Yong Lyu

To characterize the duration and determinants of SFTSV-specific antibody persistence following natural infection, informing vaccine development for severe fever with thrombocytopenia syndrome (SFTS). We conducted a retrospective cohort study among 463 convalescent SFTS patients in the Dabie Mountains, a hyperendemic region in China. Using illness onset dates and a single post-infection serum sample per participant, we reconstructed individual follow-up durations and applied Kaplan-Meier survival analysis and Cox proportional hazards models to assess time to seroreversion and its determinants. Seropositivity declined with longer time since illness onset. Age was significantly associated with antibody persistence: individuals aged ≥ 70 years showed the most rapid antibody waning, whereas those aged < 50 years showed longer detectable IgG persistence. Geographic location was also associated with durability. Compared with patients from Huoqiu County (predominantly plain terrain), those from mountainous/hilly areas had lower risks of antibody loss-Yu'an District (HR 0.060 [95%CI 0.014-0.262]) Jinzhai County(HR 0.358 [95%CI 0.202-0.635]) and Huoshan County(HR 0.390 [95%CI 0.195-0.780]). SFTSV-specific IgG antibodies persist for several years in most survivors, with longer duration observed in younger individuals and residents of highland endemic foci. These findings suggest that of age and geography in shaping post-infection immunity and support tailored vaccination and surveillance strategies in heterogeneous transmission settings. Not applicable.

Background: Whether moderate‐to‐vigorous physical activity (MVPA) mitigates the detrimental association between sedentary behavior and dyslipidemia remains unclear, as does the link between MVPA and gut microbiota. Methods: We prospectively evaluated the joint association between MVPA and sedentary time on dyslipidemia risk in a cohort of 2942 Chinese adults, where PA was measured by a validated self‐reported questionnaire. In a subcohort ( n =754), 1‐year gut microbial changes associated with MVPA were assessed via fecal samples collected twice at 1‐year intervals for 16S ribosomal RNA sequencing, with PA intensively assessed by 4 quarterly 3‐day PA diaries (2 weekdays and 1 weekend day) during the year. Results: From 2020 to 2025, 306 dyslipidemia were newly diagnosed. Prolonged sedentary hours increased dyslipidemia risk by 63% (highest versus lowest tertile: adjusted hazard ratio [HR], 1.63 [95% CI, 1.19–2.22], P _trend =0.002). Compared with participants with long sedentary hours and low MVPA levels (ie, long‐low group), HRs of dyslipidemia for those in short‐high, short‐low, and long‐high groups were 0.70 (95% CI, 0.50–0.98), 0.99 (95% CI, 0.71–1.37), and 0.83 (95% CI, 0.60–1.16), respectively. The microbial α‐diversity declined in the low MVPA group ( P =0.024), and β‐diversity shifted in both low/high MVPA groups (all P ≤0.005). We identified 7 MVPA‐associated and 13 sedentary time‐associated genera (all P _{FALSE DISCOVERY RATE} Eggerthella and Desulfovibrio correlated positively with MVPA levels but inversely with sedentary time, and Desulfovibrio was inversely associated with dyslipidemia (odds ratio, 0.78 [95% CI, 0.606–0.997]). Conclusions: MVPA attenuates the positive association between sedentary time and dyslipidemia risk and modulates gut microbial diversity and richness, suggesting microbiota‐mediated pathways for dyslipidemia prevention.

Tick-borne rickettsial disease (TBRD) is a perilous acute infection that often eludes diagnosis in its early stages. The triad of knowledge, attitudes, and practices (KAPs) among medical professionals is key to reducing missed diagnosis rates. Therefore, a meticulous evaluation of KAPs is imperative. This study aimed to delve into the understanding of TBRD and explore the beliefs and practices related to personal prevention methods among individuals in Lu’an, a hotspot for TBRD. During the summer months of 2023, convenience sampling was employed by circulating a confidential questionnaire to 1,206 participants in the endemic regions of China. This questionnaire painted a comprehensive picture of the participants’ sociodemographic profiles and their KAPs levels vis-à-vis TBRD. The findings revealed that participants scored a mere 55.78% in knowledge, while their attitudes and practices garnered impressive scores of 90.09% and 90.83%, respectively. Upon further analysis using multiple linear regression, several intriguing patterns emerged. Male participants, employed in the Infectious Disease Department, held vice-senior or higher titles, or had prior medical training demonstrated superior knowledge scores. On the other hand, medical personnel who were younger than 30, possessed graduate degrees or higher qualifications, and had training excelled in attitudes and practices. Notably, when employing the Boston Consulting Group (BCG) matrix, a significant distribution of medical personnel was observed across the four quadrants. Specifically, 37.43%, 13.19%, 19.61%, and 29.77% fell into the first, second, third, and fourth quadrants. This survey underscores the commendable attitudes and practices of medical staff towards TBRD in endemic regions of China. However, their knowledge level remains wanting and demands urgent improvement.

Objective Logistic regression model combined with receiver operating characteristic curve(ROC) was used to construct a clinical differential score model between spotted fever (SF) and severe fever with thrombocytopenia syndrome (SFTS). To provide a reference for clinical preliminary identification. Methods Patients with SF and SFTS from May 2017 to may 2021 in Lu'an secondary hospitals and above were selected, and all patients were confirmed by laboratory. The basic data, epidemic history, clinical data and laboratory data of patients with the two diseases were collected for comparative analysis, logistic regression analysis was conducted to find out the independent influencing factors, and Logistic regression model and scoring system were established. At the same time, the Roc curve was drawn to determine the optimal cut-off value and the area under the ROC curve. Results Multifactorial logistic regression analysis showed that the presence of rash (OR=153.294,,95%CI:7.800-3012.492), elevated C-reactive protein (>10 mg/L) (OR=47.095,95%CI: 3.161-701.735), and normal platelets (>100×10⁹/L ) (OR=37.727, 95% CI: 2.492-571.185) were risk factors for the development of spotted fever, and a score of 1 was assigned to each of these three factors, resulting in a total score of 3 for this scoring system. When the cutoff value was 1, the area under the ROC curve (AUC) of the modeling group was 0.985, the sensitivity was 90.7%, the specificity was 98.8%, the P value in the Hosmer-Lemeshow test was 0.881, and the Kappa value in the consistency test was 0.910. The AUC of validation group was 0.985, the sensitivity was 94.7%, the specificity was 97.1%, the P value of Hosmer-Lemeshow test was 0.977, and the Kappa value of consistency test was 0.918. Conclusion The differential scoring system constructed based on the presence of rash, elevated C-reactive protein, and normal platelets can provide a reference basis for the differentiation of SF from SFTS and has some application value.

Real-world evidence on the effectiveness of COVID-19 vaccines marketed in China against the Omicron BA.2.2 variant remains scarce. A case–control study was conducted to estimate the vaccine effectiveness (VE) of COVID-19 vaccines marketed in China (inactivated vaccines, an Ad5-nCoV vaccine, and a recombinant protein vaccine). There were 414 cases infected with SARS-CoV-2 and 828 close contacts whose test results were consecutively negative as controls during the outbreak of the Omicron variant in Lu’an City, Anhui Province, China, in April 2022. The overall adjusted VE against Omicron BA.2.2 variant infection in the vaccinated group with any COVID-19 vaccine was 35.0% (95% CI: −9.1–61.3%), whereas the adjusted VE for booster vaccination was 51.6% (95% CI: 15.2–72.4%). Subgroup analysis showed that the overall adjusted VE of the Ad5-nCoV vaccine (65.8%, 95% CI: 12.8–86.6%) during the outbreak while any dose of inactivated vaccines and recombinant protein vaccine offered no protection. The adjusted VE of three-dose inactivated vaccines was 48.0% (95% CI: 8.0–70.6%), and the two-dose Ad5-nCoV vaccine was 62.9% (95% CI: 1.8–86%). There is no protection from a three-dose recombinant protein vaccine. COVID-19 vaccines offered 46.8% (95% CI: 9.5–68.7%) protection from infection within six months. There were statistically significant differences between the VEs of heterologous booster (VE = 76.4%, 95% CI: 14.3–93.5%) and homologous booster vaccination (VE = 51.8%, 95% CI: 9.6–74.3%) (P = .036). Booster vaccination of COVID-19 vaccines offered more protection than full vaccination. A booster vaccination campaign for a booster dose after three doses of a recombinant protein vaccine must be urgently conducted.

Background. Studies have shown that discharged Coronavirus disease 2019 (COVID-19) patients have retested positive for SARS-CoV-2 during a follow-up RT-PCR test. We sought to assess the results of continued nucleic acid testing for SARS-CoV-2 patients in COVID-19 patients after they were discharged in Lu'an, China. Methods. We conducted RT-PCR tests on sputum, throat swabs, fecal or anal swabs, and urine samples collected from 67 COVID-19 patients following discharge. Samples were collected on the 7th and 14th days following discharge. Patients testing positive on the 7th or 14th day were retested after 24 hours until they tested negative twice. Results. Seventeen (17/67, 25.4%) discharged COVID-19 patients had a positive RT-PCR retest for SARS-CoV-2. Among them, 14 (82.4%) were sputum positive, five (29.4%) were throat swab positive, seven (41.2%) were fecal or anal swab positive, one (5.9%) was urine sample positive, five (29.4%) were both sputum and throat swab positive, four (23.5%) were both sputum and fecal test positive, and one (5.9%) was positive of all four specimens. The shortest period of time between discharge and the last positive test was 7 days, the longest was 48 days, and the median was 16 days. The proportion of positive fecal or anal swab tests increased from the third week. The median Cq cut-off values after onset were 26.7 after the first week, 37.7 the second to sixth week, and 40 after the sixth week. There were no significant differences between the RT-PCR retest positive group and the unrecovered positive group. Conclusions. There was a high proportion of patients who retested positive for COVID-19. Discharge criteria have remained fairly consistent so we encourage regions affected by COVID-19 to appropriately amend their current criteria.

Knowledge of the clinical progress of severe fever with thrombocytopenia syndrome (SFTS) and the associated predictors of mortality is important for providing appropriate treatment in severe cases. A multihospital retrospective study was conducted in three SFTS-endemic cities, in 2018. Of the 208 SFTS-confirmed cases, there were 189 survivors and 19 deaths. The median age was 64 years; 104 (50.0%) patients were men, and 188 (90.4%) were farmers. Furthermore, 203 (97.6%) patients reported fever and 70 (33.7%) reported fatigue. Most fatal cases had complications including multiple-organ failure, central nervous syndrome (CNS) abnormalities, and disseminated intravascular coagulation. During the fever phase, alanine transaminase, aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine, D-dimer, glucose, hydroxybutyrate dehydrogenase, lactate dehydrogenase (LDH), procalcitonin, prothrombin time, and uric acid levels were higher in fatal than in nonfatal cases (P < 0.05). Creatine kinase (CK), CK-MB (CKMB), AST, and LDH levels were significantly lower in nonfatal than in fatal cases (P < 0.05). Central nervous syndrome abnormalities (odds ratio [OR] = 20.9, 95% CI: 4.3, 100), body temperature ≥ 38.5°C (OR = 23.2, 95% CI: 3.4, 158), BUN levels ≥ 6.4 mmol/L (OR = 9.9, 95% CI: 2.2, 44), CKMB levels ≥ 100 U/L (OR = 33.2, 95% CI: 5.8, 192), and LDH levels ≥ 1,000 U/L (OR = 8.3, 95% CI: 1.9, 37) were predictors of mortality. Our findings reveal that the presence of specific complications and laboratory parameters may serve as predictors of mortality and aid in early identification of severe SFTS cases in clinical practice.

BACKGROUND:This population study aimed to investigate the demographic and clinical characteristics and outcome of cases of coronavirus disease 2019 in Lu’an City, China between January 22, 2020 and February 18, 2020 identified from the China Information System for Disease Control and Prevention (CISDCP). MATERIAL AND METHODS:Laboratory-confirmed cases of COVID-19 reported in the CISDCP were included in this study. The distribution of cases, exposure history, clustered epidemic situation, and clinical manifestations, disease severity, and key time nodes were analyzed. Once the throat swab or sputum sample was positive for SARS-CoV-2 by real-time reverse transcriptase-polymerase chain reaction testing as confirmed cases. RESULTS:There were 69 cases of COVID-19 that were confirmed between January 22 and February 18, 2020 reported. The onset time was concentrated on January 25, 2020 solstice to February 6, 2020 (71.0%), and the reporting dates were concentrated on January 31, 2020 and February 9, 2020 (69.6%). Nineteen cases (27.5%) had a history of sojourn in Hubei Province, and none of the cases reported after February 6, 2020 had a history of exposure in Hubei Province. There were 14 cluster outbreaks, and human-to-human transmission was the most common (78.6%). The most common symptoms were fever (56.5%), cough (37.7%), and self-conscious discomfort (14.5%). Besides, there were 9 severe cases (13.0%). CONCLUSIONS:The epidemic prevention and control in Lu’an City has achieved phased results. Yet, new strict control measures need to be implemented to prevent a further outbreak, especially for those who will return to Lu’an City.

Hubei province in China has had the most confirmed coronavirus disease 2019 (COVID-19) cases and has reported sustained transmission of the disease. Although Lu'an city is adjacent to Hubei province, its community transmission was blocked at the early stage, and the impact of the epidemic was limited. Therefore, we summarised the overall characteristics of the entire epidemic course in Lu'an to help cities with a few imported cases better contain the epidemic. A total of 69 confirmed COVID-19 cases and 11 asymptomatic carriers were identified in Lu'an during the epidemic from 12 January to 21 February 2020. Fifty-two (65.0%) cases were male, and the median age was 40 years. On admission, 56.5% of cases had a fever as the initial symptom, and pneumonia was present in 89.9% of cases. The mean serial interval and the mean duration of hospitalisation were 6.5 days (95% CI: 4.8–8.2) and 18.2 days (95% CI: 16.8–19.5), respectively. A total of 16 clusters involving 60 cases (17 first-generation cases and 43 secondary cases) were reported during the epidemic. We observed that only 18.9% (7/37) index cases resulted in community transmission during the epidemic in Lu'an, indicating that the scale of the epidemic was limited to a low level in Lu'an city. An asymptomatic carrier caused the largest cluster, involving 13 cases. Spread of COVID-19 by asymptomatic carriers represents an enormous challenge for countries responding to the pandemic.

Severe fever with thrombocytopenia syndrome (SFTS) is a severe viral disease caused by SFTSV. It is important to estimate the rate of missed SFTS diagnosis and to further understand the actual incidence in high endemic areas in China. This study was conducted in two high SFTS endemic provinces in 2015. Patients hospitalized in 2014 or within 1 year before investigation were selected after considering their clinical manifestations, specifically, fever, platelet, and white blood cell. During retrospective investigation, sera were collected to detect SFTSV antibodies to assess SFTSV infection. To further understand SFTSV infection, acute phase sera were detected; SFTSV infection rate among a healthy population was also investigated to determine the basic infection level. In total, 246 hospitalized cases were included, including 83 cases (33.7%) with fever, thrombocytopenia and leukopenia, 38 cases (15.4%) with fever and thrombocytopenia but without leukopenia, and 125 cases (50.8%) without fever but with thrombocytopenia and leukopenia. In total, 13 patients (5.3%) were SFTSV IgM antibody-positive, 48 (19.5%) were IgG-positive. Of the 13 IgM-positive cases, 11 (84.6%) were IgG-positive (9 with titres ≥1:400). Seropositive rates of antibodies were high (8.4% for IgM and 30.1% for IgG) in patients with fever, thrombocytopenia and leukopenia. Furthermore, among IgG-positive cases in this group, 76% (19/25) of patients’ IgG antibody titres were ≥1:400. Additionally, 28 of 246 cases were initially diagnosed with suspected SFTS and were then excluded, and 218 patients were never diagnosed with SFTS; the seropositive rates of IgM and IgG in these two groups were 25% and 67.9% and 2.8% and 13.3%, respectively. These rates were 64.3% and 21.4% in 14 sera collected during acute phase of the 28 cases mentioned above. Seropositive rate of SFTSV IgG was only 1.3% in the patient-matched healthy group, and no IgM antibody was detected. A preliminary estimate of 8.3% of SFTS cases were missed in SFTS high endemic provinces. The actual SFTS incidence was underestimated. Effective measures such as adding a new SFTS case category - “SFTS clinical diagnosis cases” or using serological detection methods during acute phase should be considered to avoid missed diagnoses.