Publications by authors named "Jeremy Ledermann"

Article Synopsis
  • The Usutu virus (USUV) is a newly emerging flavivirus related to West Nile virus and has spread from Africa to Europe.
  • Researchers tested whether Culex tarsalis mosquitoes could transmit USUV by infecting them with varying doses of the virus through bloodmeals.
  • Results showed that only a small percentage of mosquitoes established infections, and limited transmission was noted, suggesting that Cx. tarsalis is not a major transmitter of USUV.
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Central nervous system (CNS) viral infections are critical causes of morbidity and mortality in children; however, comprehensive data on etiology is lacking in developing countries such as Indonesia. To study the etiology of CNS infections in a pediatric population, 50 children admitted to two hospitals in Bandung, West Java, during 2017-2018 were enrolled in a CNS infection study. Cerebrospinal fluid and serum specimens were tested using molecular, serological, and virus isolation platforms for a number of viral and bacteriological agents.

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Assessing the potential for mosquitoes to transmit medically important arboviruses is essential for understanding their threat to human populations. Currently, vector competence studies are typically performed by collecting saliva using a glass capillary tube system which involves sacrificing the mosquito at the time of saliva collection allowing only a single data point. These techniques also require handling infected mosquitoes and glass capillaries, constituting a safety risk.

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Chikungunya virus (CHIKV) and the closely related onyong-nyong virus (ONNV) are arthritogenic arboviruses that have caused significant, often debilitating, disease in millions of people. However, despite their kinship, they are vectored by different mosquito subfamilies that diverged 180 million years ago (anopheline versus culicine subfamilies). Previous work indicated that the nonstructural protein 3 (nsP3) of these alphaviruses was partially responsible for this vector specificity.

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  • 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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Despite causing numerous large outbreaks in the 20th century, few isolates of o'nyong nyong virus (ONNV) have been fully sequenced. Here, we report the complete genome sequence of an isolate of ONNV obtained from a febrile patient in northwest Uganda in 2017, designated ONNV UVRI0804.

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  • Researchers tested 244 patients with acute meningoencephalitis to see if there was a link between CHIKV and neurological symptoms, using various lab techniques to analyze cerebrospinal fluid and blood samples.
  • The study identified four cases of possible CHIKV-related neurological disease, highlighting the need to consider CHIKV among other viral infections when diagnosing patients in endemic regions, especially during outbreaks.
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Background: Japanese encephalitis (JE) virus is recognized as a major cause of encephalitis in Bangladesh. The World Health Organization (WHO) recommends human immunization as the most effective means to control JE. Several WHO-prequalified vaccines are available to prevent JE but no vaccination program has been implemented in Bangladesh.

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Although Japanese encephalitis virus (JEV) is considered endemic in Indonesia, there are only limited reports of JEV infection from a small number of geographic areas within the country with the majority of these being neuroinvasive disease cases. Here, we report cases of JEV infection in non-encephalitic acute febrile illness patients from Bali, Indonesia. Paired admission (S1) and discharge (S2) serum specimens from 144 acute febrile illness patients (without evidence of acute dengue virus infection) were retrospectively tested for anti-JEV IgM antibody and confirmed by plaque reduction neutralization test (PRNT) for JEV infection.

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Article Synopsis
  • * A study at R.D. Kandou General Hospital in Manado involved testing samples from adults with suspected CNS infections, revealing a confirmed viral cause in three patients and probable causes in eleven.
  • * The dominant virus identified was herpes simplex virus 1, which impacted 9.5% of patients; the study emphasized the need for improved diagnostic methods to detect viral CNS infections effectively.
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A number of arboviruses have previously been isolated from naturally-infected East African bats, however the role of bats in arbovirus maintenance is poorly understood. The aim of this study was to investigate the exposure history of Ugandan bats to a panel of arboviruses. Insectivorous and fruit bats were captured from multiple locations throughout Uganda during 2009 and 2011-2013.

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Although neurological manifestations associated with dengue viruses (DENV) infection have been reported, there is very limited information on the genetic characteristics of neurotropic DENV. Here we describe the isolation and complete genome analysis of DENV serotype 3 (DENV-3) from cerebrospinal fluid of an encephalitis paediatric patient in Jakarta, Indonesia. Next-generation sequencing was employed to deduce the complete genome of the neurotropic DENV-3 isolate.

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Chikungunya fever (CHIK) is an acute viral infection caused by infection with chikungunya virus (CHIKV). The disease affects people in areas where certain species mosquito vectors are present, especially in tropical and subtropical countries. Indonesia has witnessed CHIK disease since the early 1970s with sporadic outbreaks occurring throughout the year.

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Background: An outbreak of Guillain-Barré syndrome (GBS), a disorder characterized by acute, symmetric limb weakness with decreased or absent deep-tendon reflexes, was reported in Barranquilla, Colombia, after the introduction of Zika virus in 2015. We reviewed clinical data for GBS cases in Barranquilla and performed a case-control investigation to assess the association of suspect and probable Zika virus disease with GBS.

Methods: We used the Brighton Collaboration Criteria to confirm reported GBS patients in Barranquilla during October 2015-April 2016.

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Understanding the ability of the chikungunya virus (CHIKV) to be transmitted by Aedes vectors in the Americas is critical for assessing epidemiological risk. One element that must be considered is the minimum infectious dose of virus that can lead to transmission following the extrinsic incubation period. This study aimed to determine the minimum infection rate for the two Aedes species studied.

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Article Synopsis
  • * The incidence of GBS was notably higher in older adults, with rates of 5.6 cases per 100,000 population overall, and 14.7 cases per 100,000 among those over 60.
  • * Interviews revealed that a significant number of GBS patients had experienced an illness with symptoms like rash and fever shortly before GBS developed, linking ZIKV to severe neurological complications.
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Article Synopsis
  • The Zika virus strain JMB-185 was isolated from a febrile patient in Jambi, Indonesia in 2014, and researchers performed whole genome sequencing to analyze its genetic makeup.
  • Phylogenetic analysis revealed that this strain is not closely related to Brazilian ZIKV linked to microcephaly or recent Singapore outbreaks, suggesting its unique lineage.
  • The study found that the JMB-185 strain likely circulated in Southeast Asia since 2000, showing high genetic similarity with strains from Indonesia, Thailand, and Singapore, alongside some unique amino acid changes.
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Highlands J virus (HJV) is an alphavirus closely related to western equine encephalitis virus (WEEV) and eastern equine encephalitis virus (EEEV). HJV is an avian pathogen with the potential for disruption of poultry operations, but is not known to cause human or equine disease. HJV has only been identified in the eastern United States and is thought to have a transmission cycle similar to that of EEEV involving Culiseta melanura mosquitoes and birds.

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Having a mechanism to assess the transmission dynamics of a vector-borne virus is one critical component of understanding the life cycle of these viruses. Laboratory infection systems using artificial blood meals is one valuable approach for monitoring the progress of virus in its mosquito host and evaluating potential points for interruption of the cycle for control purposes. Here, we describe an artificial blood meal system with Chikungunya virus (CHIKV) and the processing of mosquito tissues and saliva to understand the movement and time course of virus infection in the invertebrate host.

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Entebbe bat virus (ENTV; Flaviviridae: Flavivirus), closely related to yellow fever virus, was first isolated from a little free-tailed bat (Chaerephon pumilus) in Uganda in 1957, but was not detected after that initial isolation. In 2011, we isolated ENTV from a little free-tailed bat captured from the attic of a house near where it had originally been found. Infectious virus was recovered from the spleen and lung, and the viral RNA was sequenced and compared with that of the original isolate.

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The first known outbreak of eastern equine encephalitis (EEE) in Vermont occurred on an emu farm in Rutland County in 2011. The first isolation of EEE virus (EEEV) in Vermont (VT11) was during this outbreak. Phylogenetic analysis revealed that VT11 was most closely related to FL01, a strain from Florida isolated in 2001, which is both geographically and temporally distinct from VT11.

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Two species of Aedes (Stegomyia) were collected in response to the first chikungunya virus (CHIKV) outbreak on Yap Island: the native species Ae. hensilli Farner and the introduced species Ae. aegypti (L.

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An epidemic of Zika virus (ZIKV) illness that occurred in July 2007 on Yap Island in the Federated States of Micronesia prompted entomological studies to identify both the primary vector(s) involved in transmission and the ecological parameters contributing to the outbreak. Larval and pupal surveys were performed to identify the major containers serving as oviposition habitat for the likely vector(s). Adult mosquitoes were also collected by backpack aspiration, light trap, and gravid traps at select sites around the capital city.

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Sunguru virus (SUNV), a novel virus belonging to the highly diverse Rhabdoviridae family, was isolated from a domestic chicken in the district of Arua, Uganda, in 2011. This is the first documented isolation of a rhabdovirus from a chicken. SUNV is related to, but distinct from, Boteke virus and other members of the unclassified Sandjimba group.

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