Unreliability of a commercial ELISA kit for serologic monitoring of avian influenza

Pretražena su 342 uzorka seruma iz ekstenzivnih uzgoja kokoši i 184 seruma iz intenzivnih uzgoja purana uzeta u razdoblju od 27. prosinca 2004. do 9. rujna 2005. komercijalnim ELISA kompletom za protutijela virusa influence ptica. Nađeno je 45,6% pozitivnih seruma kokoši i svega 0,5% pozitivnih seruma purana. Serumi koji su dali pozitivnu ili sumnjivu reakciju ELISA testom pretraženi su i imunodifuzijom u gelu na nazočnost protutijela za virus influence ptica. Svi uzorci pretraženi ovim postupkom dali su negativan rezultat. Provjerom specifičnosti komercijalnog ELISA kompleta dobivene su pozitivne reakcije i s monovalentim standardnim antiserumima za viruse newcastleske bolesti i CELO, dok su serumi za PMV-2 i PMV-3 dali sumnjivu reakciju. Stoga se može zaključiti da je korišteni komercijalni komplet nepouzdan u serološkom monitoringu influence u peradi. S obzirom na proširenost visokopatogene influence ptica u svijetu i opasnost koju predstavlja visokopatogeni virus podtipa H5N1 za perad, ali i ljude, korištenjem komercijalnog kita bez provjere pozitivnih rezultata standardnim serološkim metodama mogu se donositi krivi zaključci s nesagledivim posljedicama.Three-hundred-and-forty-two serum samples from backyard chickens as well as 184 serum samples from farm turkeys, taken in the period from December 27th 2004 to September 9th 2005, were tested using commercial ELISA kit for avian influenza antibodies. It was found 45.6% positive chicken sera and only 0.5% positive turkey sera. Sera that were suspicious or positive in the ELISA were subjected to AGP test for avian influenza antibodies. All samples gave negative result when used AGP test. Specificity assessment of the commercial ELISA kit gave positive results even with monovalent standard antisera for Newcastle disease and CELO virus, whereas antisera for PMV-2 and PMV-3 gave suspicious result. Therefore, the commercial kit should be considered as unreliable for serologic monitoring of avian influenza in poultry. In regards to prevalence of highly pathogenic avian influenza in the world as well as animal and human health hazard posed by H5N1 highly pathogenic avian influenza virus, use of a commercial kit without confirmation with standard serological methods may lead to wrong conclusions with enormous consequences