[P3-20] An Infantile Case of Bacterial Meningitis due to Neisseria meningitidis without Spinal Fluid or Serum Culture Detection
[Introduction] Bacterial meningitis due to Neisseria meningitidis infection is very rare in Japan, especially in early infants. We experienced an early infantile case of N. meningitidis-induced meningitis that could not be definitively diagnosed using culture tests, but rather through polymerase chain reaction (PCR) analysis. [Case Report] A local medical doctor introduced a healthy one-month old infant that presented with a high fever. The patient’s anterior fontanelle was distended and he appeared quite sick. Laboratory tests showed high white blood cell (WBC) counts, strong inflammatory reactions, and extreme pleocytosis based on a lumbar puncture test. The rapid latex agglutination assay test was positive for bacterial meningitis, but only nested-PCR could definitively identify the presence of N. meningitidis. Bacteria were not detected in either serum or spinal fluid cultures. Antibiotic therapy via high-dose ceftriaxone and panipenem/betamipron was clinically effective, but we could not definitively decide the therapy duration. In addition, a brain magnetic resonance imaging (MRI) scan revealed a subdural hygroma in the subacute period. [Discussion] In our patient, bacterial meningitis was strongly suspected clinically, but we could not perform a definite diagnosis using only a culture test. Our case suggests that a cultivation survey possibly leads to an underdiagnosis of meningitis, but that the rapid latex agglutination assay test is more sensitive for diagnosis of meningitis due to N. meningitidis infection.