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

Abstract

BackgroundThe 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 presentationA 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.ConclusionsThe 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.

Variable Sensitivity in Molecular Detection of Zika Virus in European Expert Laboratories: External Quality Assessment, November 2016

“…The observation that only 52% of the laboratories correctly scored the sample with the lowest concentration of 1.8 ϫ 10 3 RNA copies/ml is of concern. Plasma/serum is often the sample of choice in diagnostic laboratories (45), and the ZIKV viral loads in plasma that have been described in the literature (10,(33)(34)(35)(36) are low and variable but are about 10 2 RNA copies/ml. With respect to analytical specificity and sensitivity, the risk of a falsenegative outcome is especially a concern in laboratories that missed more than one of the ZIKV-positive samples.…”

Zika in the Americas, year 2: What have we learned? What gaps remain? A report from the Global Virus Network

“…As the virus can be detected in different body fluids (Paz-Bailey et al, 2017), including semen from vasectomized men (Froeschl et al, 2017), sexual transmission may be responsible for an unknown proportion of cases within epidemic and endemic areas, as well as cases in non-endemic regions who acquired the virus from their sexual partners returning from areas of ZIKV transmission (Moreira et al, 2017a). The contribution to the epidemic in regions with active mosquito-borne transmission is difficult to estimate because mosquito transmission of Ae.…”

Viral Diseases Transmissible by Kissing

“…49 Saliva and urine samples present higher viral load than serum. 49,274,275 Viral RNA is prolonged shedding in saliva for some weeks after symptom onset-with a slightly longer persistence time than in urine, 274,276 as it has previously been demonstrated for other vector-borne flaviviruses. In consequence, saliva has been recommended to test for ZIKV when drawing blood or processing of blood samples may be difficult.…”

“…In consequence, saliva has been recommended to test for ZIKV when drawing blood or processing of blood samples may be difficult. 275,276 Nonvector-borne ZIKV transmission plays a role in the spread of ZIKV. 277 One American scientist contracted Zika while working in Senegal in 2008, and transmitted ZIKV infection to his wife; a sexual transmission of the virus was suggested, but other possibilities such as exchange of other bodily fluids including saliva could not be ruled out; moreover, aphthous-type oral ulcers were observed in both spouses.…”