1. Enhanced dengue sentinel surveillance in Sri Lanka
- Author
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Tissera, H, Gunasena, S, da Silva, D, Sessions, O, Palihawadana, P, Amarasinghe, A, Muthukuda, C, Botheju, C, Leong, W -Y, Lohr, Wolfgang, Byass, Peter, Wilder-Smith, Annelies, Gubler, D, Tissera, H, Gunasena, S, da Silva, D, Sessions, O, Palihawadana, P, Amarasinghe, A, Muthukuda, C, Botheju, C, Leong, W -Y, Lohr, Wolfgang, Byass, Peter, Wilder-Smith, Annelies, and Gubler, D
- Abstract
Introduction: Dengue poses a significant socioeconomic and disease burden in Sri Lanka, where the geographic spread, incidence and severity of disease has been increasing since the first dengue hemorrhagic fever (DHF) epidemic occurred in 1989. Periodic epidemics have become progressively larger, peaking in 2012 with 44 456 cases. Passive surveillance was established nationwide more than a decade ago but dengue notifications have been based on clinical diagnosis, with infrequent laboratory confirmation. To obtain more accurate data on the disease burden, a laboratory-based enhanced sentinel surveillance system was established in Colombo Municipality, the area with the highest dengue incidence. Here we describe the study design and the results of the first 2 years (2012–2014). Methods: Three government hospitals and two outpatient clinics in Colombo District were selected for the sentinel surveillance. All patients presenting with undifferentiated fever were enrolled, if consent given, capped at a maximum of 60 patients per week. Acute blood samples were taken from all enrolled subjects and tested by dengue-specific PCR, and NS1, and IgM – ELISA at the time of first presentation. A sub-set of 536 samples was sent to Duke-NUS Singapore for quality assurance, virus isolation and serotyping. Results: Between 1 April, 2012 and 31 March, 2014, 3127 patients were enrolled, 964 (30.9%) as outpatients and 2160 (69.1%) as inpatients. The mean age was 22.3 years (SD = 17.5) and the time of first presentation was at day 4 of illness. For inpatients, 1687 (78.1%) of all febrile cases had laboratory-confirmed dengue. For outpatients, the proportion of confirmed dengue was 237 (24.6%). The mean duration of hospitalization was 4.1 days (SD = 1.85). The proportion of DHF in lab-confirmed hospitalized dengue cases was 22.1% and 4 patients (0.21%) died. Serotypes 1 and 4 were the only viruses detected in this sample (serotype 1: 85%; serotype 4: 15%). The clinicians’ diagnosis for dengue at time
- Published
- 2015