Frequency of Infected Renal Stones in Patients Presenting to Institute of Kidney Diseases

Abstract

Background: Infected renal stones are a clinically aggressive subtype of urolithiasis that occurs due to the ability of urease producing bacteria and frequent UTIs. There is little local data available of their prevalence in high-burden areas such as Pakistan, despite being related to rapid stone development, staghorn form, and transition to chronic kidney disease. This study was done to determine the prevalence and clinical presentation of the infected renal stones in patients who presented with renal calculi in one of the tertiary urology centers in Peshawar.

Methods: This was a prospective, single-center, cross-sectional study conducted by the researchers at the Institute of Kidney Diseases in Peshawar, Hayatabad Medical Complex. Non-probability sequential sampling was employed to sample 246 patients who had radiographic appearance of renal calculus during a 6-month time. The age of the patients was 18-75 years. Any kidney stone shortlisted as infected had to come together with indications of some infections within the urinary system and confirmed by a positive urine culture (≥105 CFU/mL) or a stone culture. Using SPSS version 29.0 we were able to analyze structured proforma data which had demographics, clinical, laboratory as well as microbiological information.

Results: Renal stones were infected in 23.6 percent (58/246). The patients were more likely to have infected stones as compared to patients who did not have the conditions (34.0% vs. 50.0% patients with diabetes mellitus, 82.8% vs. 31.4% one infection after the other) and patients seeking medical assistance were more likely to possess a stone (41.4) than those who did not seek medical assistance (34.0). Proteus species was the most predominant uropathogen at 67.2 followed by Escherichia coli with 39.7. Infected stones had a strong correlation with larger average stone size (24.8 =10.4mm vs 16.7 =8.1mm, p<0.001), higher staghorn morphology frequencies (48.3 =6.9 =0.001), increased serum creatinine, increased surgical intervention, and the prolonged hospital stay (p = 0.05).

Conclusion: Infected kidney stones can be considered responsible of approximately 25% of patients with nephrolithiasis in our case. These stones are linked to the female population,

Frequent UTIs, diabetes, etc. more severe illnesses. To decrease morbidity, it is necessary to screen stone patients with infections on regular basis especially in the high-risk population, culture-based therapy, and timely surgical debridement. Bigger multicentric studies are required in order to inform preventive initiatives in Pakistan in region-specific contexts.