Spatial risk of Haemaphysalis longicornis borne Dabieshan tick virus (DBTV) in China.

The uncertainty and unknowability of emerging infectious diseases have caused many major public health and security incidents in recent years. As a new tick-borne disease, Dabieshan tick virus (DBTV) necessitate systematic epidemiological and spatial distribution analysis. In this study, tick samples from Liaoning Province were collected and used to evaluate distribution of DBTV in ticks. Outbreak points of DBTV and the records of the vector Haemaphysalis longicornis in China were collected and used to establish a prediction model using niche model combined with environmental factors. We found that H. longicornis and DBTV were widely distributed in Liaoning Province. The risk analysis results showed that the DBTV in the eastern provinces of China has a high risk, and the risk is greatly influenced by elevation, land cover, and meteorological factors. The risk geographical area predicted by the model is significantly larger than the detected positive areas, indicating that the etiological survey is seriously insufficient. This study provided molecular and important epidemiological evidence for etiological ecology of DBTV. The predicted high-risk areas indicated the insufficient monitoring and risk evaluation and the necessity of future monitoring and control work.

Clinical and etiological characteristics of severe hemorrhagic fever caused by coinfection of hantaan orthohantavirus and severe fever with thrombocytopenia syndrome virus.

Severe fever with thrombocytopenia syndrome (SFTS) and hemorrhagic fever with renal syndrome (HFRS) usually have different infection routes, and coinfection is relatively rare. This study examines the clinical and etiological characteristics of coinfection by these two pathogens to provide important references for clinical diagnosis and treatment. Blood samples from 22 clinically diagnosed patients with HFRS were collected for molecular detection of HFRS and common tick and mouse borne diseases. Inoculate the blood of six severe and critically patients into cells to isolate and proliferate potential viruses, and retest the cell culture to determine the pathogen. In addition, complete data were collected from these 22 HFRS and concurrent SFTS patients, and white blood cells (WBCs), platelet (PLT), blood urea nitrogen (BUN), creatinine (Cr) and other data were compared and analyzed. A total of 31 febrile patients, including 22 HFRS patients and 9 SFTS patients, were collected from September 2021 to October 2022. Among these HFRS patients, 11 were severe or critical. Severe and critical HFRS patients were characterized by rodent exposure history, pharyngeal and conjunctival hyperemia, abnormal WBC and PLT counts, and elevated BUN and Cr values. Virus isolation and molecular detection on blood samples from 6 patients showed that three of the six severe patients were positive for hantaan virus (HTNV), and two of the three HTNV positives were also positive for SFTS bunyavirus (SFTSV). The two coinfected patients exhibited different clinical and laboratory characteristics compared to those infected by either virus alone. Coinfection of HTNV and SFTSV leads to severe and complex hemorrhagic fever. Laboratory characteristics, such as the indicators of WBC, PLT, BUN, and Cr, may differ between HFRS and SFTS. These findings have implications and provide references for the diagnosis and treatment of coinfected cases.