An 18-year retrospective analysis of changing patterns in pediatric brucellosis in Jinan, China

Analyze the epidemiological characteristics and infection routes of brucellosis in children in Jinan City, Shandong Province, to provide a basis for the prevention and control of brucellosis in children in Jinan. Epidemiological data and case investigation information on brucellosis in children in Jinan from 2007 to 2024 were collected. Retrospective analysis was applied to statistically analyze the epidemiological characteristics, symptoms, diagnosis, sources of infection, exposure activities and infection routes of the cases, as well as the infection status of family members. From 2007 to 2024, a total of 48 cases of brucellosis in children were reported in Jinan, with an average annual incidence rate of 0.23/100,000. The incidence rate differed significantly between years (χ2 = 32.28, P = 0.001). The disease was more prevalent in spring and summer. There were 27 male and 21 female patients, with a male-to-female ratio of 1.29:1. The youngest patient was 1 year old, and the oldest was 14 years old. The peak age of incidence was between 6 and 11 years, accounting for 50.00% (24/48) of the cases. Most of the patients came from rural areas, accounting for 87.50% (42/48). The most common clinical symptoms were fever, followed by muscle and joint pain, fatigue, and excessive sweating. The diagnosis was mainly confirmed by infectious disease hospitals (75.00%, 36/48), with a median diagnosis time of 10.5 (7.00, 29.50) days. The main routes of infection were direct contact or respiratory transmission, accounting for 77.08% (37/48), and digestive tract transmission accounted for 20.83% (10/48). None of the patients had taken protective measures when in contact with animals, and only 29.73% (11/37) and 18.92% (7/37) washed their hands and laundry after contact with animals. In 35.42% (17/48) of the patients’ families, brucellosis had already been present, and 12 patients (70.59%) were detected only after the first case was confirmed. Brucellosis in children in Jinan City mainly occurs in rural areas, with key epidemic areas, high-incidence seasons and ages, and is often associated with feeding or close contact with sheep. Direct contact, respiratory transmission, and unsafe diet are the main transmission routes of brucellosis in children in this study. Children have weak awareness of prevention and poor hygiene habits, resulting in long diagnosis time and a tendency towards family brucellosis infection clusters. In the next step, it is necessary to strengthen the prevention and control work in key epidemic areas of brucellosis in children, strengthen the promotion of brucellosis knowledge and the diagnosis training of medical staff.