Evaluation of Nonstructural 1 Antigen Assays for the Diagnosis and Surveillance of Dengue in Singapore

Abstract

Early and accurate diagnosis of dengue is imperative for disease surveillance, which helps in the control of dengue in endemic countries. In this study, we evaluated the performance of three commercially available dengue nonstructural 1 (NS1) antigen assays (Bio-Rad PlateliaÔ Dengue NS1 Antigen ELISA, PanBio Dengue Early ELISA, and Bio-Rad Dengue NS1 Antigen Strip test) and compared them with reverse-transcription polymerase chain reaction (RT-PCR) and other commercially available serological assays for the diagnosis of dengue. The analysis showed RT-PCR to be the most sensitive and specific (100%) diagnostic method during the first 3 days of fever. The overall sensitivity of dengue NS1 antigen assays within the same period was 81.7%, indicating their potential role as a cost-effective and convenient alternative method to RT-PCR for the diagnosis of dengue fever in a primary healthcare setting. However, reduced sensitivity in detecting secondary dengue infections was one of the drawbacks of dengue NS1 antigen assays. Nonetheless, it remains a useful assay for the early detection of dengue and hence could play an important role in routine surveillance efforts to control dengue outbreaks in Singapore.

Evaluation of the Dengue NS1 Ag Strip®for Detection of Dengue Virus Antigen inAedes aegypti(Diptera: Culicidae)

“…The rapid test kit did not show any positive results when tested against uninfected mosquitoes. The results show the ability of the rapid test kit in detection all DENV serotypes, and are in agreement with studies conducted with human samples (Dussart et al 2008, Pok et al 2010). …”

“…However, to date, none has been validated for DENV detection in its mosquito vectors. Recently, the Dengue NS1 Ag Strip Ò (BioRad Laboratories), a rapid immunochromatographic assay, has been developed to detect DENV NS1 antigen from acute patient serum samples (Dussart et al 2008, Chaiyaratana et al 2009, Pok et al 2010. NS1 is a structural protein that is produced in both membrane-associated and secreted forms.…”

Identification of Concurrent Bacterial Infection in Adult Patients with Dengue

“…16 The dengue NS1 antigen was detected using commercially available assays. 17 Molecular testing involved amplification of dengue RNA by real-time reverse transcriptase nested PCR. 18 Bacterial coinfection was defined as any clinical diagnosis of bacterial infection (e.g., pneumonia) or any bacteremia or bacteruria from cultures taken within 48 hours of admission.…”

Two Cases of False-Positive Dengue Non-Structural Protein 1 (NS1) Antigen in Patients with Hematological Malignancies and a Review of the Literature on the Use of NS1 for the Detection of Dengue Infection

“…9 In the literature, the rates of false-positive dengue NS1 range between 0.5% and 2.0%. 3,[10][11][12] There were 9,072 SD Bioline Dengue Duo tests performed at the TTSH in 2013. In a separate study performed at the TTSH campus with the same laboratory facilities between 2011 and 2012, the specificity of NS1 in the SD Bioline Dengue Duo test was 98%, similar to that reported by the manufacturers.…”

“…13,14 NS1 tests are also reported to be less sensitive in secondary dengue. 3,12,15 Little is known about the causes of false-positive NS1 tests, except for possible cross-reactivity with other flaviviruses and possibly, cytomegalovirus (CMV). 11,16 The two patients were not exposed to other flaviviruses, but they were not tested for CMV.…”