Crossing the health misinformation crisis: Lessons from the giant hammerhead flatworm

We examined the recent surge in misinformation surrounding giant hammerhead flatworms (Bipaliinae, primarily Bipalium kewense), which has generated widespread confusion across multiple countries regarding their risks to human health. Prompted by a routine taxonomic identification, this study aims to restore scientific accuracy and address the growing disconnect between science and the public concerning these worms, which have become an Internet sensation. In late 2023, we were asked to identify specimens collected in Pedro Leopoldo, Minas Gerais, Brazil, that had already attracted considerable online and regional media attention, warning of a "new, invasive, and dangerous worm" and its supposed threats. After confirming the species was B. kewense, we reviewed the literature, constructed a timeline of scientific and media reports, and compared information retrieved from Google News and Google Scholar. Our findings indicate that while academic research on invasive species has steadily increased, sensationalized and often inaccurate content on hammerhead worms proliferated in the general media, particularly between 2017 and 2018. Notably, claims (2023-2024) regarding the toxicity of Bipalium spp. lack scientific support. This case illustrates the broader challenges of health misinformation in the digital age, where misleading narratives rapidly transcend countries and languages. We discuss potential drivers, including communication gaps between academia and the public, the influence of media and social networks, and behavioral factors underlying misinformation. Finally, we highlight the urgent need for innovative strategies and coordinated efforts to strengthen online science communication and ensure the dissemination of accurate information.