The Seroprevalence of Influenza A Viral Infection in Dogs and Cats in the Northwestern and Central Croatia

Influenca domaćih mesojeda je akutna, virusna, kontagiozna, respiratorna bolest koju uzrokuju različiti podtipovi virusa influence A iz porodice Ortomyxoviridae. Virus se širi izravnim dodirom s bolesnim životinjama, ali i zrakom te kontaminiranim predmetima, prostorom ili preko hrane. Infekcije najčešće prolaze subklinički ili su simptomi tek blagi i prolazni karakterizirani respiratornim sindromom koji uključuje umjerenu groznicu i kašalj. Međutim opisane su i infekcije s letalnim ishodom. U ovom istraživanju je po prvi put istražena proširenost infekcije virusom influence tip A u domaćih mesojeda kućnih ljubimaca s područja središnje i sjeverozapadne Hrvatske. U tu svrhu pretraženo je ukupno 628 uzoraka seruma od kojih 555 uzoraka seruma pasa i 73 uzorka seruma mačaka komercijalnim kompetitivnim imunoenzimnim testom (ID Screen® Influenza A Antibody Competition Multi-species). Specifična protutijela za nukleoprotein virusa influence A ustanovljena su u serumima ukupno šest životinja tako da je ukupna seroprevalencija 1%. Prema vrsti životinja seroprevalencija u pasa iznosila je 0,9%, a u mačaka 1,4%. Nisu ustanovljene epizootiološke poveznice između pozitivnih životinja kao niti klinički znakovi koja bi odgovarala infekciji virusom influence tip A. Bez obzira na relativno mali broj pozitivnih životinja, prvi dokaz infekcija domaćih mesojeda virusom influence tip A na području Republike Hrvatske ima iznimni značaj za svakodnevni klinički rad doktora veterinarske medicine jer očito i na našem području postoji opasnost od oboljenja domaćih mesojeda od influence. Još značajnije, dokaz infekcija kućnih ljubimaca virusom influence tijekom sezone influence u ljudi zasigurno predstavlja važnu smjernicu za javno zdravstvo te zahtjeva daljnja istraživanja radi određivanja uloge i značaja kućnih ljubimaca u širenju bolesti na ljude.Influenza of domestic carnivores is acute, viral, contagious disease caused by different subtypes of influenza A virus member of Orthomyxoviridae family. The virus is transmitted by direct contact with sick animals, fomites, trough aerosol and contaminated food. Infections in domestic carnivores in majority of cases causes subclinical or with mild symptoms characterized by respiratory syndrome which include fever and cough. However, there have been described infections with lethal outcome. The aim of this study was to investigate the presence and prevalence of influenza A virus infection in domestic carnivores in central and north-west Croatia for the first time. A total of 628 domestic carnivore sera samples were tested by commercial competitive ELISA test (ID Screen® Influenza A Antibody Competition Multi-species). Out of 555 dog sera samples and 73 cat sera samples specific antibodies for influenza A nucleoprotein were detected in sera of six animals,. The overall seroprevalence was 1% and seroprevalence in dogs was 0,9%, and in cats 1,4%. There was no correlation of epizootilogical data between positive animals and even more positive animals had no clinical history of respiratory disease. Despite the relatively low number of positive samples, the first evidence of influenza virus A infections of carnivores in Croatia has clinical importance for routine practice because obviously in our field there is substantial risk of clinically overt influenza infections in domestic carnivores. Even more evidence of influenza infections in pet animals during the influenza season in people certainly highlights importance of pet animals in public health and require further research to determine their importance in spreading of the disease to people