A. Clinical manifestations
The clinical features of CSF shunt infection can be quite variable and depend on the pathogenesis of the infection, organism virulence and type of shunt. The most frequent symptoms are headache, nausea, lethargy, fever and change in mental status. Pain, often related to infection at the peritoneal or pleural endings of the shunt, might be absent in as many as 60% of infection.
Infection of the proximal part of the shunt (i.e. the catheter within the CSF space) results in meningitis or ventriculitis. The infection of the distal portion of the catheter results in peritonitis, pleural infection or endocarditis, depending on the terminus location.
The commonest aetiological agents are staphylococci (both S. aureus and coagulase-negative staphylococci), Gram negative bacilli, streptococci, diphtheroids, and anaerobic bacteria.
The diagnosis of CSF shunt infection is established by direct culture of the shunt CSF. This can be obtained by tapping the reservoir under strict aseptic technique. The culture of the fluid at terminal portion should also be considered (e.g. blood culture for VA shunt, pleural or peritoneal fluid for VP shunt).
Antibiotics are important but usually shunt removal is also needed. Occasionally, if the patient is shunt-dependent, antibiotics might be given intra-ventricularly in order to try to sterilize the system.