You are here
A historical perspective, modern epizootic situation in the world and in Ukraine, immunity and the vaccine of classical swine fever
Complicated epizootic situation on classical swine fever in Ukraine was observed in 1993-1996. In 1993 on the territory of
our country there were registered 36 affected areas, in 1994 – 51 and in 1995 – 21. Only a few cases were registered in 1996.
Since classical swine fewer appeared in the United States and then spreaded out to Europe and other parts of the world, it caused
enormous losses for the economy and to the hog industry in particular. Currently the disease is endemic for the most of the
countries of Eastern Europe, Central and South America and for South East Asia. In 1997–1998 the disease was registered in
Netherlands, in 2000 in UK, in 2006 in Germany (particlularly in 2009 on wild boars), in 2012–2013 in Latvia. In 2014 the
disease was registered in Colombia with 14 outbreaks, in Latvia with 51, in Mongolia 3 and in Russia 4 outbreaks. In 2015 the
disease was registered in Mongolia (two outbreaks), Russian Federation (3), Latvia (9), Colombia (12) and Ukraine on wild boars
(1 outbreak in the Kiev region).
Until nowadays such countries as Denmark, Norway, Sweden, Finland, Luxembourg, Hungary, Ireland and USA are the
safest with regard to the classical swine fever.
The main source of the pathogen are sick animals, pigs with latent infection and recovered domestic and wild pigs, which
are infected with virus (means persistence of virus). Remaining undetected in the General herd, those pigs are particularly
dangerous in spreading disease and the maintenance of the epizootic. Important is that all age groups and breeds of the pigs are
susceptible to the classical swine fewer.
Under the natural conditions infection of pigs occurs alimentary, aerogenic, contact- conjunctival and genital way. In the
case of infection of pigs with virulent strains of the virus, it is mainly detected in blood and tissues. Infected animals allocate
pathogen with saliva, urine, feces, lacrimal nazalnam and secrets into the environment. Virus isolation occurs until the death of
the animal. In case of infection of pregnant sows (not vaccinated) with weakly virulent strains, especially in the first half of
gestation, transplacental infection of the fetus occurs. This ends in abortion or the birth of the dead (mummified) or weak piglets.
These pigs may not have clinical signs of the disease, but they are able to spread the virus for several weeks or even months,
predetermining virus infection status of the classical swine fewer.
The spread of the virus from one farm to another is possible in case of the movement of infected pigs in the incubation
period or pigs with latent infection (persistence of virus). Quite dangerous in this case is road transport. The transport of pigs over
long distances can lead to loose contacts, in this case the situation is complicated if the infection occurs by low virulence strains.
Due to the slow spread of this virus infection may occur and be undetected for weeks and months. The transport of pregnant sows
to another farm may cause the entry of virus after farrowing in this farm and therefore the appearance of the pigs, which will be
virus carriers and may lead to delayed diagnosis. The researchers point of view is that among piglings on farms can circulate
pathogens with reduced virulence. Sows transmit the virus to pigs transplacental. Pigs imported from such farms for reproduction
are the sources of the pathogen.
Entry of the virus in safe areas and for the long distances is also possible with pork or pork products. Pigs can get infected in
case of feeding them without a heat treatment slops, waste from slaughterhouses and meat processing plants.
Specialists of veterinary medicine or artificial insemination technicians can carry the virus with contaminated instruments. The use
of single needle, tools treatment of animals in case of virus-carrier animals creates a greater risk of recontamination.
Confirmed was the spread of virus between areas with forced ventilation, which are in close distance from each other.
Mechanical carriers of the virus can be people, dogs, cats, poultry and the like.
Therefore, pigs with latent infection is the most important reservoir of the virus. On the second place is pork and
manufactured from meat of infected animals pork products, which are kept in the refrigerator processing plants in chilled state.
These represent a potential risk for farms that use the waste of slaughter-houses for pigs feeding. Pigs in the incubation period
and the sow-virus carriers belong also to one the main sources of infection.
Latently infected wild boars is also a reservoir of the virus. They can infect domestic pigs through the feed chain or during the
contact of sows before insemination or artificial insemination. The secretion of estrogen at this time contributes the attraction of the wild
boars, including those, which are infected with the pathogenic agent of classical swine fever, and in the process of mating the infection of
sows. For these reasons, some researchers suggest the possibility of natural circulation for this disease.
The possibility of contact with wild pigs belongs to the reservoir of the classical swine fewer virus. This reason only may
result in the outbreak of the disease. Thus the termination of vaccination in our country, where the private households contains
56% of the swine livestock is premature decision. Given these circumstances, abolition of the disease is impossible. For the
classical swine fever wild bigs swine is recognized reservoir of this virus. Outbreak of the classical swine fever among wild pigs
at the beginning of 2015 is only a confirmation of this thesis. Thus, in Ukraine the main measurement to combat classical swine
fever belongs to a mass vaccination of pigs against this disease. Through such activities in our country at present the disease is
sporadically recorded among wild pigs. Obviously, completely abandon vaccination of pigs against classical swine fever
currently, would be unreasonable due to economic considerations. This could lead to an increase in the incidence of disease and
consequently to significant economic losses.
Key words: classical swine fever, transboundary іnfection, epіzootic situation, mechanisms of persistencia, latent іnfection,
wild boar, the vaccine.
1. Carbrey, E.A., (1988). Diagnostic procedures. In: Classical swine fever and related viral infections, Liess, B., (Ed.).
Martinus Nijho ff Publishing, Boston, Dordrecht, Lancaster.
2. Moennig V. Introduction to classical swine fever: virus, disease and control policy / Volker Moennig // Vet. Vicrobiol. –
2000. – Vol. 73.–Iss. 2–3. – P. 93–102.
3. Koritskaya M. A. Immunobiologicheskiye svoystva vaktsinnogo shtamma KS virusa klassicheskoy chumy sviney:
avtoref. dis. na soisk uch. stepeni kand. biol. nauk: spets. 16.00.03 – veterinarnaya mikrobiologiya, virusologiya, еpizootologiya,
mikologiya s mikotoksikologiyey i immunologiya / Koritskaya M.A. – FGU VDNKI: Moskva, 2005.– S. 24.
4. Makarov V.V. Klassicheskaya chuma sviney – osobennosti epizooticheskogo protsessa i problemy na sovremennom
etape / V.V. Makаrov, S.I. Dzhupina, A.A. Kolomytsev // Agrarnaya Rossiya: nauchno-proizvodstvennyy zhurnal. – 2001. – №
3. – S. 42–48.
5. Maksimovich. V.V. Differentsialnaya diagnostika klassicheskoy chumy sviney / V.V. Maksimovich. – Mozyr: KPUP
“Kolor”, 2001. – S. 7–41.
6. Malyarets P.V. Klassicheskaya chuma sviney / P.V. Malyarets, E.V. Guseva, T.A. Anufriyeva. – Vladimir: Vserossiyskiy
nauchno-issledovatelskiy institut zashchity zhivotnykh, 1995. – 58 s.
7. Jan van Oirschot. Transmission of classical swine fever virus by artificial insemination / Jan van Oirschot // Vet. microbil.
– 1999. – Vol. 67. – P. 239–249.
8. Establisment and characterization of an infectious cDNA clone of a classical swine fever virus LOM strain / Gil-Soon
Park, Seong-In Lim, Seung-Ho Hong, Jae-Young Song // J. Vet. Sci. – 2012. – Vol. 13. – № 1. – Р. 81–91.
9. Napryazhennost immuniteta protiv KChS u zhivotnykh v promyshlennykh svinokompleksakh / V.V. Kurintsov,
A.M. Starikov, V.M. Lyska [i dr.] // Veterinariya. – 2005. – №1. – S. 18–23.
10. Napryazhennost immuniteta protiv KChS u zhivotnykh v promyshlennykh svinokompleksakh / V.V. Kurintsov, A.M.
Starikov, V.M. Lyska i dr. // Veterinariya selskokhozyaystvennykh zhivotnykh. – 2008. – №1. – S. 26–32.
11. Sakovich V.T. Effektivnost skhem immunizatsii porosyat-otyemyshey dlya profilakti-ki chumy sviney / V.T. Sa-kovich,
T.A. Savelyeva, A.S. Yastrebov // Sovremennyye problemy patologii selskokhozyaystvennykh zhivotnykh: mat-ly Mezhdunar.
nauch.-prakt. konf. – Mn., 2003. – S.261–262.
12. Van Oirschot J.T. Hog Cholera: In Disease of Swine / J.T. Van Oirschot // Ed Iowa University Press, USA. – 1989. – P.
13. Informatsiinyi shchotyzhnevyk po infektsiinykh khvorobakh Derzhavnoho NDI z laboratornoi diahnostyky ta
veterynarno-sanitarnoi ekspertyzy / http://vetlabresearch.gov.ua/news
14. OIE. World Organisation for animal health / Manual of diagnostic tests and vaccines for terrestrial animals (mammals,
birds and bees), Seventh Edition. 2012. –Vol. 2. – 624 p.
15. http://www.cfsph.iastate.edu/DiseaseInfo/disease.php/name:classical swine fever
16.http://www.oint/animal-health-in-the-world/official-disease-status/class... fever/ technical-disease-cards/
17. Mushtuk I.Iu. Monitorynh klasychnoi chumy sered populiatsii dуkykh i sviiskykh svynei v systemi zakhodiv borotby:
dys. …kand. vet. nauk: 16.00.03 / Mushtuk Iryna Yuriivna. – K., 2015. – 148 s.