Quickly Now! Using Rapid DNA Testing to Identify Wildfire Victims

Source for cover photo: Pixabay

On the morning of November 8, 2018, the Butte County Fire Department received calls warning of a wildfire near Paradise, California. Camp Fire, as it was named, burned for over two weeks and became the deadliest wildfire in California history. Along with $16.5 billion worth of damage, 84 people died in the fire; one more later died in the hospital. The nearby Sacramento County Coroner’s Office was tasked with coordinating efforts to name the 84 unidentified victims, a mass casualty event far beyond the scope the office had ever faced. Forensic anthropologists, odontologists and pathologists from across California and neighboring Nevada  gathered to begin identifying the Camp Fire victims.

In mass casualty events, forensic anthropologists and odontologists rely on the remains of the victims to make identifications. Anthropologists study their bones to estimate age, sex, race and stature and odontologists compare their teeth with existing dental records. Surgical hardware and fingerprints may also yield positive identifications. However, Camp Fire had burned so hot and long that most of the bones had been reduced to ash, fingerprints had been lost, and tooth enamel – the hardest substance in the body – had degraded completely.

 Of the 84 unidentified victims, only 22 could be identified by conventional methods: 2 were identified by looking up the serial numbers found on surgical hardware, 15 were identified by forensic odontologists comparing remains with dental records, and 5 were identified by fingerprint biometrics. The remaining 62 unknown victims could not be identified through any of these modalities. The forensic scientists on scene turned to a last resort method: DNA identification.

Though more commonplace in felony investigations, forensic scientists use DNA identification as a last resort in mass disasters due to the enormous cost and time required. Conventional DNA processing is expensive, as it requires access to a laboratory and trained professionals to prepare the samples and run the analysis. Once the DNA profile is complete, there must be a matching reference sample stored in a DNA database, either local or national, to compare with the victim’s DNA and determine an identity.

In the Camp Fire aftermath, the Sacramento County Coroner’s Office combated these issues with a new process; The ANDE Rapid DNA Identification system, which is often used to process DNA in sexual assault cases. While conventional DNA analysis can take months, the ANDE system can process a DNA sample in under two hours. Equally important, the system can be operated by non-technical personnel, is incredibly portable (optimized for warzone use) and as reliably accurate as laboratory equipment. The Sacramento County Coroner’s Office rented an RV to serve as a mobile DNA processing center. The ANDE system and a small centrifuge were the only instruments needed for the monumental task of identifying the Camp Fire victims.

Figure 1. The interior of the RV used for DNA processing. Source: U.S. Department of Homeland Security. Use of this image does not imply the endorsement of the DHS.

The ANDE system optimizes the same process used in conventional DNA analysis. The forensic scientists mixed tissue samples with sterile water and bone fragments with the proprietary ANDE Bone Solution, then placed the samples in a small centrifuge and vortexed them to separate the DNA from the tissue, bone and debris. They added the DNA to test swabs and placed them in the ANDE system; it contains space for a microfluidic chip, preloaded with the chemical reagents necessary to purify and amplify the DNA fragments.

Once the system generated a DNA profile for the sample, technicians then turned to another analytical software called FAIRS. FAIRS performs familial searches and compares the victim’s DNA samples to a reference, ultimately calculating a Combined Relationship Index, or CRI. If the CRI is above a predetermined threshold, there is a high likelihood that the victim and the reference are related. However, because the ANDE system required reference samples to compare with, the Butte County Sheriff’s Office organized donation sites so that local residents could donate their DNA.

Figure 2. The ANDE Biochip can process DNA from five different DNA samples at once. Source: U.S. Department of Homeland Security. Use of this image does not imply the endorsement of the DHS.

Out of the 62 remaining unidentified victims, 56 had high CRIs, indicating that they were related to someone who had donated a DNA sample. Two more were identified when their DNA sample matched a database entry. The final four samples did not match anywhere and underwent DNA sequencing to be used in forensic genealogy analysis. Three weeks after the fire blazed through Butte County, 74 of the 85 victims had been identified. Currently, all but one of the victims have been identified. In the aftermath of mass disasters, families often wait for months or years to find out what happened to their loved ones; many will unfortunately never receive a definite answer. The application of the ANDE Rapid DNA Identification System in the post-disaster identification process allowed dozens of families to receive complete information about their loved ones. Because of its portability and simplicity, the ANDE system can be deployed to a post-disaster scene, unconstrained by the need for a full laboratory or trained forensic technicians.

TitleThe 2018 California Wildfires: Integration of Rapid DNA to Dramatically Accelerate Victim Identification
AuthorsKim Gin M.S.; Jason Tovar M.D.; Eric J. Bartelink Ph.D.; Ashley Kendell Ph.D.; Colleen Milligan Ph.D.; P. Willey Ph.D.; James Wood D.D.S.; Eugene Tan Ph.D.; Rosemary S. Turingan Ph.D.; Richard F. Selden M.D., Ph.D.
JournalJournal of Forensic Sciences

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