Beyond the multiplex PCR: clinical severity and diagnostic challenges of salmonella meningitis in infants

Abstract

Background: Salmonella meningitis is an uncommon but devastating complication of Salmonella species in the pediatric population, characterized by high mortality and an angioinvasive nature. In many regions, the diagnosis is hampered by logistical delays and the limitations of modern rapid diagnostic tools. Objective: This study aims to describe the clinical profile, laboratory findings, and outcomes of 10 confirmed Salmonella meningitis cases. Methods: We performed a descriptive analysis of 10 infants with culture-confirmed Salmonella meningitis, drawn from the 270-patient database originally described by Corrêa-Lima et al. Demographic data, clinical markers and CSF parameters were evaluated. All patients were initially treated with empirical ceftriaxone and received a loading dose of dexamethasone. Due to the retrospective nature of this study, based on medical record reviews, specific antimicrobial resistance profiles were not fully documented, limiting definitive conclusions on ceftriaxone susceptibility. Results: The sample consisted of 10 infants (60% male) with a mean age of 0.49 ± 0.30 years. All patients originated from non-metropolitan areas (100%), and 80% presented with anemia (Hb < 11g/dL) upon admission. Clinical severity was extreme: 80% presented with seizures, with 30% evolving to Status Epilepticus. Systemic complications included shock (20%) and Upper Gastrointestinal Bleeding (20%). CSF analysis demonstrated intense pleocytosis and glucose consumption: mean leucocytes 8,181.6 ± 10,334.3/mm³ (range: 117–32,400), mean protein 159.8 ± 98.1 mg/dL, and mean glucose 16.1 ± 14.0 mg/dL (reaching 0 mg/dL in severe cases). While CSF cultures were 100% positive, the initial Gram stain was negative in 20% of cases. Adding to the diagnostic challenge is the "diagnostic gap": modern rapid molecular panels (e.g., FilmArray ME) do not include Salmonella in their detection targets. The mortality rate was 40%, with 50% of deaths occurring within 24 hours of admission. Among those who underwent neuroimaging, 85.7% showed severe alterations, including empyema, hydrocephalus, and ischemia. Conclusion: Salmonella meningitis in infants is a medical emergency that demands high clinical suspicion. The 40% mortality rate, particularly the high proportion of early deaths, underscores the rapid progression of the disease despite empirical therapy with third-generation cephalosporins. Clinical suspicion must remain the primary driver for early treatment, as the Gram stain was negative in 20% of this cohort and cultures took 7 days. The 100% rural origin and 80% prevalence of anemia suggest that logistical delays and pre-existing biological vulnerabilities significantly worsen the prognosis. Early identification of "red flags" and aggressive management are vital, as the reliance on traditional microbiology and the lack of coverage in current multiplex PCR panels reinforce a cautious interpretation of negative rapid tests in high-risk pediatric patients.