Abstract
Rabies diagnosis proficiency tests on animal specimens using four techniques (FAT, RTCIT, conventional RT-PCR and real-time RT-PCR) were organised over 10 years (2009–2019). Seventy-three laboratories, of which 59% were from Europe, took part. As the panels were prepared with experimentally-infected samples, the error rate of laboratories on positive and negative samples was accurately estimated. Based on fitted values produced by mixed modelling including the variable “laboratory” as a random variable to take into account the longitudinal design of our dataset, the technique that provided the most concordant results was conventional RT-PCR (99.3%; 95% CI 99.0–99.6), closely followed by FAT (99.1%; 95% CI 98.7–99.4), real-time RT-PCR (98.7%; 95% CI 98.1–99.3) and then RTCIT (96.8%; 95% CI 95.8–97.7). We also found that conventional RT-PCR provided a better diagnostic sensitivity level (99.3% ±4.4%) than FAT (98.7% ±1.6%), real-time RT-PCR (97.9% ±0.8%) and RTCIT (95.3% ±5.1%). Regarding diagnostic specificity, RTCIT was the most specific technique (96.4% ±3.9%) followed closely by FAT (95.6% ±3.8%), real-time RT-PCR (95.0% ±1.8%) and conventional RT-PCR (92.9% ±0.5%). Due to multiple testing of the samples with different techniques, the overall diagnostic conclusion was also evaluated, and found to reach an inter-laboratory concordance level of 99.3%. The concordance for diagnostic sensitivity was 99.6% ±2.0% and for diagnostic specificity, 98.0% ±8.5%. Molecular biology techniques were, however, found to be less specific than expected. The potential reasons for such findings are discussed herein. The regular organisation of performance tests has contributed to an increase in the performance of participating laboratories over time, demonstrating the benefits of such testing. Maintaining a high-quality rabies diagnosis capability on a global scale is key to achieving the goal of eliminating dog-mediated human rabies deaths. The regular organisation of exercises on each continent using selected local strains to be tested according to the local epidemiological situation is one factor that could help increase reliable diagnosis worldwide. Rabies diagnosis capabilities could indeed be enhanced by providing adequate and sustainable proficiency testing on a large scale and in the long term
Highlights
Effective disease surveillance is vital in order to obtain an accurate estimation of an epidemiological situation and implement appropriate control measures
This paper describes 10 years’ participation by 73 worldwide national laboratories in animal rabies post-mortem diagnosis proficiency trials assessing the fluorescent antibody test (FAT), the rabies tissue culture infection test (RTCIT), conventional reverse transcription polymerase chain reaction (RT-PCR) and real-time RT-PCR laboratory competencies
Because participation in diagnosis proficiency tests organised by the European Union Reference Laboratory (EURL) is mandatory, regulatory and free of charge for National Reference Laboratories (NRLs) within the EU, many study participants are from the EU (Commission regulations No 737/2008 and No 415/2013 [13])
Summary
Effective disease surveillance is vital in order to obtain an accurate estimation of an epidemiological situation and implement appropriate control measures. Diagnostic sensitivity estimates the probability that a truly infected individual will be classified as infected using the test, and diagnostic specificity is the probability that a healthy animal will be classified as healthy using the test [3] Such performance characteristics are often estimated during the technique’s validation process and its implementation in a laboratory [4]. It is of paramount importance to be able to compare results in space (within different states, regions or districts, etc.) and in time (at different periods of the year or in different years) In such circumstances, inter-laboratory assessments can be used to ensure the appropriate reproducibility of results. This is the objective of proficiency tests [5], which assess the performance of a laboratory and not of the technique itself
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
