Snježana Kovač

Phylogenetic characterisation of feline immunodeficiency virus in naturally infected cats in Croatia indicates additional heterogeneity of subtype B in Europe

This study was performed on 29 domestic cats with a variety of clinical signs, possibly related to FIV infection. Blood samples were tested by a rapid immunochromatographic (ICA) procedure for detection of FIV antibodies. Subsequently, polymerase chain reaction (PCR) was performed to amplify a portion of the proviral gag gene. All 11 positive PCR products were sequenced and compared with previously reported FIV sequences. Croatian proviral isolates that could be amplified were clustered within subtype B, and additional heterogeneity was confirmed by the formation of three separate clusters. Phylogenetic analysis of circulating strains in Croatia and in southeast Europe is necessary to improve diagnostic methods and selection of the appropriate vaccinal strains.

Outbreak of equine influenza in Croatia in 2015 and post outbreak epidemiological situation

In March 2015, a few days after a major horse fair event in Bjelovar, Croatia, an equine influenza outbreak began and in the days that followed spread to more than 20 stud farms in the continental part of Croatia. The epidemiological investigation showed the importance of the national and international movement of asymptomatic carrier animals as a major risk factor for the introduction of the equine influenza virus and its spread in the naïve population. Molecular characterization and phylogenetic analyses confirmed that the EI outbreak was caused by an imported viral strain of the H3N8 subtype, phylogenetically similar to recent European strains belonging to Florida sublineage clade 2. The post-outbreak equine influenza seroprevalence in continental Croatia, based on ELISA testing, was 12.3% and varied between 1.1% and 32.6% on a county level. The highest seroprevalence in counties with predominantly sport and leisure horses highlighted animal management as a principal risk factor for equine influenza infection. On the other hand, variations in haemagglutination inhibition titres in the tested serum samples suggested different times of infection acquisition and unreported outbreaks of equine influenza in continental Croatia after the 2015 outbreak. Vaccination coverage, even after the large outbreak in 2015, was still below 10%, which suggests the lack of education of horse owners and represents a high risk for further outbreaks. In conclusion, influenza is a wide spread infection with multiple, often unrecorded, outbreaks in continental Croatia. A high risk of further outbreaks is present due to low vaccination coverage, an increase in the sport and leisure horse population and the intensive movement of those animals. In order to prevent *Corresponding author: Ljubo Barbić, PhD, DVM, Department of Microbiology and Infectious Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb, Heinzelova 55, 10000 Zagreb, Croatia, Phone: +385 1 2390 211; Fax: +385 1 2390 211; E-mail: ljubo.barbic@vef.hr DOI: 10.24099/vet.arhiv.0033