ObjectiveTo analyze the epidemiological characteristics of brucellosis in China and the surveillance results from the sentinel sites, in order to provide a basis for formulating precise prevention and control strategies for this infection. Methods Data on brucellosis cases and public health emergencies from 2021 to 2025 were retrieved from the Chinese Disease Prevention and Control Information System. Additionally, serological screening data of brucellosis in key populations and epidemic monitoring data of livestock were collected. The epidemiological characteristics and monitoring results of brucellosis across the country were described and analyzed. Results A total of 324 725 cases of brucellosis were reported from 2021 to 2025. The number of cases and incidence rate in 2023 were the highest (70 439 cases, 5.00/100 000). Brucellosis was mainly reported from March to August (214 062 cases, accounting for 65.92%). The cases were mainly concentrated in Inner Mongolia (83 503 cases), Xinjiang (34 770 cases), and Gansu (25 359 cases), accounting for 44.23% of the total reported cases. The affected population was dominated by male (229 378 cases, 70.64%), and majority of the cases were involved in population aged 50-59 years (104 429 cases, 32.16%). The occupation was mainly associated with farmers and herders (273 211 cases, 84.14%). A total of 328 brucellosis-related public health emergencies were reported, which involved 963 cases, with most events reported in Shandong Province (123 events). From 2021 to 2025, a total of 303 218 key populations were monitored at national-level surveillance sites, among whom 13 180 were tested seropositive, with a positive rate of 4.35%. In total, 13 273 730 sheep were quarantined, which identified 15 645 seropositive cases (positive rate: 0.12%). Similarly, 2 448 935 cattle underwent quarantine, among which 9 680 were seropositive (positive rate: 0.40%). A total of 20 441 samples were cultured for etiological surveillance of acute?phase patients, from which 1 419 strains were isolated, the predominant species was sheep strain type 3 (343 strains, 24.17%). Conclusion The national brucellosis epidemic remains severe, characterized by north-south divergence as well as occupational and seasonal clustering. It is necessary to deepen cross-sectoral joint prevention and control, implement differentiated prevention and control strategies for the north and south regions, carry out seasonal precise control, and strengthen livestock-related surveillance and laboratory testing capacity building.

ObjectiveTo analyze the epidemiological characteristics of public health emergencies associated with brucellosis in China for scientific evidence in accurate identification of the risk of such events, early detection and timely implementation of effective measures for prevention of the emergency. Methods Descriptive epidemiological methods were used to analyze the temporal, regional, and population distribution characteristics, as well as the locations and causes of brucellosis-related public health emergencies reported in the National Public Health Emergency Management Information System from 2015 to 2025. Results From 2015 to 2025, a total of 723 brucellosis-related public health emergencies were reported nationwide, which were primarily unclassified events (601 events, 83.13%), including 2 507 cases cumulatively. No death was reported. Brucellosis outbreaks were reported every year, peaking in 2021 (102 events). Brucellosis incidents occurred in each month, mainly concentrated from March to August (567 events, 78.42%). A total of 26 provinces across the country reported brucellosis outbreaks. The provinces with the largest number of incidents were Shandong (250 events, 34.58%), Chongqing (76 events, 10.51%), and Guizhou (63 events, 8.71%). The cases from incidents were mainly males (1 531 cases, 61.07%), and the high-risk age group was 30-69 years old (1 861 cases, 74.23%). The majority of cases were farmers (1 560 cases, 62.23%). Households and rural villages were the primary settings of outbreaks (548 events, 75.80%), with animal-mediated transmission and contact transmission being the main causes (620 events, 85.75%). Conclusion The frequency of brucellosis-related public health emergencies across the country remained relatively higher, with the geographical scope further expanding. It is essential to further strengthen joint prevention and control efforts, effectively manage infection sources and interrupt potential transmission routes, as well as safeguard public health and ensure the healthy development of the livestock industry.

ObjectiveTo characterize the epidemiological patterns and temporal trends of human brucellosis in Inner Mongolia Autonomous Region for evidence for developing corresponding prevention and control strategies. Methods Individual case data of human brucellosis reported in Inner Mongolia from 2015 to 2025 were retrieved from the Chinese Disease Control and Prevention Information System. Descriptive epidemiological methods were used to analyze the characteristics of temporal, regional and population distribution. The SaTScan 9.4 software was applied for spatiotemporal scan statistics, and Joinpoint regression was used to assess temporal trends. Results From 2015 to 2025, a total of 150 092 human brucellosis cases were reported in Inner Mongolia Autonomous Region, with an average annual reported incidence of 55.48/100 000. No deaths occurred. Joinpoint regression analysis revealed an overall upward trend in the reported incidence of human brucellosis in Inner Mongolia from 2015 to 2025 (AAPC=8.35%, t=3.79, P<0.05), during which the trend from 2015 to 2017 was not statistically significant (APC=1.80%, t=0.40, P>0.05), yet a significant increase was observed from 2017 to 2021 (APC=31.50%, t=13.90, P<0.05), and a significant decrease occurred from 2021 to 2025 (APC=-10.90%, t=-5.65, P<0.05). The peak incidence period was from April to August, accounting for 52.24% (78 410/150 092) of all cases. The number of reported cases was 102 731 for males and 47 361 for females, with a male-to-female ratio of 2.17∶1. The majority of cases were seen in the population aged 30-69 years (88.17%, 132 338/150 092). Farmers constituted the predominant occupation (77.87%, 116 884/150 092), followed by herders (9.56%, 14 354/150 092). The average annual reported incidence in eastern Inner Mongolia (66.01/100 000) was higher than that in western regions (43.53/100 000). Spatiotemporal clustering analysis identified five high-risk clusters, involving 32 banners/counties/districts. The median interval from symptom onset to diagnosis was 13.42 (4.38, 31.71) days, showing an overall downward trend (AAPC=-7.31%, t=-3.49, P<0.05). The proportion of cases with an interval ≤15 days showed an overall upward trend (AAPC=7.45%, t=3.54, P<0.05). Conclusion The incidence of human brucellosis in Inner Mongolia Autonomous Region shows an overall upward trend, for which our recommendation is to strengthen the inter-departmental joint prevention and control mechanisms as well as take comprehensive prevention and control measures to further contain the epidemic.

ObjectiveTo analyze the incidence and diagnostic delay of human brucellosis in Chongqing area to provide a scientific basis for optimizing prevention and control strategies. Methods The case data on human brucellosis in Chongqing City from 2011 to 2025 were obtained from the Chinese Disease Prevention and Control Information System. Joinpoint regression analysis was conducted to analyze the trend of reported incidence and diagnostic delay rate of brucellosis. ArcGIS hotspot analysis tool was used for spatial hotspot analysis. Results From 2011 to 2025, a total of 766 cases of brucellosis were reported in Chongqing City, with an average annual incidence rate of 0.17 per 100 000 population. The diagnostic delay rate was 61.23% (469/766), and the median diagnostic delay was 21 (8, 61) days. Joinpoint regression analysis showed that the reported incidence rate of brucellosis in Chongqing exhibited a fluctuating upward trend from 2011 to 2025 (AAPC=43.81%, t=4.35, P<0.001). The diagnostic delay rate presented a fluctuating downward trend (AAPC=-4.47%, t=-3.70, P<0.001). Spatial analysis revealed that the cases were mostly reported in the Three Gorges Reservoir area of northeastern Chongqing (222 cases, 28.98%) and the western Chongqing (218 cases, 28.46%). The diagnostic delay rate was relatively higher in the Three Gorges Reservoir area of northeastern Chongqing (64.41%, 143/222) and the Wuling mountainous area of southeastern Chongqing (63.36%, 83/131). The hotspots of reported incidence shifted from Pengshui Miao and Tujia Autonomous County and Wulong District to Wushan County and Tongnan District by 2025, while no significant spatial clustering of diagnostic delay rate was observed. The cases were chiefly reported in males (546 cases, 71.28%), population aged 45-59 years (383 cases, 50.00%), farmers and herdsmen (459 cases, 59.92%), and residents living in townships (547 cases, 71.41%). The diagnostic delay rate was the highest in males (62.45%), the age group ≤14 years (85.71%), township residents (61.61%), and farmers and herdsmen (60.57%). A relatively large number of cases were reported from tertiary hospitals (560 cases, 73.11%). Conclusion In the past years, the reported incidence rate of brucellosis in Chongqing City has shown a fluctuating upward trend, and the diagnostic delay rate has been improved, yet primary healthcare institutions lack the capacity to confirm the diagnosis. These findings suggest that training for the primary healthcare providers should be strengthened to improve their ability to identify and differentiate brucellosis at an early stage.

ObjectiveTo analyze the epidemiological characteristics of human brucellosis in the Xinjiang Production and Construction Corps (XPCC) for evidence for local prevention and control of this infection. Methods The data of reported cases of human brucellosis in the XPCC from 2011 to 2025 were obtained through the Chinese Disease Prevention and Control Information System, and analyzed using descriptive epidemiology for the characteristics of temporal, regional and population distribution. Joinpoint regression analysis was performed to analyze the temporal trend in incidence, and both seasonal index and circular distribution methods were applied to analyze the seasonal prevalence characteristics. Results A total of 8 867 brucellosis cases were reported in the XPCC from 2011 to 2025, with an average annual reported incidence of 19.27 per 100 000 population. Joinpoint regression analysis showed that the overall reported incidence of human brucellosis in the XPCC presented an upward trend from 2011 to 2025 (AAPC=9.78%, 95%CI: 6.02% to 16.00%, P<0.001), during which a rapid increase from 2011 to 2014 (APC=61.33%, 95%CI: 27.71% to 151.71%, P<0.001), a decline from 2014 to 2019 (APC=-14.86%, 95%CI: -30.01% to -6.00%, P<0.001), and a rise from 2019 to 2025 (APC=11.92%, 95%CI: 4.88% to 31.65%, P<0.001). Spatially, the cases were mostly concentrated in the 8th Division (1 418 cases), 3rd Division (1 357 cases), 6th Division (1 353 cases), and 4th Division (1 050 cases), accounting for 58.40% of all cases (5 178/8 867). Brucellosis in the XPCC area exhibited typical seasonal distribution, with a seasonal index>1 from March to August, representing the peak period of incidence (6 226 cases, 70.22%). The results of the circular distribution analysis indicated that the overall peak date of onset was June 5, and the overall peak period of onset spanned from March 7 to September 3. In terms of population distribution, the male-to-female ratio was 2.57∶1, with males having a higher average annual incidence rate (26.51 per 100 000) than females (11.33 per 100 000). The highest incidence rate was observed among individuals aged 50-54 years (54.67 per 100 000). Farmers and herdsmen accounted for the majority of cases (5 695 cases, 64.23%), followed by workers (1 080 cases, 12.18%). Conclusion From 2011 to 2025, the epidemic of brucellosis in the XPCC generally showed an upward trend, the high-risk population primarily comprises middle-aged and elderly male farmers and herdsmen, and the peak incidence mainly occurs in spring and summer. It is recommended to implement region-specific, targeted prevention and control measures based on the epidemic differences among cities and divisions, and to strengthen health education and protective interventions for high-risk populations during peak seasons.

ObjectiveTo analyze the seasonal characteristics of human anthrax incidence in China for theoretical evidence in prevention and control of this zoonotic infection. Methods Incidence data of human anthrax in China from 2010 to 2024 were retrieved from the China Public Health Science Data Center and the National Disease Control and Prevention Administration. Seasonality of human anthrax was analyzed using the seasonal index, along with concentration degree (M) and circular distribution method. Then the correlation between concentration degree M and circular distribution concentration trend γ value was assessed. Results A total of 4 817 cases of human anthrax, including 35 deaths, were reported in China from 2010 to 2024. The reported incidence rate ranged from 0.014 per 100 000 to 0.034 per 100 000 population, with an average annual reported incidence of 0.023 per 100 000. Seasonal index analysis indicated that the epidemic season of human anthrax in China spanned from July to October, with the incidence peak occurring in August. Concentration degree analysis yielded an overall M-value of 0.419 for national human anthrax epidemics, indicating a certain degree of seasonality, with marked seasonality in 2011 and 2021 (M=0.524 and 0.503), weak or insignificant seasonality in 2013 (M=0.230), and a certain degree of seasonality in other years (M ranging from 0.337 to 0.479). Circular distribution analysis revealed that the overall peak day of human anthrax onset was 25 August, with a tendency toward a later peak day over time. The overall peak period was from 9 June to 10 November, while the annual peak periods across the study years fell between May and December. The concentration degree M was highly positively correlated with the circular distribution concentration statistic γ (r=1.000, P<0.001). Conclusion Human anthrax incidence in China exhibits certain seasonal characteristics, with the peak occurring in summer and autumn. It is recommended to strengthen intersectoral collaboration, health education for high-risk populations, and animal epidemic monitoring before and during the epidemic peak season to effectively reduce the disease burden of anthrax.

ObjectiveTo analyze the epidemiological characteristics of human respiratory syncytial virus (HRSV) infection among acute respiratory infection (ARI) cases in Sichuan Province for scientific evidence for prevention and control of HRSV in local area. Methods ARI cases monitored at 7 sentinel hospitals for multi-pathogen surveillance of ARI in Sichuan Province between 2024 and 2025 were selected as the study subjects. Descriptive epidemiological methods were applied to analyze the demographic, temporal and regional distribution characteristics of HRSV-positive cases, as well as the distribution of HRSV subtypes. Results The overall positive rate of HRSV among the monitored subjects was 3.65% (803/22 003), in which the positive rate was 3.11% (456/14 680) for outpatients and emergency influenza-like illness (ILI) cases, and 4.74% (347/7 323) among hospitalized severe acute respiratory infection (SARI) cases, with statistically significant difference (χ²=37.02, P<0.001). The HRSV positive rate was 3.89% (445/11 443) in males and 3.39% (358/10 560) in females, showing a statistically significant difference (χ²=3.88, P<0.05). Overall, the HRSV positive rate decreased significantly with increasing age (χ²_trend=428.09, P<0.001, Z=-20.69), with children aged 0-5 years being the dominant affected group (81.57%, 655/803). Temporally, higher positive rates were observed from October to March of the following year, and the lower rates were seen from May to July. Geographically, Dazhou and Chengdu exhibited relatively higher positive rates (8.29% and 5.43%, respectively). The difference in positive rate was statistically significant among surveillance regions (χ²=390.52, P<0.001). A total of 73 samples from 2025 were subjected to HRSV subtype testing, which revealed HRSV subtype A in 60 cases (82.19%), subtype B in 12 (16.44%), and A/B co-infection in 1 (1.37%). Conclusion HRSV infection in Sichuan Province from 2024 to 2025 predominantly occurs in children aged 5 years and younger, and the infection rate gradually declines with increasing age. The epidemic peaks from late autumn to the following spring, with substantial regional differences in positivity rates. Subsequent prevention and control efforts should focus on younger children, while expanding coverage of viral subtype surveillance and continuously estimating the epidemic trends.

ObjectiveTo analyze the changes in epidemic trends of viral hepatitis B (hereinafter referred to as hepatitis B) in Chengdu City for a reference for scientific prevention and control of hepatitis B virus infection. Methods Data on hepatitis B cases in Chengdu City from 2005 to 2024 were retrieved from the Chinese Disease Prevention and Control Information System. The epidemiological characteristics and the incidence trend were analyzed respectively by descriptive epidemiology and Joinpoint regression model. Results A total of 132 880 hepatitis B cases were reported in Chengdu City between 2005 and 2024, with an average annual incidence rate of 43.78 per 100 000 population. Chronic hepatitis B cases were dominant, accounting for 83.81% (111 365 cases). The incidences of acute and unclassified hepatitis B showed declining trends (AAPC=-11.850% and -21.265%, 95%CI: -14.092% to -9.550% and -27.001% to -15.078%, both P<0.05), whereas chronic hepatitis B presented an increasing trend (AAPC=6.923%, 95%CI: 4.154% to 9.242%, P<0.05). By population subgroups, 82 655 cases were males and 50 225 were females, with annual average incidence of 53.99/100 000 and 33.39/100 000, respectively. The reported incidence was the lowest in the population aged 14 years and under (3.33/100 000) and the highest in those aged 65?74 (58.74/100 000). Farmers constituted the largest occupational group (53 159 cases, 40.01%). Among different regions, the central urban area reported more cases (77 983 cases, 58.69%), while new county?level cities and districts had higher reported incidence (49.57/100 000). Conclusion From 2005 to 2024, the incidences of acute and unclassified hepatitis B in Chengdu City exhibited a declining trend, while chronic hepatitis B incidence showed an increasing trend. Existing cases are predominantly chronic hepatitis B, with higher prevalence in males and farmers. It is recommended to implement health education and targeted screening for these key populations.

ObjectiveTo investigate the genetic characteristics of norovirus (NoV) from diarrhea patients in Tongling area for scientific evidence in prevention and control of this infection. Methods Three NoV-positive fecal samples (designated NR18, NR61, and NR246) were collected from diarrhea patients treated at medical institutions in Tongling City in 2023. Viral RNA was extracted and subjected to high-throughput sequencing. The obtained whole-genome sequences were uploaded to the NCBI database for BLAST homology alignment to identify their genotypes. Then a phylogenetic tree was constructed using MEGA 11 software, and closely related reference strains were selected based on evolutionary clades. Sequence homology analysis was performed using BioEdit software on the three viral strains and a reference strain, and amino acid mutation sites in the capsid proteins VP1 and VP2 regions were identified. Results The whole-genome length of NR18, NR61, and NR246 was 7 641 nt, 7 784 nt and 7 567 nt, respectively. Genotyping and phylogenetic analysis revealed that NR18 belonged to genotype GⅠ.4 P4 and clustered with the Guangdong isolate PV640830.1, NR61 was classified as GⅠ.2 P2 and grouped with the Japanese isolate LC122690.1, NR246 was identified as GⅡ.6 P7 and clustered with the Shaanxi isolate MW243610.2. Homology analysis demonstrated high sequence similarity between the three strains and their corresponding reference strains (nucleotide identity in ORF regions ranged from 95.3% to 99.7%, and amino acid identity in VP regions from 93.5% to 99.5%). Amino acid mutation analysis showed that NR61 exhibited the most pronounced variation, with 27 and 8 mutation sites in the VP1 and VP2 regions, respectively, relative to its reference strain, followed by NR246, with 15 and 8 mutation sites. NR18 was the most conserved, with only 8 and 1 mutation sites in VP1 and VP2, respectively. Conclusion NoV strains in Tongling City exhibited genetic diversity, with varying degrees of amino acid mutations in the VP1 and VP2 regions. It is recommended to implement routine dynamic monitoring of NoV whole-genome sequences to track viral evolution and mutation patterns of the virus, providing insights for regional NoV prevention and control.

This article reports a case of Erysipelothrix rhusiopathiae bloodstream infection in a patient with underlying liver cirrhosis. The patient, a pig farmer, was admitted to the hospital due to one-week history of fatigue. Physical examination showed mild icterus of the skin and mucous membranes, abdominal distension, and positive shifting dullness. The findings of laboratory studies included a white blood cell count of 2.8×10⁹/L, a platelet count of 21×10⁹/L, a C-reactive protein level of 57.44 mg/L, and a total bilirubin level of 57.33 μmol/L. Abdominal ultrasonography revealed liver cirrhosis, cholecystolithiasis, splenomegaly and ascites. On hospital day 2, the patient developed a fever with a maximum temperature being 38.5 ℃ and blood pressure dropped to 80/45 mmHg. Blood cultures were immediately taken, followed by prompt fluid resuscitation, empirical anti-infective therapy with piperacillin-tazobactam, and symptomatic supportive treatment. The diagnosis of Erysipelothrix rhusiopathiae bloodstream infection in the context of liver cirrhosis was confirmed by blood culture results. Piperacillin-tazobactam was continued in accordance with drug susceptibility testing results. The patient achieved clinical improvement and was discharged. Oral cephalexin was prescribed after discharge, and favorable outcomes were observed during follow-up. In this paper, we conducted a retrospective analysis of this case and reviewed relevant domestic and international literature, as well as analyzed the general characteristics, clinical manifestations, laboratory testing results, treatment and prognosis of bloodstream infection caused by Erysipelothrix rhusiopathiae in patients with liver cirrhosis, so as to improve the physician’s understanding of this condition.

This article reports a case of hemophagocytic syndrome secondary to visceral leishmaniasis. The patient was a 39-year-old male who was admitted to the hospital due to fever lasting over 10 days, accompanied by splenomegaly and pancytopenia. Auxiliary laboratory examinations upon admission exhibited serum ferritin greater than 1 000 ng/mL, soluble interleukin-2 receptor elevated to 14 003.6 pg/mL, and natural killer cell activity decreased to 12.65%. Metagenomic next-generation sequencing (mNGS) of peripheral blood detected Leishmania species with 182 951 RPM, and bone marrow smear examination revealed Leishmania donovani amastigotes, confirming the diagnosis of hemophagocytic syndrome secondary to visceral leishmaniasis. Following treatment with liposomal amphotericin B for injection combined with dexamethasone sodium phosphate injection, the patient improved, and was discharged, with a favorable outcome during follow-up. In this paper, we retrospectively analyzed the clinical data of this case, and reviewed the relevant literature to summarize the clinical pictures, diagnostic approaches, and treatment essentials of hemophagocytic syndrome secondary to visceral leishmaniasis, with an attempt to improve clinicians’ awareness of this disease.

Recombinase aided amplification (RAA) represents a rapid nucleic acid amplification technique that operates under isothermal conditions with the assistance of recombinase enzymes, featuring short reaction time, simple operation, high sensitivity and specificity, without the need for expensive instruments or equipment. This article systematically outlines the principles of RAA technology, detecting methods for the amplified products, its advantages and limitations, derivatization techniques, as well as its applications in the detection of parasitic diseases such as malaria, kala-azar, angiostrongyliasis cantonensis, schistosomiasis japonica, and echinococcosis, so as to provide a reference for wider recommendation of this technology.