Prolonged Detection of Japanese Encephalitis Virus in Urine and Whole Blood in a Returned Short-term Traveler

Huang, G Khai Lin; Tio, Shio Yen; Caly, Leon; Nicholson, Suellen; Thevarajan, Irani; Papadakis, Georgina; Catton, Mike; Tong, Steven Y C; Druce, Julian

Japanese encephalitis virus is a mosquito-borne flavivirus endemic in most parts of Asia, where it is the most common vaccine-preventable cause of encephalitis and a major cause of morbidity and mortality. In a 2011 systematic review, it was estimated that 67 900 cases occur annually [1] . The traditional diagnostic paradigm for JEV infection has been based on the understanding that the period of viremia is short-lived, and hence the utility of PCR is limited. As a result, most cases are diagnosed serologically [2] . Serological diagnosis may be complicated by cross-reactivity with other flaviviruses or the need for follow-up samples to look for a rise in antibody titre over time. Here we report prolonged detection of JEV in both urine and whole blood, but not in plasma or CSF samples, which are most commonly tested for diagnostic purposes. If reproducible in other cases, these findings could significantly improve laboratory diagnostics for JEV and provide new insights into the viral dynamics of JEV.