Diana Lupulović (1), Sava Lazić (1), Ana-Belen Blázquez (2), Estela Escribano-Romero (2), Juan-Carlos Saiz (2), Tamas Petrović (1)
(1) Naučni institut za veterinarstvo “Novi Sad”, Novi Sad
(2) Odjel za biotehnologiju, INIA, Madrid, Španjolska
E-mail: diana@niv.ns.ac.rs
Diana Lupulović (Naučni institut za veterinarstvo “Novi Sad”, Novi Sad, Serbia)
West Nile virus (WNV) prvi put je bio izdvojen u Ugandi 1937. Danas je najrasprostranjeniji flavivirus širom svijeta. Ciklus prijenosa virusa podrazumijeva komarce i ptice, a ljudi i konji su slučajni krajnji domaćini. Infekcija kod ljudi i konja često je asimptomatska, a klinički znaci bolesti uključuju groznicu i meningitis i/ili encefalitis. Virus je bio odgovoran za povremene epidemije u Europi, Africi, Bliskom Istoku i nekim dijelovima Azije prije mnogo godina. Od 1990. porastao je broj slučajeva kod ljudi, kao i učestalost i težina infekcije. U posljednjih nekoliko godina prijavljen je sve veći broj teških epidemija kod konja u Francuskoj, Italiji, Rumunjskoj i Španjolskoj.
Pošto je rizik od širenja infekcije izazvane WNV prisutan i postao je prijetnja za zdravlje ljudi i životinja, proveli smo serološko ispitivanje na prisutnost specifičnih antitijela protiv WNV kod zdravih konja. Ukupno je bilo prikupljeno 349 uzoraka seruma konja tokom 2010. godine u Beogradu, općini Šabac i 26 općina u Vojvodini i svi uzorci su testirani na prisutnost anti-WNV IgG. Testiranje je izvršeno validiranom in house ELISA metodom zasnovanom na korištenju djelimično pročišćenog rekombinantnog glikoproteina E virusa iz ekstrakta inficiranih larvi insekata, dobivenog metodom ekspresije u bakulovirusu kao i neutralizacijskim testom plak redukcije (PRNT). Rezultati su pokazali da je 42/349 (12%) testiranih konjskih seruma bilo pozitivno i da posjeduje anti-WNV IgG neutralizacijska antitijela.
Rezultati našeg istraživanja ukazuju da virus Zapadnog Nila cirkulira u populaciji konja u Srbiji. Nedavno, tokom ljeta 2012., zabilježeni su i prvi slučajevi infekcije ljudi WNV sa smrtnim ishodom u Srbiji. Iako do sada nije bilo prijavljenih slučajeva kliničke bolesti kod konja, epidemiološka situacija u susjednim zemljama u proteklih nekoliko godina nas upozorava da je neophodno da se sprovedu opsežna ispitivanja u našoj zemlji, kao i mogućnost sprovođenja posebanog programa nadzora i kontrole bolesti.
Zahvalnica: Studija je podržana od strane projekta TR31084 Ministarstva prosvete, nauke i tehnološkog razvoja Republike Srbije, od strane EU projekta NADIR-UE-228394, projekata RTA2011-00036 i AIB2010SE-00316 Ministarstva za nauku i inovaciju Španije, kao i od strane bilateralnog projekta “Procena zoonotskih virusnih aktivnosti u Srbiji”, finansiranog od strane oba Ministarstva.
Serological evidence of West Nile Virus activity in horses in Serbia
Diana Lupulović (1), Sava Lazić (1), Ana-Belen Blázquez (2),Estela Escribano-Romero (2), Juan-Carlos Saiz (2), Tamas Petrović (1)
(1) Naučni institut za veterinarstvo “Novi Sad”, Novi Sad,
(2) Odjel za biotehnologiju, INIA, Madrid, Španjolska
E-mail: diana@niv.ns.ac.rsWest Nile virus (WNV) was isolated in Uganda in 1937. Today, it is the most widely spread Flavivirus around the world. The transmission cycle of virus involves mosquitoes and birds, but humans and horses are accidental dead-end hosts. The infection in humans and horses is often asymptomatic, but the clinical signs of the disease include fever and meningitis and/or encephalitis. The virus has been responsible for occasional outbreaks in Europe, Africa, the Middle East and some parts of Asia for many years, but since 1990´s the number, frequency, and severity of cases in humans has increased. In the past few years an increasing number of severe outbreaks in horses have been reported in France, Italy, Romania and Spain.
Since the risk of spreading of WNV infection is present and became threat for animal and human health, we have conducted a serological survey for the presence of anti-WNV antibodies in healthy horses. In total, 349 horse`s sera were randomly collected during 2010 in Belgrade district area, the municipality of Sabac, and 26 municipalities in Vojvodina province and were tested for the presence of anti-WNV IgG by a validated in house ELISA, based on the use of a baculovirus expressed recombinant E viral glycoprotein partially purified from infected insect larvae extracts and by plaque reduction neutralization test (PRNT). The results showed that 42/349 (12%) tested horse sera were seropositive and presented anti-WNV IgG neutralizing antibodies.
The results of our serosurvey indicate that West Nile virus is circulating in the horse population in Serbia. Recently, during the summer 2012, the first cases of human WNV infection with fatal outcome in Serbia have been reported. Although so far there were no reported cases of clinical disease in horses, the epidemiological situation in the neighboring countries over the past few years, warns us that it is necessary to conduct extensive tests in our country, as well as the possibility of implementing a special program of surveillance and disease control.
Acknowledgments: The study was supported by grants TR31084 from Serbian Ministry of Education and Science, by grant NADIR-UE-228394 from the EU, by grants RTA2011-00036 and AIB2010SE-00316 from the Spanish Ministerio de Ciencia e Innovación (MICINN), and by and by bilateral project “Assessment of zoonotic viral activity in Serbia” funded from both Ministries.