Ventriculoperitoneal (VP) shunts are used to treat hydrocephalus

Ventriculoperitoneal (VP) shunts are used to treat hydrocephalus, diverting cerebrospinal fluid to another part of the body for reabsorption. The proximal portion of the shunt catheter is most commonly placed in one of the cerebral ventricles; the distal portion of the shunt can be internalized or externalized. Internalized shunts most commonly drain into the peritoneumof the abdomen.

The overall infection rate for VP shunts has been reported to be as high as 10%. The highest infection rates have been observed during the first month after initial placement or in patients requiring shunt revisions. This is important because up to 50% of patients will require shunt revision within two years.

Early shunt infections most frequently develop via colonization of the shunt with skin flora, presumably related to the recent surgical procedure; staphylococci are the predominant pathogens.
Late VP shunt infections (several months after insertion and revision) are usually caused by Streptococcus species and gram-negative pathogens such as Pseudomonas aeruginosa, and occur more commonly as a result of bowel perforation or peritonitis.