Evaluation of Influenza Surveillance System of Akat Amnuai Hospital, Akat Amnuai District, Sakon Nakhon Province, 1 January 2021-31 October 2025

Abstract

Influenza cases in Akat Amnuay district have increased dramatically since 2023. As of December 1, 2025 showed the highest cumulative incidence rate in 6 years and was the 3rd rank of Sakon Nakhon province. Therefore, the influenza surveillance system evaluation was performed in order to identify the system's characteristics as well as provide suggestions for system improvement and development. A descriptive cross-sectional study was conducted among those patients who sought care at Akat Amnuay Hospital during January 1st, 2021 to October 31st, 2025. The Case definitions 1 was adapted from the division of Epidemiology (DOE) criteria, while the Case definitions 2 was based on physicians' diagnoses. Medical records were selected by stratified random sampling. DDS/506 reports were all reviewed. The disease reporting processes were described. Health personnel who were involved in the surveillance system were recruited for an interview.

The results found that Akat Amnuay hospital has the case notification systems between ‘Front units’ and ‘Epidemiology service’. Epidemiologist verified and reported cases to 506/DDS. For Case definition 1, the overall sensitivity and positive predictive values (PPV) were 5.87 and 51.02%. For Case definition 2, the overall sensitivity and PPV were 61.81 and 73.46%. The sensitivity of J10-J11 codes by Case definition 1 and 2 were 72.05 and 61.81%. The completeness of records of patient types, age, gender, ethnicity, occupation, and onset place (subdistrict) were 100%, while the accuracy was all 100% except for patient type (99.36%). Gender, age, onset place (subdistrict), and onset time could be representative. The timeliness of the disease reporting process was 38.78%. The disease surveillance system was modern, simple, and appreciated by Staff accepted the implementation of the system, which was perceived as modern and easy to understand. The system was flexible and adaptable to changes in disease definitions and reporting processes. There were standby persons when the persons in charge were absent. The database was backed up daily. Surveillance data were utilized.

Epidemiologists 1) set the meeting for stakeholders to announce the disease reporting guidelines and the case definition criteria from DOE, combined with the physician's diagnosis. 2) Coordinate with the front units’ staff to notify all Influenza cases during their shift. 3) Retrieve patient data, including both primary disease codes (J10-J11) and related disease codes (especially J09 and J12), for both primary and secondary cases. Follow and update some reports that their diagnosis has been changed. and 4) Coordinate with physicians/nurses to establish guidelines for complete medical records.