CDC issues guidance for B. procyonis caused by roundworms in raccoons
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The CDC recently provided guidelines for health care providers when caring for patients suspected to be infected with Baylisascaris procyonis, a roundworm associated with raccoons.
Typically, raccoons are asymptomatic when infected with the parasite, but the larval form of B. procyonis can be fatal to humans or cause severe neurologic events if the condition is not promptly diagnosed and treated, according to the MMWR report.
“Because there is no commercially available serologic test for baylisascariasis, a history of raccoon exposure and a high index of clinical suspicion are necessary to make the diagnosis,” Anita D. Sircar, MD, an epidemic intelligence service officer at the CDC, and colleagues wrote. “Serologic testing at CDC using a recombinant antigen rBpRAG1 immunoblot assay can aid in diagnosis by detecting Baylisascaris procyonis antibody in cerebrospinal fluid and serum; however, because the assay detects immunoglobulin G antibodies, it is not possible to distinguish current from previous Baylisascaris infection, and detected antibody might represent an earlier exposure.
“Diagnosis of Baylisascaris procyonis ocular larva migrans is based on visualization of an appropriately sized larva in the eye, with or without serologic testing.”
The CDC received serologic testing results from seven potential cases of baylisascariasis in the United States from May 2013 to December 2015. The cases — occurring in Arkansas, California, Ohio, Oklahoma, Massachusetts, Minnesota and Virginia — tested positive for rBpRAG1 B. procyonis antibodies. Six patients were diagnosed with eosinophilic meningitis, and the other was diagnosed with ocular larva migrans. Although all survived, four patients were left with neurologic defects.
The recommendations to prevent B. procyonis include:
- monitoring children when playing outdoors, particularly when contacting soil;
- avoiding exposure to raccoons and their feces that harbor the roundworms;
- clearing areas where raccoons defecate;
- frequently washing hands; and
- educating children not to put their unwashed hands in their mouths.
In cases where patients are suspected of having B. procyonis, physicians should:
- treat patients as quickly as possible after exposure with oral albendazole; and
- consider pre-emptive treatment to protect the patient against larval ocular and neurological migration.
“Treatment should begin as soon as infection is considered, even if consideration is based on clinical suspicion or epidemiologic history alone,” the researchers wrote. “Patients with suspected exposure to Baylisascaris procyonis should immediately be started on a course of 20 to 50 mg/kg oral albendazole per day for 10 to 20 days, while further diagnostic investigations are being conducted.” – by Kate Sherrer
Disclosure: The researchers report no relevant financial disclosures.