[Analysis on epidemiological characteristics of typhoid and paratyphoid fever and patient medical treatment seeking flow in Guizhou Province, 2015-2024].

Objective: To analyze the epidemiological characteristics of typhoid/paratyphoid fever and the patient medical treatment flow in Guizhou Province from 2015 to 2024, and provide reference for the prevention and control of typhoid/paratyphoid fever. Methods: The incidence data of typhoid/paratyphoid fever in Guizhou from 2015 to 2024 were collected from the Infectious Disease Reporting Information Management System of the China Disease Prevention and Control Information System. The data of the epidemics were obtained from the Public Health Emergency Management Information System and the field investigation reports from local centers for disease control and prevention. Descriptive epidemiological methods were used to analyze the epidemiological characteristics of typhoid/paratyphoid fever and the patient medical-seeking flow. Results: From 2015 to 2024, a total of 4 476 cases, including 2 deaths, of typhoid/paratyphoid fever were reported in Guizhou, i.e. 3 294 cases of typhoid fever and 1 182 cases of paratyphoid fever. The annual average incidence rate was 1.22/100 000, and the case fatality rate was 0.044 7%. In the reported cases, 1 793 (40.06%) were confirmed, including 1 065 cases of typhoid fever and 728 cases of paratyphoid fever. The overall incidence rate showed a downward trend (average annual percentage change=-6.50%, P=0.005). The period with high-incidence was from June to October (2 415 cases, 53.95%). The average incidence rate was high in Qiannan Buyi and Miao Autonomous Prefecture (4.23/100 000), Liupanshui (1.63/100 000), and Tongren (1.38/100 000). The average incidence rate in rural area (1.69/100 000) was higher than that in urban area (0.76/100 000). The male to female ratio of the cases was 1.10∶1 (2 346∶2 130), and the majority of the cases were aged 5-69 years (3 917 cases, 83.09%). The majority of the cases were the jobless and unemployed (1 625 cases, 36.30%), home-cared children (695 cases, 15.53%), and students (654 cases, 14.61%). A total of 6 epidemics of typhoid/paratyphoid fever were reported with an attack rate of 0.43% (107/24 919). The epidemics occurred in 3 schools, 3 rural communities, and 3 urban-rural fringe communities. There were 5 waterborne transmission cases and 1 foodborne transmission case. In the 4 476 cases of typhoid/paratyphoid fever, 10.37% sought medical treatment in local areas, 85.30% sought medical treatment in the province, and 4.33% sought medical treatment in other provinces. In 33 counties (districts) in Guizhou, there were 1 572 typhoid/paratyphoid fever cases seeking medical treatment in the province, in whom 1 505 (95.74%) went to the provincial or prefectural capital cities for medical treatment. In the 194 cases seeking medical treatment in other province, 108 went to Yunnan (55.67%). In the 4 476 typhoid/paratyphoid fever cases reported in Guizhou, 2 081 were reported by county (district) level medical institutions (46.49%), and 29 were reported by township (community) level medical institutions (0.65%). The M (Q1, Q3) of interval between onset and diagnosis were 5 (3, 9) days, with 476 cases (10.63%), 529 cases (11.82%), 1 605 cases (35.85%), 1 275 cases (28.49%), 397 cases (8.87%), and 194 cases (4.34%) being diagnosed within 0, 1-2, 3-6, 7-13, 14-29 and ≥30 days respectively. Conclusions: From 2015 to 2024, the incidence of typhoid/paratyphoid fever decreased significantly to a historical low level in Guizhou. However, it was still high compared with others areas in China. The diagnosis of typhoid/paratyphoid fever needs to be improved. A notable proportion of cases seek medical care across regions, which increases the potential risks of transmission, endemic spread, and outbreaks. It is necessary to strengthen the performance of grassroots medical institutions and conduct joint prevention and control, integration of medical and prevention, surveillance and early warning, risk assessment, standardized diagnosis, and precise intervention.