Evaluation of Dengue Surveillance System in Vientiane Capital City, Lao People

Abstract

In July 2010, we evaluated the dengue surveillance system in Vientiane Capital City (VCC) to provide recommendations for improvement of the system. We interviewed 29 stakeholders from the Department of Health, and one central and two district hospitals in VCC. Sensitivity and predictive value positive (PVP) were calculated using dengue data from June to July 2009 and June 2010. In addition, timeliness of reporting and data quality in June to July 2009 were also evaluated. The surveillance system was simple and paper-based, with both passive and active components. There were no designated surveillance officers in the central hospital. In 2010, the Department of Health provided training and frequency of data collection was increased. Overall sensitivity increased from 50% in June-July 2009 to 68% in June 2010. However, sensitivity decreased in the central hospital where higher number of patients was found. PVP was 100% in June-July 2009 and 96% in June 2010. Sixty percent and 32% of patients were reported within one week after diagnosis in the central and district hospitals respectively. Proportion of accurate data was more than 90% for case classification, gender and age. Sensitivity of surveillance improved with training and active surveillance. However, active surveillance only increased sensitivity when the caseload was not high. To improve the system, there should be designated trained surveillance staff in central hospitals and date of onset for each patient should be collected.
 
Keywords: dengue, surveillance system, Vientiane Capital City, Lao People’s Democratic Republic