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OHSU concludes investigations of accidental monkey deaths

External review panel recommends best practices for hiring, training, safety, operations

March 22, 2021 Update:

Following the accidental deaths of two rhesus macaques at the Oregon National Primate Research Center on Aug. 13, 2020, Oregon Health & Science University conducted both an internal root-cause analysis of the accident and an internal review by its Institutional Animal Care and Use Committee. In addition, Peter Barr-Gillespie, Ph.D., chief research officer and executive vice president, commissioned an external review composed of senior veterinary and research experts from around the country to further examine the incident.

That report provided several recommendations to improve the training and practice of animal care at the ONPRC. OHSU is publicly releasing that report today.


“Following a thorough review of the evidence, OHSU’s Institutional Animal Care and Use Committee has concluded that the immediate cause of the accidental deaths of two rhesus macaques Aug. 13, 2020, was the result of tragic human error. However, the IACUC also determined that more robust training and supervision, in addition to more thorough monitoring of the training program by the committee, might have prevented the tragic incident.

We remain deeply saddened by the loss of these animals, which had been in our care for 12 and 18 years, respectively, and are sincerely grateful to the veterinary professionals who have devoted to their careers to providing high-quality, compassionate care to the animals at our center.

OHSU and other academic health centers, universities, physicians and scientists throughout the world agree that knowledge gained through biomedical research in relevant animal models is essential to developing new ways to identify, prevent, treat or eradicate disease and to improve human and animal health, including ongoing research into vaccines and treatments for COVID-19.”



Following the accidental deaths of two rhesus macaques at Oregon Health & Science University’s Oregon National Primate Research Center, the university’s Institutional Animal Care and Use Committee, or IACUC, convened a subcommittee to conduct an investigation.

The subcommittee included the chair of OHSU’s West Campus IACUC; the director of the animal care and us program, which reviews and provides feedback on IACUC policies; an OHSU nonscientist; an OHSU scientist; and an individual not affiliated with OHSU.

Over the course of 10 weeks, the subcommittee:

  • Interviewed 21 people with direct knowledge of events leading up to, during and after the accident.
  • Reviewed relevant documentation, including standard operating procedures and training records.
  • Re-enacted the procedures leading up to the incident.


Investigation findings

Following an exhaustive internal review, the IACUC subcommittee found:

  • The technician assigned to the cage wash Aug. 13, 2020, did not follow the written standard operating procedure for sanitizing the cages.
    • The technician had moved the rhesus macaques from dirty cages into a clean rack of cages, moved one dirty rack of cages to the cage wash machine and then returned to the housing room for a second dirty rack.
    • The technician mistakenly grabbed the clean rack containing two rhesus macaques, placed it into the cage washer, started the prewash cycle and then returned to the housing room, where the technician noticed the mistake and promptly returned to stop the cage washer.
    • The West Campus overhead emergency paging system was used to alert veterinarians of the incident, and they responded to the cage washing area within two minutes.
    • One of the monkeys had passed away by the time the veterinarians entered the building. The second monkey survived the incident without showing outward signs of the trauma and veterinary staff quickly anesthetized the animal, initiated treatments for shock and heat stress, and began a thorough physical examination.
    • As the examination and treatments continued, tissue damage became apparent. Prior to allowing the animal to regain consciousness, veterinarians humanely euthanized the animal.
    • Leading up to the date of the incident, the cage wash technician trained for six weeks in a different cage sanitation area, trained for two days in the area of the incident, and then worked independently for the first time in the new area on the day of the incident.
    • The two cage sanitation areas differ in type of cage wash equipment, cage design and standard operating procedures.
    • The trainers judged the technician was prepared to work alone, and the employee agreed, but the trainee’s competency through an objective proficiency assessment had not been confirmed.
    • The technician conveyed an understanding of the general standard operating procedure for cage washing, but did not appear to know the differences between procedures for the two cage wash areas.
    • This fatal gap in understanding indicated that the technician was not ready to work alone.


Mitigation measures


Immediately following the incident Aug. 13, 2020, the attending veterinarian stopped all automated cage washer activities throughout the campus and implemented procedures for hand sanitizing all cages and monitoring for the effectiveness of sanitation.

At a special meeting of the IACUC, convened Aug. 21, 2020, the attending veterinarian presented, and the IACUC approved, the immediate implementation of a two-person verification procedure to allow a slow restart to automated cage washer operations. This procedure remains in effect and requires a second person to verify each cage is empty prior to initiating the cage washer cycle, and all steps of the written standard operating procedures have been executed. Any deviations from this process must be reported to management, the attending veterinarian and the IACUC.


All cage wash technicians have been retrained to use the two-person verification system and have confirmed an understanding of the responsibility for reporting any deviations from the written standard operating procedures.

The cage washer training program has been revised, and formal proficiency evaluations have been implemented. Before working independently, all trainees must prove competency for completing tasks according to the written standard operating procedures. Proficiency evaluations are now administered by the trainer and reviewed by the supervisor and operations manager, and the attending veterinarian must now provide final review and written approval for a trainee to work independently.

The effectiveness of training by individual certified trainers is also under review.


The attending veterinarian has reorganized the management and supervisory structure of the operational unit, which includes the cage wash function (Equipment Sanitation Team). A unit head of operations position now oversees all operational units and reports directly to a veterinarian.

The IACUC requires the following additional changes to the program:

  • A robust training and quality control program must be developed and implemented to include regular review of the training program by the IACUC.
  • While improvements in training, supervision and documentation are required, the IACUC recommends investigation of engineering and architectural changes to reduce opportunities for human error.

External review

OHSU’s Chief Research Officer Peter Barr-Gillespie, Ph.D., has engaged an external review panel to make recommendations for improvements consistent with best practices at other primate research centers. The panel now will broadly examine hiring, training, safety and operations in animal care at ONPRC, and their work is expected to take several months.

Regulatory reporting

As with any serious issue or incident involving the animals in our care, OHSU’s vice president of research administration and institutional official has reported the investigation findings and OHSU’s mitigation plan with the Office for Laboratory Animal Welfare (OLAW) of the National Institutes of Health, where highly trained veterinary staff thoroughly review the mitigation response to determine whether it is complete and appropriate, thereby ensuring that we have done everything possible to minimize the possibility of recurrence.

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