Mpox, a zoonotic disease caused by the mpox virus (MPXV), has seen a significant shift in its epidemiological status since 2022, evolving from an initial local outbreak to a global epidemic. This recent outbreak of MPXV mainly emerged in several European and American countries and subsequently spread to over 100 countries and regions worldwide. The rapid evolution of MPXV, coupled with increased international interactions, has led to a gradual rise in mpox cases in certain regions of Asia, mostly involving MPXV clade II and its branch strains. In contrast, the more pathogenic and clinically severe MPXV clade Ib has been relatively rare, with no reports in China to date. Here, we analyzed the whole gene sequence of imported MPXV clade Ib variant from the first infection case detected in China. Through whole genome sequencing, we successfully obtained a full-length MPXV genome of 195,405 base pairs (bp). Phylogenetic analysis revealed that the genetic sequence of the MPXV in this case was predominantly clustered with MPXV clade Ib sequences previously reported from multiple African and European countries. Compared with the MPXV clade Ib reference strain DQ011155.1, there are 127 nucleotide alterations and 57 amino acid mutations in the MPXV genome of this case. Given that the MPXV clade Ib has started to appear in China, we must pay more attention to the prevention of and control measures for the spread of mpox.

Following the lifting of COVID-19 pandemic control measures, a progressive increase in influenza A virus activity, particularly the H1N1 subtype, has been observed in Jiaxing. This study systematically characterized the genomic evolution of influenza A(H1N1) viruses circulating in Jiaxing, China during the 2023–2024 epidemic seasons through whole-genome sequencing and phylogenetic analysis. Viral RNA was detected by quantitative real-time PCR (qPCR) and 83 influenza A(H1N1) isolates (48 from 2023 and 35 from 2024 surveillance) were selected for whole-genome sequencing. Launch RDP4, MEGA11 and iTOL were used to analyze the homology, molecular evolutionary clusters and resistance sites of influenza A(H1N1) virus. The positivity rates of influenza A(H1N1) virus in Jiaxing were 10.66% in 2023 and 5.09% in 2024, respectively. Compared with vaccine strain A/Wisconsin/67/2022, the influenza A(H1N1) virus in 2023 and 2024 showed high homology, with the nucleotide homology of hemagglutinin gene ranging from 97.9% to 99.2% and that of neuraminidase gene ranging from 98.3% to 99.1%. Among 83 Jiaxing strains, 80 were classified as clade 6B.1A.5a.2a and 3 were assigned to clade 6B.1A.15a.2a.1. These strains were further categorized into subclades C.1 (45), C.1.9(17), C.1.9.3 (18), and D (3). Additionally, an HA/NA reassortant strain (A/ZJNH/SWL1331/2023) was identified in 2023, followed by an oseltamivir-resistant strain (A/ZJPH/SWL1544/2024) carrying the H275Y substitution in 2024. A total of 31 amino acid substitutions were identified in the HA1 segment of Jiaxing influenza A(H1N1) strains, affecting three antigenic sites: Ca (S137P, A139D, A141T/V, R142K, D222G), Cb (L70F, S71F), and Sb (I185S, D187N, S190G), plus an additional Ca1 substitution (K169Q). During 2023–2024, multiple genomic sites of influenza A(H1N1) viruses in Jiaxing have acquired mutations, underscoring the need for enhanced continuous surveillance and prevention of H1N1 influenza.

Molecular diagnostic assays for cholera detection have superior sensitivity to conventional assays and are now being accepted as the new standard method, especially the real-time PCR/RT-PCR. However, limited throughput capacity and long detection duration prevent them from detecting more specimens and more targets in one turnaround time simultaneously. In this study, we utilized nucleic acid extraction-free, direct RT-PCR and high-speed amplification to develop a novel multiplex assay, a quadplex direct one-tube real-time RT-PCR assay, for rapid detection of the serogroup and cholera toxin toxigenicity of Vibrio cholerae targeting the epsM, ctxA, rfb-O1, and rfb-O139 genes. Performance of the multiplex assay was evaluated by comparison with the monoplex real-time PCR assay according to the China Cholera Prevention Manual. Detection data from clinical specimens showed that the new assay had good diagnostic sensitivities for epsM (100%, n = 301), ctxA (100%, n = 125), rfb-O1 (100%, n = 85), and rfb-O139 (97.87%, n = 49). Analysis of the analytical sensitivities with serial dilutions of positive standards showed that the detection limits of the new assay for Vibrio cholerae epsM,ctxA,rfb-O1, and rfb-O139 were up to 200, 590, 115, and 1052 copies per mL lower than the monoplex real-time PCR (910, 345, and 1616 copies/mL respectively, for ctxA,rfb-O1, and rfb-O139). The results indicate that the multiplex assay is a rapid, sensitive, specific, and easy-to-use detection tool for Vibrio cholerae, especially suitable for rapid identification and screening detection of mass specimens.

The rapid evolution of influenza A/H3N2 virus underscores the imperative for ongoing surveillance. In this study, we analyzed 7,872 respiratory samples collected from patients with influenza-like symptoms in Jiaxing, China, between 2019 and 2024, selecting 117 influenza A/H3N2 strains for whole-genome sequencing. Between 2019 and 2024, the influenza A/H3N2 virus in Jiaxing experienced six epidemic peaks, evolving from clades 3 C.2a1b.1a/1b, 3 C.2a1b.2, and 3 C.2b1b.2a.2a.3/3b to clade 3 C.2a1b.2a.2a.3a.1. Compared with the 2019–2021 period, influenza A/H3N2 viruses circulating in Jiaxing during 2022–2024 demonstrated a longer evolutionary distance and increased hemagglutination titers. Additionally, seven novel amino acid substitutions (H156S, Y159N, T160I, S186D, D190N, I192F, N96S) were identified in HA antigenic epitopes of circulating influenza A/H3N2 viruses during 2023–2024. Notably, based on predicted vaccine effectiveness, the 2023–2024 influenza vaccine retained strong protective efficacy. In conclusion, this study characterizes the evolutionary features of influenza A/H3N2 virus in Jiaxing during 2019–2024. These results enhance our understanding of the natural evolution of influenza virus and the emergence of new variants, providing critical insights into influenza vaccine effectiveness.