Long-term kinetics of Zika virus RNA and antibodies in body fluids of a vasectomized traveller returning from Martinique: a case report

BACKGROUND: The magnitude of the current Zika virus (ZIKV) epidemic has led to a declaration of a Public Health Emergency of International Concern by the WHO. Findings of viable viral particles in semen for several weeks are corroborating reports of sexual transmission of ZIKV. Serious consequences of a positive diagnostic result particularly in the pregnant patient are calling for precise diagnostic tools also at later time points after infection. Currently, recommendations suggest a diagnostic period of direct viral detection of 5 to 7 days after onset of symptoms in serum or plasma, and up to 3 weeks in urine samples. CASE PRESENTATION: A vasectomized 41-year-old German returning from Martinique presented at the outpatient clinic of the Department for Infectious Diseases and Tropical Medicine, Munich, with subfebrile temperature, rash, malaise, severe retro-orbital pain and occipital lymphadenopathy. The main complaints resolved after ten days without specific treatment. We are reporting on clinical course and results of direct and indirect detection methods of ZIKV in different sample types including whole blood, ejaculate, urine, serum, plasma and saliva samples up to 119 days post symptom onset. Ejaculate samples remained PCR positive for ZIKV until day 77, whole blood samples until day 101. CONCLUSIONS: The case presentation adds to the still limited knowledge of kinetics of detection of ZIKV by direct as well as indirect methods. Here, a complete data set including results from PCR, serology and cell culture is provided allowing an improved evaluation of optimum diagnostic periods for testing a variety of sample types. Moreover, a high viral load of ZIKV RNA was detected in ejaculate of the vasectomized patient. This finding sheds new light on the possible localizations of ZIKV replication in the human male reproductive tract.