Download MMWR in Review: Mouse infestation likely source of lymphocytic

MMWR in Review, Infectious Diseases
MMWR in Review: Mouse infestation likely source of lymphocytic
choriomeningitis in teen
by Christina A. Rostad M.D.; Larry K. Pickering M.D., FIDSA, FAAP
Editor's note: This article summarizes key points from a Centers for Disease Control and Prevention (CDC)
report published in Morbidity and Mortality Weekly Report (MMWR). The Comment section may include
information that did not appear in the original publications. To subscribe to MMWR, visit www.cdc.gov/MMWR.
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Talley P, et al. "Notes from the Field: Lymphocytic Choriomeningitis Virus Meningoencephalitis from a
Household Rodent Infestation - Minnesota, 2015." MMWR. 2016;65(9):248-249,
http://dx.doi.org/10.15585/mmwr.mm6509a4.
In April 2015, a 15-year-old female presented to her pediatrician with a five-day history of fever, myalgia,
photophobia and headache. Her basic laboratory evaluation, including white blood cell (WBC) count and
erythrocyte sedimentation rate, was normal and she was provided supportive care.
One week later, she returned with persistent headache, photophobia and new onset of meningismus. She was
hospitalized and found to have irritability, hypotension and pancreatitis. Her cerebrospinal fluid revealed
pleocytosis (WBC 1,287 cells/uL) with a lymphocytic predominance, low glucose (36 mg/dL) and elevated
protein (94 mg/dL).
She was treated empirically for bacterial and herpes simplex virus meningitis. She returned to baseline clinically
and was discharged from the hospital on day 11.
Following hospitalization, the Minnesota Department of Health's Unexplained Critical Illnesses and Deaths
Project identified antibodies to lymphocytic choriomeningitis virus (LCMV) by immunofluorescence assay in
serum collected on hospital day four. The CDC's Viral Special Pathogens Branch subsequently performed
serologic testing by enzyme-linked immunosorbent assay, which demonstrated an immunoglobulin M titer of
>1:6,400, consistent with acute infection.
Mouse fecal pellets from the patient's home tested positive for LCMV by polymerase chain reaction. The family
was referred for integrated pest management services, and no further household cases were reported.
Comment
LCMV is a zoonotic arenavirus transmitted to humans by exposure to urine, saliva or other excreta of infected
rodents. Clinical manifestations include fever, retro-orbital headache, photophobia, anorexia and nausea. LCMV
commonly causes a biphasic illness, with aseptic meningitis or encephalitis occurring in the second phase. Most
patients recover without sequelae; however, children younger than 5 years of age, immunocompromised people,
pregnant women and adults over 65 years are at increased risk of morbidity and mortality.
Congenital infection with LCMV can cause a spectrum of abnormalities similar to other congenital infections and
should be included in the differential diagnosis with these organisms. Treatment primarily is supportive, and no
specific antiviral medications are available.
Preventing LCMV infections involves preventing rodent infestations in residences, since approximately 5% of
common house mice are chronically infected with LCMV. Through contact with wild rodents, pet rodents can
acquire LCMV and become reservoirs of infection within households.
Copyright © 2016 American Academy of Pediatrics
MMWR in Review, Infectious Diseases
Pediatricians and veterinarians are in unique positions to advise families about infection risks from various
organisms associated with nontraditional pets, including rodents (mice, guinea pigs, hamsters), reptiles (turtles,
lizards, snakes) and small mammals in the home. Infection risks from these pets are greater in households with
children younger than 5 years of age.
Dr. Rostad is a post-graduate training fellow in pediatric infectious diseases at Emory University School of
Medicine. Dr. Pickering was editor of the AAP Red Book from 2000-'12. He is adjunct professor of pediatrics at
Emory University School of Medicine.
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