Now that better testing is available for Zika virus infection it is possible to go back and re-analyse older samples stored from previously undiagnosed patients that exhibited Zika-like symptoms.
Today, the Journal Eurosurveillance looks at just such an occurrence from 2014, where a man returned to Italy from Thailand, developed a fever and rash - and was hospitalized.
Based on suggestive but inconclusive lab results, clinical signs, and travel history - he was initially diagnosed with Dengue. Nineteen days after his return, his girl friend developed similar symptoms, despite not having left the country.
Test results on her were inconclusive as well.
Stored serum samples from both patients were re-analysed in 2016 using newly developed Plaque reduction neutralisation tests (PRNTs), and both showed positive results for ZIKV neutralising antibodies.
Eurosurveillance, Volume 21, Issue 8, 25 February 2016
Received:16 February 2016; Accepted:25 February 2016