Staphylococcus aureus CAPD-related infections are associated with nasal carriage

Staphylococcus aureus nasal carriage has been shown to be associated with an increased risk of S. aureus exit-site infections, but its association with peritonitis is less well established. We performed a four-year prospective study to determine the relationship between S. aureus continuous ambulatory peritoneal dialysis (CAPD)-related infections and nasal carriage. All patients who had been started on CAPD from 1989 to 1992 had regular nose cultures. S. aureus nasal carriage was defined as two of three positive nose cultures. A total of 41 carriers and 105 noncarriers were studied. The rates of S. aureus exit-site infection (0.23 vs 0.09 episode/patient/year, p < 0.005), peritonitis (0.33 vs 0.10 episode/patient/year, p < 0.005), and catheter loss (0.12 vs 0.05, p < 0.01) were significantly higher among the carriers. Life-table analysis showed a significant risk of S. aureus exit-site infection and peritonitis for carriers (p < 0.01). Logistic regression analysis showed that S. aureus nasal carriage was the most important predictive factor for S. aureus peritonitis. In conclusion, our study showed that S. aureus nasal carriage is related to an increased incidence of S. aureus CAPD-related infections.