Naegleria fowleri

Commonly called as “brain eating amoeba”. This free living amoeba is commonly found in warm freshwater (e.g. lakes, rivers, and hot springs) and soil. It enters through the nose after swimming or diving in contaminated lakes and rivers. Rarely it has been associated with neti pot (small pot used for nasal rinse) use as tap water may be contaminated. The amoeba then migrates to the brain via the olfactory nerve. It causes PAM or primary amoebic meningoencephalitis which presents as fever, headache, nausea, vomiting followed by neck stiffness, seizures, altered consciousness and coma. Only 5 cases so far have survived the infection in North America. PAM and Naegleria fowleri infection can be diagnosed in the laboratory by detecting organisms in cerebrospinal fluid (CSF), biopsy, or tissue specimens, or by nucleic acid detection in CSF, biopsy or tissue specimens or by detection of antigen in CSF, biopsy, or tissue specimens. The motile amoebae can often be seen moving rapidly under a microscope when looking at a fresh sample of CSF. The amebae can also be stained with a variety of stains, such as Giemsa-Wright or a modified trichrome stain. Culture can be done as co-culture with E.coli.

IIF of Naegleria fowleri in brain tissue, viewed under UV microscopy.