Assessment of replicate numbers for titrating avian influenza virus using dose-response models
Loading...
Date
2019
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Veterinary Diagnostic Investigation
Abstract
Embryonating chicken eggs (ECEs) are among the most sensitive laboratory host systems for avian influenza
virus (AIV) titration, but ECEs are expensive and require space for storage and incubation. Therefore, reducing ECE use would
conserve resources. We utilized statistical modeling to evaluate the accuracy and precision of AIV titration with 3 instead of
5 ECEs for each dilution by the Reed–Muench method for 50% endpoint calculation. Beta-Poisson and exponential doseresponse
models were used in a simulation study to evaluate observations from actual titration data from 18 AIV isolates. The
reproducibility among replicates of a titration was evaluated with one AIV isolate titrated in 3 replicates with the beta-Poisson,
exponential, and Weibull dose-response models. The standard deviation (SD) of the error between input and estimated virus
titers was estimated with Monte Carlo simulations using the fitted dose-response models. Good fit was observed with all
models that were utilized. Reducing the number of ECEs per dilution from 5 to 3 resulted in the width of the 95% confidence
interval increasing from ±0.64 to ±0.75 log
10
50% ECE infectious doses (EID
50
) and the SD of the error increased by 0.03
log
10
EID
50
. Our study suggests that using fewer ECEs per dilution is a viable approach that will allow laboratories to reduce
costs and improve efficiency.
Description
Keywords
Avian influenza virus, Embryonating chicken egg titration, Virus quantification
Citation
Spackman, E., Malladi, S., Ssematimba, A., & Stephens, C. B. (2019). Assessment of replicate numbers for titrating avian influenza virus using dose-response models. Journal of Veterinary Diagnostic Investigation, 31(4), 616-619. https://doi.org/10.1177/10406387198538