The astrovirus MLB2, normally prevalent in feces, can spread outside the digestive system and cause central nervous system infection in immunocompromised patients, according to Dr. Samuel Cordey and his associates.
The initial case-patient was a 21-year-old woman who was admitted because of an unusually severe headache and a fever. She was diagnosed with acute meningitis. Next-generation sequencing (NGS) identified 155 reads of astrovirus MLB2 in the patient’s cerebrospinal fluid, 9,340 in an anal swab, 18 in the patient’s plasma, and 16 in the urine. NGS did not identify any other RNA viruses, and no viral or bacterial pathogens were found in DNA sequencing.
In a subsequent pilot study, 943 stool samples from 615 patients and 424 CSF samples from 404 patients were tested for astrovirus MLB2 via reverse transcription PCR. Stool samples were positive for MLB2 in six patients, five of whom were severely immunocompromised. CSF samples were positive for MLB2 in one patient, a recipient of a hematopoietic stem cell transplant.
The study findings “could place astrovirus MLB2 in the differential diagnosis not only of diarrhea but also of aseptic meningitis and protracted infection in highly immunocompromised hosts. Potential determinants of extraintestinal dissemination, such as viral load kinetic, immune response, and host and viral genetic factors, require further characterization,” the investigators said.
Find the study in Emerging Infectious Diseases (doi: 10.3201/eid2205.151807).