Garden snails are common, and their presence often raises questions about potential health risks. While they can host disease-causing agents, the overall risk to human health is generally low with appropriate precautions. Understanding the pathogens they carry and how transmission occurs helps minimize exposure.
Pathogens Carried by Garden Snails
Garden snails can harbor various pathogens. A primary concern is the parasitic rat lungworm (Angiostrongylus cantonensis). This parasite primarily resides in the pulmonary arteries of rats, its definitive hosts. Infected rats excrete larvae in their feces, which snails and slugs ingest, becoming intermediate hosts. Within the snail, these larvae mature to an infective stage.
Beyond rat lungworm, garden snails can also carry bacteria such as Salmonella and Escherichia coli (E. coli). These bacteria are often present in their environment, including soil and decaying matter, and can be found on their bodies or in their guts. Their presence underscores the need for hygiene when handling snails or consuming produce from areas they inhabit. Snails can also be associated with fungi, though less commonly.
How Diseases are Transmitted
Transmission of pathogens from garden snails to humans primarily occurs through accidental ingestion of parasite larvae or bacteria. This can happen if tiny snails, slugs, or their microscopic parts are consumed with unwashed produce, especially leafy greens. Slime trails left by infected snails can also contain larvae, posing a risk if transferred to food and then ingested.
Direct contact with snails followed by touching the mouth or eyes without proper handwashing is another transmission route. Children are particularly susceptible if they handle snails and then put their hands in their mouths. Pets can also become infected by consuming snails. While the larvae typically do not fully mature in humans or pets, their migration through the body can cause serious health issues.
Protective Measures
Minimizing the risk of disease transmission from garden snails involves several practical steps. Thoroughly washing all produce harvested from gardens is essential, especially leafy greens where snails and their slime may be present. Washing produce under running water helps remove any hidden snails, slugs, or their residues.
When working in the garden or handling snails, wearing gloves offers a protective barrier. After gardening or any contact with snails or soil, wash hands thoroughly with soap and water to remove potential contaminants. Discourage pets from eating snails and educate children about not touching snails or putting their hands in their mouths after playing in garden areas. Non-chemical methods like copper tape, crushed eggshells, or beer traps can also help reduce snail presence in cultivated areas.