​Kembara Xtra - Medicine - Asymptomatic Bacteriuria

​Kembara Xtra - Medicine - Asymptomatic Bacteriuria 
ESSENTIAL DESCRIPTION

Specific bacterial growth of 105 CFU/mL in one or two consecutive midstream urine samples from men or women older than 18 is referred to as asymptomatic bacteriuria (ASB). For those who don't exhibit any clinical signs, this term is appropriate.


EPIDEMIOLOGY

Premenopausal females: 1-5% in incidence
Maternity: 2-10%
Older men and women: 4% to 19%
Older people who are institutionalized: 15–50%
Prevalence is variable, rising with age, female gender, sexual activity, and the existence of genitourinary (GU) abnormalities. Pregnancy accounts for between 1 and 10% of cases.
Long-term care residents in women (25–50%) and males (15–40%), respectively, with short- and long-term indwelling catheters (9–23% and 100%).

PATHOPHYSIOLOGY AND ETIOLOGY

The microbiology is similar to other UTIs, with bacteria coming from the gut, periurethral region, or vagina.
In ASB, the organisms are less pathogenic than those that cause UTI. Escherichia coli is the most widespread microbe. Klebsiella pneumoniae, Enterobacter, Proteus mirabilis, Staphylococcus aureus, group B Streptococcus (GBS), and Enterococcus are further prevalent microorganisms.
Genetics
Genetic variants that weaken innate immunity and delay bacterial clearance have been linked to ASB. These genetic differences affect the activity of the toll-like receptor 4 (TLR4).

RISK FACTORS include pregnancy, advanced age, female gender, sexual activity, the use of spermicide-containing diaphragms, GU abnormalities such as neurogenic bladder and urinary retention, and the use of urinary catheters (including indwelling, intermittent, and condom catheters). Other risk factors include institutionalized elderly people, diabetes mellitus, immune comorbidity, spinal cord injuries or functional impairment, and hemodialysis.

CONDITIONS OFTEN Associated with

according to the risk variables


Asymptomatic - Lack of UTI-related symptoms including fever, acute dysuria (lasting less than a week), new or worsening urine urgency/frequency/incontinence, or acute gross hematuria in the diagnosis history.


Afebrile, no suprapubic and costovertebral angle discomfort on physical examination

UTI, uncomplicated cystitis, and contaminated urine specimen are all different diagnoses.

DETECTION & INTERPRETATION OF DIAGNOSIS
Initial examinations (lab, imaging)
Urine analysis (UA)
- Pyuria, leukocyte esterase, and nitrite are frequently found in ASB.
Urine culture. There are just two circumstances in which screening urine culture in asymptomatic patients is advised:
Screening for ASB in males and non-pregnant women is not advised. - Pregnancy: screening between 12 and 16 weeks' gestation or at first prenatal appointment if later. - Prior to transurethral resection of prostate (TURP) or any urologic treatments where mucosal bleeding is anticipated.

Tests in the Future & Special Considerations
For urine culture, a non-contaminated urine sample should be used.
After ASB treatment in pregnant women, frequent screening urine cultures should be performed; however, this is not necessary in cases of GBS bacteriuria.

According to the Infectious Diseases Society of America, a patient with substantial bacteriuria with or without pyuria and no symptoms suggestive of a UTI should be classified as having ASB.
– The definition of significant bacteriuria depends on the sex, type, and quantity of the urine sample.
- Clean catch specimen by midstream
Male: >100,000 CFU/mL of a single bacterial species Female: Needs two consecutive positive specimens, but with the same requirements as male
Male and female catheterized specimens: >100 CFU/mL of one bacterial species; one-time collection only.
Positive nitrite is a sign of the presence of bacteriuria but cannot distinguish UTI from ASB or poor collection method. The presence of pyuria or leukocyte esterase is prevalent but not a marker of infection.

ALERT / TREATMENT GENERAL MEASURES

 Only two circumstances warrant the use of antibiotics in the treatment of ASB:
- MaternityReason: Treatment lowers the risk of low birth weight and premature delivery, which are perinatal problems, by preventing acute pyelonephritis in up to 70% of pregnant women.
- Before TURPThe use of antibiotics can successfully ward off sepsis and postoperative bacteremia.
The treatment of ASB in other conditions (non-pregnant women, diabetic women, patients with indwelling catheters, patients with spinal cord injury, or elderly people living in the community) does not provide any known clinical benefit, does not lower the risk of symptomatic infection, and does not increase morbidity or mortality. It raises the price of medical care, the risk of drug side effects, the rate of re-infection, and the development of resistant organisms.
Recommendation against screening for all solid organ transplants other than kidneys or after one month after kidney transplantation; insufficient data to support care of nonurologic procedures

MEDICATION Pregnancy - To avoid GBS disease in the unborn child, women with GBS bacteriuria occurring at any stage of pregnancy and of any colony count are advised to have intrapartum antibiotic prophylaxis with IV penicillin or clindamycin (penicillin allergy).
– There is no universal agreement on the best antibiotics to use or the recommended treatment time during pregnancy, however 4 to 7 days of treatment is associated with a higher cure rate than one day.
– The bacterial pathogen, local resistance rate, side effects, and patient comorbidities should all be taken into consideration when choosing an antibiotic.
- Frequently employed oral antibiotics (FDA-B)
Cefuroxime 250 mg BID for 5 days; Cephalexin 500 mg BID for 5 days; Nitrofurantoin 100 mg BID for 5 days (low level of resistance, may cause hemolysis in glucose-6-phosphate dehydrogenase deficiency); Fosfomycin 3 g for 1 single dose (not effective when glomerular filtration rate is 30 mL/min, may be used in highly resistant bacteria such as methicillin-resistant S. aure 
- Pregnant women should avoid trimethoprim in the immediate future. After 32 weeks of pregnancy, stay away from sulfa.
Fluoroquinolones (FDA-C) and tetracyclines (FDA-D) are contraindicated before invasive urologic interventions.
Antibiotics should be started the night before or right up until the surgery. Up until the indwelling catheter is removed following the procedure, antibiotic should be continued.

PERIODICAL CARE AFTERCARE AND RECOMMENDATIONS
Despite the lack of agreement on the subject, monthly urine culture monitoring is advised after ASB treatment, with the exception of GBS (1).
patient observation
Any emergence of UTI symptoms or signs should call for antibiotic treatment.

DIET
Daily cranberry juice or twice-daily cranberry capsules may lessen the incidence of ASB during pregnancy, however this has not been proven in a significant study.

EDUCATION OF PATIENTS
When UTI symptoms emerge, the patient should see a doctor.

COMPLICATIONS In contrast to women whose initial screening urine cultures were negative or whose bacteriuria was treated, late pregnancy pyelonephritis affects 20–35% of bacteriuric women. Poorer fetal outcomes (low birth weight infant, infant with group B streptococcal infections) and early delivery are linked to pyelonephritis. The probability of developing pyelonephritis again will drop from 20–35% to 1-4% with antimicrobial therapy, as will the risk of giving birth to a child with a low birth weight from 15% to 5%.
Up to 60% of patients who undergo traumatic urologic procedures with untreated bacteriuria go on to acquire bacteremia following the procedure, and 5–10% suffer severe sepsis or septic shock.