Early diagnosis of dengue in travelers: Comparison of a novel real-time RT-PCR, NS1 antigen detection and serology

Huhtamo, Eili; Hasu, Essi; Uzcátegui, Nathalie Y.; Erra, Elina; Nikkari, Simo; Kantele, Anu; Vapalahti, Olli; Piiparinen, Heli

doi:10.1016/j.jcv.2009.11.001

« Previous Next »Journal of Clinical Virology
Volume 47, Issue 1 , Pages 49-53, January 2010

Early diagnosis of dengue in travelers: Comparison of a novel real-time RT-PCR, NS1 antigen detection and serology

Eili Huhtamo
- Department of Virology, Haartman Institute, Faculty of Medicine, University of Helsinki, P.O. Box 21 (Haartmaninkatu 3), FI-00014 University of Helsinki, Finland
- Corresponding author. Tel.: +358 9 19126706; fax: +358 9 19126491.
Essi Hasu
- Department of Virology, Haartman Institute, Faculty of Medicine, University of Helsinki, P.O. Box 21 (Haartmaninkatu 3), FI-00014 University of Helsinki, Finland
Nathalie Y. Uzcátegui
- Department of Virology, Haartman Institute, Faculty of Medicine, University of Helsinki, P.O. Box 21 (Haartmaninkatu 3), FI-00014 University of Helsinki, Finland
Elina Erra
- Helsinki University Central Hospital, Department of Medicine, Division of Infectious Diseases, Helsinki, Finland
Simo Nikkari
- Centres for Military Medicine and for Biological Threat Preparedness, Tukholmankatu 8A, 00290 Helsinki, Finland
Anu Kantele
- Helsinki University Central Hospital, Department of Medicine, Division of Infectious Diseases, Helsinki, Finland
Olli Vapalahti
- Department of Virology, Haartman Institute, Faculty of Medicine, University of Helsinki, P.O. Box 21 (Haartmaninkatu 3), FI-00014 University of Helsinki, Finland
- Department of Virology, HUSLAB, Helsinki University Central Hospital Laboratory, P.O. Box 400 (Haartmaninkatu 3), FI-00029 HUS, Finland
- Division of Microbiology and Epidemiology, Department of Basic Veterinary Sciences, P.O. Box 66 (Agnes Sjöbergin katu 2), FI-00014 University of Helsinki, Finland
Heli Piiparinen
- Department of Virology, Haartman Institute, Faculty of Medicine, University of Helsinki, P.O. Box 21 (Haartmaninkatu 3), FI-00014 University of Helsinki, Finland

Received 18 August 2009; accepted 4 November 2009. published online 07 December 2009.

Abstract

Background

The increased traveling to dengue endemic regions and the numerous epidemics have led to a rise in imported dengue. The laboratory diagnosis of acute dengue requires several types of tests and often paired samples are needed for obtaining reliable results. Although several diagnostic methods are available, proper comparative data on their performance are lacking.

Objectives

To compare the performance of novel methods including a novel pan-DENV real-time RT-PCR and a commercially available NS1 capture-EIA in regard to IgM detection for optimizing the early diagnosis of DENV in travelers.

Study design

A panel of 99 selected early phase serum samples of dengue patients was studied by real-time RT-PCR, NS1 antigen ELISA, IgM-EIA, IgG-IFA and cell culture virus isolation.

Results

The novel real-time RT-PCR was shown specific and sensitive for detection of DENV-1-4 RNA and suitable for diagnostic use. The diagnostic rate using combination of RNA and IgM detection was 99% and using NS1 and IgM detection 95.9%. The results of RNA and NS1 antigen detection disagreed in 15.5% of samples that had only RNA or NS1 antigen detected.

Conclusions

The diagnostic rates of early samples are higher when either RNA or NS1 antigen detection is combined with IgM detection. Besides the differences in the RNA and NS1 detection assays, the observed discrepancy of results could suggest individual variation or differences in timing of these markers in patient serum.

Keywords: Dengue, Traveler, Diagnosis, Real-time RT-PCR, NS1 antigen, Serology, Virus isolation