Evaluation of Scrub Typhus Surveillance System in Kanchanadit Hospital, Kanchanadit District, Suratthani Province, 2016

Abstract

Background: Scrub typhus remains an important public health in Thailand, including Suratthani Province. This report aims to evaluate scrub typhus surveillance system in Kanchanadit Hospital, Kanchanadit District, Suratthani Province, which reported the highest cases in 2016. Both quantitative and qualitative attributes were determined in the evaluation.
Methods: Medical records of patients living in Kanchanadit District who had illness met the case definitions of scrub typhus in Kanchanadit Hospital from 1 January 2016 to 31 December 2016 were reviewed. Data of these patients were compared to those retrieved from the disease surveillance system during the same period. Quantitative attributes of the surveillance evaluation including sensitivity, positive predictive value (PPV), representativeness, timeliness, and quality of data were determined. Hospital personnel involving the surveillance system were interviewed to determine the qualitative attributes.
Results: There were 51 cases met scrub typhus definitions by medical record review and 11 cases were reported in the surveillance system. The sensitivity of surveillance was 21.57% and the PVP was 100.0%. Only 18.18% of the cases could be reported within 3 days (timely reporting). Data quality was very good but might not be representative. The surveillance system was reported to be simple, flexible, acceptable and stable. However, the surveillance data were not much used for public health.
Conclusion: Poor sensitivity of the surveillance system needs much improvement. This poor sensitivity might partly be due to the diagnosis of disease since patients with scrub typhus had not specific clinical features and confirmatory laboratory was rarely carried out for diagnosis. Only one health personnel for disease reporting in the hospital might also result in poor sensitivity and timeliness. It is essential to improve case definition of the disease for increase in specificity, develop guideline for disease surveillance system in the hospital, increase personnel involving the system, develop the computerized alert system for rapid notification of the disease, and improve or develop the laboratory facility in the hospital and regional level for better diagnosis.