Primary Amoebic Meningoencephalitis (PAM)

Primary amoebic meningoencephalitis (PAM) is a rare and often deadly disease caused by the protozoan parasite Naegleria fowleri. This condition occurs when the parasite infects the brain, leading to inflammation of the brain and its surrounding tissues.

Cause and Transmission

Naegleria fowleri is typically found in warm freshwater environments such as lakes, rivers, and hot springs. The parasite can enter the human body through the nasal passages when contaminated water is introduced, often during activities like swimming or diving. Once inside, it migrates to the brain via the olfactory nerve, where it begins to feed on brain tissue.

Symptoms

The symptoms of PAM can develop rapidly, usually within 3-7 days after exposure. They may include:

• Headache
• Fever
• Nausea and vomiting
• Confusion and disorientation
• Seizures
• Weakness or paralysis of the face, arm, or leg

Diagnosis

Diagnosing PAM can be challenging due to its rarity and the similarity of its symptoms to those of other conditions. Diagnosis is typically made through a combination of:

• Clinical presentation and medical history
• Imaging studies such as CT or MRI scans to visualize brain inflammation
• Laboratory tests, including cerebrospinal fluid (CSF) analysis for the presence of the parasite or its antigens

Treatment and Prognosis

Treatment for PAM usually involves a combination of antifungal and antibacterial medications, although these are not always effective. The most commonly used drugs include miltefosine, amphotericin B, and fluconazole. Despite aggressive treatment, the prognosis for individuals with PAM is generally poor, with a high mortality rate.

Prevention

Preventing PAM involves avoiding contaminated water or taking precautions when engaging in water activities in warm freshwater environments. This can include:

• Avoiding submerging the head in potentially contaminated water
• Using nose clips when swimming in lakes, rivers, or other bodies of fresh water that may be contaminated
• Avoiding stirring up sediment while swimming, as this can release amoebas into the water

Public health efforts also play a crucial role in preventing PAM by monitoring water quality and issuing warnings when necessary.