This is the first head-to-head assessment this website of PCR and a selection of widely-applied commercial serological assays (NS-1 antigen, IgM and IgG antibodies). It is also the first diagnostic assessment that has demonstrated the improved diagnostic accuracy when selections of PCR, NS-1 antigen, IgM and IgG antibody test results are combined. Shoklo Malaria Research Unit (SMRU) undertakes surveillance for malaria and other infectious diseases, and provides general

medical care for the migrant and refugee population, in five clinics in rural Thailand, on the Thailand-Myanmar (Burma) border. We conducted dengue surveillance from April to August 2008 in the SMRU clinics at Mawker Thai village (MKT) and Maela refugee camp (MLA), both located

in rural Tak province approximately 500 km northwest of Bangkok. Adult patients (age ≥15 years old) presenting Proteases inhibitor to the clinics with fever ≥38°C of less than seven days duration and any clinical symptoms or physical signs consistent with dengue (abnormal bleeding, eye redness, headache, myalgia or rash) were included in the surveillance and blood was drawn to inform clinical management (blood culture, complete blood count, and plasma for serology). Patients who had a clear alternative diagnosis such as malaria, urinary tract infection or pneumonia were excluded from the surveillance. In addition to dengue virus, patients were serologically investigated for leptospirosis (ELISA with confirmation by the microscopic agglutination test) and rickettsial infection (ELISA with confirmation by indirect immunofluorescence assay), the other common causes of undifferentiated fever in SE Asia. A 6 ml acute venous blood specimen was collected

from each patient in a sterile EDTA tube (Becton Dickinson, Franklin Lakes, NJ, USA) for dengue rRT-PCR, NS-1 antigen detection, and dengue IgM and IgG antibody detection tests. The patients were reviewed at a 10–14 day follow-up DCLK1 visit and a repeat 6 ml convalescent venous blood specimen was collected for dengue IgM and IgG antibody tests. Plasma was separated by centrifugation and frozen at −80 °C prior to the assays. Viral RNA was extracted from 150 μl of the acute plasma specimens using the NucleoSpin RNA virus extraction kit (Macherey Nagel, Düren, Germany) according to the manufacturer’s instructions and was stored at −80 °C prior to testing. One-step SYBR Green-based rRT-PCR, modified from Shu et al., was performed using the RotorGene 6000 real-time PCR system (Corbett Research, San Francisco, CA, USA).11 The reaction volume was 25 μl, comprising 10 μl of extracted RNA, 1 μl of each primer (10 μM), 12.5 μl of 2X SYBR Green reaction mix (containing 0.