Giant land snails: invasive disease carriers and tropical pets

Originating in East Africa and now invasive in many tropical regions worldwide, the giant land snail (Lissachatina fulica), is a popular exotic pet, a culinary ingredient, and also a vector of several human pathogens, including rat lungworm, known to cause meningitis.

In this study, researchers assessed and mapped the risk of disease transmission associated with invasion and pet trade of L. fulica. They conducted a literature review to identify relevant parasites and pathogens, finding 36 documented species including helminths, bacteria and protozoans, of which 15 species were known to infect humans.

Using GBIF-mediated occurrences of the snail, the authors created an ensemble model of its distribution potential based on bioclimatic variables of temperature and rainfall. The models suggested climatic suitability for L. fulica throughout all tropical regions. Mapping against human densities suggested that the snail thrived in densely populated areas.

By crawling geolocated social media posts on Instagram tagged with the species' name, the authors extracted and verified 750 images of L. fulica, most from temperate European regions, depicting the snail as a pet. Many users would hold the snail in their hands or even on their face, seemlingly unaware of the health risks associated with these animals.

With potential for increased transmission of pathogens through both tropical spread and pet ownership in less climatically suitable regions, L. fulica represents a serious health risk. To prevent infections, the study called for raising public awareness and regulating pet trade and ownership worldwide.