delay can miss linked transmission events and impedes timely, targeted public health interventions.

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Crimean-Congo Hemorrhagic fever (CCHF) is an important zoonotic disease transmitted to humans both by tick vectors and contact with fluids from an infected animal or human. Although animals are not symptomatic when infected, they are the main source of human infection. Uganda has reported sporadic human outbreaks of CCHF in various parts of the country since 2013.

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Nipah virus (NiV) is a lethal bat-borne zoonotic virus that causes mild to acute respiratory distress and neurological manifestations in humans with a high mortality rate. NiV transmission to humans occurs via consumption of bat-contaminated fruit and date palm sap (DPS), or through direct contact with infected individuals and livestock. Since NiV outbreaks were first reported in pigs from Malaysia and Singapore, non-neutralizing antibodies against NiV attachment Glycoprotein (G) have also been detected in a few domestic mammals.

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Article Synopsis
  • Nipah virus infections have been a serious problem in Bangladesh since 2001, causing many outbreaks almost every year.!
  • A special hospital program was set up to find and respond to these infections quickly by testing people who might have the virus.!
  • From 2006 to 2021, they tested over 7,100 people and discovered 322 cases of Nipah virus, mostly linked to eating raw date palm sap or spreading between people, with a very high death rate of 71%.!
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Ebola disease (EBOD) is a public health threat with a high case fatality rate. Most EBOD outbreaks have occurred in remote locations, but the 2013-2016 Western Africa outbreak demonstrated how devastating EBOD can be when it reaches an urban population. Here, the 2022 Sudan virus disease (SVD) outbreak in Mubende District, Uganda, is summarized, and the genetic relatedness of the new variant is evaluated.

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From its discovery in Malaysia in the late 1990s, the spillover of the Nipah virus from its pteropid reservoir into the human population has resulted in sporadic outbreaks of fatal encephalitis and respiratory disease. In this chapter, we revise a previously described quantitative reverse transcription polymerase chain reaction method, which now utilizes degenerate nucleotides at certain positions in the probe and the reverse primer to accommodate the sequence heterogeneity observed within the Nipah henipavirus species.

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Lymphocytic choriomeningitis virus is an underreported cause of miscarriage and neurologic disease. Surveillance remains challenging because of nonspecific symptomatology, inconsistent case reporting, and difficulties with diagnostic testing. We describe a case of acute lymphocytic choriomeningitis virus disease in a person living with HIV in Connecticut, USA, identified by using quantitative reverse transcription PCR.

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Nipah virus (NiV) is a highly pathogenic paramyxovirus with a high case fatality rate. Due to its high pathogenicity, pandemic potential, and lack of therapeutics or approved vaccines, its study requires biosafety level 4 (BSL4) containment. In this report, we developed a novel neutralization assay for use in biosafety level 2 laboratories.

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Article Synopsis
  • - In 2016, Rift Valley fever reemerged in Uganda's Kabale District, with confirmed human cases and a notable seropositivity rate of 13% in both humans and animals.
  • - A countrywide survey involving 3,181 livestock samples showed an overall RVFV seropositivity of 6.9%, with higher rates in cattle (10.7%) versus goats and sheep, and among females and adults compared to males and juveniles.
  • - The study highlights risk factors for RVFV seropositivity, including animal species, age, grazing methods, and regional differences, indicating the potential for targeted surveillance to prevent future outbreaks in humans and animals.
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