#Genomic characterisation of Crimean-Congo haemorrhagic fever virus (#CCHFV) in #Tajikistan identifies a novel reassortant virus

 

Abstract

Crimean-Congo haemorrhagic fever virus (CCHFV) is an important human tick-borne pathogen, able to cause severe haemorrhagic fever. CCHFV is endemic in Tajikistan, which records between 5–38 cases of CCHF a year from southern regions. Molecular surveillance of CCHFV is crucial to implement effective prevention and control strategies, understand viral evolution, study transmission dynamics, and develop effective diagnostics, therapeutics, and vaccines. While the presence of Asia-1 and Asia-2 genotypes has been previously reported, only two historical samples from Tajikistan have been fully sequenced. In this study we developed and applied a genotype IV-specific tiling PCR enrichment approach recovering 52 CCHFV genome segment sequences from clinical and Hyalomma tick samples collected between 2017–2023. Most sequences belonged to the Asia-2 genotype, but one virus exhibited an Asia-1 S segment combined with Asia-2 M and L segments, representing the first evidence of such viral reassortment event in Tajikistan.

Source: 

Link: https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014204

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Detection and isolation of #H5N1 clade 2.3.4.4b high pathogenicity avian #influenza virus from #ticks (Ornithodoros maritimus) recovered from a naturally infected slender-billed #gull (Chroicocephalus genei)

 

Abstract

Laridae birds, such as gulls, are known reservoirs of H13 and H16 low pathogenic avian influenza subtypes. However, during the recent outbreaks linked to the reemergence of high pathogenicity avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b of the Goose/Guangdong lineage, European populations of those birds suffered significant losses. HPAI cases were registered not only along the coastlines but also inland areas, particularly in France and Central Europe. During a diagnostic investigation of a group of Laridae birds, part of a HPAIV outbreak registered in the South of France in 2023, larval stages of Ornithodoros maritimus, a nidicolous soft tick parasitizing seabirds, were recovered from a slender-billed gull (Chroicocephalus genei). Affected birds exhibited gross and histopathological lesions consistent with systemic HPAI infection. Immunohistochemistry revealed marked neurotropism, oculotropism and multicentric epitheliotropism. Viral isolation and sequencing analysis confirmed the presence of HPAI H5N1 clade 2.3.4.4b in both the gull and ectoparasites, showing from 98.505% to 99.989% nucleotide identity across six out of eight RNA segments. While additional research is needed to properly assess the vector competence of O. maritimus, ticks may represent an interesting non-invasive surveillance tool for HPAIV surveillance. This is the first time a HPAIV is successfully isolated from ticks larvae. These findings represent a first step toward understanding the potential role played by ticks in the diffusion of avian influenza viruses within marine bird colonies and among other ecosystems, considering the occurrence of specific behavioral traits, such as kleptoparasitim and the position of gulls at the interface between wild and domestic species.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Agence Nationale de la Recherche, https://ror.org/00rbzpz17

INRAe Animal Health Department

Source: 

Link, https://www.biorxiv.org/content/10.1101/2025.11.28.689408v1

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Discovery of a Novel #Parahenipavirus, Parahenipavirus_GH, in #Shrews in South #Korea, 2022

Abstract

Highly pathogenic henipaviruses (Nipah and Hendra viruses) and parahenipaviruses (Langya virus) have demonstrated significant zoonotic potential. We aimed to identify Henipavirus or Parahenipavirus species in rodents and shrews in South Korea to underline the potential zoonotic transmission risk. Kidney and lung tissues from 285 rodents and shrews were screened for Henipavirus and Parahenipavirus using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) targeting the Gamak virus and Daeryong virus (DARV) sequences. Based on the qRT-PCR results, 75 out of the 285 individuals tested positive, with the highest viral loads in the kidneys of Apodemus agrarius, Crocidura lasiura, and Crocidura shantungensis. A kidney sample from C. shantungensis that exhibited the lowest Ct value was further analyzed using PCR, Sanger sequencing, and metagenomic analysis, yielding a near-complete genome of a novel Parahenipavirus, designated Parahenipavirus_GH (PHNV-GH), which is phylogenetically related to DARV and Jingmen virus but exhibits distinct genomic features. Ixodes granulatus ticks were also identified on the host shrew. The identification of PHNV-GH in southern South Korea expands the known geographical distribution range of parahenipaviruses and highlights the ongoing risk of zoonotic transmission. Given the uncertain transmission dynamics and pathogenic potential of parahenipaviruses, comprehensive environmental surveillance and characterization of emerging parahenipaviruses are essential for preventing future outbreaks.

Source: Viruses, https://www.mdpi.com/1999-4915/17/6/867

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