Introduction
Angiostrongylus infection is a parasitic disease caused by the larvae of Angiostrongylus species, primarily Angiostrongylus cantonensis. This infection, also known as eosinophilic meningitis, is primarily transmitted to humans through the consumption of contaminated food, typically raw or undercooked snails, slugs, or other intermediate hosts like certain crustaceans. The parasite's larvae migrate to the central nervous system, leading to a range of neurological symptoms.
While A. cantonensis is the most common species associated with human infection, Angiostrongylus costaricensis has also been implicated in cases of abdominal infection. Understanding the nature of this parasitic infection, its symptoms, and the treatment options available is crucial for timely diagnosis and care.
What is Angiostrongylus Infection?
Angiostrongylus infection is caused by roundworms, or nematodes, belonging to the genus Angiostrongylus. The primary species of concern for humans are:
Angiostrongylus cantonensis – This species is the leading cause of eosinophilic meningitis. It primarily infects rats but can also affect humans, particularly in regions where rats and snails are common.
Angiostrongylus costaricensis – This species is less common but can cause abdominal symptoms, including abdominal pain and eosinophilic gastroenteritis.
Humans generally become infected when they ingest larvae found in contaminated food, particularly raw or undercooked snails, slugs, or even contaminated vegetables that have come in contact with these animals. Occasionally, ingestion of infected crustaceans like freshwater prawns can also lead to infection.
Symptoms of Angiostrongylus Infection
The symptoms of Angiostrongylus infection can vary depending on the species of parasite and the organ systems affected. The most common manifestations of Angiostrongylus cantonensis infection, which primarily affects the nervous system, include:
1. Eosinophilic Meningitis
Severe headaches
Neck stiffness
Nausea and vomiting
Fever
Sensitivity to light
Numbness or tingling in limbs
Paralysis in severe cases
These symptoms are often linked to inflammation caused by the larvae migrating into the central nervous system, specifically the meninges surrounding the brain and spinal cord. Eosinophilic meningitis is diagnosed when there is an elevated level of eosinophils (a type of white blood cell) in cerebrospinal fluid (CSF).
2. Abdominal Symptoms (Angiostrongylus costaricensis)
Infection with A. costaricensis can result in the following:
Abdominal pain (often severe)
Nausea and vomiting
Diarrhea
Eosinophilic gastroenteritis
In rare cases, the larvae can cause the formation of cysts in the intestine or other abdominal organs, leading to additional complications.
Diagnosis of Angiostrongylus Infection
Diagnosing Angiostrongylus infection can be challenging due to the variety of symptoms that overlap with other conditions. The process typically involves:
1. Clinical History and Symptom Review
A thorough patient history is essential, particularly any recent travel to areas where Angiostrongylus is endemic or any known exposure to raw or undercooked snails, slugs, or other intermediate hosts.
2. Blood and Cerebrospinal Fluid (CSF) Testing
Elevated Eosinophils: An elevated level of eosinophils in the blood or CSF is often indicative of an Angiostrongylus infection, though it is not definitive.
Serological Testing: Specific antibody tests can sometimes help confirm infection with A. cantonensis.
3. Imaging Studies
In severe cases, neuroimaging like MRI or CT scans may be performed to rule out other potential causes of neurological symptoms, such as tumors or stroke, and to observe any brain damage caused by the larvae.
Treatment Options for Angiostrongylus Infection
While there is no specific cure for Angiostrongylus infection, treatment generally focuses on relieving symptoms and preventing complications. The management plan may involve a combination of the following approaches:
1. Symptomatic Treatment
The primary treatment for Angiostrongylus infection involves managing the symptoms, especially for cases of eosinophilic meningitis:
Pain Relievers: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen can help alleviate pain and inflammation.
Corticosteroids: Drugs like prednisone may be prescribed to reduce the inflammation around the brain and spinal cord.
Antipyretics: Medications such as acetaminophen can be used to control fever.
Antiemetics: These medications help manage nausea and vomiting, which are common symptoms.
2. Anthelmintic Treatment
Albendazole and Mebendazole are anthelmintic medications that can be used to treat parasitic infections. While they are effective in some cases of Angiostrongylus infection, their use is often debated for eosinophilic meningitis because they may not directly kill the larvae in the brain but may help eliminate the parasite from other parts of the body.
Ivermectin has been used experimentally, with some studies suggesting it can be effective in treating Angiostrongylus species. It is more commonly used for other parasitic infections but may be considered for severe cases.
3. Management of Complications
In severe cases, complications like seizures or paralysis may arise. In these instances:
Anticonvulsants may be prescribed to prevent seizures.
Physical therapy may be needed for neurological rehabilitation if there is paralysis or motor impairment.
4. Prevention and Supportive Care
Preventing exposure to contaminated food is key to avoiding infection. This includes avoiding the consumption of raw or undercooked snails, slugs, or crustaceans.
Hydration and nutritional support may be required for patients who experience prolonged symptoms.
Prevention of Angiostrongylus Infection
Prevention is primarily focused on reducing exposure to potential intermediate hosts like snails, slugs, and contaminated vegetables. Recommendations include:
Thoroughly washing and cooking vegetables that may have come in contact with snails or slugs.
Avoiding the consumption of raw or undercooked snails or slugs (this is a common practice in many regions where the infection is endemic).
Control of rodent populations in and around homes or farms, as rats are a key host for A. cantonensis.
Using gloves and proper hygiene when handling raw produce or animals that may carry the parasite.
Prognosis and Long-Term Outlook
For most individuals with mild to moderate symptoms of Angiostrongylus infection, the prognosis is generally good with proper treatment. Infections involving A. cantonensis typically improve over several weeks, and most patients recover fully. However, severe cases that result in neurological impairment or complications like paralysis can have a long recovery period, and some patients may experience lasting effects like chronic headaches or mild cognitive dysfunction.
Source : https://www.databridgemarketresearch.com/reports/global-angiostrongylus-infection-treatment-market
Conclusion
Angiostrongylus infection, caused by the Angiostrongylus genus of parasitic nematodes, is a potentially serious disease that affects the central nervous system. Although relatively rare, the infection can lead to significant neurological damage if not properly diagnosed and treated. Early detection, symptomatic treatment, and supportive care are crucial in managing the disease and preventing complications.
In regions where the infection is common, public health initiatives focused on preventing exposure to contaminated food, controlling intermediate hosts, and educating the population are essential to reducing the incidence of Angiostrongylus infection. If you suspect you may have been exposed to contaminated food or have symptoms of eosinophilic meningitis, it is important to seek medical attention promptly for diagnosis and appropriate treatment.