Monitoring Influenza C and D Viruses in Patients With Respiratory Diseases in Japan, January 2018 to March 2023.

BACKGROUND: Influenza viruses can cause zoonotic infections that pose public health risks. Surveillance of influenza A and B viruses is conducted globally; however, information on influenza C and D viruses is limited. Longitudinal monitoring of influenza C virus in humans has been conducted in several countries, but there has been no long-term monitoring of influenza D virus in humans. The public health risks associated with the influenza D virus therefore remain unknown. METHODS: We established a duplex real-time RT-PCR to detect influenza C and D viruses and analyzed respiratory specimens collected from 2144 patients in Japan with respiratory diseases between January 2018 and March 2023. We isolated viruses and conducted hemagglutination inhibition tests to examine antigenicity and focus reduction assays to determine susceptibility to the cap-dependent endonuclease inhibitor baloxavir marboxil. RESULTS: We detected three influenza C viruses belonging to the C/Kanagawa- or C/Sao Paulo-lineages, which recently circulated globally. None of the specimens was positive for the influenza D virus. The C/Yokohama/1/2022 strain, isolated from the specimen with the highest viral RNA load and belonging to the C/Kanagawa-lineage, showed similar antigenicity to the reference C/Kanagawa-lineage strain and was susceptible to baloxavir. CONCLUSIONS: Our duplex real-time RT-PCR is useful for the simultaneous detection of influenza C and D viruses from the same specimen. Adding the influenza D virus to the monitoring of the influenza C virus would help in assessing the public health risks posed by this virus.

Antiviral susceptibility of SARS-CoV-2 and influenza viruses from 3 co-infected pediatric patients.

In Japan, influenza activity was low throughout the COVID-19 pandemic until the 2022-23 season, when the first influenza outbreak occurred since the 2020-21 season. In our influenza surveillance during the COVID-19 pandemic, co-infection with SARS-CoV-2 and influenza virus had not been detected; however, in January 2024, we identified three pediatric outpatients co-infected with these viruses: one with SARS-CoV-2 Omicron EG.5 sublineage HK.3 and influenza A(H3N2) and two with SARS-CoV-2 Omicron BA.2.86 sublineage JN.1.5 and influenza A(H1N1)pdm09. We evaluated the susceptibility of SARS-CoV-2 against RNA-dependent RNA polymerase inhibitors (remdesivir and molnupiravir) and 3C-like protease inhibitors (nirmatrelvir and ensitrelvir), and that of influenza viruses against neuraminidase inhibitors (oseltamivir, peramivir, zanamivir, and laninamivir) and the cap-dependent endonuclease inhibitor baloxavir. All viruses tested were susceptible to these antiviral drugs and did not possess amino acid substitutions associated with reduced antiviral susceptibility. The patients were treated with anti-influenza drugs and did not develop severe symptoms despite the co-infection. Since SARS-CoV-2 and influenza viruses continue to evolve, continuous monitoring of their circulation remains essential to assess public health measures and support clinical management.

Genomic evolutional analysis of surgical resected specimen to assess osimertinib as a first-line therapy in two patients with lung cancer harboring EGFR mutation: Case series.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) is crucial for patients with lung cancer harboring EGFR mutations. However, almost all patients experience disease progression, regardless of their response to the targeted therapy, necessitating the development of additional treatment options. Two patients with lung cancer harboring EGFR-L858R mutations in exon 21 were treated by surgical resection during successful osimertinib treatment. Because the pathological diagnosis was suspected to be pleural metastasis, osimertinib treatment was continued until disease progression. We analyzed the evolution of genomic alterations and the levels of AXL using tumor specimens obtained by repeated biopsies during the course of treatment: initial diagnosis, operation, and disease progression. Genetic alterations detected at the three time points were dramatically changed and showed reductions in numbers, while EGFR-L858R mutations were detected in all samples tested in both patients. Immunohistochemical expression of AXL remained positive from the beginning of analysis to disease progression. Clonal evolution under oncogenesis is related to gradual accumulation of genomic alterations during tumor growth. However, our case series revealed that volume reduction procedures may cause this phenomenon. Therefore, identification of intrinsic drug-resistant cells in tumors may be as important as detection of acquired genetic alterations.