In a total of 1536 blood serum samples analysed by ELISA, antibodies for IAV nucleoprotein (NP) were detected in 30.3%. Results from HI show that the most common subtype of swIAV in the Croatian pig population was H1N1 (44.6%), followed by H3N2 (42.7%) and H1N2 (26.3%). Antibodies to at least one subtype were detected in 62.19% of blood serum samples. Detection of swIAV antigen was performed by IHC and detected in 8 of 28 lung samples collected post-mortem. The matrix (M) gene was detected in nine of one hundred and forty-two lung tissue samples and in seven of twenty-nine nasopharyngeal swabs. Phylogenetic analysis of amplified HA and NA gene fragments in Croatian isolates suggests the presence of swIAV H1avN1av.

Artritis-encefalitis koza (AEK) je neizlječiva virusna bolest proširena u većini zemalja koje se bave intenzivnim uzgojem koza. Ekonomsko značenje ove bolesti očituje se uginućem jaradi, smanjenim prirastom i mliječnošću, prijevremenim lučenjem iz uzgoja. U razdoblju od 2012. do 2019. godine na području 16 županija u Republici Hrvatskoj pretraženo je 10 715 uzoraka krvi, a tijekom tog osmogodišnjeg razdoblja specifična protutijela za virus AEK bila su potvrđena u 4 353 uzoraka krvnog seruma pa zaključno možemo govoriti o seroprevalenciji od 40,62 %. Rezultati genotipiziranja odabranih sojeva LVMP ukazuju na cirkulaciju genetske skupine A i B u populaciji koza i to su prva takva istraživanja provedena u Hrvatskoj. Dokaz prisutnosti genotipa A u stadu koza u kojem je istovremeno dokazan i genotip B ukazuje na činjenicu da sojevi LVMP nisu ograničeni na jednu vrstu već da sojevi MVV koji se uglavnom nalaze u ovaca, cirkuliraju i u koza. Rezultati višegodišnjeg istraživanja provedenog na Hrvaskom veterinarskom institutu ukazuju na široku rasprostranjenost virusa AEK u uzgojima koza u Republici Hrvatskoj. Ako znamo da jednom zaražena jedinka ostaje doživotni nositelj i prenositelj virusa postavlja se pitanje uspješnosti cijele proizvodnje pa je stoga jedini dugoročno održiv način uzgoja uzgoj slobodan od AEK.

Dr. sc. Lorena JEMERŠIĆ*, dr. med. vet., izvanredna profesorica, (dopisni autor: e-mail: jemersic@veinst. hr), znanstvena savjetnica, dr. sc. Jelena PRPIĆ, dipl. ing. mol. biol., znanstvena suradnica, dr. sc. Besi ROIĆ, dr. med vet., znanstvena savjetnica, Darko ŽELJEŽIĆ, dr. med. vet., viši stručni suradnik, dr. sc. Tomislav KEROS, dr. med. vet., znanstveni savjetnik, Hrvatski veterinarski institut, Zagreb, Hrvatska Sažetak Divlja je svinja jedna od najstarijih preživjelih vrsti životinja na euroazijskom području. Danas je proširena u Europi, Aziji, Africi, a uvedena je i na područje Sjeverne Amerike. Zbog svoje visoke prilagodljivosti, klimatskih promjena, načina gospodarenja lovištima i malog broja prirodnih neprijatelja, divlja je svinja najmanje ugrožena vrsta životinja i njezin broj sustavno raste. Danas ona predstavlja ugrozu poljoprivrednicima kojima nanosi štete, a zbog hrane ulazi i u prigradska te gradska okružja. Prepoznata je za jednog od najznačajnijih rezervoara virusnih infekcija životinja, ali i nekih zoonoza. Naime, divlja svinja može doći neposredno i posredno u dodir s domaćim životinjama te na taj način prenijeti uzročnike virusnih infekcija. Obzirom da je lov jedna od važnijih turističkih ponuda Hrvatske, a divlja svinja jedna od najtrofejnijih divljih životinja, dodir divlje svinje s ljudima može ugroziti i zdravlje ljudi. U ovom smo radu opisali ulogu divljih svinja pri prijenosu najznačajnijih virusnih infekcija u svinjogojskoj industriji Europe, poput šireće afričke svinjske kuge te nama poznate klasične svinjske kuge i za druge vrste životinja poput bolesti Aujeszkoga. Opisali smo i značenje divlje svinje kao rezervoara virusa hepatitisa E, danas sve značajnije zoonoze. Ujedno je dat osvrt na moguću pojavnost navedenih infekcija ili njihovu prisutnost u divljih svinja s područja Republike Hrvatske. Ključne riječi: divlja svinja; rezervoari; virusne infekcije; Europa; Hrvatska; afrička svinjska kuga; klasična svinjska kuga; hepatitis E

A total of 131 blood samples and 175 spleen samples were collected from three cervid species: roe deer (Capreolus capreolus), red deer (Cervus elaphus) and fallow deer (Dama dama) inhabiting the continental part of Croatia. Serum samples were tested for antibodies against bovine herpesvirus 1, parainfluenza-3 virus, bluetongue virus, bovine respiratory syncytial virus, hepatitis E virus, bovine viral diarrhoea virus and enzootic bovine leukosis virus. The tested sera were negative for bovine viral diarrhoea virus, enzootic bovine leukosis virus, bluetongue virus, bovine respiratory syncytial virus and hepatitis E virus antybodies. The antibody prevalence in roe deer and red deer samples was 21.11% for bovine herpesvirus 1 and 75.55% for parainfluenza-3 virus. Sera from bovine herpesvirus 1 positive animals were subsequenty tested with comparative virus neutralization test and bovine herpesvirus 1 neutralising antibodies were found in 18 (out of 19) sera. In fallow deer, no antibodies against any of the viral pathogens were detected. All spleen samples tested for bovine viral diarrhoea virus and enzootic bovine leukosis virus came back negative, except for one red deer spleen sample found to be weakly diarrhoea virus-positive. Our findings provide the first information on the exposure of Croatia-inhabiting cervid species to viral pathogens, and could serve as valuable baseline data for future investigations regarding deer exposure to various pathogens and the distribution of diseases shared between wildlife and livestock. As of now, the epidemiology of these viruses in the Croatian cervid population has been only poorly understood, so that further research is recommended.

Istraživan je utjecaj infekcije virusom artritis encefalitisa koza (AEK), kliničkog artritisa i subkliničkog mastitisa na trajanje laktacije, ukupno mlijeko i sastav mlijeka. Istraživanje je provedeno na uzorku od 808 koza pasmine francuska alpska koza s proizvodnih mliječnih farmi u Hrvatskoj. Uzeti su uzorci krvi za serološka testiranja i uzorci mlijeka za detekciju subkliničkog mastitisa. Prisutnost kliničkog artritisa dijagnosticirana je pregledom i palpacijom zglobova. Podaci o laktacijama i proizvodnji preuzeti su od Hrvatske poljoprivredne agencije (HPA). Zasebno su testirani utjecaji AEK infekcije i kliničkog artritisa na ukupno mlijeko, trajanje laktacije i sastav mlijeka (mast, protein, laktoza) pomoću GLM procedure za modele koji su uključivali godinu mjerenja, broj laktacije i subklinički mastitis. Infekcija AEK virusom potvrđena je u 53,72 % koza od ukupnog broja koza. Od ukupnog uzorka 23,08 % inficirano je s AEK i imalo subklinički mastitis bakterijske etiologije. Nadalje 22,47 % od ukupnog broja imalo je klinički artritis. Od ukupnog broja 16,95 % bilo je AEK pozitivno i imalo klinički artritis. Utjecaj infekcije virusom AEK potvrđen je za sva analizirana svojstva u smislu smanjenja proizvodnih rezultata. Klinički artritis je pokazao značajan utjecaj na smanjenje većine proizvodnih vrijednosti osim na ukupno mlijeko, udio (%) masti laktoze i ukupnu laktozu (kg). Subklinički mastitis nije značajno utjecao na trajanje laktacije, kao ni udio (%) i udio masti, proteina i laktoze.

We have investigated the influence of infection with Caprine Arthritis Encephalitis Virus (CAEV), developed clinical arthritis and recorded subclinical mastitis on the length of lactation, milk yield and its composition per lactation. The study was carried out on the sample of 808 goats of French Alpine breed from production farms in Croatia. Samples of blood were taken for serological tests and milk samples for subclinical mastitis detection. Presence of clinical arthritis was noted by inspection and palpation of the joints. Lactation and production data were collected by Croatian Agricultural Agency. The influence of infection status for CAEV and clinical arthritis, separately, were tested on milk yield, length of lactation and milk composition (fat, protein and lactose) using GLM procedure for models including the year of measurement, lactation number of the animal and subclinical mastitis record. CAEV was serologically confirmed in 53.72 % of the total number of goats. From the total sample 23.08 % were infected with CAEV with confirmed subclinical mastitis of bacteriological etiology. In addition, 22.47 % of the total sample had clinical arthritis. Of the total sample 16.95 % were CAEV infected and with diagnosed clinical arthritis. Influence of virus infection was confirmed on all of the analyzed traits, with lower production results. Clinical arthritis had significant influence on decrease in most of analyzed traits, exceptions being total milk, fat amount (%) and lactose content (%) and amount (kg). Diagnosed subclinical mastitis was not found to be significant influence in models of duration of lactation, or fat, protein and lactose content (%).

Istražena je povezanost prevalencije i etiologije supklinickog mastitisa s pojavnoscu klinickog artritisa u 543 francuske alpske koze seroloski pozitivne na virus artritisa-encefalitisa (AEK) iz proizvodnih farmi sa sjeverozapada Hrvatske. Cilj je bio odrediti je li seroloska pozitivnost na AEK povezana s pojavnoscu supklinickog mastitisa bakterijske etiologije i istražiti je li AEK glavni uzrok pojavnosti klinickog artritisa u pretraženih koza. Sve su koze bile pregledane na pojavu klinickog artritisa. Uzorci krvi iz jugularne vene bili su testirani na AEK imunoenzimnim testom. Uzorci mlijeka, uzeti iz svake polovine vimena zasebno, pretraženi su na prisutnost bakterijskih uzrocnika mastitisa. Svi prikupljeni podatci unakrsno su klasificirani u kontingencijskim tablicama. Od ukupnog broja koza, AEK je seroloski potvrđen u 50, 8%. Supklinicki mastitis je potvrđen u 52, 3% koza. Istodobna pojava supklinickog mastitisa i AEK zabilježena je u 30% od ukupnog broja, dok je 21, 9% koza s klinickim artritisom bilo seroloski pozitivna na AEK. Statisticke su analize potvrdile pozitivnu povezanost pojave supklinickog mastitisa i AEK seropozitivnosti. Slicni su rezultati dobiveni i za povezanost pojavnosti klinickog artritisa i AEK seropozitivnosti. Također je zabilježena slaba pozitivna povezanost između supklinickog mastitisa i klinickog artritisa. Rezultati upucuju na to da bi AEK mogao utjecati na ucestalost supklinickog mastitisa. Rezultati također nalažu dodatno istraživanje AEK infekcije kao glavnog uzroka pojave klinickog artritisa u istraženim stadima.

Prevalence of Caprine Arthritis Encephalitis Virus (CAEV) and occurrence of clinical arthritis were investigated on 543 goats of French Alpine breed on six intensive production farms in North-Western Croatia. The aim of the study was to determine seropositivity to CAEV and to examine the occurrence of clinical arthritis in relation to CAEV seropositive goats. All goats were examined clinically and presence of arthritis was noted. The blood samples were tested for antibodies against CAEV using the immunoenzyme test. All collected data were cross-classified in two-way contingency tables. Of the total number of goats, CAEV was serologically confirmed in 50.8% and 31.6% of all goats were diagnosed with clinical arthritis. CAEV seropositive goats were 21.9% and they also expressed clinical signs of arthritis. Statistical tests confirmed positive association between clinical arthritis diagnosis and seropositivity to CAEV with Phi coefficient of 0.25 (P<0.01). Results suggest that serious eradication programs should be introduced in north western Croatian goat herds, but also that further investigations in all Croatian herds should be conducted and measures should be applied on all herds.

Bluetongue (BT) is a viral infectious non‑contagious disease of domestic and wild ruminants. Insect species of the genus Culicoides (Diptera: Ceratopogonidae) serve as biological vectors that transmit bluetongue virus (BTV) to susceptible hosts. The infection is present in the Mediterranean region. Recently, it has also been reported in Central, Western, and Northern Europe where BTV‑8 was recognised as the causative serotype. In the meantime, BTV‑14 has appeared in the North‑Eastern part of Europe. In the present study, BTV serotype 16 (BTV‑16) was detected by virus neutralisation (VNT)‑assay and real‑time reverse transcription‑PCR (rRT‑PCR) in 1 antelope and BTV‑1 in 3 of 10 Oryx antelopes (Oryx leucoryx) imported in Croatia from the Sultanate of Oman. No BTV vectors were collected during the antelope quarantine on the Veliki Brijun Island. Also, no BTV antibodies were detected in sheep, cattle, and deer on the Island. Entomological studies did not reveal any new vector species that may have been introduced with the infected antelopes on their transportation. It was the first time that BTV was demonstrated in animals imported in Croatia. It involved BTV‑1, which had never been demonstrated before and BTV‑16, which had been previously recorded in domestic ruminants.

Tick-borne encephalitis (TBE) is a growing public health concern in central and northern European countries. Even though TBE is a notifiable disease in Croatia, there is a significant lack of information in regard to vector tick identification, distribution as well as TBE virus prevalence in ticks or animals. The aim of our study was to identify and to investigate the viral prevalence of TBE virus in ticks removed from red fox (Vulpes vulpes) carcasses hunted in endemic areas in northern Croatia and to gain a better insight in the role of wild ungulates, especially red deer (Cervus elaphus) in the maintenance of the TBE virus in the natural cycle. We identified 5 tick species (Ixodes ricinus, Ixodes hexagonus, Haemaphysalis punctata, Dermacentor reticulatus, Rhipicephalus sanguineus) removed from 40 red foxes. However, TBE virus was isolated only from adult I. ricinus and I. hexagonus ticks showing a viral prevalence (1.6%) similar to or higher than reported in endemic areas of other European countries. Furthermore, 2 positive spleen samples from 182 red deer (1.1%) were found. Croatian TBE virus isolates were genetically analyzed, and they were shown to be closely related, all belonging to the European TBE virus subgroup. However, on the basis of nucleotide and amino acid sequence analysis, 2 clusters were identified. Our results show that further investigation is needed to understand the clustering of isolates and to identify the most common TBE virus reservoir hosts in Croatia. Sentinel surveys based on wild animal species would give a better insight in defining TBE virus-endemic and possible risk areas in Croatia.

Background: Porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) have been present for the last 2 decades in Croatia, causing large economical losses in the pig production. The clinical features of the infections are mostly manifested by the development of respiratory problems, weight loss and poor growth performance, as well as reproductive failure in pregnant sows. Even though the infections are continuously recognized in some regions in Croatia, the heterogeneity of the detected viral strains from 2012 has not yet been investigated. The objective of this study was to compare virus strains of PCV2 and PRRSV detected until 2008 in Croatia with strains isolated in 2012 to gain a better epidemiological understanding of these two infections.Results: PCV2 and PRRSV strains detected in 2012 in fattening pigs from regions where these two diseases have been previously described were compared to strains that have been detected in the same regions within the past two decades. The phylogenetic analysis revealed that the circulating PCV2 and PRRSV strains are distantly related to the previously described Croatian viral strains. However, when compared to known isolates from the GenBank a high genetic identity of PRRSV isolates with isolates from Hungary, Denmark and the Netherlands was found.Conclusion: The results of this study reveal that even though PCV2 and PRRSV are constantly present in the investigated regions in Croatia, the viral strains found in 2012 genetically differ from those detected in earlier years. This indicates that new entries into the pig population appeared with regard to both infections, probably as a result of pig trade.

Serological data imply that pseudorabies (Aujeszky’s disease) is present in domestic pigs and wild boars in Croatia. Therefore, this study included testing of brain tissue samples collected from 200 domestic pigs and 105 wild boars originating from seventeen districts of Croatia. The presence of pseudorabies virus (PrV) DNA was confirmed in samples originating from six domestic pigs (3%) and one wild boar (0.95%). Positive samples were sequenced and analysed on the basis of a gC genome fragment. PrV strains have shown to be genetically identical and they are strongly related to some representative strains in the relatively heterogeneous Clade A. The results clearly show that PrV is still circulating among the domestic pig population in Croatia. Furthermore, the presence of pseudorabies virus in wild boars underlines the importance of this species as a PrV reservoir. Continued surveillance is necessary to track the viral spread in order to achieve final eradication of the disease.