SouthernWorldwide.com – A parasitic tapeworm, scientifically known as Echinococcus multilocularis and commonly referred to as the “fox tapeworm,” has been identified for the first time in wildlife along the West Coast of the United States.
Researchers from the University of Washington conducted a study near Puget Sound in Washington State. Their findings revealed the presence of this tapeworm in 37 out of 100 sampled coyotes. This parasite is capable of causing a rare but potentially fatal disease in humans.
The study, which was published in PLOS Neglected Tropical Diseases earlier this year, also highlighted that the presence of the parasite in wildlife does not necessarily mean human infections are widespread. The risk to the general public is considered to remain low.
Lead author Yasmine Hentati, who recently earned her doctorate in environmental and forest science from the UW, explained the high prevalence in coyotes. She stated that coyotes frequently consume raw rodents, which is the primary method of infection for them.
Through genetic testing, the research team discovered that the coyotes harbored a newer and more infectious European variant of the tapeworm. This strain has become the dominant one in both the United States and Canada.
The authors noted that prior to the 2010s, this parasitic tapeworm was exceedingly rare in North America. Cases were largely limited to the remote islands of Alaska.
However, over the past 15 years, the parasite has expanded its geographical range. Reports indicate an increase in both dog and human infections across the Midwestern United States and Canada.
Dr. Linda Yancey, an infectious disease specialist at Memorial Hermann in the Houston area, confirmed that coyote cases have been migrating westward from the upper Midwest for several years. Infected animals have indeed been found on the West Coast.
Dr. Yancey also pointed out that while Eastern Europe does report some cases, the infection is very infrequently encountered in the U.S.
Globally, most diagnoses of echinococcosis occur in individuals who have either immigrated from or traveled to Central and East Asia, the Middle East, and North Africa. Western China, according to Dr. Yancey, has the highest prevalence of human infections with the fox tapeworm.
Humans can contract the infection by inadvertently ingesting worm eggs. This can happen after handling contaminated soil or consuming contaminated food. The Cleveland Clinic also notes that infection can occur through contact with an infected pet, followed by touching one’s mouth.
The hallmark of this infection is the development of fluid-filled sacs known as cysts. These cysts contain thousands of immature tapeworms and commonly form in the liver, but they can also spread to other parts of the body.
The infection often goes unnoticed for many years, or even decades, due to the very slow growth rate of the cysts.
According to the Centers for Disease Control and Prevention (CDC), there are two primary forms of the illness: cystic echinococcosis and alveolar echinococcosis.
In cystic echinococcosis, cysts typically develop in the liver and lungs. The body’s response is to create a protective wall around these slowly growing cysts.
Symptoms can manifest as abdominal pain or an enlarged belly if the liver is affected. If the lungs are involved, individuals might experience coughing and shortness of breath. The CDC explains that these signs usually only appear when the cysts grow large enough to exert pressure on surrounding healthy organs and tissues.
The infection becomes dangerous if a cyst ruptures, which often occurs due to trauma. If the cyst fluid is released into the body, it can potentially lead to death.
Alveolar echinococcosis is a rarer and more lethal form of the infection. It progresses as a tumor-like mass that invades and destroys surrounding tissue, most commonly in the liver. However, it can also metastasize to other areas, including the brain.
In severe instances, this form of the infection can result in liver failure and death, according to experts.
Dr. Yancey cautioned that symptoms of liver failure include fatigue, a yellowing of the skin and eyeballs, and abdominal pain.
She added that this infection can mimic cancer, making it crucial to seek medical attention if any symptoms are observed.
While the overall risk of contracting this infection remains low, simple preventative measures can further minimize exposure.
“The most important and simplest way to protect yourself from the fox tapeworm is good hand hygiene,” Dr. Yancey advised.
She recommends washing hands thoroughly before eating and after spending time outdoors or handling soil in areas where the tapeworm is known to exist.
“For dog owners, it’s essential to prevent your animals from eating wild rodents and to ensure all your pets receive regular veterinary care,” Dr. Yancey added.
The CDC also advises avoiding contact with wild animals that can carry the tapeworm, such as foxes, coyotes, and stray dogs.
“Routine testing and treatment for all types of worms help keep your pets healthy and you safe,” Dr. Yancey concluded.
