The use of a decision tree based on the rabies diagnosis scenario, to assist the implementation of alternatives to laboratory animals.

Brazilian federal legislation makes the use of alternatives mandatory, when there are validated methods to replace the use of laboratory animals. The objective of this paper is to introduce a novel decision tree (DT)-based approach, which can be used to assist the replacement of laboratory animal procedures in Brazil. This project is based on a previous analysis of the rabies diagnosis scenario, in which we identified certain barriers that hinder replacement, such as: a) the perceived higher costs of alternative methods; b) the availability of staff qualified in these methods; c) resistance to change by laboratory staff; d) regulatory obstacles, including incompatibilities between the Federal Environmental Crimes Act and specific norms and working practices relating to the use of laboratory animals; and e) the lack of government incentives. The DT represents a highly promising means to overcome these reported barriers to the replacement of laboratory animal use in Brazil. It provides guidance to address the main obstacles, and, followed step-by-step, would lead to the implementation of validated alternative methods (VAMs), or their development when such alternatives do not exist. The DT appears suitable for application to laboratory animal use scenarios where alternative methods already exist, such as in the case of rabies diagnosis, and could contribute to increase compliance with the Three Rs principles in science and with the current legal requirements in Brazil.

Comparative costs of the Mouse Inoculation Test (MIT) and Virus Isolation in Cell Culture (VICC) for use in rabies diagnosis in Brazil.

The decision to use laboratory animals rather than in vitro methods is frequently based on the financial costs involved, so the objective of our study was to compare the costs of performing the Mouse Inoculation Test (MIT) and Virus Isolation in Cell Culture (VICC) for use in rabies diagnosis in Brazil. Based on observations of laboratory routines at the Pasteur Institute, São Paulo, we listed the fixed cost (FC) and variable cost (VC) items necessary to perform both tests. Considering that 200 MITs are equivalent to 350 VICC assays, in terms of facilities and staff-hours needed per month, we calculated, for both tests, the average total cost per sample, the costs of the implementation of the laboratory structure, and the costs of routine use. With regard to absolute values, the total cost was mainly influenced by FC items, as they represented 60% of the cost for the MIT and 86% of the cost for VICC. A sample analysed by the MIT costs around 205% more than one analysed by using VICC. The MIT costs 74% and 406% more than VICC, when implementation costs and routine use per month, respectively, are taken into account. Our results can assist in the resolution of costing disputes that could hinder the replacement of animals for rabies diagnosis in Brazil. The method demonstrated here might also be useful for cost comparisons in other situations where animal use still continues when validated alternatives exist.

Perceived barriers to the adoption of alternatives to laboratory animal use for rabies diagnosis.

The use of laboratory animals is still common practice, but some uses can be replaced by alternative methods, such as Virus Isolation in Cell Culture (VICC) instead of the Mouse Inoculation Test (MIT) for rabies diagnosis. The objective of this work was to describe current rabies diagnosis methods in Brazil and other countries, and the constraints associated with replacing this use of mice with alternative methods. Nine out of 12 Brazilian and 14 out of 43 non-Brazilian respondents reported that they currently used the MIT. Respondents in countries other than Brazil, male respondents, and those already employing in vitro methods for rabies diagnosis, expressed higher levels of support for the use of alternatives. The most frequently reported constraints associated with the use of alternatives were lack of laboratory facilities, equipment and materials (cited 17 times by respondents), and lack of financial resources (cited 15 times). The results indicate that many laboratories continue to use mice for rabies diagnosis. The proportion of laboratories that use mice appears to be especially high in Brazil, despite animal protection laws and technical guidelines that favour the use of alternatives. The barriers to the adoption of alternative methods identified in the current study provide a basis for facilitating changes in Brazil and elsewhere.