Evaluation of Dengue Surveillance System, Chaiyaphum Province, 2023

Abstract

Background: In 2023, Chaiyaphum Province reported a dengue incidence higher than the 5-year median and ranked fourth nationwide. However, these figures may underestimate the true burden, as some districts reported fewer cases than expected despite widespread outbreaks. Therefore, an evaluation of the dengue surveillance system was conducted to examine reporting procedures, assess quantitative and qualitative attributes, and propose strategies for system improvement.

Methods: A cross-sectional study was conducted among patients visiting hospitals between January and December 2023 using multistage sampling. Medical records in four hospitals were selected by stratified random sampling by ICD-10 coding then simple random sampling. Case definitions were based on both national surveillance criteria and physicians’ diagnoses. Quantitative attributes were assessed from medical records, and qualitative aspects were evaluated through staff interviews.

Results: The system demonstrated sensitivity of 85.85% by national surveillance definition and 83.47% by physicians’ diagnoses. The positive predictive values were 92.75% and 73.79%, respectively. Completeness of key variables (age, sex, onset date, address) was 100%. The accuracy of those variables was more than 98% though the onset date was lower (66.75%). The timeliness for reporting and outbreak responses was 95.64 and 74.76% respectively. Personnel perceived the system as simple, adaptable, stable, and useful for communicable disease control.

Recommendations: We recommended that (1) establishing prompt hospital-based alert and network notification systems for dengue case detection and response; (2) reinforcing relevant departments to complete surveillance data by hospital executives and epidemiology staff; (3) enhancing dissemination of surveillance data for stakeholder; and (4) developing a work manual and training new personnels the epidemiology in hospitals.