Basic Demographic Processes in Croatia

U radu se razmatraju glavni demografski procesi u suvremenom razvoju hrvatskog stanovništva: ukupna, prirodna i emigracijska depopulacija i demografsko starenje. Objašnjava se međusobna kauzalnost procesa opće i parcijalne depopulacije. Rezultati upućuju na njihove dalekosežne negativne posljedice u budućem razvoju hrvatskog stanovništva.The paper describes the basic processes of contemporary development of the Croatian population: total, natural and emigrational depopulation and demographic ageing. The causal connection between the processes of general and partial depopulation is explained and the results indicate their far-reaching unfavourable effects to the future development of Croatian population

The Issues of Statistical Monitoring of Emigration

Za Hrvatsku se može reći da je „tradicionalno“ iseljenička zemlja. Emigracijski procesi u Hrvatskoj kontinuirano traju već više od 150 godina. Uz manje ili više intenzivnu emigraciju, u Hrvatskoj je od osamostaljenja svake godine prisutna i prirodna depopulacija. Takva je situacija rezultirala dubokom demografskom krizom u kojoj se Hrvatska nalazi. U najnovije vrijeme, od pristupanja Europskoj uniji, svjedoci smo najnovijeg emigracijskog vala iz Hrvatske jer se hrvatskim državljanima otvorilo tržište rada većine zemalja Europske unije. Opće je poznato da postoji problem vezan za točnost broja iseljenih osoba koje prikazuje hrvatska službena statistika. U radu se uspoređuju podatci hrvatske službene statistike i statistika odabranih zemalja u koje su se hrvatski državljani najviše iseljavali. Cilj rada je utvrditi i analizirati nerazmjer između hrvatskih službenih podataka o iseljenim osobama i službenih podataka o useljenim osobama država u koje su se hrvatski državljani najviše iseljavali.It could be said that Croatia is “traditionally” an emigration country. Emigration processes in Croatia have been going on continually for over 150 years. With a more or less intensive emigration, since its independence, Croatia has also been experiencing a natural depopulation. Such a situation has resulted in the deep demographic crisis that the country is currently in. In recent times, since joining the European Union, we’ve been witnesses to the newest emigration wave from Croatia, as Croatian citizens have gained access to the job market of almost all EU countries. It is known that there are issues related to how correct the number of emigrated persons is, as shown by the official Croatian statistics. In this paper, we compare the official Croatian statistics data to the statistics of selected countries that Croatian citizens have most emigrated to. The goal of this paper is to find and analyze the discrepancy between the official Croatian statistics about the number of emigrated persons and the official data about immigrated persons in the countries where Croatian citizens emigrated to the most

Emigration Between 2011 and 2021 From Smaller Territorial Units (Counties, Cities and Municipalities)

Hrvatska već dugi niz godina ima negativan migracijski saldo, što znači da je tijekom određenog razdoblja veći broj iseljenih od broja useljenih osoba. Točne podatke o broju iseljenih iz Hrvatske teško je utvrditi iz više razloga. Postoji i problem takozvanog fiktivnog stanovništva, koje je prijavljeno u Hrvatskoj iako u njoj ne živi. Velik broj iseljenih osoba ne prijavljuje da se iselilo, iako su to dužni po zakonu. Razlog je tome, kao i fiktivnom prijavljivanju, zadržavanje ili stjecanje određenih beneficija u Hrvatskoj. U Hrvatskoj postoji velika razlika između regija u intenzitetu iseljavanja. Cilj ovoga rada je analizirati iz kojih se dijelova Hrvatske stanovništvo najviše iseljavalo te iz kojih se iseljavalo najmanje.For a number of years now, Croatia has had a negative net migration rate, which means that more people have emigrated than immigrated during a period of time. It is difficult to establish the real number of persons who have emigrated from Croatia due to a number of reasons. There is also the issue of the so-called flfictional population«, persons who are registered as living in Croatia, even though they do not actually live there. A large number of persons have not registered themselves as having left the country, even though they are obliged to do so by law. The reason for this, as well as the fictional registration in Croatia, is maintaining or gaining certain benefits in Croatia. In Croatia, there is a large difference among regions in terms of emigration intensity. The goal of this paper is to analyze which parts of Croatia suffered the most from emigration, and which felt the least effect of this process

Serološko istraživanje lajmske borelioze u pasa s područja grada Zagreba u Hrvatskoj.

Sera from 120 apparently healthy dogs, 74 purebred, 46 mixed-bred, 57 females and 63 males in the Zagreb area (Croatia) were examined by enzyme-linked immunoadsorbent assay (ELISA) for antibodies to Borrelia burgdorferi. During triple i/v immunization of dog at 1, 7 and 14 day, on each occasion with 5 ml 1.4×107 cells/ml of B. burgdorferi sensu stricto, strain B31 ATCC 35210, a positive control serum was obtained at day 28 p.i., while negative control serum was obtained prior to immunization. The antigen for ELISA was prepared from the same bacterial strain sonicated on ice. The sonicate was quantified by sodium dodecyl sulphate polyacrilamid gel electrophoresis (SDS PAGE). IgG antibodies to B. burgdorferi were estimated in 6 (5%) samples of dog sera in titre ranging from 1:100 to 1:2000 (Optical density-OD=0.650 + 36.49, n=6). Antibodies to B. burgdorferi were found in two females and four males, two Labrador retrievers and in one German shepherd, a Hungarian viszla, one cocker spaniel, and a German wirehaired pointer at 2.5 to 8 years of age. Of 114 seronegative samples three samples were found to be very close to the margin of optical density that determined seropositive result (OD=0.562). Estimated seroprevalence to B. burgdorferi in dog sera suggested that dogs in the Zagreb area are infected with B. burgdorferi and that the Zagreb area is part of a wider Central European Lyme boreliosis endemic area.Imunoenzimnim testom (ELISA) pretraženo je 120 uzoraka klinički zdravih pasa, 74 čistokrvna, 46 križanih, 57 ženki i 63 mužjaka područja grada Zagreba na prisutnost protutijela za B. burgdorferi. Trokratnom i/v imunizacijom psa 1., 7. i 14. dana s po 5 ml kulture B. burgdorferi sensu stricto soj B 31 ATCC 35210 u količini 1,4 × 107 bakterija/ml dobiven je 28. dan od početka imunizacije pozitivni kontrolni serum, a negativni je uzet prije imunizacije. Od istog soja načinjen je ultrazvučno lizirani antigen za imunoenzimni testž (ELISA) čiji je proteinski sastav određen elektroforezom u poliakrilamidnom gelu uz dodatak natrijevog dodecilsulfata (sodium dodecyl sulphate polyacrilamid gel electrophoresis - SDS PAGE). U 6 (5%) uzoraka seruma pasa ustanovljen je titar IgG protutijela od 1:500 do 1:2000 (ODp=0,650 + 36,49, n=6) u dvije kuje i četiri psa u dobi od 2,5 do 8 god., u dva labradora i po jednog njemačkog ovčara, mađarske vižle, koker španijela i njemačkog oštrodlakog ptičara. Od 114 seruma u kojih apsorpcijska vrijednost nije prelazila graničnu apsorpcijsku vrijednost za pozitivne (OD=0,562) u tri seruma apsorpcijska vrijednost je bila blizu granične apsorpcijske vrijednosti. Ustanovljena IgG protutijela za B. burgdorferi u serumima pasa ukazuju da psi područja grada Zagreba bivaju inficirani bakterijom B. burgdorferi i da je to područje dio šireg srednjeeuropskog endemskog žarišta lajmske borelioze

REGIONAL ASPECTS OF DEPOPULATION IN CROATIA (1991-2011)

Demografske prilike u Hrvatskoj izrazito su nepovoljne. Osnovni demografski procesi koji potvrđuju postojeće promjene jesu depopulacija, emigracija i starenje stanovništva te prostorna/regionalna populacijska polarizacija. Razdoblje razmatrano u radu obilježava intenziviranje navedenih negativnih demografskih procesa. Njihovi su uzroci vrlo kompleksni i prisutni su dugi niz godina. Demografske prilike nisu jednako nepovoljne u svim županijama Hrvatske. Općenito se može ustvrditi da županije s većim udjelom ruralnih prostora imaju nepovoljnije demografske trendove od županija u kojima su urbani prostori više zastupljeni. Dugogodišnja nebriga o ruralnim prostorima transformirala je hrvatsko selo iz demografskoga „inkubatora“ u prostor izumiranja stanovništva. Urbana su naselja privlačila ruralno stanovništvo, stoga je u njima s odgodom došlo do razvoja depopulacijskih procesa. Ratna su zbivanja 1990-ih, zbog brojnih ratnih gubitaka i složenih demografskih posljedica, ubrzala već postojeće nepovoljne demografske trendove kako na nacionalnoj tako i na regionalnoj/ županijskoj razini. Postojeći demografski i ekonomski okviri teško mogu pokrenuti bilo kakvo značajnije poboljšanje općega stanja. To se osobito odnosi na ruralne prostore koji se ne nalaze u blizini urbanih centara.Demographic trends in Croatia are extremely unfavourable. The most important demographic processes which have affected the existing situation are depopulation, emigration, ageing of population and spatial/regional polarization. The period considered in the research is characterized by the intensification of negative demographic processes. The causes of demographic problems are complex and long lasting although the demographic characteristics are not equally unfavourable in all Croatian counties. In general, predominantly rural counties have more negative demographic trends than the urban ones. Long lasting neglect of rural areas has transformed them from “demographic incubators” into the areas of population extinction. As the rural population migrated towards cities, depopulation processes in the cities were delayed, unlike the rural areas. Croatian Homeland War in 1990s, due to numerous war losses and complex demographic situation, intensified the existing negative demographic trends on national and regional/county level. Current demographic and economic circumstances are not likely to encourage any significant improvement of the situation particularly in rural areas, remote from urban centres

CONTEMPORARY DEMOGRAPHIC FEATURES OF PODGORJE

Podgorje obuhvaća prostor hrvatske jadranske obale u podnožju Velebita. Adminsitrativno gledano, istraživanjem su obuhvaćena naselja Grada Senja, te općina Karlobag i Starigrad, koja svojim teritorijem participiraju na obali Jadranskog mora. Promatrani je prostor podijeljen između Ličko-senjske (Grad Senj i Općina Karlobag) i Zadarske županje (Općina Strarigrad). Podgorje ima vrlo negativna demografska obilježja. Ukupna depopulacija traje, s iznimkom jednog međupopisja (1981. – 1991.), kontinuirano od 1910. godine kada je zabilježen maksimum naseljenosti (16 782 stanovnika). U sljedećih se sto godina broj stanovnika skoro prepolovio. Prema najnovijim popisu stanovništva iz 2011. godine Podgorje je imalo samo 8 894 stanovnika. Prirodna depopulacija je u Podgorju prisutna dugi niz godina što vrlo negativno utječe na demografske prilike. Starenje stanovništva je u vrlo uznapredovalom stadiju. Godine 1971. indeks starenja iznosio je 58, dok je prema posljednjem popisu iz 2011. vrijednost toga demografskog pokazatelja porasla na čak 187,8. Razlozi ovakvog nepovoljnog demografskog stanja su kompleksni. Fizičkogeografska obilježja nepovoljno su u prošlosti utjecala na razvoj (krški reljef s mnogo strmih oblika, jaka bura). Danas se Podgorje nalazi u zoni preklapanja nodalno-funkcionalnih područja Rijeke, kojoj gravitira njegov sjeverni dio te Zadra, kojem gravitira njegov južni dio. Izgradnjom autoceste Zagreb – Split i planiranom izgradnjom autoceste ili brze ceste Rijeka – Žuta Lokva, Podgorje će se u biti naći u svojevrsnoj prometnoj izolaciji, što neće povoljno djelovati na demografske i ekonomske tokove. Unatoč položaju na jadranskoj obali koji nudi dobru mogućnost razvoja turizma, s iznimkom Starigrada, gdje je polazišna točka za izlete u NP Paklenica, ta djelatnost u Podgorju nije znatnije razvijena, što nepovoljno utječe na demografske prilike.Podgorje encompasses the area of the Croatia Adriatic coast at the foot of Velebit. Viewed administratively, included in the research are the settlements of the town of Senj, plus the municipalities of Karlobag and Starigrad, which with their territory participate on the coast of the Adriatic Sea. The observed area is divided between Lika-Senj County (Town of Senj and the Municipality of Karlobag) and Zadar County (Municipality of Starigrad). Podgorje has very negative demographic features. The overall depopulation has lasted, with the exception of one intercensal period (1981-1991), continuously from 1910 when the largest population was noted (16,782 residents). In the following one hundred years the number of inhabitants almost halved. According to the latest census of the population from 2011 Podgorje had only 8,894 inhabitants. The natural depopulation has been present in Podgorje for many years, which influences the demographic conditions very negatively. The ageing of the population is in a very advanced stage. In 1971, the ageing index was 58, whilst according to the last census from 2011, the value of this demographic indicator had risen to as much as 187.8. The reasons for this unfavourable demographic situation are complex. The physicalgeographical features have unfavourable affected development in the past (the karst relief with many steep configurations, and strong ‘bura’ wind). Today Podgorje is located in the zone of the overlapping nodal-functional regions of Rijeka, to which its northern part gravitates, and Zadar, to which its southern part gravitates. With the construction of the Zagreb-Split motorway and with the planned motorway or the Rijeka-Žuta Lokva express road, Podgorje will in effect find itself in a kind of transport-like isolation, which will not act favourably on the demographic and economic trends. Despite the position on the Adriatic coast which offers the good possibility for the development of tourism, with the exception of Starigrad, where there is a starting point for trips into Paklenica National Park, this activity in Podgorje is not more significantly developed, which unfavourably affects the demographic conditions

Uloga mišolikih sisavaca kao rezervoara leptospira u šumama hrasta lužnjaka Hrvatske.

In the year 2000, three hundred and eighty-one animals werw caught in 11 locations in the pedunculate oak forests extending across the wider region of the Sava River valley, an area known as an old natural focus of leptospires. Two hundred and twenty-seven animals were investigated for leptospiral carriership, 381 were tested for the existence of specific antibodies to leptospira. Through cultivation of kidney sections in the Korthof’s nutrient medium, 17 strains of leptospira were isolated from 3 species of myomorphous mammals, of which in the house mouse (Mus musculus) the serovar sejroe in 10 animals (71.4%), in the black-striped field mouse (Apodemus agrarius) the serovar pomona in 4 animals (5.4%) and in the yellownecked field mouse (Apodemus flavicollis) the serovars australis, pomona and one unindentified isolate in 3 animals (4.5%), representing a total of 7.5% of animals. Using the microscopic agglutination test in 47 animals (12.3%), antibodies to leptospira were found for 8 serovars, for the most part the serovar pomona, then (in decreasing order) for the serovars saxkoebing australis, and hardjo. The percentage of serologically positive animals ranged from 34.4% in the house mouse, 13,9% in the black-striped field mouse, 10.8% in the yellow-necked fieldmouse, 9.4% in the bank vole (Clethrionomys glareolus), to 6.5% in the long-tailed field mouse (Apodemus sylvaticus). The research results suggest that pedunculate oak forests can be considered as an integral part of a vast natural focus of leptospirosis. The specificity and role of this biotope in maintaining leptospira should be investigated to a greater extent in the future.U šumama hrasta lužnjaka, na 11 lokaliteta koji se prostiru u širem području rijeke Save, poznatom kao staro prirodno žarište leptospiroza, tijekom 2000. godine ulovljeno je 381 životinja. Na kliconoštvo leptospira pretraženo je 227 životinja i 381 životinja na prisutnost specifičnih protutijela za leptospire. Kultivacijom komadića bubrega u Korthof-ovom hranilištu, izdvojeno je 17 sojeva leptospira, u 3 vrste mišolikih sisavaca, od čega u kućnog miša (Mus musculus) serološka varijanta sejroe u 10 ili 71,4% životinja, u poljskog miša (Apodemus agrarius) serološka varijanta pomona u 4 ili 5,4% i žutogrlog miša (Apodemus flavicollis) serološka varijanta australis, serološka varijanta pomona i jedan nedeterminirani izolat u tri ili 4,5% životinja, što predstavlja ukupno 7,5% životinja. Reakcijom mikroskopske aglutinacije u 47 ili 12,3% životinja ustanovljena su protutijela za 8 seroloških varijanti leptospira, od čega najviše za serološku varijantu pomona, a zatim redom serološku varijantu saxkoebing, australis i hardjo. Postotak serološki pozitivnih životinja kretao se od 34,4% u kućnog miša, 13,9% u poljskog miša, 10,8% žutogrlog miša, 9,4% u riđe voluharice (Clethrionomys glareolus) do 6,5% u šumskog miša (Apodemus sylvaticus). Rezultati istraživanja upućuju na zaključak da šume hrasta lužnjaka možemo smatrati sastavnim dijelom velikog prirodnog žarišta leptospiroze. Specifičnosti i ulogu ovog biotopa u održanju leptospira trebalo bi u budućnosti opsežnije istražiti

Potencijal okolišnih i demografskih čimbenika u predviđanju prisutnosti bolesti Aujeszkoga u divljih svinja (Sus scrofa L.)

Aujeszky disease is a viral disease, primarily of suids, caused by Suid-alphaherpesvirus 1, also known as the Aujeszky disease virus. The potential transmission of virus from wild boars to domestic pigs underlines the necessity of studying the epidemiology of Aujeszky disease in wild boars. The aim of this study was to evaluate the potential of demographic, environmental and population management predictors in predicting that ELISA tested animals will be seropositive. We used 222 wild boar blood samples, collected from 10 different hunting grounds and Medvednica Nature Park. In total, 12 predictors were used in this study, three of which were demographic (age category, sex, population density), two represented population management (hunting method, relative hunting bag) and seven environmental characteristics (altitude, watercourses, meadows, scrublands, forests, agricultural area and infrastructure area). The model selection was based on the Akaike Information Criterion, corrected AIC and Akaike weight. The model with the lowest value (ΔAIC <2 units) was selected as representing the better model fit. Predictors were selected using logistic forward stepwise regression. The age of the wild boars proved to be positively correlated with prediction of seropositive animals, while altitude and population density proved to be negatively correlated. The selected models were shown to be able to predict ADV seropositive animals with an average accuracy between 77.12 and 78.67%, and seronegative animals between 82.46 % and 85.09. The odds ratio values ranged between 12.53 and 14.52. Our results are in accordance with previous studies, and the impact of population density in the case of Aujeszky disease in wild boars remains unclear.Bolest Aujeszkoga je virusna bolest prvenstveno divljih i domaćih svinja uzrokovana svinjskim alfaherpesvirusom 1, također zvanim i virusom bolesti Aujeszkog. Mogućnost prijenosa virusa s divljih na domaće svinje naglašava nužnost provedbe epidemioloških istraživanja ove bolesti u divljih svinja. Cilj ovoga istraživanja bio je procijeniti ulogu demografskih, okolišnih i uzgojnih mjera u predviđanju da će životinja testirana ELISA testom biti seropozitivna. Koristili smo 222 uzorka krvi divljih svinja prikupljenih na području 10 lovišta i Parka prirode Medvednica. Ukupno je korišteno 12 pretkazivača, od čega tri demografska (dob, spol i gustoća populacije), dva uzgojna (metoda lova i relativna odstrjelna kvota) i sedam okolišnih (nadmorska visina, vodotoci, livade, šikare, šume, oranice i izgrađeno zemljište). Izbor modela proveden je na temelju Akaike Informacijskog Kriterija, korigiranog kriterija i Akaike težine. Model s najnižim Akaike Informacijskim Kriterijem odabran je kao najprikladniji. Pretkazivači su odabrani primjenom logističke stupnjevite regresije s izborom unaprijed. Dob divljih svinja pokazala je pozitivan odnos prema predviđanju seropozitivnih jedinki, dok su nadmorska visina i gustoća populacije pokazali negativan odnos. Odabrani modeli pokazali su mogućnost predviđanja seropozitivne jedinke s prosječnom točnošću između 77,12 i 78,67%, a seronegativne između 82,64 i 85,09%. Omjeri vjerojatnosti varirali su između 12,53 i 14,25. Naši rezultati su podudarni s prijašnjim istraživanjima, pri čemu utjecaj gustoće populacije na bolest Aujeszkog u divljih svinja ostaje nedostatno poznat

Effect of Statin Therapy Duration on Bone Turnover Markers in Dyslipidemic Patients

Background and Purpose: Statins are cholesterol-lowering drugs decreasing bone resorption by inhibition of the farnesyl diphosphate synthase step in the mevalonic acid pathway and therefore are believed to have beneficial effects on bone status. The objective was to examine the relationship between statin therapy duration and bone turnover markers in dyslipidemic patients. Patients and Methods: Two hundred and eighty subjects were divided into five groups depending on duration of statin therapy: (controls 0 yrs); (0.1-1.5 yrs); (2-5 yrs); (6-10 yrs); (11-30 yrs). ELISA method was applied on fasting serums using bone formation markers: Osteoprotegerin (pmol/l) and Osteocalcin (ng/ml) and bone resorption markers: sRANKL (pmol/l) and CrossLaps (ng/ml). In statistical analysis, multiple regressions were used. Results: A common influence of studied predictor variables was statistically significant for sRANKL, Serum CrossLaps and osteocalcin (P<0.001), while statistical significance was not found for osteoprotegerin. The largest shares of contributions were recorded in Model 2 for the statin group (40%) and BMI (36%) and in Model 1 for statin group (35%) and total cholesterol (28%). Conclusions: Statins showed favorable influence on osteocalcin and sRANKL, indicating improved bone metabolism in patients with longer duration of statin therapy

Protutijela za viruse humane influence u prokazivačkih pataka u ornitološkom rezervatu Kopački rit.

Direct transmission of avian influenza viruses to humans has been confifi rmed and ever since it has been the main topic of influenza virus research. The opposite form of virus transmission is still unclear. In our study we used duck flocks as sentinels for surveillance of wild birds for influenza viruses and the possibility of bird infections with human influenza A viruses. Tested sera were collected from ducks in a free breeding system on a fish pond in the ornithological reserve Kopački rit (Croatia). Ducks were bred in an isolated unit for the first three weeks, and this was followed by four weeks breeding on the fifi sh pond without contact with humans. Sera were tested by haemagglutination inhibition (HI) test using human influenza viruses A/New Caledonia/20/99/ VR-116 (H1N1), A/Panama/2007/99 (RESVIR - 17) (H3N2), B/Hong Kong/330/01 and B/Sichuana/379/99 as antigens. To determine the time of infection, sera were collected twice during the period of isolation (day 0 and day 21) and at the end of breeding (day 49). Sera collected during the period of isolation were negative to influenza A and influenza B viruses. The high titer of influenza A specific antibodies in the serum samples at the end of breeding confirmed infection during exposure on the fish pond. As ducks on the fish pond had no contact with humans and were only in close contact with wild migratory birds these results confirmed that wild migratory birds were a source of infection and present a reservoir of influenza viruses. Very high seroprevalence in sentinel ducks with a high HI titers in some animals was determined at the end of breeding. The results of this study indicate that sentinel ducks were infected with influenza A virus strains closely related to the human strains used as an antigen. Also this study confirmed that sentinel ducks could be successfully used in influenza monitoring in wild birds.Mogućnost prijenosa ljudskih sojeva virusa influence izravno s ljudi na ptice još uvijek nije dovoljno istražena. U ovom radu prikazana je uporaba domaćih pataka kao modela prokazivačkih (engl. sentinel) životinja za promatranje širenja influence u divljih ptica, te je pomoću njih istražena infekcije ptica virusima influence antigenski bliskim humanim sojevima. Pretraživani su uzorci seruma pataka slobodno držanih na ribnjaku u ornitološkom rezervatu Kopački Rit. Patke su prva tri tjedna bile uzgajane u zatvorenom objektu, a potom su sljedeća četiri tjedna bile uzgajane na ribnjaku bez dodira s ljudima. Serumi su bili uzorkovani nultoga i 21. dana u zatvorenom objektu te 49. dana, tj. nakon završetka uzgoja na ribnjaku. Svi uzorci seruma bili su pretraženi inhibicijom hemaglutinacije, a kao antigeni bili su rabljeni humani sojevi virusa influence A/New Caledonia/20/99/VR-116 (H1N1) i A/Panama/2007/99 (RESVIR - 17) (H3N2), te humani sojevi virusa nfluence B/Hong Kong/330/01 i B/Sichuana/379/99. Svi pretraženi uzorci seruma uzeti u zatvorenom objektu nultog i 21. dana uzgajanja bili su negativni, dok su u uzorcima seruma uzetima na kraju uzgoja na ribnjaku (49. dana) ustanovljena specifična protutijela za viruse influence tipa A. Ovi rezultati potvrđuju infekciju pataka tijekom boravka na ribnjaku bez kontakta s ljudima što dokazuje da su divlje ptice bile izvor zaraze. Visoka seroprevalencija, te poglavito visoki titri specifičnih protutijela u pojedinih životinja dokaz su infekcije virusima influence antigenski srodnima humanim sojevima rabljenima u testu inhibicije hemaglutinacije. Postignuti rezultati potvrđuju mogućnost uporabe jata domaćih pataka kao prokazivačkih životinja za promatranje širenja influence u divljih ptica, te upućuju na nužnost daljnjega istraživanja mogućnosti infekcije ptica humanim sojevima virusa influence