The reemergence of dengue virus (DENV) infection has created a requirement for improved laboratory diagnostic procedures. In this study, DENV genome detection in urine was evaluated as a diagnostic method. The DENV genome was detected by realtime reverse transcriptase PCR (RT-PCR) in urine and serum of dengue patients. The detection rate of DENV genome in urine was 25% (2/8) on disease days 0 to 3 and 32% (7/22) on days 4 to 5. The rate was 50% or higher on days 6 to 16, 52% (11/21) on days 6 to 7, 78% (7/9) on days 8 to 9, 80% (4/5) on days 10 to 11, 50% (2/4) on days 12 to 13, and 60% (3/5) on days 14 to 16. The last positive urine sample was on day 16. The detection rates in serum were highest on days 0 to 3 and were greater than 50% on days 0 to 7. Detection rates decreased thereafter, and the last positive detection was on day 11. These results indicate that the time frames for positive detection differ between urine and serum samples, whereby detection rates of 50% or higher are evident between days 6 to 16 for urine samples and days 0 to 7 for serum samples. Nucleotide sequences of PCR products were identical between urine and serum samples. The detection of DENV genome in urine samples by real-time RT-PCR is useful to confirm DENV infection, particularly after viremia disappears.
Dengue virus (DENV) infections occur in most of the tropical and subtropical areas of the world. DENV infection with any of four serotypes leads to a broad spectrum of clinical symptoms and severity, including asymptomatic infection, dengue fever (DF), and fatal dengue hemorrhagic fever (DHF). DF/DHF is considered one of the most important reemerging infectious diseases (4). Physicians and pediatricians in countries in which these diseases are not endemic are often unfamiliar with the symptoms and unaware of the potential importation of patients with DF/DHF. As such, DF/DHF often may not be considered part of a differential diagnosis. Furthermore, laboratory diagnosis is hampered in areas where the disease is endemic because of the limited number of facilities with diagnostic capacity, and specimen collection in a proper time frame is not easy in areas were DF/DHF is endemic.Several laboratory diagnostic techniques have been used for the confirmation of dengue virus infection: viral isolation, viral antigen detection, viral genome detection, and antibody (Ab) detection. IgM capture enzyme-linked immunosorbent assay (ELISA) and real-time reverse transcriptase PCR (RT-PCR) are commonly used (6,8,16). NS-1 antigen detection tests have also recently become commercially available (10); however, they cannot determine specific viral types. The antibody/antigen detection of DENV provides less information than the other detection assays, and the virus can be successfully isolated only during limited stages of infection. For detailed analyses, the detection of the DENV genome in serum samples by RT-PCR is widely used. A fluorogenic probe-based assay, which has a number of advantages over conventional RT-PCR, has recently been developed. I...