WEST NILE VIRUS INFECTION: RE-EMERGENT DISEASE IN CROATIA
Autori:
Tatjana Vilibić-Čavlek, Ljubo Barbić, Sunčanica Ljubin-Sternak, Iva Pem-Novosel, Vladimir Stevanović, Ira Gjenero-Margan, Gordana Mlinarić-Galinović
Sažetak
Virus Zapadnog Nila (VZN) malen je, ovijen, kuglast virus koji pripada porodici Flaviviridae, roduFlavivirus, serokompleksu japanskog encefalitisa. Prirodni rezervoari VZN-a su ptice, a glavni vektori komarci roda Culex. Do sada je opisano sedam genskih linija VZN-a, od kojih su najrasprostranjenije linije 1 i 2 (Afrika, Sjeverna i Južna Amerika, Europa, Azija i Australija). Infekcija VZN-om u oko 80% slučajeva prolazi asimptomatski. U 20% zaraženih javlja se nespecifična febrilna bolest (VZN-groznica), a u manje od 1% razvija se neuroinvazivni oblik bolesti (meningitis, encefalitis, sindrom poliomijelitisa). Na području Hrvatske protutijela na VZN dokazana su u ljudi, medvjeda i konja. U kolovozu i rujnu 2012. godine prvi put su zabilježeni klinički slučajevi neuroinvazivne infekcije VZN-om u ljudi te asimptomatska akutna infekcija u konja u tri županije istočne Hrvatske. Dijagnoza je potvrđena serološkim testovima (imunoenzimni test, IgG-aviditet, neutralizacijski test redukcije plakova).
Summary
West Nile virus (WNV) is a small, enveloped, spherical virus that belongs to the family Flaviviridae, genus Flavivirus, Japanese encephalitis serocomplex. Natural reservoirs of WNV are birds, and the main vectors are mosquitoes of the genus Culex. There are seven genetic lineages of WNV. Lineages 1 and 2 are the most widely distributed (Africa, North and South America, Europe, Asia and Australia). About 80% of infections are asymptomatic. In 20% of patients nonspecific febrile disease occurs (West Nile fever). Less than 1% of infected persons will develop neuroinvasive WNV disease (meningitis, encephalitis, and poliomyelitis). In Croatia, antibodies to WNV were demonstrated in humans, bears and horses. In August-September 2012 clinical cases of human WNV neuroinvasive disease and asymptomatic acute infection in horses were reported for the first time in three eastern Croatian counties. The diagnosis was confirmed by serologic tests (enzyme immunoassay, IgG avidity, plaque-reduction neutralization test).
