Treatment Decision for Symptomatic Patient with Low-Count Gamma Hemolytic Streptococcus Before Hip Surgery
Do not treat this patient for a urinary tract infection. This represents asymptomatic bacteriuria (ASB) with contamination, not a true UTI, and the 2019 IDSA guidelines provide a strong recommendation against screening for or treating ASB in patients undergoing elective non-urologic surgery, including orthopedic procedures 1.
Key Diagnostic Considerations
The negative urinalysis is the critical finding here. The absence of pyuria (negative UA) strongly argues against true UTI, even in a symptomatic patient 2. The combination of:
- Low colony count (2000 CFU/ml, well below the traditional 10^5 CFU/ml threshold)
- Gamma hemolytic streptococcus (typically a contaminant or commensal organism)
- Negative urinalysis (no pyuria, no leukocyte esterase, no nitrites)
...indicates this is likely specimen contamination or colonization rather than infection 3, 2.
Why Symptoms Don't Change the Management
While the patient reports symptoms, pyuria is the key distinguishing feature between true UTI and asymptomatic bacteriuria 1. Without pyuria on UA, the "symptoms" may be:
- Related to another cause (vaginal irritation, urethral syndrome, overactive bladder)
- Misattributed by the patient
- Not actually indicative of bladder infection
In women with recurrent UTI symptoms, a prior negative culture and negative urinalysis are highly predictive (95% specificity, 87% positive predictive value) of another negative culture, suggesting these patients need further evaluation for non-infectious causes rather than antibiotics 4.
Evidence Against Treatment in Pre-Surgical Patients
The 2019 IDSA guidelines specifically address orthopedic surgery patients and found 1:
- 3,167 preoperative patients were screened for ASB
- 403 (12.7%) had ASB
- Treatment of ASB showed "very low certainty for an effect on all outcomes"
- Patients who developed prosthetic joint infections postoperatively had different pathogens isolated from the surgical site compared to preoperative urine, proving the urine was not the infection source 1
- Baseline risk of symptomatic UTI without treatment was only 36 per 1,000 patients 1
Harms of Unnecessary Treatment
Treating ASB increases antimicrobial resistance, risk of Clostridioides difficile infection, adverse drug effects, and healthcare costs without improving surgical outcomes 1. The IDSA emphasizes "high certainty that any antimicrobial increases the risk of harm" even when benefits are uncertain 1.
Appropriate Management Algorithm
Recognize this is not a UTI: Negative UA + low count + gamma hemolytic strep = contamination/colonization 3, 2
Do not obtain additional urine cultures or treat with antibiotics 1
Proceed with standard perioperative prophylaxis for hip surgery (typically cefazolin), which is all that is indicated 1
Evaluate symptoms for alternative causes: Consider vaginal discharge, urethral syndrome, or overactive bladder if symptoms persist 5, 2
Only reconsider if patient develops fever >72 hours postoperatively with new urinary symptoms AND pyuria on repeat UA 1
Critical Pitfall to Avoid
Do not be misled by the patient's symptoms into treating what appears to be contamination. The absence of pyuria is the decisive factor. Treating this patient would constitute overtreatment of ASB, which the IDSA strongly recommends against with a "strong recommendation, low-quality evidence (GRADE 1C)" 1. The evidence shows no benefit for preventing prosthetic joint infections and clear harms from unnecessary antibiotic exposure 1.