Measles Surveillance Evaluation under Measles Elimination Program in Ratchaburi Hospital and Photharam Hospital, Ratchaburi Province, Thailand, 2024

Abstract

Introduction: The World Health Organization (WHO) has identified measles elimination as a global and regional priority, emphasizing the importance of an effective disease surveillance system. In response, Thailand has implemented the surveillance system—Measles Elimination (ME)—focusing on the detection of febrile rash cases, laboratory confirmation, and timely public health response. This study aimed to evaluate both the quantitative and qualitative performance of the ME in Ratchaburi Province in 2024.

Methods: A descriptive cross-sectional study was conducted at Ratchaburi Hospital and Photharam Hospital from January 1 to December 31, 2024. Four case definitions were applied to assess surveillance sensitivity: (1) fever with maculopapular (MP) rash or clinically suspected measles as per the WHO standard definition used in the ME, (2) fever with MP rash, (3) fever with a defined rash or clinically suspected measles, and (4) fever with a defined rash only. A “defined rash” referred to maculopapular or erythematous rash, excluding vesicular, urticarial, or petechial lesions. Quantitative attributes, namely, sensitivity, positive predictive value (PPV), accuracy, completeness, representativeness, and timeliness, were assessed. Qualitative attributes, namely, acceptability, simplicity, flexibility, stability, and public health usefulness, were evaluated through in-depth interviews with local staff.

Results: Thirty cases at Ratchaburi Hospital and forty-one cases at Photharam Hospital met the ME case definition. Among these, only two and fourteen cases were reported to the ME, corresponding to sensitivities of 6.7% and 34.1%, respectively. Both hospitals achieved a PPV of 100%. Data completeness and accuracy at Ratchaburi Hospital were 100% for all variables, whereas Photharam Hospital showed incomplete data for symptom onset date (96%) and diagnosis date (84%), with 58% accuracy for onset date. Representativeness was limited, with ME showing older patient ages and a higher proportion of Thai nationals compared to hospital records, while sex distribution was similar. Timeliness of reporting was 100% within 48 hours at Ratchaburi Hospital and 56% at Photharam Hospital, with a median reporting interval of one day (range: 1–20 days). Qualitative findings indicated varied understanding among staff, lack of continuous training, and limited use of ME during non-outbreak periods. The province’s non-measles, non-rubella discarded rate was 1.50 per 100,000 population, below the WHO target of ≥2 per 100,000.

Discussion and Recommendations: The ME surveillance system in Ratchaburi demonstrated high accuracy in laboratory confirmation but limited sensitivity, data completeness, and engagement of frontline personnel. Continuous training, improved data integration, and promotion of routine data use for decision-making beyond outbreak periods are recommended to strengthen the system’s overall performance and support Thailand’s progress toward achieving the WHO measles elimination goal.