[Analysis of symptomatic differences in 391 patients with Brucella infections in different age groups]

In order to investigate the clinical manifestations and laboratory findings associated with brucellosis for the purpose of facilitating prompt clinical diagnosis and effective treatment, as well as to offer a laboratory reference for the prevention of brucellosis outbreaks. In this study, a retrospective cohort design was employed to gather epidemiological characteristics, clinical symptoms, and associated laboratory data from 391 patients diagnosed with bacterial culture-positive brucellosis at the People's Hospital of Ningxia Hui Autonomous Region between 2019 and 2023. The patients were categorized into four age groups, with each group representing a 20 years age interval. Statistical analyses were conducted to examine the differences between these age groups using R version 4.3.2 and SPSS version 24.0 software. The results showed that among the 391 cases of brucellosis patients, fever (241 cases, 61.64%), lumbar and leg joint pain (225 cases, 57.54%), abnormal liver function (124 cases, 31.71%), spleen enlargement (78 cases, 19.95%), and cholecystitis (75 cases, 19.18%) were identified as the most prevalent clinical symptoms. Furthermore, the presence of clinical symptoms such as fever, lumbar and leg joint pain, abdominal pain and distension, headache, dizziness, rash, and complications including abnormal liver function, cholecystitis, spleen enlargement, exhibited statistical significance across four distinct age groups (P<0.05). The initial presentation of acute fever and rash was more pronounced in the pediatric cohort. In contrast, the youth group exhibited a higher prevalence of acute fever, liver function abnormalities, dizziness, headache, and splenomegaly. Furthermore, the strong-age group and the older age group more frequently experienced lumbar and leg joint pain, and symptoms related to the liver, gallbladder, spleen, and digestive system. In terms of laboratory examination, the rates of decreased white blood cell count (WBC), red blood cell count (RBC) and platelet count (PLT) were 18.91% (73 cases), 28.94% (112 cases) and 22.34% (86 cases), respectively. C-reactive protein (CRP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total biluric acid (TBA), adenosine deaminase (ADA), alkaline phosphatase (ALP), glutamyl transpeptidase (GGT), procalcitonin (PCT), and D-Dimer (D-Dimer). The proportion of patients with elevated quantitative test results was 88.56% (271 cases), 50.90% (197 cases), 52.20% (202 cases), 23.82% (91 cases), 75.72% (290 cases), 23.06% (89 cases), 40.89% (157 cases), 68.34% (218 cases) and 73.33% (209 cases), respectively. Among them, the quantitative detection results of CPR, ALP and D-Dimer had statistical significance among the 4 age groups (χ²=16.366,28.089,7.880,P<0.05). Abnormally elevated laboratory parameters, including C-reactive protein (CRP), alkaline phosphatase (ALP), and D-dimer, were more pronounced in middle-aged and older cohorts, with a positive correlation to advancing age. Among the 391 brucella culture positive specimens, the top three departments with the highest number of isolations were infectious disease (52.4%, 204 cases), emergency (9.5%, 37 cases) and orthopedics (8.4%, 33 cases). In conclusion, the clinical manifestations of brucellosis are multifaceted and heterogeneous, frequently involving multiple organ systems, and the laboratory test results exhibit considerable variability. These findings indicate that clinicians should integrate clinical features of brucellosis with laboratory test results, considering the patient's age group, to enhance diagnostic accuracy and triage efficiency in suspected cases. Improving relevant diagnostic examinations can thereby aid in the effective control and prevention of the disease.