A rare parasitic worm that infects people's brains is causing concern in Maui, where a number of similar cases have been reported during the past few months. Two residents and two visitors have become infected with the parasite, and another four cases are under investigation.
Before the cases recorded this year, there have been only two other infections on the island in the last 10 years.
The Rat Lungworm
The parasite is called rat lungworm or Angiostrongylus cantonensis, and it can infect the brain, causing meningitis, according to the CDC. People who are suffering from this infection can experience neck stiffness, headaches, nausea, abnormal sensations in arms and legs and even vomiting.
While most of the people recover without a treatment, rare cases of the infection can result in serious neurological problems or even death.
Dr. Lorrin Pang, Maui district health officer, explained in a live-streamed Facebook presentation the reasons why this parasite is so dangerous. The rat lungworm can live in the host's body for months, and it can cause inflammation from the body's immune response, which can ultimately damage the nervous system. Additionally, the infection can be accompanied by pain.
The parasite has been prevalent in parts of Asia and the Caribbean for decades, as the first case was encountered in Taiwan in 1944. However, recently it has started to spread across the United States — to Hawaii, Alabama, California, and Louisiana.
Additionally, according to a study carried out in 2013, whose findings were published in the Hawaii Journal of Public Health, the geographical distribution of the disease "changed dramatically" over the past decades.
Causes And Prevention Of The Infection
A possible reason that would explain the rise in the global spread of this disease is the lack of boundaries in transportation. The disease can be carried by infected rats on container ships, as well as by intermediate hosts such as snails or slugs.
The ingestion of uncooked snails or slugs can, therefore, transport the parasite into the human body. As a result of eating contaminated food, people can get the infection. Additionally, according to the CDC, hands can be contaminated too.
"[...] contamination of the hands during the preparation of uncooked infected snails or slugs could lead to ingestion of the parasite," notes the CDC page.
As a means of prevention, people who live in areas that are more exposed to this parasite should be educated not to eat snails or slugs that are not properly cooked. Potentially contaminated vegetables, shrimps, and land crabs should also be boiled as a precautionary method.
According to Dr. Constantine Tsigrelis, an infectious disease specialist with University Hospitals Cleveland Medical Center, treating this disease can be complicated, as doctors don't wish to exacerbate an immune response that could kill the parasite.
The reasoning behind this reluctance is that the immune response could also injure the nervous system or the brain in the process of attacking the parasite.
"An anti-parasitic drug could kill the worm but the problem is that the dying organisms can create a very severe inflammatory response and the patient can get worse," noted Tsigrelis.