Rapid Reliable EID50 Determination for live Newcastle Disease Viruses and Vaccines | ||
| Zagazig Veterinary Journal | ||
| Volume 50, Issue 4, December 2022, Pages 276-286 PDF (558.64 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/zvjz.2022.179646.1196 | ||
| Authors | ||
| Amal A M Eid* 1; Abd El-Shakour N Ismail2; Hagar F Gouda3; Reham Mohamed ElBakrey4 | ||
| 1Avian and Rabbit Diseases, Faculty of Veterinary Medicine, Zagazig University, Sharkia, Egypt | ||
| 2Avian and Rabbit Medicine Department, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511, Egypt | ||
| 3Animal Wealth Development Department (Biostatistics subdivision), Faculty of veterinary medicine, Zagazig University, 44511, Egypt | ||
| 4Department of Avian and Rabbit Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Sharkia, 44511, Egypt. | ||
| Abstract | ||
| Newcastle disease (ND) was first recognized more than nine decades ago and continues to be a problem for poultry producers besides being enzootic in many countries including Egypt. Diagnostic and ND virus/vaccine titration are core objects in virus evaluation. A rapid assay based on micro plate hemagglutination (HA) activity was applied to investigate its reliability as alternative method for virus titration. A comparative determination of EID50 /0.1ml was carried out via chicken embryo (CE) inoculation for 35 Newcastle disease virus (NDV) strains. They are previously identified by pathogenicity indices and revealed variable virulence (lentogenic-mesogenic and velogenic). The data for both methods were analyzed using SPSS version 25. A Wilcoxon signed-rank test showed that HA titer method did not elicit a statistically significant change in median of reading Virus titer of samples with the median of standard embryonated chicken egg (ECE) method (Z = -0.197, p = 0.844). Spearman’s correlation coefficient (r= 0.42, p =0.01) showed a noteworthy moderate correlation between two methods. Heat map showed the differences between each pair of methods and the relationship between them. Bland-Altman plot revealed difference which fit normality distribution W=0.96, p=0.24. Accordingly, the use of HA activity assay for NDV/vaccine titration is a rapid easy and reliable, especially when needed for primary evaluation. | ||
| Keywords | ||
| NDV; ECE; HAU; EID50; live viral vaccines | ||
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