Methicillin resistant Staphylococcus aureus ventriculoperitoneal shunt infection
Data suggest that use of vancomycin as prophylactic agent for cerebrospinal shunt placement reduces the rate of shunt infections in the context of high prevalence of Methicillin resistant Staphylococcus aureus. 1).
Case series
2012
A retrospective cohort analysis of 333 consecutive ventriculoperitoneal shunt series was performed at Seoul National University Children's Hospital in Korea between January 2005 and February 2011. Overall, 35 shunts (10.5%) were infected, which represented an infection rate of 0.075 infection cases per shunt per year. VP shunt infection occurred at a median of 1 month (range, 6 days to 8 months) after insertion. An independent risk factor for shunt infection was undergoing an operation before the first year of life (relative risk 2.31; 95% confidence interval, 1.19-4.48). The most common causative microorganism was coagulase negative staphylococci in 16 (45.7%) followed by Staphylococcus aureus in 8 (22.9%). Methicillin resistance rate was 83.3% among coagulase-negative staphylococci and S. aureus. In this study, cerebrospinal fluid shunt infection rate was 10.5%. Infection was frequently caused by methicillin-resistant coagulase-negative staphylococci and S. aureus within two months after shunt surgery. Vancomycin may be considered as the preoperative prophylaxis for shunt surgery in a situation where methicillin resistance rate is very high 2).
1991
In a study of ventriculoperitoneal shunt infections conducted retrospectively between 1983 and 1987 and prospectively in 1988 39 infections from 372 shunt procedures (incidence 10.5%) were identified. The most common organism isolated was Staphylococcus aureus (18; 47%) followed by Staphylococcus epidermidis (10; 26%). Forty-two per cent of staphylococci were methicillin-resistant. Gram-negative infections were associated with myelomeningoceles and Gram-positive infections with other forms of hydrocephalus (P = 0.048). Lymphocyte predominance was found more frequently than polymorphonuclear predominance in cerebrospinal fluid 3).
Case reports
2009
A 6-year-old female presented with a large staphylococcal abdominal abscess manifesting as abdominal distension without significant clinical signs or blood and cerebrospinal fluid findings of infection. The patient had undergone repeated surgeries for craniopharyngioma at 2 years of age and had suffered central pontine and extrapontine myelinolysis during the clinical course, had severely impaired hypothalamic function, and was in a vegetative state on presentation. In addition, she had previously suffered epidural, subdural, and cerebral parenchymal abscesses, which had resolved completely. She underwent percutaneous irrigation drainage of pus and removal of the shunt coupled with intense antibiotic administration, which cured the abscess without recurrence. Culture revealed methicillin-resistant Staphylococcus aureus.
Preexisting intracranial infection, which had extended down into the abdominal cavity through the peritoneal tube of the shunt, coupled with the patient's impaired immune function, had probably caused the abdominal abscess. Abdominal abscess is a potential complication of ventriculoperitoneal shunting, and timely diagnosis and treatment may achieve a good outcome 4).
2005
Phenotypic variants of Staphylococcus aureus may be misidentified by routine microbiological methods, and they may also respond poorly to antibacterial treatment. Using molecular methods, we identified small-colony variants of methicillin-resistant S. aureus (which were misidentified by 3 widely used automated identification systems as methicillin-susceptible coagulase-negative staphylococci) as the cause of recurrent ventriculoperitoneal shunt-related meningitis 5).