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Showing posts from July 31, 2025

Detection of #Hemagglutinin #H5 #Influenza A Virus #RNA and Model of Potential Inputs in an Urban #California #Sewershed

Abstract In 2024, highly pathogenic avian influenza A H5N1 caused outbreaks in wild birds, poultry, cows, and other mammals in the United States with 61 human cases also reported by the CDC. Detection of influenza A H5 RNA in wastewater has been previously reported in sewersheds in Texas and North Carolina with nearby impacted dairy herds following the emergence of H5N1 in dairy cows. Here, we conduct retrospective testing of total influenza A and H5 hemagglutinin genes in wastewater as well as present and apply new assays for detection of H1 and H3 genes across a respiratory virus season in an urban California sewershed from September 2023 to May 2024. Total influenza A, H1, and H3 were regularly detected, while H5 was first detected in March . We developed a model that uses Monte Carlo simulations and previously published parameters to estimate the numbers of infected people, poultry, wild birds, or liters of H5-contaminated milk required to result in measured H5 concentrations in wa...

#Genetic characterization of the #marmot gut #virome in high-altitude #Qinghai Province and identification of novel #viruses with zoonotic potential

ABSTRACT The high-altitude ecosystems of Qinghai Province, China, harbor unique viral communities shaped by extreme environmental conditions and host adaptations. This study presents a comprehensive genetic characterization of the marmot gut virome , revealing novel viral strains with zoonotic potential . Using viral metagenomics, we analyzed intestinal contents from 70 marmots collected from Chengduo and Maqin counties. Sequencing on the Illumina NovaSeq 6000 platform identified 19 viral genomes belonging to four major families : Adenoviridae, Astroviridae, Parvoviridae, and Picornaviridae , along with four novel circular Rep-encoding single-stranded DNA (CRESS DNA) viruses. Phylogenetic analyses demonstrated close relationships between marmot-derived strains and viruses from humans, bats, and other mammals , highlighting potential cross-species transmission risks . Notably, bat-associated adenoviruses showed closer phylogenetic proximity to human strains, while novel parvoviruses for...

Highly pathogenic avian #influenza: #pandemic #preparedness for a #scenario of high #lethality with no #vaccines

Abstract Highly Pathogenic Avian Influenza (HPAI) viruses, particularly H5N1 and H7N9, have long been considered potential pandemic threats , despite the absence of sustained human-to-human transmission. However, recent outbreaks in previously unaffected regions , such as Antarctica, suggest we may be shifting from theoretical risk to a more imminent threat . These viruses are no longer limited to avian populations. Their increasing appearance in mammals , including dairy cattle and domestic animals , raises the likelihood of viral reassortment and mutations that could trigger a human pandemic. If such a scenario unfolds, the world may face a crisis marked by high transmissibility and lethality, without effective vaccines readily available. Unlike the COVID-19 pandemic, when vaccines were rapidly developed despite inequities in access, the current influenza vaccine production model , largely reliant on slow, egg-based technologies, is insufficient for a fast-moving outbreak. While newe...

#Mpox - Multi-country external #situation #report no. 56 published 31 July 2025 (#WHO, edited)

  {Excerpt} Highlights -- All clades of monkeypox virus (MPXV) continue to circulate in several countries.  - When mpox outbreaks are not rapidly contained and human-to-human transmission is not interrupted, they continue to pose a risk of sustained community transmission .   -- Since the last edition of this report, one new country, the Gambia , has reported an mpox case for the first time.  - Genomic sequencing analysis has identified clade IIb MPXV.  -- Furthermore, Mozambique, has reported cases of mpox due to clade Ib MPXV for the first time.   -- Twenty-one countries in Africa have reported ongoing mpox transmission in the past six weeks.  - Clade IIb MPXV continues to be reported in West Africa, while Central African countries report both clade Ia and clade Ib MPXV, and East African countries report clade Ib MPXV.  -- The recent overall downward trend of confirmed cases across the continent is driven by the decline in cases in Sie...

#Italy, Integrated #WNV & #USUV #Surveillance - Bulletin no. 3, July 31 2025 (IZS Teramo): 57 new human cases reported

{Excerpts} During the epidemiological week comprised between 24 and 30 July 2025, there were fifty-seven new confirmed cases of human infection with West Nile Virus . -- Since the start of the epidemic season, eighty-nine cases have been reported (there were thirty-two cases in the last week report), of which: -- forty were WNND (West Nile Neuroinvasive Disease): - 2 cases in Piedmont, 1 Lombardy, 3 Veneto, 1 Emilia-Romagna, twenty-three Latium, ten Campania); -- two cases of asymptomatic infection were detected among blood donors (one in Veneto and one in Campania); -- forty-six cases of West Nile Fever have been confirmed:  - one in Lombardy, five in Veneto, thirty-five in Latium, four in Campania, one in Sardinia; -- one asymptomatic case is from Campania; -- Among confirmed cases, eight fatalities have been recorded: one in Piedmont, two in Latium and five in Campania. The case-fatality rate among WNND so far is at 20% (during epidemic seasons 2018 it was 20% and in 2024, 14%)....

A Phylogeny-Informed Mathematical #Modeling of #H5N1 #Transmission Dynamics and Effectiveness of #Control Measures

Abstract The highly pathogenic avian influenza (HPAI) subtype H5N1 is a severe viral disease which continues to pose a significant threat to public health and a rigorous understanding of its transmission dynamics across its major pathways is essential for developing effective control strategies . Phylogenetic analysis suggests that H5N1 spillover occurs primarily between wild and domestic birds . However, increasing contact between these species and humans increases the risk of zoonotic transmission . In this work, we develop a mathematical model to examine the transmission dynamics of H5N1 and evaluate the effectiveness of proposed control measures. The model employs a compartmental framework that includes human, domestic, and wild bird populations. We then use this model to estimate the basic reproduction number for each population group and perform a sensitivity analysis to assess the contribution of the parameters to the spread of the disease. Numerical simulations are also conduct...