Report details raccoon roundworm infections in 2 California children in 2024

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Raccoon
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Yesterday in Morbidity and Mortality Weekly Report, investigators from the US Centers for Disease Control and Prevention (CDC) and local health officials recounted 2024 raccoon roundworm infections in two children in Los Angeles County, California, that left one with severe cognitive, motor, and visual deficits due to initial misdiagnosis.

After possibly ingesting raccoon feces and/or contaminated soil, the two unrelated boys presented with signs and symptoms such as encephalopathy, roundworm larva in the eye, peripheral and cerebrospinal fluid eosinophilia (high levels of a kind of white blood cell), behavioral changes, and unsteady gait. 

The patients, who had brain abnormalities on imaging, were found to be infected with Baylisascaris procyonis, a roundworm parasite often found in raccoons that can cause baylisascariasis, a rare and potentially serious human disease.

"Baylisascaris procyonis (raccoon roundworm) is an intestinal parasite that causes widespread, typically asymptomatic infection in raccoons (Procyon lotor) in the United States, where up to 80% of raccoons in the Northeast, Midwest, and West Coast regions are affected," the researchers wrote.

Severe persistent neurologic complications

The first patient, age 14 years, had autism and a history of pica (consumption of nonedible items). The second patient, age 15 months, had previously been healthy.

Health care providers should suspect B. procyonis infection in patients with eosinophilic meningoencephalitis, especially young children or persons with developmental disabilities or pica and consider empiric treatment with albendazole.

Both patients received the antiparasitic drug albendazole and corticosteroids. The first patient recovered neurologically, but the second patient developed severe persistent neurologic complications after a substantial delay in receiving an accurate diagnosis and treatment.

Epidemiologic investigation identified raccoon feces that had fallen from a rooftop latrine (communal raccoon defecation site) as the possible source of exposure for the teen, but a source wasn't identified for the younger child. 

"Health care providers should suspect B. procyonis infection in patients with eosinophilic meningoencephalitis, especially young children or persons with developmental disabilities or pica and consider empiric treatment with albendazole," the authors concluded. "In addition, the public should be aware of exposure prevention strategies, including preventing raccoon activity around properties, avoiding exposure to raccoon feces, and safely removing raccoon latrines."

Quick Takes: US COVID uptick, new polio cases in 4 countries, measles outbreak in Michigan

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  • COVID-19 activity is picking in the United States, according to the latest update from the Centers for Disease Control and Prevention (CDC). Although wastewater levels are low nationally, the CDC said cases are rising in many Mid-Atlantic, Southeastern, Southern, and West Coast states. According to the CDC COVID Data Tracker, test positivity for the week ending July 26 rose to 6.5%, up from 4.9% the previous week, while the rate of COVID-related emergency department visits for all ages climbed from 0.6% to o.7%. The percentage of US deaths from COVID rose from 0.3% to 0.4%. Seasonal flu and respiratory syncytial virus (RSV) activity remain low. The CDC also noted that respiratory infections caused by Mycoplasma pneumoniae remain elevated in some parts of the country.
  • Four countries reported new polio cases this week, according to the latest update from the Global Polio Eradication Initiative. Pakistan reported three cases of wild poliovirus type 1 (WPV1), bringing its WPV1 total for the year to 17 cases. Cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) were reported in Yemen (43), Nigeria (5), and Ethiopia (1). The 43 cVDPV2 cases in Yemen were primarily from 2024, bringing that year's total to 107 cases, with 12 reported in 2025.
  • The Central Michigan District Health Department yesterday announced a measles outbreak in Osceola County after confirming additional cases. The department said the outbreak (defined as three or more cases) has been traced to residents who were infected while traveling out of state in mid-June. No public exposures have been identified. Michigan has reported 27 measles cases this year, 15 of which are tied to outbreaks.

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