Giulia Matusali1, Francesca Colavita2, Fabrizio Carletti3, Eleonora Lalle3, Licia Bordi3, Francesco Vairo3, Giuseppe Ippolito3, Maria R Capobianchi3, Concetta Castilletti3. 1. National Institute for Infectious Diseases "Lazzaro Spallanzani" IRCCS, Via Portuense 292, 00149 Rome, Italy. Electronic address: giulia.matusali@inmi.it. 2. National Institute for Infectious Diseases "Lazzaro Spallanzani" IRCCS, Via Portuense 292, 00149 Rome, Italy. Electronic address: francesca.colavita@inmi.it. 3. National Institute for Infectious Diseases "Lazzaro Spallanzani" IRCCS, Via Portuense 292, 00149 Rome, Italy.
Abstract
BACKGROUND: In Italy, dengue virus is the most frequent agent of imported viral infections. The use of rapid diagnostic tests (RDTs) may be of help as a preliminary user-friendly quick assay to facilitate dengue diagnosis, as ordinary laboratory diagnosis of dengue fever may require special efforts in terms of tools availability, interpretation of results, and skilled personnel. The performance of RDTs, however, may vary according to different epidemiological and laboratory background. METHODS: We reviewed five years of laboratory records of two dengue RDT results (Colorimetric SD-Bioline Dengue-Duo-RDT and Fluorimetric SD-Biosensor-STANDARD-F-Dengue-RDT), able to detect viral NS1 antigen and specific IgM and IgG. Diagnostic parameters were calculated using as reference the results of molecular (RT-PCR) and serological (immunofluorescence, IFA) tests. Overall performance, calculated considering the final case definition, was included in the accuracy assessment of RDTs. RESULTS: The combined use of NS1 and IgM/IgG RDT for the detection of acute dengue cases resulted in an overall sensitivity and specificity of 87.2% and 97.9% for Colorimetric RDT, 96.2% and 96.2% for Fluorimetric RDT. NS1 was the most reliable marker of acute infection, while IgM resulted falsely positive in nine samples, including sera derived from 2 Zika and 4 non-arbovirus infected patients. CONCLUSIONS: The inclusion of RDT in the diagnostic algorithm is of undeniable help in the prompt management and surveillance of dengue infection in non-endemic areas. Confirmatory tests are, however, necessary to rule in or rule out dengue fever diagnosis.
BACKGROUND: In Italy, dengue virus is the most frequent agent of imported viral infections. The use of rapid diagnostic tests (RDTs) may be of help as a preliminary user-friendly quick assay to facilitate dengue diagnosis, as ordinary laboratory diagnosis of dengue fever may require special efforts in terms of tools availability, interpretation of results, and skilled personnel. The performance of RDTs, however, may vary according to different epidemiological and laboratory background. METHODS: We reviewed five years of laboratory records of two dengue RDT results (Colorimetric SD-Bioline Dengue-Duo-RDT and Fluorimetric SD-Biosensor-STANDARD-F-Dengue-RDT), able to detect viral NS1 antigen and specific IgM and IgG. Diagnostic parameters were calculated using as reference the results of molecular (RT-PCR) and serological (immunofluorescence, IFA) tests. Overall performance, calculated considering the final case definition, was included in the accuracy assessment of RDTs. RESULTS: The combined use of NS1 and IgM/IgG RDT for the detection of acute dengue cases resulted in an overall sensitivity and specificity of 87.2% and 97.9% for Colorimetric RDT, 96.2% and 96.2% for Fluorimetric RDT. NS1 was the most reliable marker of acute infection, while IgM resulted falsely positive in nine samples, including sera derived from 2 Zika and 4 non-arbovirus infectedpatients. CONCLUSIONS: The inclusion of RDT in the diagnostic algorithm is of undeniable help in the prompt management and surveillance of dengue infection in non-endemic areas. Confirmatory tests are, however, necessary to rule in or rule out dengue fever diagnosis.
Authors: Joseph R Biggs; Ava Kristy Sy; James Ashall; Marsha S Santoso; Oliver J Brady; Mary Anne Joy Reyes; Mary Ann Quinones; William Jones-Warner; Amadou O Tandoc; Nemia L Sucaldito; Huynh Kim Mai; Le Thuy Lien; Hung Do Thai; Hien Anh Thi Nguyen; Dang Duc Anh; Chihiro Iwasaki; Noriko Kitamura; Marnix Van Loock; Guillermo Herrera-Taracena; Joris Menten; Freya Rasschaert; Liesbeth Van Wesenbeeck; Sri Masyeni; Sotianingsih Haryanto; Benediktus Yohan; Eva Cutiongco-de la Paz; Lay-Myint Yoshida; Stephane Hue; Maria Rosario Z Capeding; Carmencita D Padilla; R Tedjo Sasmono; Julius Clemence R Hafalla; Martin L Hibberd Journal: PLoS Negl Trop Dis Date: 2022-05-04