Influenza study of backyard animals in Georgia

Abstract

ObjectiveThe purpose of this study was to identify zoonotic influenzaviruses in swine and poultry populations in Georgia and to definetheir pandemic potential.IntroductionAquatic birds are the main reservoirs of influenza viruses,however pigs represent an essential host in virus ecology as they aresusceptible to both avian and human influenza viruses. Circulatingzoonotic influenza (A/H7N9, A/H5N1, and A/H3N2v) viruses couldmutate into forms easily transmissible from human-to-human andbecome a public health concern. Georgia is located along routes usedby migrating birds where different species of aquatic birds are found.In 2006, highly pathogenic influenza virus A/H5N1 was detected intwo wild swans in Adjara (western Georgia). Moreover, in the frameof wild bird surveillance, various subtypes of influenza A viruseswere detected in mallard and gulls in Georgia (Lewis, 2013). Thusdomestic animals in Georgia have a potential chance to contractinfluenza viruses from wild birds.MethodsThe Kakheti region, the leading region in cattle breeding andpoultry production in Georgia, was selected for study. Villages wereselected for door-to-door visits to search for ill backyard animalsshowing influenza-like symptoms. In case of identification of a sickanimal, samples were obtained for laboratory investigations; samplecollection forms were filled out to generate epidemiological data.Cloacal and tracheal swabs were taken from poultry; and pharyngealand nasal swabs were collected from pigs. Each specimen wasscreened for influenza A matrix gene by real-time RT-PCR using aprotocol from the Centers for Disease Control Prevention.ResultsEighty four villages in the Kakheti region were surveyed fordomestic animals with influenza-like illness symptoms. In total,164 specimens were collected from 112 backyard animals in55 households (107 samples were from 55 poultry and 57 sampleswere from 57 pigs). All samples tested negative for Influenza A virusby real time RT-PCR. The questionnaire data revealed that the agerange of both pigs and poultry varied from one month to two years;median and mode were both 1 year. Chickens and ducks primarilyfreely ranged in backyards (67%), while half the number of pigs werekept in closed premises. Equally, 61% of pigs and poultry had contactwith other pigs or poultry within the premises.ConclusionsIn spite of the negative findings, we cannot exclude the circulationof influenza viruses in domestic animals in Georgia. Especially,considering the fact that a domestic duck with influenza A/H10virus was identified during veterinarian training in 2010 in Grigoleti(Black sea cost of Georgia) manifesting no clinical symptoms.Therefore, larger scale studies, including swabbing more backyardanimals without any clinical symptoms are necessary to identify inter-species virus transmission in the country.