Seasonal Variation in the Peritoneal Dialysis-Related Infections: A Single Center Experience in the Mediterranean

Seasonal variation in the incidence of peritoneal dialysis-related infections (PDRI) has been sparingly investigated, especially in the Mediterranean. Our aim was to explore this association in Malta. All PDRI occurring between Jan-2008 and Dec-2012 were retrospectively studied.A total of 137 patients were followed-up for a median time of 32.5 months (range: 2-81). During this time, 19% never had PDRI, 11.7% transferred permanently to hemodialysis and 6.6% received a kidney transplant. A total of 279 PDRI were identified, equating to 145 catheter-related infections (CRI) and 144 peritonitis episodes (including 10 catheter related peritonitis). A spring peak in the overall gram positive PDRI (0.61 vs. 0.34/patient-year-at-risk, P=0.05), together with a peak in gram negative peritonitis in the warm period (0.13 vs. 0.07/patient-year at risk, P=0.04) was identified. The incidence rate ratios (Confidence Interval) involving the overall gram positive PDRI, gram positive peritonitis, coagulase-negative Streptococci (CoNS) and Streptococci were 1.82 (1.18-2.82, P=0.007), 2.20 (1.16-4.16, P=0.02), 2.65 (1.17-6.02, P=0.02] and 3.18 (1.03-9.98, P=0.04) in spring when compared to winter. No significant difference in the overall PDRI, peritonitis or CRI rates between seasons or warm/cold period was identified.To our knowledge, this is the first study which examines the effect of seasons on the incidence of PDRI in the Mediterranean basin. Findings suggest that spring confers a higher risk for gram positive PDRIs, gram positive peritonitis, CoNS and Streptococcus, whilst the warm period was associated with a peak in the gram negative peritonitis.