Title:“Proposals for Amendments in the Diagnosis and Treatment of Encephalitis caused by Free-living Amoebae”
Volume: 20
Issue: 2
Author(s): Abdul Mannan Baig*
Affiliation:
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi,Pakistan
Keywords:
Intracranial pressure, mannitol, brain-eating amoeba, ventriculoperitoneal shunt, surgical reduction, intracranial
pressure, free-living amoeba, Acanthamoeba, Balamuthia, Naegleria fowleri.
Abstract: Encephalitis caused by Free-living amoebae (FLA) has a mortality rate of around 95-
98%, a fraction that has not changed in the past decades. Pathogenic FLA include Acanthamoeba,
Balamuthia mandrillaris, and Naegleria fowleri that are known to target the brain after an extra
cerebral infection in the case of Acanthamoeba and Balamuthia mandrillaris, or directly the brain,
as in the case of the Naegleria fowleri. The Acanthamoeba spp. and Balamuthia mandrillaris
cause granulomatous amoebic encephalitis (GAE) while Naegleria fowleri, the so termed “brain
eating amoeba” causes primary amoebic meningoencephalitis (PAM). The attempts to obtain a
speedy diagnosis and an aggressive treatment protocol are the areas where advances can make a
difference and reduce the mortality rates. At first, we highlight the reasons behind the diagnostic
delays and treatment failures and provide proposals to establish a quick diagnosis in both PAM
and GAE. Secondly, we emphasize the use of a transcribrial device, and a prompt, but vigilant
surgical reduction of the intracranial pressure in these patients which could be life-saving. We also
debate that an exudate obtained from the olfactory region by irrigation via a modified transcribrial
device or by conventional methods, instead of a cerebrospinal fluid sample, could serve as a
source of obtaining amoeba in PAM for a real-time polymerase chain reaction-based definitive diagnosis
of PAM. Also, introduced is the rationale that has the potential to deliver the drugs to the
brain in patients with PAM and the GAE localized to the frontal lobe of the brain, by bypassing
the blood brain barrier. We put forward these proposals for debate and deliberation to our fellow
colleagues in order to spot the potential of their application to reduce the mortality rates caused by
the rare but fatal encephalitis caused by these FLA.
