Evaluation of syphilis and congenital syphilis surveillance system in Sawanpracharak Hospital, Nakhon Sawan Province, Thailand, 2024-2025

Abstract

Introduction: Syphilis is a sexually transmitted infection caused by Treponema pallidum, transmitted through sexual contact, direct contact with infectious lesions, or vertically from mother to fetus. Although curable with appropriate treatment, untreated syphilis can be life-threatening. Surveillance data indicated that syphilis and congenital syphilis incidence rates in Mueang Nakhon Sawan District in 2024 declined from 2023, yet remained above the five-year median baseline. This study aimed to evaluate the syphilis and congenital syphilis surveillance system at Sawanpracharak Hospital by describing its operational processes, assessing quantitative and qualitative system attributes, and proposing recommendations for enhancing surveillance effectiveness.

Methods: A mixed-methods design was employed. The quantitative component involved 736 patients diagnosed with syphilis, congenital syphilis, or clinically similar conditions at Sawanpracharak Hospital between January 2024 and December 2025. Data were collected through medical record review and compared with surveillance system records. The qualitative component comprised in-depth interviews with surveillance personnel.

Results: The surveillance system demonstrated a sensitivity of 57.88% and a positive predictive value of 95.89%, reflecting high reporting accuracy but suggesting possible incomplete case ascertainment. Timeliness of reporting within seven days was 51.98%. Data completeness for sex, age, ethnicity, sub-district of residence, date of illness onset, and date of diagnosis reached 100%, while accuracy for sex, age, nationality, and date of diagnosis exceeded 70%. Sub-district of residence recorded the lowest accuracy at 60.8%. Surveillance data were broadly consistent with hospital database records. Qualitative assessment indicated good acceptability, flexibility, and stability; however, limitations were identified in the clarity of diagnostic criteria and ease of use of the reporting system.

Conclusions : The syphilis surveillance system demonstrated reasonably satisfactory quantitative attributes, with qualitative attributes — including acceptability, flexibility, and stability — rated as good. Persistent limitations included reporting form complexity, redundant data entry across multiple systems, and ambiguity in reporting guidelines and case definitions, which may have adversely affected completeness and timeliness. Streamlining the reporting process and improving system usability are recommended to enhance overall surveillance effectiveness.