ETIDIOH - NEW

Highlights •  Antiviral susceptibility to NA inhibitors and PA inhibitor baloxavir was determined for seasonal and zoonotic influenza viruses circulating globally during 2020–2023. •  Low global frequencies (0.1-0.2%) of seasonal influenza viruses with reduced or highly reduced inhibition by NAI inhibitors were observed as in previous years. •  Low global frequencies of seasonal influenza viruses (∼ 0.1%) with reduced susceptibility to baloxavir were observed, with the rate in Japan elevated (3.3%) in 2022–2023, as has been seen previously. •  For zoonotic viruses, 2.7% contained genetic markers associated with reduced or highly reduced inhibition to NA inhibitors and none contained markers associated with reduced susceptibility for baloxavir. •  For the treatment of influenza , NA inhibitors and baloxavir remain suitable. ABSTRACT Antiviral susceptibility of influenza viruses is monitored by the World Health Organization Global Influenza Surveillance and Respon...

Abstract Background Every year, more than one billion people around the world are infected with influenza , an acute infection of the respiratory tract. Influenza spreads from person to person through air, contaminated hands or objects. Antiviral and immunomodulatory drugs are available for treatment of patients and prophylaxis of exposed persons. Reverse transcription polymerase chain reaction (RT-PCR), nucleic acid amplification tests (NAATs) and rapid tests are available for the diagnosis of influenza.  Objective   The aim of this World Health Organization (WHO) guideline is to provide recommendations for the diagnosis, drug treatment and prophylaxis of influenza. Method This updated guideline has been developed in accordance with standards for trustworthy guidelines. The recommendations are based on systematic reviews on safety and effectiveness. They take into account the magnitude of benefits and harms of treatments, the reliability of the evidence, and the needs of pati...

Abstract During 2023-2024, highly pathogenic avian influenza A(H5N1) viruses from clade 2.3.2.1c caused human infections in Cambodia and from clade 2.3.4.4b caused human infections in the Americas . We assessed the susceptibility of those viruses to approved and investigational antiviral drugs . Except for 2 viruses isolated from Cambodia , all viruses were susceptible to M2 ion channel-blockers in cell culture-based assays. In the neuraminidase inhibition assay , all viruses displayed susceptibility to neuraminidase inhibitor antiviral drugs oseltamivir, zanamivir, peramivir, laninamivir , and AV5080. Oseltamivir was ≈4-fold less potent at inhibiting the neuraminidase activity of clade 2.3.4.4b than clade 2.3.2.1c viruses. All viruses were susceptible to polymerase inhibitors baloxavir and tivoxavir and to polymerase basic 2 inhibitor pimodivir with 50% effective concentrations in low nanomolar ranges. Because drug-resistant viruses can emerge spontaneously or by reassortment, close m...