登革热病毒实验室检测：临时指南，2025年4月

-2-levels combined withviral RNA, NS1antigen, or IgM suggest secondary infection.IgM/IgG ratiosmayaidin thedifferentiationofprimary and secondary infections.oThere is no universal consensus on the optimal diagnostic algorithm, andalgorithms should be adapted to suitthe context, considering the endemicity of DENV and other orthoflaviviruses co-circulating in the country, thepresence/absence of programmatic orthoflavivirus vaccination programmes, and the testing capacity of thenational laboratory system. This guidance outlines a proposed diagnostic algorithm for suspected denguecases, specifying the appropriate diagnostic methods based on days post symptom onset:•In the acute phase (0–7 days), NAAT targeting viral RNA, NS1 antigen detection by ELISA or RDT, or acombination test (NS1 + IgM) are recommended for early confirmation of dengue infection.•Testing in the convalescent phase (>7 days) involves IgM serology, followed by paired sera testing at a10–14 day interval or theuse of combination tests (NS1 + IgM) to enhance detection of primary andsecondary infections. However, IgM serology may cross-react with other orthoflaviviruses, and anegative result does not exclude dengue. Further testing, such as seroconversion with convalescentserum or differential diagnosis, may be required for confirmation.oDENV testing of suspected or confirmed cases should be handled using a risk-based approach in line with theWHO Laboratory biosafety manual, fourth edition(1).oDengue testing in endemic countries should be integrated across all levels of the national laboratory system,according toinfrastructure and biosafetyrequirements.oGenomic sequencing isan importanttool for analyzing and characterizing the DENV genome, with 19 identifiedgenotypes across the four serotypes.oDengue diagnostic tests are not prequalified by WHO.Procurement of DENV tests should be guided byevidence of good quality and satisfactory performance from independent evaluations. -3-Purposeof this document and updates from previous guidanceThis interim guidance synthesizes current evidence on DENV laboratory testing and diagnostics.Itis intended toprovide practical and useful guidance for laboratories, countries and stakeholders implementing dengue diagnosticsin the context of the global emergency.Relationship to existing WHOpublications:This documentupdates and supersedesChapter 4“Laboratorydiagnosis anddiagnostictests”oftheWHODengueguidelines for diagnosis, treatment, prevention and control (2)reflecting critical advancesincluding the following:opresents updatedcase definitionsbased on recent WHO publications;oillustrates the progression of diagnostic markers for primary and secondary DENV infections in relation todaysfromsymptom onset following the bite of an infected mosquito;oincludes a proposeddiagnostic algorithmfor a suspected dengue casewhichdetails the available diagnosticmethods and the appropriate timing for their use based on dayspostsymptom onset;odescribesthe comprehensive range ofdiagnostic techniquesand methodologiesavailable for dengueincludingcombination testsand rapiddiagnostic tests;oincludes a table presenting the range of analytes and corresponding test methodologies for dengue diagnosis,testing indications, and the advantages and limitations of eachdengue diagnostictest type;oincludes a section on genomic surveillancewhichdescribesthe utilityofnext generationsequencing inoutbreak investigation and DENVgenomicsurveillance;odescribesDENV testing acrossthe tiers of the laboratory network proposingdiagnosticoptions for each level ofthe laboratory network including at the point of care;oincludesatable on the considerations for selecting dengue diagnosticswhichpresents essential considerationsfor selecting dengue diagnostics including test characteristics and practical requirements.Other sections of the 2009 guidelines (treatment, prevention) remain valid and should be read in conjunction with thisupdate.The interimguidancealso updates andcomplements the following WHO publications:oLaboratory testing for Zika virus and dengue virus infections (3),byexpandingguidance on detecting DENV;oRecommendations for laboratory detection and diagnosis of arbovirus infections in the Region of the Americas(3),byfocusing on dengue andrefiningtheDENV-specific recommendations;oTechnical note: algorithm for laboratory confirmation of dengue cases (5),byincorporatingRDTsintothediagnosticalgorithm and includingcombination test (NS1 and IgM);oComprehensive guideline forprevention and control of dengue and dengue haemorrhagic fever(6), byintroducinganew diagnostic algorithm and modern technologies.Target audienceThis document provides guidance for laboratory professionals, public health officials,clinicians and other stakeholdersinvolved indenguetesting, surveillance and disease control programme management. IntroductionDengue is a growing global public healthconcern, as global transmission continues to strain healthcare systems andimpedeeconomic stability(7)