A report published in the New England Journal of Medicine on November 5, shows that tapeworms may be able to spread cancer to humans.
The unique case occurred in Medellín, in a patient whose immune system had been weakened by HIV, and marks the first known transmission of cancer cells from a parasite to a human.
However, leading researcher Dr Atis Muehlenbachs stated that both tapeworms and HIV affect millions of people worldwide, “so there may be more cases that are unrecognised”.
The 41-year-old man, who died of lung cancer, developed multiple large tumours in various parts of his body.
Biopsies showed that the tumours were ten times smaller than in normal human cancer cells, which is when Colombian doctors turned to the US based Centres for Disease Control and Prevention (CDC) – who led the research – for answers.
The doctors believe that the man in question may have ingested some microscopic tapeworm eggs, most likely in food contaminated by mouse droppings, insects or human faeces.