Comprehensive Laboratory Analysis of a Scrub Typhus and H1N1 Influenza Co-Infection: A Case Report from Hainan, China

作者：Chen S, Wang F, Wu S, Chen Y, Niu Y, Guo Y, Lin D, Cui X, Peng R, Xu Z, Wu B, Liao M, Du Y, Zhang L, Yin F · 发表于：Pathogens (Basel, Switzerland) · 年份：2025 · DOI：10.3390/pathogens14080810 · 被引用次数：26 · 研究领域：Scrub Typhus、Coinfection、Influenza, Human、Influenza A Virus, H1N1 Subtype、Orientia tsutsugamushi、Humans、Female、Aged、China、Antibodies, Bacterial

Co-infection of Orientia tsutsugamushi and influenza A virus complicates diagnosis and treatment in endemic regions because of overlapping clinical features and potential synergistic inflammation. We describe a 68-year-old woman from Hainan, China, who presented with five days of high fever (39.2 °C), nonproductive cough, eschar formation, lymphadenopathy, cytopenias, elevated liver enzymes, and raised inflammatory markers. On the day of admission, influenza A was confirmed by rapid antigen test and Orientia tsutsugamushi IgM/IgG was detected via colloidal-gold immunochromatography, prompting concurrent oseltamivir and doxycycline therapy. Quantitative PCR on day 2 measured an Orientia tsutsugamushi load of 2.85 × 104 copies/mL (Cq 28.86), and targeted next-generation sequencing on day 3 revealed a high H1N1pdm09 viral burden (>1 × 106 copies/mL) with low-level human herpesvirus 1 co-detection. Nested PCR and Sanger sequencing assigned Orientia tsutsugamushi to the Karp_A lineage and influenza A to clade 6B.1A.5a.2a. The patient defervesced by hospital day 2, laboratory indices normalized by day 3, and radiographic abnormalities resolved by day 6. This first documented Orientia tsutsugamushi-influenza A co-infection in China highlights the value of integrating rapid serology, qPCR quantification, nested PCR genotyping, and tNGS for early, precise dual-pathogen identification. Systematic multi-pathogen screening during overlapping transmission seasons is recommended to guide t...