• Health care associated meningitis/ ventriculitis is seen in patients undergoing neurosurgeries, head trauma, external ventricular drainage, lumbar punctures etc.
• The etiology depends on local epidemiology but commonly includes multi drug / extremely drug resistant gram negative pathogens including Acinetobacter, Pseudomonas, Klebsiella and Staphylococcus aureus/ epidermidis.
• Diagnosis is a challenge since sensorial obtundation (a cardinal symptom of meningitis) may be due to the underlying disease/ surgery. The CSF may be abnormal due to pre existing bleed/ surgery induced chemical meningitis. The patients are frequently on antibiotics and hence microbial isolation rates are low.
• CSF should be sampled and sent for cell count, protein, sugar and aerobic cultures. Elevated CSF lactate (> 4 mmol/l) and procalcitonin help in differentiating between infective and chemical meningitis. The results of cultures especially those obtained through EVD should be carefully interpreted since they may grow colonizers/ contaminants. Contrast MRI is recommended to pick up meningitis, ventricular enhancement, abscesses, cerebritis, and empyemas.
• Empirical therapy depends on local flora but usually includes high dose meropenem with vancomycin. Therapy should be modified based on culture reports. Surgical drainage of pus and removal of hardware may be needed. For carbapenem resistant pathogens, intraventricular / intrathecal therapy with colistin/ polymyxin B/ aminoglycosides is indicated. The drugs are best administered through an Omaya reservoir but may sometimes have to be given through EVD/ lumbar punctures. Doses of drugs that can be administered in the CSF are listed in Table (Annexure 2). The duration of therapy varies depending on the causative organism but is generally 2-3 weeks (Table).

Treatment of health care associated meningitis and ventriculitis

Organism	Preferred drug	Alternative drug
Methicillin sensitive Staphylococcus	Cloxacillin	Ceftriaxone
Methicillin resistant Staphylococcus	Vancomycin	Linezolid/Cotrimoxazole if susceptible
Non ESBL gram negative	Ceftriaxone	Cefotaxime/ Ceftazidime
ESBL gram negative	Meropenem	Cotrimoxazole/ Moxifloxacin
Carbapenem resistant gram negative	Systemic Colistin/ Polymyxin B with (depending upon susceptibility) high dose tigecycline/minocycline/ fosfomycin/ co-trimoxazole/ quinolones/chloramphenicol With intraventricular/ intrathecal colistin/ polymyxin / aminoglycosides

 

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