Medically reviewed by ehealthlyf.com and last updated on: 24/01/2023
Table of Contents
What Is a Urinary Tract Infection?
Urinary tract infection UTI is an infection caused by bacteria that affect the urinary system, including the urethra (called urethritis), ureters, bladder (called cystitis), and kidneys (called pyelonephritis).
Urine is a byproduct of our filtration system. When the kidneys remove extra water and waste from the body, urine is created. Typically, this urine does not contain any germs. Urine can pass through the urinary system without any contamination. However, there are conditions when bacteria from outside can enter your urinary system, which leads to infections and inflammations.
The symptoms of Urinary Tract Infection are typically mild and treatable with antibiotics. But inappropriate use can lead to antibiotic resistance. Therefore, it is necessary to develop appropriate criteria for using narrow-spectrum antibiotics to treat UTIs for the shortest possible time.
What Is the Urinary System?
It includes
Kidneys are the organs located in the back of your body, above the hips. Their main function is to remove waste from your blood, which then becomes urine.
Ureters are the thin tubes that transport urine from the kidneys to the bladder.
The bladder is a sac-like container in which urine is stored before it is removed from the body.
The urethra is a tube that carries your urine from the bladder to the outside.
Epidemiology
Up to 60% of women have at least one symptomatic Urinary Tract Infection during their lifetime. This is more likely to happen to young, sexually active women between the ages of 18 and 24. Approximately 25% of these women experience spontaneous symptom resolution. UTIs are more common in men than in women, and they are most common in older men and men with urologic structural abnormalities.
Pathophysiology
Women are more likely than men to experience cystitis (lower UTIs) because of anatomical variations in women, such as a shorter urethral length and a moister periurethral environment. Urinary tract infections start with periurethral contamination by a uropathogen present in our gut, followed by colonisation of the urethra, and finally moving towards the bladder or kidney by using the flagella and pilli of the pathogen. Bacterial attachment to the uroepithelium is the primary cause of UTI pathogenesis. When the host defence mechanism becomes weaker than the bacterial virulence mechanism, infection occurs.
Pyelonephritis (upper Urinary Tract Infections) occurs when urothelial pathogens ascend to the kidneys by the ureters. In severe cases of pyelonephritis, the affected kidney may be enlarged.
Urinary tract infections are classified as complicated or uncomplicated based on the presence or absence of structural abnormalities, renal obstruction, sex, and pregnancy.
| Category | Definition |
| Uncomplicated UTI | Lower urinary symptoms (dysuria, frequency, urgency) in healthy nonpregnant women. |
| Complicated UTI | Pregnant women, men, renal failure, immunosuppression, obstruction, renal transplantation, individuals with risk factors predisposing to persistent or relapsing infection (eg: calculi, indwelling catheters, or other drainage devices)Healthcare-associated |
| CA-UTI | Presence of indwelling catheters with signs and symptoms of UTI and no other source of infection. Presence of ≥ 10³ CFU/ml in a single catheter urine specimen or midstream urine, despite the removal of the urinary catheter in the previous 48 hours. |
| Asymptomatic bacteriuria | Women: two consecutive voided urine specimens with isolation of the same bacteria at ≥ 10³ CFU/ml. Men: a single, clean-catch, voided urine specimen with 1 bacteria isolated to ≥ 10³ CFU/ml. A single catheterized urine specimen with 1 bacteria isolated ≥ 10³ CFU/ml |
Risk Factors
Urinary Tract Infections are caused by microorganisms, usually bacteria. Escherichia Coli, a bacterium in the intestine, causes more than 90% of bladder infections (cystitis). Females are more prone to this infection than males.
Other risk factors include:
- A previous history of UTI
- Sexual activity
- Pregnancy
- Bacterial changes
- Structural complications in the urinary tract such as enlarged prostate
- Age; older adults and young children are more liable
- Poor hygiene
Some of the predisposing factors are tabulated below:
| Patient population | Risk factors |
| Premenopausal women of any age | Diabetes Diaphragm use, especially those with spermicide Sexual intercourse, history of UTI or UTI during childhood, mother or female relatives with a UTI history |
| Postmenopausal and older adult women | Urinary catheterization, Urinary incontinence. Estrogen deficiency, history before menopause, functional or mental impairment |
| Men and women with structural abnormalities | Intrarenal barrier associated with nephrocalcinosis, uric acid nephropathy, polycystic kidney disease, hypokalemia, and renal lesions from sickle cell diseaseExtrarenal barrier associated with congenital anomalies of ureter or urethra, calculi, benign prostrate hypertrophy. |
Distribution of uropathogens may differ according to infection or patient population
| Uncomplicated UTI | Escherichia Coli, Staphylococcus saprophyticus, Enterococcus spp., Klebsiella pneumonia, Proteus mirabilis |
| Complicated UTI | Similar to uncomplicated UTI Antibiotic-resistant E. coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus spp., Staphylococcus spp. |
| CA-UTI(catheter-associated UTI) | Proteus mirabilis, Morganella morganii, Providencia stuartii, Corynebacterium urealyticum, Candida spp. |
| Recurrent UTI | Proteus mirabilis, Klebsiella pneumonia, Enterobacter spp., Antibiotic-resistant E. coli, Enterococcus spp, Staphylococcus spp |
Clinical Presentation ( UTI Symptoms)
A UTI causes redness and irritation in the lining of the urinary tract, i.e., it gets inflamed.
Symptoms of bladder infections (cystitis) include
- Bloody urine
- Pain or burning sensation during urination (dysuria)
- Cramps in the lower abdomen or pelvic area
- Frequent urination
- Urge to urinate despite having an empty bladder
- Incontinence (urine leakage)
- Abnormal urine colour ( cloudy urine) and strong or foul-smelling of urine
Symptoms of kidney infection (pyelonephritis) include the following
- Fever
- Chills
- Nausea or vomiting
- Back pain
Other symptoms include
- Mental changes or confusion
- Penis pain
- Pain during sex
Fever is the most common sign of UTI in infants. Seek help from healthcare professionals for confirming UTIs in infants.
Diagnosis
Your doctor will instruct you to go for the following tests for the diagnosis of UTI
- Urine Analysis: Test to analyze red blood cells, white blood cells, and bacteria. The presence of RBC and WBC in your urine indicates UTI.
- Urine Culture: To determine the type of bacteria present in your urine.
If your disease does not respond to treatment or if you get frequent infections, your doctor may use the following tests
- Ultrasound: Images of internal organs are created by sound waves. It is painless and done topically on your skin.
- Cystoscopy: This test uses a special instrument fitted with a lens and light source ( cystoscopy) to get inner images.
- CT Scan: Types of X-ray that take cross-sections of the body.
When to seek medical help?
Talk to your healthcare professional if you have any symptoms of Urinary Tract Infection, mild or severe. Antibiotic intake prescribed by your doctor can treat your symptoms. In rare cases, hospital administration becomes inevitable.
Goals of Therapy
Symptomatic relief is the main goal of UTI treatments. With appropriate antibiotic therapy, the clinical response can be observed within 24 hours for cystitis and 48–72 hours for pyelonephritis. If no response is observed after 72 hours, imaging studies may be performed. Patients should receive treatment with drugs that are low in toxicity and that have a low potential for changing normal bowel flora.
UTI Treatment
Most uncomplicated UTIs are treated in outpatient settings, whereas patients with symptoms like fever and systemic infections should be treated with parenteral antibiotics after hospitalisation. Initial therapy is based on the local susceptibility of E. coli and other uropathogens.
Some commonly used antibiotics include
- Nitrofurantoin
- Amoxicillin
- Sulfonamides (sulfa drugs)
- Cephalosporins
- Doxycycline
- Fluoroquinolones like ciprofloxacin
- Sulfamethoxazole/Trimethoprim
- Fosfomycin Trometamol
- Nitrofurantoin
It is the most recommended treatment for cystitis. It is not used for treating pyelonephritis, as nitrofurantoin achieves a high concentration in urine but does not infiltrate well into the renal parenchyma. Nitrofurantoin should be avoided in patients with CrCl of 30ml/minute/1.73m² or fewer. However, due to the risk of side effects, long-term use of nitrofurantoin in elderly patients is not recommended.
Fluoroquinolones
Fluoroquinolones like levofloxacin and ciprofloxacin are recommended for treating uncomplicated pyelonephritis and complicated UTIs. The FDA’s drug safety communication states that serious adverse effects like tendinitis, CNS effects, peripheral neuropathy, etc. become superior to the benefits in patients with uncomplicated cystitis when other treatment options are available.
Trimethoprim/Sulfamethoxazole
It is highly effective against uncomplicated cystitis, with a cure rate of 90% to 100%. It is also used to treat UTIs in men.
Fosfomycin Trometamol
Has in vitro activity against most of the Enterobacteriaceae species. But increased use of fosfomycin is associated with its resistance.
Oral β lactam agents
β-lactam antibiotics like amoxicillin/clavulanate, cefaclor, cefdinir, cefpodoxime, and ceftriaxone have lower efficacy than fluoroquinolones and Trimethoprim / Sulfamethoxazole.
It is considered an alternative for managing uncomplicated UTIs. Amoxicillin and ampicillin are currently not recommended for empiric therapy because of increased resistance.
The following antibiotics and their doses are recommended by the IDSA and the European Association of Urology
ACUTE COMPLICATED CYSTITIS
| Antibiotics | Dose | Therapy Duration | Comments |
| Recommended agents | |||
| Nitrofurantoin monohydrate/monocrystal | 100 mg PO BID | 5 days | |
| Trimethoprim/sulfamethoxazole | 160/800 mg PO BID | 3 days | Widely used, but limited data |
| Trimethoprim | 100 mg PO BID | 3 days | |
| Fosfomycin | 3g PO once | Once | |
| Alternative agents | |||
| Amoxicillin/ clavulanate | 500/125 mg PO | 5-7 days | |
| Cefpodoxime proxetil | 100 mg PO BID | 5-7 days | |
| Cefdinir | 300 mg PO BID | 5-7 days | |
| Cephalexin | 500 mg PO BID | 5-7 days | |
| Ciprofloxacin | 250 mg PO BID | 3 days | |
| Levofloxacin | 250-500 mg PO daily | 3 days |
ACUTE UNCOMPLICATED PYELONEPHRITIS
| Antibiotics | Dose | Therapy Duration | Comments |
| Recommended antibiotics for outpatient management | |||
| Ciprofloxacin | 500 mg PO BID | 7 days | If local FQ resistance is >10%, give ceftriaxone 1g IV once or the dose of aminoglycoside pending culture results. |
| Ciprofloxacin | 1g ER PO daily | 7 days | |
| Levofloxacin | 750 mg PO daily | 5 days | |
| Alternatives or definitive therapy after susceptibility is confirmed | |||
| Trimethoprim/sulfamethoxazole | 160/800 mg PO BID | 14 days | Give ceftrioxone1g IV once or aminoglycoside pending culture results |
| Cefpodoxime proxetil | 200 mg PO BID | 10-14 days | |
| Amoxicillin/ clavulanate | 500 mg PO TID | 10-14 days | |
| Inpatient management or those unable to take oral medications | |||
| Ciprofloxacin | 400 mg IV q12hr | 7 days | May add aminoglycoside pending culture results. Complete the course with PO antibiotics after being afebrile for 48 hrs |
| Levofloxacin | 500 mg IV q24hr | 7 days | |
| Ceftriaxone | 1 g IV q24hr | 14 days | |
| Cefepime | 1-2 g IV q12hr | ||
| Piperacillin/tazobactam | 3.375 g IV q6hr |
ACUTE COMPLICATED CYSTITIS or CA-UTI WITHOUT UPPER TRACT SYMPTOMS
| Antibiotics | Dose | Therapy Duration | Comments |
| Recommended empiric therapy | |||
| Ciprofloxacin | 500 mg PO BID | 5-7 days | Empiric therapy on the basis of antibiotic resistance pattern then streamlines on the basis of cultures and treatment for 5-7 days. |
| Ciprofloxacin | 1 g ER PO daily | 5-7 days | |
| Levofloxacin | 750 mg PO daily | 5-7 days | |
| Ampicillin/sulbactam | 1.5-3 g IV q6hr | ||
| Ceftriaxone | 1g IV q24 hr | ||
| Gentamycin/ tobramycin | 3-5 mg/kg IV once | ||
| Prevention of recurrent UTIs | |||
| Nitrofurantoin | 50 mg PO qhs | ||
| Trimethoprim/sulfamethoxazole | 40/200 mg PO daily |
UTIs in Pregnancy and Lactation
Asymptomatic bacteriuria (ASB) is common in pregnancy, which increases the risk of UTIs. Pregnant women should be screened for ASB, preferably during the first 12–16 weeks of pregnancy. E. coli is the most common pathogen that causes UTI in pregnancy, and it is usually treated with oral antibiotics.
UTIs in lactation are treated with antibiotics that are considered safe in lactation. Trimethoprim/sulfamethoxazole, nitrofurantoin, and most -lactam agents are commonly used. Although there is a low risk of direct toxicity from antibiotic exposure in breast milk in infants, hypersensitivity reactions and changes in bowel flora in infants that cause diarrhoea should be monitored.
| UTIs and Asymptomatic Bacteriuria( ASB) in pregnant women | |||
| Nitrofurantoin monohydrate/ monocrystal | 100 mg PO BID | 5-7 days | Except during the first trimester or near term |
| Amoxicillin | 500 mg PO TID | 3-7 days | |
| Amoxicillin/ clavulanate | 500 mg PO TID | 3-7 days | |
| Cephalexin | 500 mg PO QID | 3-7 days | |
| Cefpodoxime | 100 mg PO BID | 3-7 days | |
| Fosfomycin | 3 g PO once | once | |
| Trimethoprim/sulfamethoxazole | 160/800 mg PO BID | 3 days | Except during the first trimester or near term |
Complications
If treated properly, lower urinary tract infections rarely lead to complications. It can cause serious health problems if left untreated.
Some of the complications include
- High chance of repeated infections. Ie, you may experience another infection within six months or a year.
- Permanent kidney damage
- Giving birth to a premature or low-weight baby if UTI was untreated in pregnancy
- The narrow urethra in men
- Sepsis: a life-threatening condition where infection travels up from the urinary tract to the kidneys
UTI Prevention
You can prevent the risk factors of UTI by following the methods.
Practising hygienic habits
It can prevent UTIs to some extent. Women are recommended to wipe from front to back after a bowel movement. Women should also practice hygienic methods during their menstrual cycle. UTIs in women can be avoided by changing pads and tampons frequently and refraining from using feminine deodorants.
Drinking plenty of water
Drinking more water and other fluids can aid in the removal of bacteria from your urinary tract.
Changing your urination habits
Frequent urination can help prevent the infection, especially if you have recurrent Urinary Tract Infections. Drinking lots of fluid makes this easier, but ensure that your food will not irritate your bladder like alcohol, caffeinated drinks, spicy foods, and citrus juices.
Empty your bladder soon after sex
Also drink plenty of water.
Changing your birth control
Diaphragms used for controlling birth may lead to UTIs in most women. Seek help from your doctor if you are getting infections after using it.
Using water-based lubricant during sex
If you have vaginal dryness, try to use water-based lubricants to avoid infections. Spermicides cannot be used if you have frequent UTIs
Changing your clothing
Avoid tight-fitting dresses and switch to cotton underwear.
Prognosis
A UTI is an infection that can be completely cured with appropriate treatment. It can be uncomfortable before treatment, but once your doctor identifies the reason and prescribes you appropriate antibiotics, there will be a drastic improvement. It is your responsibility to take the medications for the entire time period prescribed. Try not to stop your medications when your symptoms have subsided. If you have frequent UTIs or symptoms that are not improving, your doctor may test for antibiotic resistance, which is more serious and requires hospitalisation and intravenous antibiotics.
FAQs
1. How does a man get Urinary Tract Infections?
The common reasons that are responsible for getting Urinary Tract Infections in males are
- Drinking less water
It is recommended that you drink 7 to 8 glasses of water per day. Men who drink less water are more likely to develop UTIs.
- The Inactive life and unhygienic conditions
If a man doesn’t have the habit of cleaning his penis properly, then the dead cells and the accumulated dirt will tend to develop under the foreskin. Gradually, it will lead to harmful bacterial growth, resulting in a UTI. Uncircumcised males with tight foreskin are more susceptible to getting UTIs.
- Bowel incontinence
A male who has faecal or bowel incontinence has a high risk of developing a UTI. The leakage of the faeces will cause harmful bacteria to reach the urinary tract. Males with bowel incontinence are three times more at risk of developing UTIs.
- Prostate Enlargement
The non-cancerous enlargement of the prostate restricts the blood flow through the urethra. It prevents the bladder from emptying completely, and the bacteria remain in the body for a longer period of time. It increases the chance of developing UTIs.
Some of the reasons that are not so common are
- Diabetes
A man with diabetes mellitus will have poor blood circulation, which increases the risk of developing UTIs. High blood sugar can also contribute to UTIs. While urinating, some residues remain on the penis and the high sugar content allows the bacteria to grow and develop UTIs.
- Indulging in anal sex
The E. coli bacteria that is present in the anus, when it enters the urinary system, will develop UTIs.
- Long-term use of a urinary catheter
The catheters will provide an additional introduction site for bacteria. Long-term use will increase the risk of UTIs.
- Recent urinary or kidney surgery
Urinary surgery or an examination of your urinary tract with the use of medical instruments will increase the risk of UTIs