Abstract
A reliable surveillance strategy of tick-borne encephalitis virus (TBEV) is necessary to ensure adequate disease control measures. However, current approaches assessing geographical TBEV circulation are ineffective or have significant limitations. In this study we investigated a total of 1363 goat and 312 sheep bulk tank milk samples for the presence of TBEV. Samples were collected from systematically selected farms in Lithuania every 4–5 days from April to November in 2018 and 2019. To validate results, we additionally tested 2685 questing ticks collected in the vicinity of milk collection sites. We found 4.25% (95% CI 3.25–5.47) and 4.48% (95% CI 2.47–7.41) goat and sheep milk samples to be positive for TBEV, respectively. Furthermore, geographical distribution of TBEV in milk samples coincided with the known TBE endemic zone and was correlated with incidence of TBE in humans in 2019. When sampling time coincides, TBEV detection in milk samples is as good a method as via flagged ticks, however bulk milk samples can be easier to obtain more frequently and regularly than tick samples. The minimal infectious rate (MIR) in ticks was 0.34% (CI 95% 0.15–0.64). Therefore, our results confirm that testing milk serves as a valuable tool to investigate the spatial distribution of TBEV at higher resolution and lower cost.
Highlights
Tick-borne encephalitis virus (TBEV) is a zoonotic flavivirus that is considered to be the most important causative agent of tick-borne infections in Europe [1]
TBEV is maintained in nature by Ixodes ticks that serve as vectors and constitute the central reservoir for the virus [2]
TBEV is usually transmitted to humans through the bites of infected ticks, alimentary infection via unpasteurized milk or milk products has been recognized as an additional route of transmission
Summary
Tick-borne encephalitis virus (TBEV) is a zoonotic flavivirus that is considered to be the most important causative agent of tick-borne infections in Europe [1]. TBEV is transmitted after consumption of goat milk, but infection through cow or sheep milk has been reported as well [3,4,5,6,7]. Human surveillance alone is not enough to effectively monitor the circulation of TBEV, since national health authorities of European countries use non-uniform TBE case definitions and TBE risk assessment strategies [8]. Such estimations may be affected by uneven vaccination coverage [9]. Socioeconomic, political, environmental, or meteorological factors may play a role in determining exposure risk [10,11,12,13]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
