Raccoon disease. (Clinical Capsules).

Ten of the 12 severe or fatal cases of raccoon roundworm encephalitis identified in the United States since 1981 have occurred in children aged 9 months-6 years (MMWR 50[51]:1153-55, 2002).

Humans become infected by ingesting infected Baylisascaris procyonis eggs, so the diagnosis should be considered in a child with sudden onset of eosinophilic encephalitis and a history of soil ingestion. Findings include cerebrospinal fluid eosinophilic pleocytosis, peripheral eosinophilia, deep white matter abnormalities on MRI, and positive serologic cerebrospinal fluid and serum titers.

Antihelminthic therapy (albendazole, 25-50 mg/kg of body weight per day for 10 days) started within 1-3 days of possible infection might prevent clinical disease by killing larvae before they enter the CNS, but it is not likely to help after symptom onset, the CDC said.