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Table 3 Mitigation strategies for medium- and high-risk animal activities based on the US BMBL 5th edition regulations [21]

From: Biosafety and biosecurity requirements for Orientia spp. diagnosis and research: recommendations for risk-based biocontainment, work practices and the case for reclassification to risk group 2

Mitigation strategyExperimentally-infected animalsArthropods and necropsy of infected animals
Personnel protectionExperimental Orientia spp. and any work on isolates of the organism would be undertaken in a Class II BSCa meaning that the risk of airborne exposure of staff is minimal. If a Class II BSC is not available and there is a risk of aerosol exposure, staff should be fitted with and wear an N-95 respirator.
All work on samples that are suspected of containing Orientia spp. and any work on isolates of the organism would be undertaken by staff wearing gloves with avoidance of sharps wherever possible, minimising the risk of inoculation.
Outer garments, such as lab coats or Tyvek overalls, should be worn during work which has the potential to produce splashes or aerosols of bacteria.
Workers can be provided with a medical alert card to take to medical clinics should an accidental exposure occur. This card contains information about the nature of the work, the agent being worked with, and appropriate medical management to help inform and educate health care providers who may not be familiar with scrub typhus or laboratory animals.
As for experimentally-infected animals
Primary containmentClass II BSCAs for experimentally-infected animals
Secondary biocontainmentABSL2BSL3/ABSL3
Animal HandlingAppropriate PPE for the species of animal should be worn. Working with non-human primates (NHP) poses a risk of infection with Macacine herpesvirus and PPE should be utilized to prevent infection with this virus.
If using rodents, the risk of bites can be mitigated by acclimatizing the animals to handling or by wearing bite-resistant gloves.
Non-human primates should also be trained and acclimatized to the various procedures encountered in the course of the protocol. Use of pole, collar, and chair restraint devices minimize direct animal handling for examination, injections/inoculations, and treatments. If this is not possible, NHP should be anesthetized using an appropriate anaesthetic protocol for the procedure.
Necropsy of scrub typhus-infected animals should be undertaken in appropriate facilities based on the infection status of the animal. If the animal is infectious, (i.e. active bacteraemia or infection), the animal should be necropsied in a Class II BSC and/or within an ABSL3 or BSL3 laboratory. If the animal is non-infectious, standard necropsy procedures can be followed.
As for experimentally-infected animals
Disinfection (any of the following options)Autoclave – 121 °C for 30 min
Dry heat - 160-170 °C for at least 60 min
Chemical (At least 30 min contact time)
 1% Virkon (surfaces) or 2% Virkon (liquids)
 1% sodium hypochlorite
 70% ethanol,
 Quaternary ammonium disinfectants.
As for experimentally-infected animals
TrainingAdditional, specialized training should occur when working with laboratory animals. The type of training may vary depending on the regulatory requirements of the country in which the work is being performed.
Staff working with NHP should receive training about Macacine herpesvirus since this is an extremely dangerous zoonotic disease that can lead to death if not treated.
Staff should be trained and proficient in animal handling, restraint, sample collection, treatment administration, necropsy procedures, and other experimental procedures on animals before working with scrub typhus-infected animals.
As for experimentally-infected animals
  1. aBSC biological safety cabinet