What is the interpretation and recommended treatment for a child with a non-functioning ventriculoperitoneal (V-P) shunt, normal cerebrospinal fluid (CSF) analysis, and normal glucose levels, but with growth of Staphylococcus capitis and Micrococcus in consecutive CSF cultures?

From the Guidelines

The recommended treatment for a child with a non-functioning ventriculoperitoneal (V-P) shunt who has normal CSF analysis but cultures showing Staphylococcus capitis and Micrococcus is to consider these likely contaminants rather than true infections, especially with normal CSF glucose and otherwise normal analysis. No antibiotic treatment is needed based on these culture results alone, as supported by the guidelines for the management of bacterial meningitis 1. The shunt should be evaluated for mechanical failure and revised surgically if necessary. If there are no clinical signs of infection (fever, neck stiffness, altered mental status), and inflammatory markers in CSF are normal (normal protein, cell count, and glucose), these skin commensals likely represent contamination during sample collection. However, if the patient shows clinical signs of infection or deterioration, empiric antibiotics could be started while awaiting repeat cultures. Vancomycin (15 mg/kg IV every 6 hours) would be appropriate initial coverage if treatment is deemed necessary, as recommended by the clinical practice guidelines for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children 1. The non-functioning shunt requires neurosurgical evaluation regardless of infection status, as mechanical failure needs to be addressed to restore proper CSF drainage and prevent increased intracranial pressure. Key considerations include:

• Evaluating the shunt for mechanical failure and revising it surgically if necessary
• Monitoring the patient for clinical signs of infection
• Considering empiric antibiotics if the patient shows signs of infection or deterioration
• Following guidelines for the management of bacterial meningitis and CNS shunt infections 1

From the Research

Interpretation of CSF Shunt Infection

• The presence of Staphylococcus capitis and Micrococcus in consecutive CSF cultures indicates a possible infection of the ventriculoperitoneal (V-P) shunt 2, 3.
• The normal cerebrospinal fluid (CSF) analysis and normal glucose levels do not rule out the possibility of a shunt infection, as some infections may not cause significant changes in CSF parameters 4.
• The growth of Staphylococcus capitis and Micrococcus in CSF cultures is consistent with the common causes of shunt infections, which are often caused by skin-derived bacteria such as Staphylococcus and Streptococcus species 2, 3.

Recommended Treatment

• The treatment of CSF shunt infections typically involves a combination of surgical and antibiotic therapy 2, 5, 6.
• Vancomycin is often the antibiotic of choice for treating CSF shunt infections, particularly those caused by Staphylococcus species 2.
• The use of intraventricular vancomycin may be considered, starting with a dose of 10 mg daily, with monitoring of CSF vancomycin concentrations to adjust dosing as needed 2.
• Surgical treatment may involve removal of the infected shunt and replacement with a new shunt, or distal shunt externalization followed by new shunt insertion once the CSF is sterile 5, 6.
• The duration of antibiotic treatment may vary, but a course of 12 days or less may be sufficient in some cases 6.