Detection and Characterization of Alongshan Virus in Ticks and Tick Saliva from Lower Saxony, Germany with Serological Evidence for Viral Transmission to Game and Domestic Animals

Abstract

The newly discovered group of Jingmenviruses has been shown to infect a wide range of hosts and has been associated with febrile illness in humans. During a survey for Jingmenviruses in ticks from Lower Saxony, Germany, Alongshan virus (ALSV) was identified in Ixodes spp. ticks. Additional virus screenings revealed the presence of ALSV in the bodies and saliva of ticks collected at several locations in Lower Saxony. Vector competence studies that included Ixodes ricinus and Dermacentor reticulatus validated the replication of ALSV within those tick species. In vitro feeding experiments with ALSV-injected Ixodes ricinus demonstrated effective viral transmission during blood feeding. To evaluate the potential viral transmission during a natural blood meal, sera from wild game and domestic animals were investigated. One serum sample from a red deer was found to be positive for ALSV RNA, while serological screenings in game and domestic animals revealed the presence of ALSV-specific antibodies at different locations in Lower Saxony. Overall, those results demonstrate the broad distribution of ALSV in ticks in Lower Saxony and hypothesize frequent exposure to animals based on serological investigations. Hence, its potential risk to human and animal health requires further investigation.

Keywords: Alongshan virus; Jingmenviruses; LIPS assay; Lower Saxony; artificial infection; ticks.

Figure 1

Growth kinetics of the ALSV copy number per tick over a period of 21 or 49 days. (a): Growth kinetics of I. ricinus with 10⁶ copies inoculum; (b): Growth kinetics of I. ricinus with 10³ copies inoculum. The experiment was repeated three times for I. ricinus. (c): Growth kinetics of the ALSV copy numbers per D. reticulatus tick over a period of 49 days and inoculum of 10⁶ copies/tick. The experiment was conducted once.

Figure 2

Results of virus transmission experiments with ALSV-injected ticks. ALSV RNA copies/mL blood were measured on 7 different time points (1–7) after 10 h (sampling in the afternoon) or 14 h (sampling in the morning) of incubation of ALSV-injected ticks in feeding chambers 5, 6 and 8. Feeding experiments lasted 3½ days.

Figure 3

(a) Seroprevalence of wild and domestic animals based on LIPS data (red: positive serum sample(s) in this area; blue: serum samples screened in this area; grey: not screened); (b) overall seroprevalence of domestic or wild animals. Detailed map information in Figure S1. Maps were created in R v. 4.1.0 with administrative boundaries retrieved from the Global Administrative Areas Database (gadm.org).

Figure 4

Results of LIPS assay based on 167 animal sera from game animal (wild boar, red deer and roe deer) samples and 179 domestic animal (goat, sheep and horse) samples for the VP2 of ALSV in RLU/µL. Total dataset shown in Tables S4–S9.