Doctors at Seattle Children’s Hospital are sharing a case report on a toddler who died from a rare amoeba infection to help improve future diagnostic efforts.
Key facts
- •The toddler's infection was identified 30 days after his initial hospital visit.
- •Balamuthia mandrillaris has a global fatality rate of approximately 90 percent.
- •Doctors misdiagnosed the boy with Takayasu arteritis, leading to immunosuppressive treatment.
- •Genetic sequencing of cerebrospinal fluid successfully identified the amoeba.
- •A 2010 case in Kentucky showed that earlier identification can lead to patient survival.
A toddler in Washington state died after an infection with the rare amoeba Balamuthia mandrillaris, according to a case report published in BMJ Case Reports. The boy initially presented with symptoms that led doctors to misdiagnose him with childhood Takayasu arteritis, a rare inflammatory condition. By the time the amoeba was identified through a brain biopsy and genetic sequencing 30 days after his first hospital visit, the child had suffered irreversible brain damage.
By the numbers
Diagnostic challenges and misdiagnosis
The boy's initial symptoms included vomiting, lethargy, and weakness. Imaging revealed a brain hemorrhage and blocked arteries, which led medical teams to treat him with immunosuppressive drugs. While these drugs initially appeared to improve his condition, doctors now believe the treatment may have inadvertently allowed the amoeba to spread more rapidly. The boy returned to the hospital multiple times as his condition worsened, eventually requiring intubation and becoming unresponsive.
Recommendations for future cases
The doctors involved in the case advocate against premature diagnostic closure when faced with uncertain conditions. They recommend that clinicians perform diagnostic testing on cerebrospinal fluid for infectious microbes before starting or increasing immunosuppressive therapies. Metagenomic next-generation sequencing was successfully used to identify the pathogen in this case, and experts suggest it could serve as a noninvasive tool for earlier detection in the future.
About the pathogen
Balamuthia mandrillaris is an ultra-rare, opportunistic pathogen found in soil and water worldwide. Since its identification in 1986, only about 200 human cases have been recorded globally, with a fatality rate of approximately 90 percent. While the exact transmission route is often unclear, experts believe infection may occur through inhaling windblown dust or contact with contaminated soil or water through wounds.
Timeline
- 1986The Balamuthia mandrillaris amoeba was first identified in a San Diego Zoo monkey.
- Day 25The boy was re-admitted to the hospital as his condition deteriorated.
- Day 28The boy became unresponsive and required intubation.
- Day 30Doctors performed a brain biopsy and genetic sequencing that identified the amoeba.
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This article was independently rewritten by ManyPress editorial AI from reporting originally published by Ars Technica.
