Transplants

Inoculations and transplants

In order to minimise the risks of work-acquired infection, work involving the introduction of infectious agents or transplant material that may harbour infectious agents into animals must be risk assessed prior to starting.

The assessment must take into account risks to researchers conducting procedures and those that may affect husbandry staff eg infection by biting or shedding in excreta.

For human pathogens there are four levels of animal containment (CL 1-4) for work with vertebrates that are deliberately inoculated with biological agents in Hazard Groups 1-4, or with material suspected of containing those agents.

Similar containment levels exist for genetically modified micro organisms in line with the GM class of the agents/activities that have been determined through the risk assessment, see: Compendium of Guidance SACGM. Remember to include the animal work to be involved in any GM notification.

In addition, certain infectious agents, such as SAPO or Schedule 5 agents, require slightly different containment measures which in many cases are more onerous in terms of procedures and physical infrastructure of the facility.

Completed risk assessments must be approved and signed off by the user department’s biological safety committee/BSO before being presented to the animal facility with other project documentation.

Risks of infection and containment measures for animals transplanted with human tissue

Current guidance from ACDP/HSE dating back to 1997 Working safely with research animals: Management of infection risks states that where infectious agents or material suspected of containing agents of a certain Hazard Group are introduced into animals, then the corresponding Containment Level should be used.

'Humanised’ animals

Development of immuno-compromised mice since the current guidance was published has allowed their humanisation to increasing degrees. The current acme of this progression are NSG type mice which can be humanised with implanted human tissue such that, in addition to many and varied applications to human biological systems, many more types of human pathogens can be studied in them.

The risks from the propagation or creation of human pathogens in these animals are enhanced over those for older animal types and must be carefully considered.

University policy

In consideration of the above, it is University policy that work involving transplant of human material into animals must be conducted at CL2 unless the risk assessment concludes that the most suitable CL is lower (or higher).