At Army instructions and based on the Army’s testing of what they were running into, most of the dealing of the animals was through the veterinarians.
“In October 1989, 100 crab-eating macaques were imported from Ferlite Farms, located in Calamba, Laguna south of Manila, Philippines, and ended up at the Reston Primate Quarantine Unit. At that time, the Reston facility already had 500 macaque monkeys housed in their facility. Shortly after their arrival, scientists started noticing an abnormally high mortality rate; by the beginning of November 1989, 29 of the 100 monkeys had died. In a post-mortem examination, the on-site veterinarian, Dan Dalgard, noticed that the interior of the body looked very strange with a massively swollen spleen and blood inside the intestines. He suspected that the deaths were caused by simian hemorrhagic fever or SHFV.
Reston’s veterinarian then sent samples of the tissues to the United States Army Medical Research Institute of Infectious Diseases or USAMRIID, located north of Reston at Fort Detrick, Maryland. USAMRIID is the only laboratory in the Defense system that can study high risk viruses that require maximum biohazard containment. The virus that caused the SHFV was considered to require a Biosafety Level 4 (BSL-4) designation, the highest level of containment. When working in a BSL-4 lab, scientists wear a Hazmat suit and have a self-contained oxygen system. They work in negatively pressured room to prevent viruses from escaping and must go through a series of showers before entering and exiting. In the case of the SHFV filovirus, the veterinarian at the Reston facility sent the frozen samples to the USAMRIID wrapped in tin foil. By the time the samples arrived at their destination, they had thawed and fluids were dripping from the packaging.
Meanwhile, back at the Reston facility, veterinarians euthanized the remaining monkeys from the October shipment, however, despite those precautions, monkeys in other rooms began to show the same symptoms and die.
USAMRIID analyzed the Reston virus and determined that the cause of death was Ebola, the same strain that had caused the outbreaks in Zaire and Sudan in 1976. In those outbreaks, more than 600 cases were noted with a mortality rate of 53 percent in Sudan and 88 percent in Zaire. By the time USAMRIID had ascertained that the Ebola - Zaire virus was responsible, six weeks had passed since the monkeys started dying in Reston, Virginia. A program was put in place by USAMRIID, the Centers for Disease Control and the Virginia Department of Health to prevent the virus from spreading. When USAMRIID staff arrived for a walkthrough of the Reston facility, they found staff and animal handlers were still working without taking precautions. The decision was made to euthanize all of the facility’s monkeys, however, during the process, a single monkey escaped. It took the better part of two days to catch and euthanize the escapee, an incident that could have led to further infections. For the following eleven days, the Reston Primate Quarantine Unit was decontaminated using bleach. Decontamination also included a three day period when the building was filled with formaldehyde fumes to ensure complete cleansing.
Of the 1787 staff members who had contact with the infected monkeys at the Reston facility, only two were hospitalized. It was also found that six people who had worked with the primates had serologic evidence (i.e. antibodies) of an ebola infection. Both hospitalized staff survived their illnesses. Scientists later found that the Reston virus was a new variant, now known as EBO-R, that had slight genetic differences from the other known ebola viruses. An additional six individuals had In the Reston variant, there was a high death rate among infected monkeys, however, it was not deadly to humans.’
Ansel, thank you for posting the narrative of what happened at the Reston monkey import facility.
A few salient points that need to be made clear:
1) There is no firm evidence that the Ebola Reston strain ever spread through aerosols. That particular facility was, by the accounts, very dirty (a “monkey hell” in one description), and the virus could easily have been carried between rooms, for instance, on someone’s sleeve.
2) Ebola Reston is not a mutation of Ebola Zaire; they both split from some ancestor filovirus, probably tens of thousands of years ago. I haven’t looked at the phylogenetic trees, so I am guessing; the point is, that these have both been circulating for a while in animal reservoirs.
3) There is no evidence that Ebola Reston causes symptomatic disease in humans. As far as I know, 15 people were documented to be seropositive for Ebola Reston (that is, they have antibody evidence of previous infection), but no one has ever become ill from it. The WHO still recommends handling Reston under BSL4 conditions, because there remains the possibility that some people would develop full-blown Ebola fever disease from exposure to Reston virus.