Scientists conducted a genetic analysis of worms found in the feces of ancient Scandinavians in Denmark. An article about the discovery appeared in Nature Communications.
Vlasoglav is a roundworm that causes trichocephalosis. The worm earned its name from its distinctive body shape: the front part is threadlike, through which only the esophagus passes, while the rear portion is noticeably broader. In today’s developed nations, infections are rare, yet in less affluent regions it remains more common.
Researchers from the University of Copenhagen examined the latrines of ancient Scandinavians in Copenhagen and Viborg. There they recovered worm eggs in good condition, cleaned the samples, and sequenced their DNA. The specimens date to roughly a millennium ago. The researchers note that the eggs are designed to endure long periods in soil, allowing parasite genetic material to preserve well under favorable conditions. In natural settings, the eggs mature in soil for about three months before waiting to be ingested by a new host, where they later hatch in the digestive tract. The eggs can survive for extended durations under the right circumstances.
The team compared these ancient genetic data with DNA from modern whipworms and with findings from multiple regions, including Africa. The analysis supports the view that whipworms dispersed globally with humans, an ancient migration that began in Africa roughly 55,000 years ago. This conclusion aligns with patterns of genetic diversity, which are greatest in East Africa, as observed in recent studies and extensive sampling across continents.