Current Status of Vector-Borne Diseases in Croatia: Challenges and Future Prospects

Abstract

Different vector-borne pathogens are present or have (re-)emerged in Croatia. Flaviviruses tick-borne encephalitis (TBEV), West Nile (WNV), and Usutu (USUV) are widely distributed in continental regions, while Toscana virus (TOSV) and sandfly fever viruses are detected at the Croatian littoral. Recently, sporadic clinical cases of Tahyna orthobunyavirus (TAHV) and Bhanja bandavirus infection and seropositive individuals have been reported in continental Croatia. Acute infections and serologic evidence of WNV, TBEV, USUV, and TAHV were also confirmed in sentinel animals and vectors. Autochthonous dengue was reported in 2010 at the Croatian littoral. Lyme borreliosis is the most widely distributed vector-borne bacterial infection. The incidence is very high in northwestern and eastern regions, which correlates with numerous records of Ixodes ricinus ticks. Acute human Anaplasma phagocytophilum infections are reported sporadically, but there are many records of serologic evidence of anaplasmosis in animals. Mediterranean spotted fever (Rickettsia conorii) and murine typhus (Rickettsia typhi) are the main rickettsial infections in Croatia. Human leishmaniasis is notified sporadically, while serologic evidence of leishmaniasis was found in 11.4% of the Croatian population. After the official eradication of malaria in 1964, only imported cases were reported in Croatia. Since vector-borne diseases show a growing trend, continuous monitoring of vectors is required to protect the population from these infections.

First detection of tick‐borne encephalitis virus (TBEV) in raw milk samples in North‐Western Iran

“…Although it is generally expected that IgG antibodies to TBEV remain detectable for a longer period compared to the virus itself, our study presents a contrasting scenario. This can be attributed to two key factors: The rapid slaughter of animals, which likely restricted the full development of their antibody response, and the seasonal aspect of our sample collection, conducted during summer when TBEV is known to be more active (Blomqvist et al., 2021 ; Vilibic‐Cavlek et al., 2023 ). As a result, the virus is detectable primarily during the initial clinical phase, highlighting the importance of using both serological and molecular methods for accurate diagnosis and treatment (Balogh et al., 2010 ; Grešíková et al., 1975 ).…”

An Overview of Tick-Borne Encephalitis Epidemiology in Endemic Regions of Continental Croatia, 2017–2023

“…The disease is endemic in northwestern and eastern continental regions between the Sava and Drava rivers. Endemicity is highest in northwestern counties, with average incidence rates ranging from 3.61 to 6.78 per 100,000 inhabitants [ 17 , 18 ]. In recent years, TBEV has occurred in some areas of the Gorski Kotar, the mountainous region of the central continental part of Croatia [ 6 ].…”

A DNA barcode reference library of Croatian mosquitoes (Diptera: Culicidae): implications for identification and delimitation of species, with notes on the distribution of potential vector species

“…In Croatia, the first clinical cases of WNV infection were reported in 2012 [ 19 ], associated with Culex pipiens complex, and possibly some other species [ 20 ]. After 2012, WNV infections occurred continuously in Croatia [ 21 ]. The main vector of Usutu virus (USUV) infection is Culex pipiens , although the virus has also been found in several other species [ 22 , 23 ].…”