P3.Q324: A Rapid Progression of Amebic Meningoencephalitis

Introduction: Primary amebic meningoencephalitis is a disease of the central nervous system caused by Naegleria fowleri, a free-living ameba, with extremely poor prognosis. This case highlights the rapid progression of a 17-year-old female with amebic meningoencephalitis.

Case Description: A previously healthy 17-year-old female initially presented to an urgent care two days prior with right-sided headache of one day duration. She was diagnosed with migraines. Over the next several hours, she began to develop nausea and emesis, worsening headache, neck stiffness, and fever, prompting to ED #1. She was discharged with medications for sinusitis. She developed worsening dizziness, weakness, and inability to ambulate without assistance. She was taken to ED #2 for evaluation. The lumbar puncture was referred. She received empiric antibiotics for presumptive bacterial meningitis. She was transferred to our Pediatric ED with declining mental status and alteration of her respiratory status. On arrival she was afebrile, tachypneic, GCS of 11 with non-purposeful response to verbal stimuli, jaw clenched, and respiratory distress. She was intubated for declining mental status. The initial Head CT showed early hydrocephalus. The lumbar puncture was deferred. She was admitted to the PICU for further management. Her social history consisted of having 7 cats and 1 dog, known tick exposure, multiple recent trips to local lake within the last 2 weeks, and a recent trip to Florida 6 weeks prior.
On admission to the PICU, echocardiogram showed severely diminished left ventricular systolic function. MRI Brain showed severe leptomeningitis above and below the tentorium, bifrontal encephalitis with evolving cortical infarct, ventriculitis, and stable mild hydrocephalus. An EVD was placed. Within hours she became hemodynamically unstable. Twelve hours later the second Head CT showed interval development of diffuse cerebral edema, tonsillar herniation, and hypoxic ischemic encephalopathy. The patient continued to decline and eventually herniated. Brain death exams were performed, and she was declared dead. Two days later CSF studies returned positive for Naegleria fowleri.

Discussion: Primary amebic meningoencephalitis is a disease of the CNS caused by Naegleria fowleri. There are only 157 known infections in the Unites States between 1962 to 2022. These infections have primarily occurred in southern-tier states in the summer months. It is naturally found in warm freshwater environments, and poorly maintained or minimally chlorinated swimming pools. Early signs and symptoms of Naegleria fowleri infection mimic bacterial meningitis. The fatality rate is 97%, with only 4 known survivors since 1962 in the US. The known survivors have been attributed to early diagnosis, and treatment therapeutics including multiple medications including Miltefosine, as well as using hypothermia.

Conclusion: The purpose of this case report is to raise awareness of Naegleria fowleri, its habitat, and to improve early diagnosis by history taking, and starting early treatment to increase survival chances.