A case of a rare brain infection caused by a free-living amoeba in contaminated waters has been reported in Kerala, India.
A 15-year-old individual from Panavalli in the coastal district of Alappuzha contracted the disease known as primary amoebic meningoencephalitis (PAM). While additional information about the patient is not available, health officials recall a previous occurrence of the disease in the Alappuzha municipality area in 2017.
UNDERSTANDING PRIMARY AMOEBIC MENINGOENCEPHALITIS (PAM) AND ITS SYMPTOMS
Primary amoebic meningoencephalitis is an uncommon but severe brain infection caused by Naegleriafowleri, a free-living amoeba commonly found in warm freshwater environments, including lakes, hot springs, and poorly maintained swimming pools. PAM typically occurs when contaminated water enters the nasal passage, allowing the amoeba to travel to the brain.
Once Naegleriafowleri reaches the brain, it triggers inflammation in the meninges (the protective membranes covering the brain and spinal cord) and the brain itself. The infection progresses rapidly and manifests severe neurological symptoms such as high fever, intense headache, vomiting, seizures, hallucinations, and coma. Unfortunately, PAM is often fatal, with only rare cases of survival reported.
PRECAUTIONS AND RISKS: AVOIDING CONTAMINATED WATER SOURCES
Given the severity of the disease, district health officials in Alappuzha advice people to refrain from bathing in contaminated water. The main symptoms to watch for include fever, headache, vomiting, and seizures. Naegleriafowleri poses a risk in warm freshwater environments, and individuals should exercise caution while swimming or engaging in water-related activities. Proper maintenance of swimming pools, hot springs, and similar facilities is essential to minimize the risk of amoeba contamination.
VIGILANCE AND PREEMPTIVE MEASURES TO COMBAT PAM
The recent case of primary amoebic meningoencephalitis in Kerala serves as a reminder of the potential dangers associated with free-living amoebae in contaminated water. Heightened vigilance and adherence to precautionary measures, such as avoiding bathing in contaminated water and maintaining hygienic swimming facilities, are crucial in preventing the spread of Naegleriafowleri and reducing the risks of PAM.
HOW PRIMARY AMOEBIC MENINGOENCEPHALITIS DIAGNOSED?
Diagnosing primary amoebic meningoencephalitis (PAM) is a complex task due to the rarity of the infection and the non-specific nature of early symptoms. Additionally, the limited availability of diagnostic tests further complicates the diagnostic process. This article explores the challenges faced in diagnosing PAM and the recommended laboratory tests for accurate identification.
RARITY AND NON-SPECIFIC SYMPTOMS: HINDRANCES TO DIAGNOSIS
PAM is an exceptionally rare infection, making it difficult for healthcare professionals to consider it as a potential diagnosis. Furthermore, the early symptoms of PAM are non-specific and can resemble other common illnesses, leading to delayed recognition and appropriate testing. The combination of rarity and non-specific symptoms often contributes to misdiagnosis or delayed diagnosis.
RECOMMENDED LABORATORY TESTS FOR PAM DIAGNOSIS
Laboratory tests play a crucial role in diagnosing PAM. However, it is important to note that these tests are available in only a few laboratories in the United States, further complicating the diagnostic process. The recommended diagnostic tests include:
Wet Mount: A wet mount examination involves observing a sample, typically cerebrospinal fluid, under a microscope to detect the presence of the amoeba Naegleriafowleri. This method allows direct visualization of the amoeba and can aid in confirming the diagnosis.
Giemsa Staining: Giemsa staining is another diagnostic technique used to identify Naegleriafowleri in cerebrospinal fluid specimens. This staining method enhances the visibility of the amoeba under a microscope, facilitating its identification.
LIMITATIONS OF IMMUNODIAGNOSIS IN PAM
Immunodiagnosis, which involves detecting specific antibodies against Naegleriafowleri, is not useful in the diagnosis of PAM. This is primarily due to the rapid progression of the disease. By the time the immune response develops, the infection has often advanced significantly, rendering immunodiagnosis ineffective for early detection.
MAIN TREATMENT MODALITIES FOR PAM
Antimicrobial Drugs: Medications such as amphotericin B, a potent antifungal agent, are commonly used in the treatment of PAM. These drugs work by targeting and killing the amoeba, but their effectiveness can be limited due to the challenges in reaching therapeutic levels in the brain.
Supportive Care: Since PAM can cause severe neurological symptoms and complications, supportive care is essential. This includes measures to control brain swelling, manage seizures, and maintain the patient’s vital functions. Supportive care may involve the use of medications such as corticosteroids to reduce brain inflammation and anticonvulsants to control seizures.
Investigational Therapies: Given the limited treatment options available for PAM, some experimental or investigational therapies have been explored, including the use of other antimicrobial drugs, combinations of medications, and immunomodulatory agents. However, the evidence supporting these therapies is limited, and their effectiveness remains uncertain.
Hypothermia: In certain cases, therapeutic hypothermia, which involves cooling the body to lower its temperature, may be considered as an adjunctive treatment. This approach aims to reduce brain inflammation and potentially limit the damage caused by the infection.