Dengue diagnostics: serious inaccuracies are likely to occur if pre-analytical conditions are not strictly followed

• Autor(a) principal: Felipe Campos de Melo Iani
• Data de Publicação: 2020
• Outros Autores: Myrian Morato Duarte, Ana Carolina Barbosa Caetano, Jéssica Caroline Wenceslau Cocovich, Frederico Figueiredo Amâncio, Maira Alves Pereira, Talita Émile Ribeiro Adelino, Sérgio Caldas, Marcos Vinícius Ferreira Silva, Glauco de Carvalho Pereira
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFMG
• Texto Completo: https://doi.org/10.1590/0074-02760200287; http://hdl.handle.net/1843/50610; https://orcid.org/0000-0002-3629-8529; https://orcid.org/0000-0002-5253-4261; https://orcid.org/0000-0002-9773-0194; https://orcid.org/0000-0002-5732-7173; https://orcid.org/0000-0002-8026-7017; https://orcid.org/0000-0002-1471-0084; https://orcid.org/0000-0003-1489-794X; https://orcid.org/0000-0002-5365-4329
• topic: Dengue; RNA; Serum samples; Storage conditions; Diagnosis; Dengue; Vírus da dengue; Testes laboratoriais

BACKGROUND: The heat-labile nature of Dengue virus (DENV) in serum samples must be considered when applying routine diagnostic tests to avoid issues that could impact the accuracy of test results with direct implications for case management and disease reporting. OBJECTIVES: To check if pre-analytical variables, such as storage time and temperature, have an impact on the accuracy of the main routine diagnostic tests for dengue. METHODS: Virus isolation, reverse transcription real-time polymerase chain reaction (RT PCR) and NS1 enzyme-linked immunosorbent assay (ELISA) were evaluated using 84 samples submitted to different pre-analytical conditions. FINDINGS: Sensitivity and negative predictive value were directly affected by sample storage conditions. RT-PCR and virus isolation showed greater dependence on well-conserved samples for an accurate diagnosis. Interestingly, even storage at -30ºC for a relatively short time (15 days) was not adequate for accurate results using virus isolation and RT-PCR tests. On the other hand, NS1 ELISA showed no significant reduction in positivity for aliquots tested under the same conditions as in the previous tests. MAIN CONCLUSIONS: Our results support the stability of the NS1 marker in ELISA diagnosis and indicate that the accuracy of routine tests such as virus isolation and RT-PCR is significantly affected by inadequate transport and storage conditions of serum samples.