Special types of urinary tract infections
(A) Asymptomatic bacteriuria
1. Definition.
Asymptomatic bacteriuria, also known as asymptomatic urinary tract infection, is when a certain amount of bacteria is isolated from a urine specimen and the patient does not have any signs or symptoms of urinary tract infection. The diagnostic criteria for asymptomatic bacteriuria are: for asymptomatic female patients or patients with indwelling urinary catheters. Urine culture bacterial colony count ≥ 105 CFU/ml; male patients with clean urine specimens cultured with 1 strain of bacteria colony count ≥ 103 CFU/ml: male or female patients with catheterized urine specimens with 1 colony count ≥ 102 CFU/ml.
2. Prevalence.
The prevalence of asymptomatic bacteriuria in healthy premenopausal women was 1.0%-5.0%. 1.9%-9.5% for pregnant women, 2.8%-8.6% for postmenopausal women (50-70 years old), 9.0%-27.0% for women and 0.7%-1.0% for men in the diabetic population, >15.0% for elderly women in the community, 3.6%-19.0% for elderly men in the community, 25.0%-50.0% for elderly women in long-term care, and 15.0%-40.0% for the spinal cord injury population, and 23.0%-89.0% for those with intermittent catheter catheterization. For sphincterotomy the latter was 57.0%, for hemodialysis 28.0%, for short-term indwelling catheter 9.0%-23.0%, and for long-term indwelling catheter 100.0%.
3. Relationship between asymptomatic bacteriuria and pusuria.
The incidence of concurrent pusuria in patients with asymptomatic bacteriuria ranges from 30% in young women to 100% in patients with indwelling urinary catheters. It is important to note that pusuria is not an indication for the use of antibacterial drugs.
4.Treatment
(1) Conditions that do not require screening and treatment include asymptomatic bacteriuria in premenopausal and infertile women, diabetic women, the elderly, patients with spinal cord injury, patients with indwelling catheters, and children.
(2) Conditions requiring screening and treatment.
(1) Pregnant women: asymptomatic bacteriuria is one of the first subclinical infections to be identified as being strongly associated with adverse perinatal outcomes. Pregnant women with asymptomatic bacteriuria are 20-30 times more likely to produce a preterm or low birth weight infant than women without bacteriuria. Urine culture testing is recommended once a month for each of the first 3 months of pregnancy. Treatment of asymptomatic bacteriuria during pregnancy may reduce the risk of pyelonephritis from 20-35% to 1-4% and may improve the condition of the fetus, reducing the likelihood of low birth weight and preterm birth. Pregnant women with asymptomatic bacteriuria or symptomatic urinary tract infections should be treated with oral antimicrobial medications and reviewed regularly. The choice and regimen of antimicrobial drugs include: amoxicillin 500 mg orally every 8 hours for 3-5 d; amoxicillin a clavulanic acid potassium 500 mg orally every 12 hours for 3-5 d; cefadroxil 500 mg orally every 8 hours for 3-5 d or fosfomycin aminotriol 3 g orally as a single dose treatment.
② Patients requiring surgical operation of the urinary tract: such patients are at risk of intraoperative mucosal rupture and bacteraemia with bacterial entry into the blood, and need to be screened and treated. In the case of prostatic hyperplasia, for example, preoperative asymptomatic bacteriuria, if not controlled, has a 60% probability of bacteraemia after transurethral electrodesis of the prostate, with 6%-10% of patients developing urogenital sepsis. The probability of these infectious complications can be greatly reduced by appropriate preoperative antimicrobial therapy. The application of specific antimicrobial drugs should refer to the results of the drug sensitivity test. The application scheme: 1 d before surgery or immediately before surgery can be applied. If no urinary catheter is left in place after surgery, the antimicrobial drugs can no longer be used, and if a catheter is still left in place, the antimicrobial drugs should not be stopped until the catheter is removed after surgery.
(B) Recurrent urinary tract infections
Recurrent urinary tract infections (RUTI) must meet the following criteria: ≥2 episodes of urinary tract infection within 6 months or ≥3 episodes within 1 year ml. Even in healthy adult women with normal urinary tract anatomy and function, RUTIs are common, with approximately 27% of patients with urinary tract infections experiencing recurrent urinary tract infections within 6 months and 3% of patients with urinary tract infections within 6 months experiencing recurrent urinary tract infections within 6 months. About 27% of patients with urinary tract infections can develop another urinary tract infection within 6 months, and 3% of patients can have more than 3 infections within 6 months.
1. Classification
(1) Bacterial persistence: caused by the same bacteria. The diagnosis is made when the same bacteria are still cultured in the urine after 2 weeks of treatment with sensitive antibacterial drugs. This condition is commonly associated with a combination of anatomical or functional abnormalities of the urinary system. It is a complex urinary tract infection.
(2) Reinfection: This refers to reinfection caused by a different type of microorganism in the patient. Patients belong to uncomplicated urinary tract infections and the infection is caused by a new infection with low self resistance rather than a failure of treatment of the first infection.
2. Diagnosis.
The most important thing to diagnose recurrent urinary tract infections is that the number of their onset must meet the diagnostic criteria. The symptoms, signs and laboratory tests at the onset are similar to those of urinary tract infections in general. Imaging tests mainly include abdominal x-ray plain film, intravenous urography, cystourethrography, urological ultrasound, CT, MRI, etc. The purpose is to detect possible anatomical abnormalities and/or co-morbidities of the urinary system. Female patients should undergo gynecologic examination to exclude gynecologic abnormalities and gynecologic reproductive tract infections and other diseases.
3. Treatment.
A distinction should be made between patients with persistent bacteria or re-infection. If the bacteria persist, the patient mostly has complicated urinary tract infection, and with reference to the principles of treatment of complicated urinary tract infection, surgical procedures are taken to remove or treat the foci of infection and give corresponding antibacterial medication: in patients with re-infection, the urinary tract anatomy and function are usually normal, and the treatment is mainly divided into the following two aspects.
(1) Treatment of acute episodes: the same short course of antimicrobial drugs as for acute uncomplicated cystitis.
(2) Prevention in the interictal period.
(1) Behavioral therapy, including drinking more water, urinating after sex, and rubbing the anus from front to back after defecation;
(2) Treatment with OM I89 (Uro.Vaxom@) vaccine (Escherichia coli lysate) can significantly reduce recurrent disease, but this drug is not yet available in China;
③Phytopharmaceutical prevention, mainly refers to the oral cranberry products to reduce the recurrence of urinary tract infection, the efficacy is controversial;
④Low-dose, long-course antibacterial drug therapy: this antibacterial drug prophylaxis can be started after 1 to 2 weeks of acute attack treatment and negative urine culture. Continuous prophylactic use of antimicrobial drugs and a single dose of antimicrobial drugs within 2 h after sexual intercourse can prevent recurrent urinary tract infections. The dosing regimen includes: methotrexate sulfamethoxazole (TMP/SMX) 40-200 mg orally every 24 hours or 48 hours. Methotrexate 100 mg orally twice every 24 hours, cefadroxil 125-250 mg orally once daily, cefaclor 250 mg orally once every 24 hours, furantoin 50-100 mg orally once every 24 hours or fosfomycin aminotriol 3 g orally once every 10 days, and all the above drugs for a long-term course of 3-6 months. Another regimen is a single dose after sex, including: TMP/SMX 40-200mg orally and ciprofloxacin 125mg orally. Cefadroxil 250mg orally. Norfloxacin 200mg orally. Ofloxacin 100mg orally or furantoin 50-100mg orally or fosfomycin aminotriol 3g orally.
(C) Genitourinary fungal infections
Candida spp. are the most common fungi involved in the primary genitourinary tract, with Candida albicans being the most common intra-hospital fungal urinary tract infection pathogen. In the United States, Candida spp. is the 4th leading cause of nosocomial acquired bacteremia and has the highest morbidity and mortality rate of all bacteremia at 40%. The main risk factors and contributing factors are diabetes mellitus, renal transplantation, advanced age, invasive urinary tract operations, female sexuality, concomitant bacteriuria, prolonged hospitalization, congenital urinary tract malformations or structural abnormalities, ICU unit stay, use of broad-spectrum antibacterial drugs, urinary tract built-in catheters, bladder dysfunction, obstructive urinary tract disease, and renal calculi.
1, clinical assessment: bladder and prostate fungal infections are mostly asymptomatic, only 4% of patients will have symptoms such as urinary frequency, difficult urination, hematuria, etc. Cystoscopy can reveal white patches, mucosal edema and red spots on the bladder wall; kidney is the main target organ invaded by Candidaemia. Kidney Candida infection manifests as symptoms of pyelonephritis with lumbar pain and fever, and may produce ureteral obstruction, forming Candida-infected perinephric abscess or abscess kidney, etc.
The diagnosis of candiduria is based on urine fungal smear and urine fungal culture, but the specimen is easily contaminated. ultrasound and CT examination may reveal changes in the collecting system associated with fungal infection. Ultrasound and CT are likely to reveal changes in the collecting system associated with fungal infection and to evaluate urinary tract obstruction.
2.Treatment
(1) Principles of antimicrobial therapy and commonly used antimicrobial drugs
(1) Treatment of asymptomatic candiduria: the same as asymptomatic bacteriuria.
(2) Symptomatic candiduria are required to receive treatment H citation, need to refer to the specimen culture results and drug sensitivity test results to select drugs.
a. Cystitis and pyelonephritis: fluconazole 40 mg orally once daily for 2-4 weeks; flucytosine 25 mg/kg orally four times daily for 7-10d; amphotericin B 0.3-1.0 mg/kg intravenously once daily for 1 week. Patients taking immunosuppressive drugs need to extend the treatment course appropriately. Amphotericin B bladder flush (5-7d) is effective against fluconazole-resistant Candida spp. and can effectively clear Candiduria, but relapses quickly.
b, prostatitis and testicular epididymitis: fluconazole 400 mg orally once daily for 4 weeks; surgical drainage is required with abscess formation.
c, fungal ball: fluconazole 400 mg orally, once daily. 2-4 weeks; flucytosine 25 mg/kg orally, 4 times daily, 2-4 weeks: amphotericin B 0.3-1.0 mg/kg intravenously, once daily, 1-7d; combined with surgical drainage.
d. Most smooth Candida and Candida klebsiella have low susceptibility to fluconazole, and amphotericin B treatment is recommended; patients with renal insufficiency need to adjust the dose of antifungal drugs according to the glomerular filtration rate and creatinine clearance, fluconazole can be cleared by routine hemodialysis and needs to be administered after hemodialysis or additional dose, and amphotericin B is not cleared by hemodialysis.
(2) Surgical and surgical interventions: Patients with indwelling catheters or renal ureteral endoprostheses should be removed or replaced with new catheters and endoprostheses, and those who need permanent urinary diversion should choose suprapubic cystocentesis and fistula; those who need surgical treatment to relieve obstruction by B ultrasound and cT and other imaging tests clearly have urinary obstructive diseases, those with fungal bulbs or local abscess formation need surgical drainage; those with congenital malformations or structural abnormalities in Surgical orthopedics after infection control.