Which of the following is TRUE about Acute Primary Amoebic Meningoencephalitis?
High-Yield Explanation
Primary amebic meningoencephalitis is caused by free-living amebas belonging predominantly to the Naegleria and Acanthamoeba genera. Acanthamoeba meningoencephalitis is a subacute or chronic illness that also is usually fatal. Naegleria infections associated with freshwater swimming. Histologic evidence suggests that Naegleria traverses the nasal mucosa and the cribriform plate to the central nervous system. A careful examination of the cerebrospinal fluid often provides a presumptive diagnosis of Naegleria infection. The fluid is usually bloody and demonstrates an intense neutrophilic response. The protein level is elevated and the glucose level decreased. No bacteria can be demonstrated on stain or culture. Early examination of a wet mount preparation of unspun spinal fluid reveals typical trophozoites. Staining with specific fluorescent antibody confirms the identification. Acanthamoeba encephalitis usually involve older, immunocompromised persons, and a history of freshwater swimming is generally absent. The clinical course of Acanthamoeba disease is more prolonged than that of Naegleria infection and occasionally ends in spontaneous recovery; the disease in immunocompromised hosts is invariably fatal. The spinal fluid usually demonstrates a mononuclear response. Amebas can occasionally be visualized in or cultured from the cerebrospinal fluid or biopsy specimens. Ref: Ray C.G., Ryan K.J. (2010). Chapter 51. Rhizopods. In C.G. Ray, K.J. Ryan (Eds), Sherris Medical Microbiology, 5e.