Rare leprosy strain found in fifth-century German boat burial

Rare Leprosy Strain Discovered in Fifth-Century German Grave

Archaeologists analyzing genomes from an abandoned Roman-era settlement in northwestern Germany have discovered a rare strain of Mycobacterium leprae inside the skeletal remains of a man who died during the fifth century. The finding marks the first time this specific bacterial lineage has been detected in Central or Northern Europe.

The Tech TL;DR:

• Researchers investigated the genomes of a dozen people buried at the Fallward burial ground, analyzing skeletal samples to learn more about the individuals.
• The infected man carried a bacterial strain previously traced only as far back as Egypt between the fourth and second centuries BCE.
• Despite carrying the pathogen, the individual showed no bone damage, indicating the infection was either asymptomatic or limited entirely to soft tissue.

Excavation Details and Grave Goods at Fallward

The Fallward cemetery, located near the North Sea coast between the Weser and Elbe rivers, yielded roughly 200 cremation burials and 60 inhumation graves. Originally excavated in the 1990s, the site featured exceptionally well-preserved wooden and metal artifacts. Among the interments, a distinct grave designated as “Grave 265” stood out from the others. The man inside was buried in a 13-foot oak boat sealed with a roof-like structure, accompanied by a bronze basin, a water bird-shaped box, a maple stool bearing a hunting scene and runic inscription, and an ornate chair carved from an alder trunk. According to Hauke Jöns of the Lower Saxony Institute for Historical Coastal Research, the presence of a late Roman military belt within the tomb indicated that the deceased maintained connections across vast geographic distances.

Genetic Analysis Links Pathogen Origins to the Danube Region

Genetic testing performed by the research team confirmed that the man buried in Grave 265 originated from the Danube region, far from his final resting place in northwestern Germany. Ben Krause-Kyora of Kiel University noted that the individual could have served as a mercenary in the Roman army before settling between the Elbe and Weser rivers. Osteological analysis revealed well-developed upper arm muscles, suggesting he may have worked as a boatman or fisherman prior to his death around age 50. Almut Nebel of Kiel University observed that the absence of skeletal lesions meant the man either carried an asymptomatic infection or one restricted to soft tissues while traveling long distances.

What Remains Unknown About the Transmission Path

While the preserved leprosy DNA allowed researchers to trace the bacterial strain back to roots that may have evolved in Egypt, the exact transmission of the pathogen remains to be fully understood.

# Example genomic data processing pipeline for ancient DNA analysis
# Validating coverage and mapping against reference genomes
bwa mem -t 4 hg19.fa ancient_sample_R1.fastq.gz ancient_sample_R2.fastq.gz | samtools view -bS - > sample.bam
samtools sort sample.bam -o sample_sorted.bam
samtools index sample_sorted.bam