Banović et al.
Tick-borne encephalitis virus seropositivity among tick infested individuals in Serbia
Pathogens 2021, 10, 301, doi.org/10.3390/pathogens100330301
In Serbia, the TBE virus (European subtype) has been detected for the first time in 1972 in the Pešter plateau (in southwestern Serbia), and additional virus strains have been isolated at Fruška Gora mountain (in the north of Serbia), as well as in rural suburbs of Belgrade. Despite the fact of TBE being a notifiable disease in Serbia since 2004, there is no active surveillance program in place and TBE diagnosis is performed only in one medical facility by serological methods.
A prospective cohort study has been carried out to evaluate the risk to acquire a TBE virus infection and to identify new TBE foci by analyzing TBE antibodies two months after a tick bite using a commercial immunofluorescence test. A total of 676 patients who had reported to have been bitten by a tick were invited to participate in this study, and 113 of them agreed. Ticks taken from the patients were identified as Ixodes ricinus (N=117), Rhipicephalus sanguineus (N=2) and Dermacentor reticulatus (N=2). None of the patients developed TBE, however seven of them developed the first stage of Lyme disease and were treated with antibiotics. Two months after the tick bite, TBE IgG antibodies could be detected in 13.27% of the patients, while only in 4% in the control group, TBE antibodies could be detected.
The majority of seropositive patients reported their tick bite in rural areas, mostly in the proximity of Fruška Gora mountain (rural parts of Sremska Kamenica and Obrovac), the Rtanj mountain and Veliko Gradište). Some seropositive patients were bitten in urban parts of Novi Sad and Sremska Kamenica town. All these localities lie in northern Serbia. These results indicate that exposure to ticks is associated with a high risk of TBE virus infection in the Serbian population, and new TBE virus risk areas have been identified.