AVALIAÇÃO DO USO DE SANGUE EM PAPEL-FILTRO PARA DETECÇÃO E QUANTIFICAÇÃO DE ANTICORPOS PARA O VÍRUS DA DOENÇA DE NEWCASTLE

The present study describes the evaluation of a filter paper blood sampling technique for assessment of the level of antibodies against the Newcastle disease virus (NDV) by hemagglutination inhibition (HI) test. Blood samples were collected from ninety eigth chickens with a known history of vaccination against NDV and analyzed by HI method. The blood was impregnated onto Whatman no. 1 filter paper with 3cm2 and also collected in tubes for obtaining serum. The papers were stored at room temperature and tested within fourty five days. The resulting sensitivity, specificity, positive predictive value and negative predictive value of the filter paper HI compared to serum HI was 89%, 73%, 76% and 87%, respectively. It was found index precision of the 80% and the correlation coefficient r = 0.81%. The overall average geometrical titer of antibodies was 33.1 and 33.6 in eluates and in sera, respectively. Association between the two methods was found to be highly significant (p < 0.001) when analyzed by Fishers test. The results indicate the potential use of filter paper blood sampling technique as an alternative to serum for detection of the antibodies against NDV. KEY-WORDS: Chicken, hemagglutination inhibition, serology.