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Showing posts from January 29, 2025

#Zika virus disease - #India

Situation at a glance Between 1 January and 31 December 2024, a cumulative total of 151 Zika virus disease (ZVD) cases were reported from three states in India ( Gujarat, Karnataka, and Maharashtra states). Maharashtra State reported a cumulative total of 140 ZVD cases through the Integrated Disease Surveillance Programme (IDSP). Additionally, Karnataka and Gujarat states reported ten and one cases , respectively, in 2024. As of 31 December 2024, no cases of microcephaly and/or Guillain-Barre syndrome (GBS) associated with this outbreak have been reported. Zika virus (ZIKV) is transmitted to humans by the bite of an infected Aedes mosquito . Zika virus is also transmitted from mother to fetus during pregnancy, as well as through sexual contact, transfusion of blood and blood products, and possibly through organ transplantation. There is no specific treatment available for Zika virus infection or disease. Description of the situation Between 1 January and 31 December 2024, a cumulative ...

Dispersal of #influenza virus #populations within the respiratory tract shapes their evolutionary #potential

Abstract Viral infections are characterized by dispersal from an initial site to secondary locations within the host. How the resultant spatial heterogeneity shapes within-host genetic diversity and viral evolutionary pathways is poorly understood. Here, we show that virus dispersal within and between the nasal cavity and trachea maintains diversity and is therefore conducive to adaptive evolution , whereas dispersal to the lungs gives rise to population heterogeneity . We infected ferrets either intranasally or by aerosol with a barcoded influenza A/California/07/2009 (H1N1) virus . At 1, 2, or 4 days postinfection, dispersal was assessed by collecting 52 samples from throughout the respiratory tract of each animal. Irrespective of inoculation route, barcode compositions across the nasal turbinates and trachea were similar and highly diverse, revealing little constraint on the establishment of infection in the nasal cavity and descent through the trachea. Conversely, infection of the ...

#Strength and durability of indirect #protection against #SARS-CoV-2 infection through #vaccine and infection-acquired #immunity

Abstract Early investigation revealed a reduced risk of SARS-CoV-2 infection among social contacts of COVID-19 vaccinated individuals, referred to as indirect protection. However, indirect protection from SARS-CoV-2 infection-acquired immunity and its comparative strength and durability to vaccine-derived indirect protection in the current epidemiologic context of high levels of vaccination, prior infection, and novel variants are not well characterized. Here, we show that both vaccine-derived and infection-acquired immunity independently yield indirect protection to close social contacts with key differences in their strength and waning. Analyzing anonymized SARS-CoV-2 surveillance data from 9,625 residents in California state prisons from December 2021 to December 2022, we find that vaccine-derived indirect protection against Omicron SARS-CoV-2 infection is strongest within three months of COVID-19 vaccination [30% (95% confidence interval: 20–38%)] with subsequent modest protection....

A comprehensive #review of current #insights into the #virulence factors of #SARS-CoV-2

ABSTRACT The evolution of SARS-CoV-2 pathogenicity has been a major focus of attention. However, the determinants of pathogenicity are still unclear. Various hypotheses have attempted to elucidate the mechanisms underlying the evolution of viral pathogenicity , but a definitive conclusion has yet to be reached. Here, we review the potential impact of all proteins in SARS-CoV-2 on the viral pathogenic process and analyze the effects of their mutations on pathogenicity evolution. We aim to summarize which virus-encoded proteins are crucial in influencing viral pathogenicity, defined as disease severity following infection. Mutations in these key proteins, which are the virulence factors in SARS-CoV-2, may be the driving forces behind the evolution of viral pathogenicity. Mutations in the S protein can impact viral entry and fusogenicity . Mutations in proteins such as NSP2, NSP5, NSP14, and ORF7a can alter the virus’s ability to suppress host protein synthesis and innate immunity . Mutat...

#Lithuania - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

The State Food and Veterinary Service of the Republic of Lithuania would like to inform you about an outbreak of high pathogenicity avian influenza (HPAI) on a laying hens establishment in total 9 aviaries, 246,387 in total. On the same day then suspicion was received, officially appointed veterinarians visited the farm, samples of dead hens were taken monitoring for Avian influenza, and Newcastle disease and sent to the National Institute for Food and Veterinary Risk Assessment (National Reference Laboratory) for avian influenza testing. Temporary restrictions were imposed on the farm immediately, pending laboratory results. Highly pathogenic avian influenza was confirmed in all samples and the H5N1 subtype was identified. {Farm is located in Klaipedos Region.} Source: WOAH,  https://wahis.woah.org/#/in-review/6220 _____

The #Swiss national #program for #surveillance of #influenza A viruses in #pigs and #humans: genetic variability and zoonotic transmissions from 2010 – 2022

Abstract Influenza A viruses (IAV) are likely candidates for pandemics . This report summarizes the results of the Swiss national program for surveillance of influenza viruses in pigs and transmissions to humans between 2010 and 2022. Challenges and optimization options in the program are discussed. Nasal swabs or lung tissue samples from pigs with influenza-like signs (e.g. fever, cough) were screened by real-time RT-PCR for swine influenza virus (SIV) genomes, including that of the 2009 pandemic strain A(H1N1)pdm09; positive samples were subtyped for H1, N1, H3 and N2 by RT-PCR and Sanger sequencing. In parallel, humans with influenza-like symptoms and recent contact to diseased pigs were asked to self-sample themselves with a nasal swab. Human swabs were tested for IAV and positive swabs further subtyped to identify potential cross-species transmission between swine and humans. In the pigs, SIV was detected in 375 of 674 farm visits . H1N1 is the only subtype detected in Swiss pigs ...

A mathematical #model of #H5N1 #influenza #transmission in #US dairy #cattle.

Abstract We present a stochastic metapopulation transmission model that simulates the spread of H5N1 avian influenza through individual dairy cows in 35,974 dairy herds in the continental United States . Transmission is enabled through the movement of cattle between herds , as indicated from Interstate Certificates of Veterinary Inspection (ICVI) data. We estimate the rates of under-reporting by state and present the anticipated rates of positivity for cattle tested at the point of exportation over time. We investigate the likely impact of intervention methods to date on the underlying epidemiological dynamics, demonstrating that current interventions have had insufficient impact , preventing only a mean 175.2 reported outbreaks. Our model predicts that the majority of the disease burden is, as of January 2025, concentrated within West Coast states , due to the network of cattle movements and distribution of the respective dairy populations . We quantify the extent of uncertainty in th...