Background 4 month old male hydronephenosis, possible upj urinalysis came back: negative leukocytes estrase wbc clumps yeast (budding) high bacteria high what does this indicate since his estrase was negative which usually indicates infection?

Leukocyte esterase is an indirect test for white blood cells (WBC); clumps of WBC is more accurate and suggests infection, which often complicates urinary tract obstruction and hydronephrosis. Infection might be due to bacteria or yeast see in the urinalysis, or both. Presumably the patient (your son?) is being carefully followed by his doctors; discuss with them. Good luck.

I agree that the presence of wbcs is consistent with an infection. A urine cath culture is usually helpful in confirming the diagnosis and in guiding treatment. Please follow up with your Nephrologist. Watch for signs of poor feeding and fever.