Veterynarna biotehnologija – Veterinary biotechnology, 2022, 40, 110-120 [in Ukrainian]. https://doi.org/10.31073/vet_biotech40-10
State Scientific and Research Institute of Laboratory Diagnostics and Veterinary and Sanitary Expertise
DEVELOPMENT OF STANDARDIZED METHODOLOGICAL APPROACHES TO ORGANIZATION AND CONDUCTING OF INTERLABORATORY COMPARATIVE TESTS FOR RABIES IN UKRAINE
Introduction. Rabies is important infections for all humanity. All the methods of laboratory diagnosis for rabies in the world are standardized. Laboratory diagnosis for rabies in Ukraine is carried out exclusively in regional laboratories of veterinary medicine. Therefore, professional verification, namely conducting interlaboratory comparative tests in accordance with the requirements of the international standard is a required element of external control of the quality of routine laboratory tests.
The goal of the work. Development of standardized methodological approaches to the preparation and evaluation of the control samples compliancein the organization of a round of interlaboratory comparative tests on “Detection of rabies antigen”.
Materials and methods. FITC Anti-Rabies Globulin Kit; FAG “Rabitest-RIF” Kit and related reagents. Rabies virus (CVS-11 (ATCC VR 959)) was obtained in cell culture (BHK-21 C13 (ATCC CCL-10)) for further testing of infectious titer according to the method. White mice were infected with an intracerebral titrated dose of rabies virus (0.03 ml/head). The impression smear of a mice brain was made and direct immunofluorescence testing was performed according to DSTU 7053: 2009.
Results of research and discussion. An impression smear of white mice brain suspension with a minimum number of defective interfering particles was selected as a matrix. For this purpose, the reference strain of rabies virus CVS-11 was used for cell culturing, by appropriate titration and determination of infectious activity, which was 6.35±0.06 TCID50/ml at the 6th passage.
The next stage was the implementation of standardized methodological approaches to the preparation and evaluation of control samples: identification of rabies virus in DFA; homogeneity and quality of control samples; stability in storage conditions and models of transport conditions.
As a result of the conducted tests, 120 control samples were made, which were recognized to meet requirements in 2021.
The round attended 18 state laboratories, which received control samples with instructions and protocol for test results feedback. The obtained results of control samples testing were sent to the coordinator (SSRILDVSE) and compared with the assigned values. According to the results of the round of interlaboratory comparative tests, all participants received the result “COMPLIANCE”.
Conclusions and prospects for further research. The developed principles of control samples preparation (impression smear of white mice brain suspension) to ensure proper quality. Conditions for expanding the accreditation of the SSRILDVSE Testing Center in accordance with DSTU EN ISO/IEC 17043: 2014 by virological test “Detection of rabies antigen” are provided. Round on interlaboratory comparative tests “Detection of rabies antigen” in accordance with DSTU EN ISO/IEC 17043: 2014 was conducted in 2021.
Keywords: rabies, laboratory accreditation, interlaboratory tests, professional testing, rabies diagnosis, control samples.