Outcomes of adults with invasive meningococcal disease with reduced penicillin susceptibility in Auckland 2004-2017

Purpose The purpose of this study was to assess the clinical outcomes of adults with invasive meningococcal disease (IMD) and to compare the outcomes of patients with IMD caused by a penicillin susceptible isolate (minimum inhibitory concentration (MIC) <= 0.06 mg/L) with patients with IMD caused by an isolate with reduced penicillin susceptibility (MIC > 0.06 mg/L). We also assessed the outcomes of patients with IMD caused by an isolate with reduced penicillin susceptibility who were treated exclusively with intravenous (IV) benzylpenicillin. Methods Retrospective study of all culture positive IMD in adult patients (age >= 15 years) in the Auckland region from 2004 to 2017. Results One hundred and thirty-nine patients were included; 94 had penicillin susceptible isolates (88 cured, 6 died), and 45 had an isolate with reduced penicillin susceptibility (41 cured, 1 possible relapse, 3 died). The median benzylpenicillin/ceftriaxone treatment duration was 3 days for both groups. There was no difference in the patient outcomes of both groups. Eighteen patients with IMD caused by an isolate with reduced penicillin susceptibility received benzylpenicillin alone and were cured. Conclusions This study provides further support to existing data that has shown that short duration IV beta-lactam treatment is effective for IMD in adults. Only a small number of patients with meningitis caused by an isolate with reduced penicillin susceptibility received benzylpenicillin alone, limiting its evaluation. For Neisseria meningitidis meningitis, we recommend ceftriaxone as empiric treatment and as definitive treatment when this is caused by an isolate with reduced penicillin susceptibility.

Automated summary

This study aimed to evaluate the clinical outcomes of adults with invasive meningococcal disease (IMD) and compare the outcomes of IMD patients caused by different penicillin susceptibility isolates. The study found that short-term intravenous beta-lactam treatment is effective for adults with IMD. It also suggests using ceftriaxone as definitive treatment for IMD caused by isolates with reduced penicillin susceptibility.