Urinary Tract Infections
For urinary tract infection in a child, see Urinary Tract Infection in a Child.
Essentials
Diagnosis
- The symptoms indicate the level of the urinary tract infection (UTI).
- Cystitis: urinary frequency, urinary urgency, burning on urination
- Pyelonephritis: fever, back or flank pain, CRP > 40 mg/l
- In a basically healthy woman aged 18 to 65 years, an occasional cystitis can be diagnosed on the basis of typical symptoms (e.g. using a structured telephone interview) without laboratory examinations, provided that there is nothing suggesting a sexually transmitted disease or other gynaecological infection.
- In other patients with suspected cystitis and in all patients with suspected pyelonephritis, the diagnosis must be based on symptoms and bacterial culture of the urine Urinalysis and Bacterial Culture.
- If the symptoms are atypical, chemical dipstick screening or standard particle counting can be used to support the diagnosis.
- Post-treatment follow-up cultures are only needed if symptoms do not resolve but always during pregnancy. This also applies to pyelonephritis.
Treatment
- A UTI is treated according to the level of infection.
- Cystitis is treated with an antimicrobial drug for 3 days in women and 7 days in men.
- Pyelonephritis is treated with an antimicrobial drug that has high penetration into renal tissue.
- The duration of treatment is 5-14 days, depending on the drug used.
| Population group | Prevalence (%) |
|---|
| Healthy premenopausal women | 1.0-5.0 |
| Pregnant women | 1.9-9.5 |
| Postmenopausal women, 50-70 yrs | 2.8-8.6 |
| People with diabetes | Women 9-27 Men 0.7-11 |
| Elderly people living at home | Women 10.8-16 Men 3.6-19 |
| Elderly people in 24-h care | Women 25-50 Men 15-40 |
| Patients with spinal cord injury | 50 |
| Patients with chronic indwelling catheter | 100 |
- It is not necessary to collect a urine specimenin occasional acute cystitis of a woman aged 18 to 65 years if the clinical picture is unambiguous.
- Rapid tests (chemical screening of urine, particle count in urine) can be used to confirm the diagnosis in clinically unclear cases.
- Narrow-spectrum antimicrobial drugs (trimethoprim, nitrofurantoin, pivmecillinam) are the primary choice. Duration of treatment is 3 days Duration of Antibacterial Treatment for Uncomplicated Urinary Tract Infection in Women (see table T1).
- If the patient's urine flow is abnormal due to functional or structural defects or if the patient has renal failure, longer antimicrobial courses (5-7 days) may be necessary.
Treatment of cystitis in a female patient
| Drug | Dose | Treatment duration |
|---|
| Trimethoprim | 160 mg twice daily or 300 mg once daily | 3 days |
| Nitrofurantoin | 75 mg twice daily | 3 days |
| Pivmecillinam | 200 mg 3 times daily or 400 mg twice daily | 3 days |
| Fosfomycin (may require special permit) | Single 3-g dose | Single dose |
- Gram-negative ESBL bacteria produce extended spectrum beta-lactamases and are thus resistant to penicillins and cephalosporins.
Treatment of cystitis caused by ESBL bacteria in women
| Drug | Dose | Note | Treatment duration |
|---|
| Nitrofurantoin | 75 mg twice daily | | 3 days |
| Pivmecillinam | 400 mg 3 times daily | Not effective against all strains | 3 days |
| Fosfomycin | Single 3-g dose | May require special permit | Single dose |
- Fever and flank or back pain, as well as CRP concentration > 40 mg/l, suggest a renal level infection. Urinary symptoms may be absent.
- A patient with pyelonephritis who is in good general condition can be treated at home with oral medication Oral Treatment for Symptomatic Severe Urinary Tract Infections in Non-Elderly. Treatment duration with fluoroquinolones is 5-7 days in women and 10-14 days in men Treatment Duration of Febrile Urinary Tract Infection, and 7-14 days with other antimicrobial agents (table T2).
- Because of fluoroquinolone-resistant pathogens, checking the urine culture results is especially important in those patients with pyelonephritis whose treatment was started with empirical fluoroquinolone therapy.
Treatment of acute pyelonephritis
| Drug | Dose | Note | Treatment duration |
|---|
| Fluoroquinolone | | A noteworthy share of E.coli strains isolated from the urine may be resistant to fluoroquinolones. Find out about the local situation. | Women: 5-7 days
Men 10-14 days |
| 500 mg twice daily p.o. | | |
| 500-750 mg once daily p.o. | | |
| Cefuroxime | 1 500 mg 3 times daily i.v. | When oral treatment is not feasible. After a response is seen, further treatment should be carried out with an oral fluoroquinolone, a first generation cephalosporin, amoxicillin-clavulanic acid or sulpha-trimethoprim.
A noteworthy share of E.coli strains isolated from the urine may be resistant to cefuroxime. Find out about the local situation. | 10-14 days |
| Sulpha-trimethoprim | 160/800 mg twice daily p.o. | May be used if the strain is known to be sensitive. | Women: 7-10 days
Men: 10-14 days |
UTI in a male patient
- UTIs in men require further urological investigations.
- Prostatic hyperplasia Benign Prostatic Hyperplasia predisposes the patient to infections.
- For treatment, see Table T8
- In a febrile UTI, treatment duration is 10-14 days (table T2).
- UTI in men is often associated with prostatitis or epididymitis.
- Palpation of the prostate and the scrotal organs is indicated.
- Effective concentrations will not be achieved in the prostate with nitrofurantoin or pivmecillinam.
- A urologist should be consulted after a febrile infection.
- Acute prostatitis Acute Bacterial Prostatitis is a rare infection with severe symptoms; almost all cases are sequelae of a recent prostate biopsy.
- Chronic bacterial prostatitis Chronic Prostatitis should be suspected if the UTI recurs after treatment (same causative bacteria).
- If bacterial culture remains negative, the condition in question may be chronic pelvic pain syndrome Syndroma Pelvis Spastica.
Treatment of cystitis in a male patient (usually 7-10 days)
Treatment of asymptomatic bacteriuria and cystitis during pregnancy
| Drug | Notes |
|---|
| Nitrofurantoin 75 mg twice daily | Nitrofurantoin is not recommended close to delivery (in weeks 38-42 of pregnancy), as it will cause a risk of haemolytic anaemia in the newborn. |
| Pivmecillinam 200 mg 3 times daily | Repeated courses of mecillinam should be avoided during pregnancy, because pivmecillinam lowers the serum carnitine concentration. |
| First generation cephalosporins | Cephalexin 500 mg 3 times daily |
| Amoxicillin 500 mg 3 times daily | Can only be used if the sensitivity of the causative agent has been confirmed |
| Fosfomycin 3 g single dose | May require a special permit |
UTI among residents in long-term care facilities
- Asymptomatic bacteriuria is common among these patients, and urine cultures should be taken and empirical treatment started only after other possible diseases and infections that may be affecting the patient's general condition have been excluded and if, based on clinical signs and symptoms, a decision has been made to treat the UTI with antibiotics.
- Due to the multiplicity and variety of the causative agents and their changing sensitivity to antimicrobials, a urine specimen for culture should always be obtained when UTI in an institutionalized patient is treated with antimicrobials.
- The antimicrobial drug should be chosen individually according to the epidemiological situation in the institution and the patient's clinical condition; the aim should be to use antimicrobials with the narrowest possible spectrum.
Recurrent UTI
- The same strain: recurrence within 2 weeks after treatment (relapse)
- A new strain, or recurrence more than 2 weeks after treatment (reinfection)
- In recurrent cystitis, prophylactic antimicrobial medication is used only if non-pharmacological treatment and, in postmenopausal women, topical oestrogen has/have been found ineffective. Antibiotics for Preventing Recurrent Urinary Tract Infection (Uti) in Non-Pregnant Women. An alternative to continuous medication is advance prescription of courses of therapy to be taken in case of recurrence.
- Checklist for patients with at least three UTIs within one year: see Table T9.
Checklist for recurrent infections
| Is the diagnosis of recurrent UTI correct? | Differential diagnostic alternatives: asymptomatic bacteriuria, bladder pain syndrome, sexually transmitted diseases, prostatitis, gynaecological infections, chronic pelvic pain syndrome. In young, healthy women with recurrent bacterial growth in urine, recurrent cystitis is the most probable diagnosis. |
| Are there reversible causes predisposing to recurrent UTIs? | Obstructed urine flow, insufficient fluid intake, constipation, poor blood glucose control in people with diabetes, diabetes medication causing glucosuria |
| Can recurrent UTI be prevented without antimicrobial medication? | Increasing the amount of water drank by 1.5 litres/day may reduce the risk of recurrent UTIs. N.B. Beware of the risk of hyponatraemia developing in the elderly! |
| Other possible measures, but without scientific evidence to support their usefulness | Management of constipation, avoidance of exposure to cold, frequent bladder emptying (every 3 hours during the day), use of vitamin C, postcoital bladder emptying, avoidance of spermicide use and of wearing a pessary. |
- Checklist before starting prophylactic antimicrobial treatment:
- Are there any contraindications?
- Will a postcoital dose be sufficient?
- Can a course of antimicrobial medication be prescribed for the particular patient to have at home in case need arises?
- Patients should be reminded to contact health care if symptoms do not subside in 2 days.
- Are there any factors supporting the use of prophylactic antimicrobial medication?
- Immunosuppression, renal level infections, patient severely frustrated with the situation
- Antimicrobial treatment for the prevention of recurrent cystitis
Alternatives for postcoital antimicrobial prophylaxis
Further investigations
- Imaging studies or urological investigations of the urinary tract are not necessary in women who have recurrent episodes of cystitis or a single episode of pyelonephritis.
- Consultation with a urologist is recommended in a febrile UTI of a male patient.
- Investigations are warranted if
- an acute pyelonephritis recurs or there is no response to appropriate treatment within a few days
- there are signs of an obstruction to the urine flow or other clearly complicating factors.
- Abdominal pains in conjunction with pyelonephritis or an atypical causative agent (e.g. proteus or candida) are indications for ruling out renal infection stones.
- The first-line additional investigation is renal ultrasonography.
References
- Ahmed H, Davies F, Francis N et al. Long-term antibiotics for prevention of recurrent urinary tract infection in older adults: systematic review and meta-analysis of randomised trials. BMJ Open 2017;7(5):e015233. [PubMed]
- Hooton TM, Vecchio M, Iroz A et al. Effect of Increased Daily Water Intake in Premenopausal Women With Recurrent Urinary Tract Infections: A Randomized Clinical Trial. JAMA Intern Med 2018;178(11):1509-1515. [PubMed]
- Jepson RG, Williams G, Craig JC. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev 2012;10(10):CD001321. [PubMed]
- Benevent J, Araujo M, Beau AB et al. First trimester pregnancy exposure to fosfomycin and risk of major congenital anomaly: a comparative study in the EFEMERIS database. Infection 2023;51(1):137-146. [PubMed]
- Schulz GS, Schütz F, Spielmann FVJ et al. Single-dose antibiotic therapy for urinary infections during pregnancy: A systematic review and meta-analysis of randomized clinical trials. Int J Gynaecol Obstet 2022;159(1):56-64. [PubMed]
- Konwar M, Gogtay NJ, Ravi R et al. Evaluation of efficacy and safety of fosfomycin versus nitrofurantoin for the treatment of uncomplicated lower urinary tract infection (UTI) in women - A systematic review and meta-analysis. J Chemother 2022;34(3):139-148. [PubMed]