Source: Emerging Infectious Diseases Journal, https://wwwnc.cdc.gov/eid/article/30/11/24-0892_article

Abstract
Since 2013, a total of 167 human infections with swine-origin (variant) influenza A viruses of A(H1N1)v, A(H1N2)v, and A(H3N2)v subtypes have been reported in the United States. Analysis of 147 genome sequences revealed that nearly all had S31N substitution, an M2 channel blocker-resistance marker, whereas neuraminidase inhibitor–resistance markers were not found. Two viruses had a polymerase acidic substitution (I38M or E199G) associated with decreased susceptibility to baloxavir, an inhibitor of viral cap-dependent endonuclease (CEN). Using phenotypic assays, we established subtype-specific susceptibility baselines for neuraminidase and CEN inhibitors. When compared with either baseline or CEN-sequence–matched controls, only the I38M substitution decreased baloxavir susceptibility, by 27-fold. Human monoclonal antibodies FI6v3 and CR9114 targeting the hemagglutinin’s stem showed variable (0.03 to >10 µg/mL) neutralizing activity toward variant viruses, even within the same clade. Methodology and interpretation of laboratory data described in this study provide information for risk assessment and decision-making on therapeutic control measures.

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https://etidioh.wordpress.com/2024/10/09/antiviral-susceptibility-of-swine-origin-influenza-a-viruses-isolated-from-humans-usa/

#abstract #antivirals #baloxavir #drugsResistance #h1n1v #h1n2v #h3n2v #influenzaA #oseltamivir #peramivir #research

#USA, Two #human #infections with novel #influenza A viruses were reported to CDC this week, #CDC: https://www.cdc.gov/flu/weekly/index.htm

One infection with an influenza #H1N1v virus was reported by #Ohio, one infection with an influenza #H1N2v was reported by #Pennsylvania. Both patients were briefly hospitalized due to underlying medical conditions and have since recovered. Exposure to swine before onset.

#Epidemiological #inference at threshold of #data availability: an #influenza #H1N2v #spillover event in #UK, J Roy Soc Interf.: https://royalsocietypublishing.org/doi/10.1098/rsif.2024.0168

From limited data available, we generate historical estimates of probability that #outbreak had died out in days following detection of the 1rst case. Our method suggests that outbreak could have been said to be over with 95% certainty between 19 & 29 days after 1rst case was detected, depending upon probability of a case being detected.

#Influenza at #human - #animal interface - #Summary and #risk #assessment, from 8 June to 19 July 2024, #WHO: https://cdn.who.int/media/docs/default-source/influenza/human-animal-interface-risk-assessments/influenza-at-the-human-animal-interface-summary-and-assessment--from-8-june-to-19-july-2024.pdf?sfvrsn=3ebd42dc_3&download=true

New human cases: From 8 June to 19 July 2024, the detection of influenza A(#H5) virus in four humans, #H5N1 in 3 humans, #H5N6 in 1 human, and #H9N2 in 1 human were reported officially. Additionally, the detection of H1N2 variant #H1N2v virus in 2 humans was reported.

#USA reported two new #human #infections with #Influenza A variant virus #H1N2v, CDC: https://www.cdc.gov/flu/weekly/index.htm

Two human infections with a novel influenza A virus were reported by the #Pennsylvania Department of Health. The patients, who are close #contacts, were both infected with influenza A(H1N2) variant (A(H1N2)v) viruses. Both patients are ≥18 years of age and sought healthcare during the week ending June 22, 2024 (Week 25). One of the patients was hospitalized, and one was not.