title: 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.
authors: Travel Clinic, Zurich, Switzerland.
authors: Danielle
authors: D
authors: Gyurech
authors: Travel Clinic, Zurich, Switzerland.
authors: Julian
authors: J
authors: Schilling
authors: Bernhard Nocht Institute for Tropical Medicine/World Health Organization Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Hamburg, Germany; German Centre for Infection Research (DZIF), Hamburg-Lübeck-Borstel, Hamburg, Ger.
authors: Jonas
authors: J
authors: Schmidt-Chanasit
authors: medica, medizinische Laboratorien Dr. F. Kaeppeli, Zurich, Switzerland.
authors: Pascal
authors: P
authors: Cassinotti
authors: medica, medizinische Laboratorien Dr. F. Kaeppeli, Zurich, Switzerland.
authors: Franz
authors: F
authors: Kaeppeli
authors: medica, medizinische Laboratorien Dr. F. Kaeppeli, Zurich, Switzerland.
authors: Marinko
authors: M
authors: Dobec
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000276:immunology*; D000956:Antigens, Viral / Q000276:immunology*; D003429:Cross Reactions; D003715:Dengue / Q000175:diagnosis* / Q000276:immunology; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D013557:Switzerland; D017361:Viral Nonstructural Proteins / Q000276:immunology; D000071243:Zika Virus Infection / Q000175:diagnosis* / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; C079340:NS1 protein, Dengue virus type 2; C546113:NS1 protein, Dengue virus type 3; C082515:NS1 protein, dengue-1 virus; D017361:Viral Nonstructural Proteins