False positive dengue NS1 antigen test in a traveller with an acute Zika virus infection imported into Switzerland

Abstract

We report the first case of an acute Zika virus infection imported into Switzerland by a traveller returning from Canoa Quebrada, Ceará state, in the north-eastern part of Brazil. Due to a false positive dengue virus NS1 antigen test, IgG antibody seroconversion and a suggestive clinical picture,an acute dengue fever was initially considered. However, because of lack of specific IgM-antibodies, stationary IgG antibody titre and a negative dengue virus PCR test result, a dengue virus infection was excluded and a cross-reaction with other, causative flaviviruses was postulated. Based on recent reports of Zika fever cases in the north-eastern parts of Brazil, an acute Zika virus infection was suspected. Because of a lack of commercially available Zika virus diagnostic tests, the case was confirmed in the WHO reference laboratory. As the clinical presentation of Zika virus infection can be confused with dengue fever and chikungunya fever, and because of possible public health implications, all patients returning from affected areas should be additionally tested for Zika virus. This case illustrates the urgent medical need for a broadly available assay capable of differentiating Zika from Dengue infections.

Clinical and laboratory profile of Zika virus infection in dengue suspected patients: A case series

“…The test result was reagent in one case, showing cross-reactivity between dengue and Zika. Serological cross-reactivity between ZIKV and DENV has been observed in earlier studies [5,48]. This cross-reactivity leads to the misdiagnosis of dengue because of the similarity of the clinical symptoms in addition to serological cross-reactivity.…”

Specificity of Dengue NS1 Antigen in Differential Diagnosis of Dengue and Zika Virus Infection

“…Gyurech et al ( 5 ) reported false-positive test results for dengue NS1 antigen in a patient with acute Zika virus infection. Of the 3 NS1 tests used in that study, only the SD Bioline Dengue Duo (Standard Diagnostics, Inc., Gyeonggi-do, South Korea) showed positive results for 3 of 4 sequential serum samples from the patient.…”

Nanoswitch-linked immunosorbent assay (NLISA) for fast, sensitive, and specific protein detection

“…As we have demonstrated, low cross-reactivity can be used to accurately distinguish between different viral strains, which can have implications for treatment options. Additionally, low cross-reactivity is important in identifying between a novel virus and other closely related viruses before optimal antibodies are developed, as was initially the case in distinguishing Zika virus from other Flaviviridae such as dengue fever, leading to public health challenges during the early stages of the recent Zika outbreak (23).…”