In Australia it is alarm for the spread of the so -called ‘snail killer’ or pulmonary worm of the rat (Angiostrongylus cantonensis): a lethal parasite for dogs and dangerous also for humans.
“Snail Killer” alarm in Australia
According to a new research by the University of Sydney, the cases have multiplied in dogs, arousing concern between doctors and health authorities. The infection, considered rare but potentially fatal, was found in a small but growing number of dogs in the areas affected by strong rains and occasionally also in human beings. An alarming situation, as pointed out by the infectiousologist Matteo Bassetti, director of infectious diseases of the San Martino Polyclinic of Genoa, who posted an image of this parasite on Facebook: “It is not a crocodile belt, but the photo of a parasite. The pulmonary worm of the rat (Angiostronghlus Cantonensis) is reaping victims among dogs in Australia: 93 cases: 93 cases Confirmed since 2020, with deaths and paralysis. Globalization contributes to the geographical diffusion of the disease.
The parasite and symptoms of the infection
As mentioned, the rat pulmonary worm (Angiostrongylus Cantonensis) is a parasite that originated in Southeast Asia but has spread to other parts of the world, including North America, Europe and Australia. The natural guest of the parasite are the wild rats, but it can accidentally make its way to other animals through a complicated transmission process that involves snails and locks as intermediate guests. When it finds its way in humans and dogs, the pulmonary worm of the rats can cause a disease called neural angiostrongoliase. In humans, it is diagnosed as a sort of meningoenencephalitis eosinophilis. Symptoms in humans include headache, a rigid neck, tingling or skin pain, fever, nausea and vomiting. In rare cases, it can cause permanent brain damage or to be fatal, especially in subjects with compromised immune system.
Symptoms in dogs include tail paralysis, urinary incontinence and abnormal pain responses. The time between eating the infected or snail snail and getting sick is usually in one and three weeks. The doctoral researcher of the University of Sydney Phoebe Rivory, author of the recent study, explained that it is not the parasite itself that does the damage, but the attempts of the body to fight him. “In dogs and human beings, the parasite enters the brain, but rather than progress towards the lungs as in the rats, it is killed in the brain by our own immune response. It is that clear immune response that causes severe headache and sensations,” said Rivory. The New South Wales Health says that it is rare that humans develop meningitis in response to rat pulmonary worms, and most of the people who contract it have no symptoms, while others can only have mild and short -term symptoms.
Transmission and prevention
The rats infected with adult worms expel the larvae in their feces, which are then ingested by snails and locks. Dogs and people are more likely to contract the parasite when they deliberately or accidentally eat a raw snail that transport the larvae, or the unwashed vegetables, such as lettuce, contaminated with an infected melma. The parasite is not contagious from person to person. Researchers from the University of Sydney examined the prevalence of the disease in dogs on the basis of the fact that they are a sentinel population for humans – that is, the increase in disease rates in dogs can be an early alarm signal of the risk of human disease.
The researchers analyzed 180 clinical samples taken between 2020 and 2024 by dogs suspected of having had the disease and confirmed 93 cases, all of Sydney and Brisbane or around, with a “gradual tendency to rise”. They also discovered a peak of 32 cases in 2022, in correlation with high levels of rainfall, which tends to overload the proliferation of snails. Finally, as regards prevention, the health authorities recommend to always carefully wash fruit and vegetables, as well as avoiding direct contact with snails and frogs, especially in rural areas.