Temperature of a Dengue Rapid Diagnostic Test under Tropical Climatic Conditions: A Follow Up Study.

Onanong Sengvilaipaseuth,Phoutthalavanh Souvannasing,Audrey Dubot-Pérès,Sommay Keomany,Stuart D Blacksell,Koukeo Phommasone,Xavier De Lamballerie,Ooyanong Phonemixay,Manivanh Vongsouvath,Mayfong Mayxay,Paul N Newton,Ana Paula Arez

doi:10.1371/journal.pone.0170359

Abstract

The Dengue Duo Rapid Diagnostic Test (SD Dengue RDT) has good specificity and sensitivity for dengue diagnosis in rural tropical areas. In a previous study, using four control sera, we demonstrated that that the diagnostic accuracy of these RDTs remains stable after long-term storage at high temperatures. We extended this study by testing sera from 119 febrile patients collected between July-November 2012 at Salavan Provincial Hospital (southern Laos) with RDTs stored for 6 months at 4°C, 35° and in a hut (miniature traditional house) at Lao ambient temperatures. The dengue NS1 antigen results from RDTs stored at 35°C and in the hut demonstrated 100% agreement with those stored at 4°C. However, lower positive percent agreements, with broad 95%CI, were observed for the tests: IgM, 60% (14.7–94.7) and 40% (5.3–85.3) for RDTs store at 35°C and in the hut, compared to those stored at 4°C, respectively. This study strenghtens the evidence of the robustness of the NS1 antigen detection RDT for the diagnosis of dengue after storage at tropical temperatures.

Highlights

Imunochromatographic-based rapid diagnostic tests (RDTs) have multiple advantages, including providing results in less than 1 hour after sample collection, that can be performed at the patient’s bedside using a relative small volume of blood requiring limited technical skill to perform
Comparisons of results obtained using RDTs stored in the different conditions are presented in Table 1
Perfect agreement was observed between the results obtained with these different RDTs for the NS1 antigen component

Summary

Introduction

Imunochromatographic-based rapid diagnostic tests (RDTs) have multiple advantages, including providing results in less than 1 hour after sample collection, that can be performed at the patient’s bedside using a relative small volume of blood requiring limited technical skill to perform. This is especially relevant to low -resource countries where there is limited access to laboratory facilities. Over 2.5 billion people, nearly half of the world’s population, are at risk of contracting dengue, and 70% of those live in southeast Asia and the western Pacific [1,2].

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Results

Conclusion