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Evaluation of the Dengue NS1 Ag Strip® for detection of dengue virus antigen in Aedes aegypti (Diptera: Culicidae).

Environmental Health Institute, National Environmental Agency, Singapore, Singapore.
Vector borne and zoonotic diseases (Larchmont, N.Y.) (Impact Factor: 2.53). 03/2011; 11(6):789-92. DOI: 10.1089/vbz.2010.0028
Source: PubMed

ABSTRACT Dengue fever is currently one of the most important mosquito-borne diseases that affect humans. With neither vaccines nor treatment available, prevention of the disease relies heavily on surveillance and control of mosquito vectors. In the present study, we have evaluated and showed the potential use of the Dengue NS1 Ag Strip(®) for the detection of dengue virus (DENV) in Aedes aegypti. Initial results showed that the sensitivity of the test kit in detecting DENV in wild-caught mosquitoes is comparable to that of real-time reverse transcriptase-polymerase chain reaction. The detection of naturally infected Ae. aegypti with the NS1 rapid test kit in our dengue cluster investigation further illustrates its potential use for surveillance of DENV in wild mosquito populations. The kit can easily be used in a simple field station, and minimal training is required. The results can be obtained in less than an hour. Employment of the kit in the field could help guide mosquito control operations in the prioritization of resources in controlling the transmission of DENV. In this study the potential of the kit for field surveillance of infected dengue vectors, which are epidemiologically important, has been demonstrated.

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    ABSTRACT: Dengue, caused by the dengue virus (DENV) is the most important vector borne infection in the tropics and can present as dengue fever(DF) or dengue haemorrhagic fever(DHF).1 DENV exists as four different serotypes, all of which have been circulating in Sri Lanka for the past 30 years. 2 DENVs are transmitted by the mosquito species Aedes aegyptii and Aedes albopictus, both of which are endemic to the South Asian region of the world. In Sri Lanka, the primary vector in transmitting DENV is A. aegyptii while A. albopictus serves as the secondary vector.3 Though DF and DHF have been around for at least the last thirty years in Sri Lanka, it was not until 2000 that dengue was identified as a major public health problem in the island. This was mainly due to the increase of DHF cases leading to dengue shock syndrome (DSS) and death.4 Molecular epidemiological studies carried out on DENV serotypes before and after the emergence of DHF indicate that changes in the molecular pattern and evolution of DENV are likely to have contributed to the clear cut differences in clinical severity of DF and DHF in Sri Lanka.2,8 A number of studies have been carried out worldwide to identify the dynamics of DENV within the vector to determine how they contribute to the changes in the dynamics of DF/DHF in the relevant region. However, such studies have been lacking in Sri Lanka. The first step in such a direction would be to identify the prevalence and DENV carriage of Aedes species of mosquitoes in endemic regions. Hence, the aim of this study was to identify the abundance of Aedes mosquitoes in two regional areas of Sri Lanka and to identify the presence, if any, of DENV in them, using a commercially available NS1 immunochromatography assay (SD Diagnostics) which was evaluated in a previous study for the detection of DENV NS1 in mosquitoes.1 . Mosquitoes (n=165) were collected from the areas of Kegalle and Peradeniya within the period of July and September 2011 during which many DF/ DHF cases had been reported in these towns (Table 1). Individual collection sites were not GIS mapped or identified through any other mapping modes.
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    ABSTRACT: Early diagnosis of dengue virus (DENV) infection can improve clinical outcomes by ensuring close follow-up, initiating appropriate supportive therapies and raising awareness to the potential of hemorrhage or shock. Non-structural glycoprotein-1 (NS1) has proven to be a useful biomarker for early diagnosis of dengue. A number of rapid diagnostic tests (RDTs) and enzyme-linked immunosorbent assays (ELISAs) targeting NS1 antigen (Ag) are now commercially available. Here we evaluated these tests using a well-characterized panel of clinical samples to determine their effectiveness for early diagnosis. Retrospective samples from South America were used to evaluate the following tests: (i) "Dengue NS1 Ag STRIP" and (ii) "Platelia Dengue NS1 Ag ELISA" (Bio-Rad, France), (iii) "Dengue NS1 Detect Rapid Test (1st Generation)" and (iv) "DENV Detect NS1 ELISA" (InBios International, United States), (v) "Panbio Dengue Early Rapid (1st generation)" (vi) "Panbio Dengue Early ELISA (2nd generation)" and (vii) "SD Bioline Dengue NS1 Ag Rapid Test" (Alere, United States). Overall, the sensitivity of the RDTs ranged from 71.9%-79.1% while the sensitivity of the ELISAs varied between 85.6-95.9%, using virus isolation as the reference method. Most tests had lower sensitivity for DENV-4 relative to the other three serotypes, were less sensitive in detecting secondary infections, and appeared to be most sensitive on Day 3-4 post symptom onset. The specificity of all evaluated tests ranged from 95%-100%. ELISAs had greater overall sensitivity than RDTs. In conjunction with other parameters, the performance data can help determine which dengue diagnostics should be used during the first few days of illness, when the patients are most likely to present to a clinic seeking care.
    PLoS ONE 11/2014; 9(11):e113411. DOI:10.1371/journal.pone.0113411 · 3.53 Impact Factor

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