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Urinary tract infections (UTIs) are caused by the rapid growth of bacteria in different parts of the urinary system, namely, the kidneys, ureters, urethra, and bladder.
UTIs are major contributors to the global burden of disease and health expenditure and affect people of all ages.
How Common Is It?
UTI affects nearly 150 million people globally every year, which points to its overwhelming prevalence. UTI can affect people of all genders but is most common in women. Women have a shorter urethra, which makes it easier for the infection-causing bacteria to reach the bladder.
An overwhelming 40% of women have grappled with this condition at one point or another and approximately 20% experience recurrence. Recurrent UTI is mostly due to the antibiotic resistance developed by the causative organisms through biofilm formation.
Types of Urinary Tract Infections
The urinary tract comprises the bladder and urethra in the lower part of the system and the kidneys and ureters in the upper part. Depending upon which section of the tract harbors the bacteria, UTIs can be divided into two broad categories.
- Lower UTIs, where the infection is limited to the bladder and urethra, is more common and less dangerous.
- Upper UTIs develop when the bacteria enter the ureters or kidney (upper urinary tract) and can lead to serious kidney damage if not treated in time.
The three common types of UTIs are:
The urethra is a narrow tube that carries urine from the bladder to be excreted outside the body. The inflammation of this duct due to an infection is referred to as urethritis.
Although most cases of urethritis result from sexually contracted infections, sometimes the swelling can be a by-product of physical trauma or injury to the urethra.
Infection-causing bacteria can travel up the urethra into the bladder and give rise to a common type of UTI known as cystitis.
These bacteria multiply within the bladder and attach themselves to its internal lining, causing superficial irritation and inflammation, which usually resolves after a short duration.
An infection that spreads further upstream through the ureters into the kidneys is known as pyelonephritis. This kind of UTI usually results from a blockage in the urinary tract, which may cause a backflow of urine into the kidneys.
Because your kidneys are involved, this kind of infection can disrupt your renal function, damage your kidneys, and lead to other serious health complications. However, prompt treatment can help contain the damage and safeguard you from any potential risks.
Causes of Urinary Tract Infections
The most common culprit behind 90% of UTI cases is enteric bacteria, a strain of bacteria that naturally populate the human intestinal tract but rarely cause any health concern.
It is when these otherwise harmless bacteria enter the urinary tract that infections may occur. The urinary tract provides an ideal breeding ground for the overgrowth of these bacteria, often resulting in a full-blown infection.
Symptoms of Urinary Tract Infections
Common symptoms of UTI include:
- Frequent urge to urinate but only passing a small quantity of urine
- Burning sensation when urinating
- Change in urine color
- Cloudy urine
- Intensely foul-smelling urine
- Pus or blood in the urine
- Painful urination
- Pain radiating from the bladder, lower abdomen, groin, or pelvis
- Back pain
- Malaise, general discomfort, or being unwell
- Diminished energy levels characterized by lack of interest in activities and constant fatigue
- Vaginal irritation
- Pain while having penetrative sex
Treatment for Urinary Tract Infections
UTIs are usually treated with antibiotics and biofilm disruptors.
Your doctor will prescribe antibiotics in accordance with the results of the lab tests.
When a patient is colonized with bacteria, their symptoms may actually get more bothersome if they are treated with antibiotics. Also, overtreating with antibiotics for negative urine cultures can lead to antibiotic-resistant organisms.
True culture-positive UTIs should only be treated with antibiotics if the patient is symptomatic and experiences pain, blood in the urine, fever, etc. Make sure you take the complete course of antibiotics. Drink ample amounts of water to facilitate the removal of the bacteria through the urine.
Some doctors also prescribe phenazopyridine (Pyridium) to reduce bladder pain during urination.
Note: Individuals with recurrent UTIs must not self-medicate by using leftover antibiotics.
2. Biofilm disruptors
The UTI-causing bacteria and their extracellular secretions can adhere to the epithelial lining of the urinary tract, forming a biofilm. (1)
Biofilms can hamper the action of most antibiotics, making treatment difficult. They contribute to the development of antibiotic resistance and recurrence of the infection in some individuals.
Biofilm disruptors are composed of enzymes that shatter the biofilm matrix of the bacteria by dissolving the sugar and fibrin lining of the pathogenic biofilm.
Diagnosis of Urinary Tract Infections
The diagnostic tools used for detecting UTIs include:
- A urinalysis to check for the presence of blood cells, proteins, bacteria, and other biochemical compounds that indicate UTI
- Urine culture to identify the causative bacteria and the appropriate antibiotic to be given
- An X-ray of the urinary tract (cystogram) for individuals with recurrent UTIs to check for kidney stones or swelling in the kidneys
- A cystoscopic exam, in which a small tube is inserted into the urethra, to check the inside of the bladder and urethra for any problems that might be causing the symptoms
Recurrence of Urinary Tract Infections
The following factors can make you more prone to a UTI recurrence:
1. Functional problems
If you have any kind of structural deformity in the urinary tract, you are more likely to suffer from recurrent episodes of UTI.
Vesicoureteral reflux, for instance, is a common form of urinary tract dysfunction that is characterized by a backward flow of urine from the bladder into one or both of the ureters and sometimes even to the kidneys.
When urine passes from the ureters into the bladder, a set of valves keeps it from moving backward. A problem arises when either or both of these valves have defects. Some people are born with such malfunctioning valves. Others may develop this condition due to excessive pressure inside the bladder.
2. Female anatomy
The urethra in females is much shorter than that in males. Hence, bacteria can reach the bladder more easily in females. In addition, the urethra is in close proximity to the vaginal area, which naturally is colonized with bacteria.
Certain female hormones can make women more prone to UTIs.
4. Sexual intercourse
Sexually active women are more prone to recurrent UTIs. During sexual intercourse, bacteria in the vaginal area are pushed up into the urethra and travel to the bladder. Urine in the bladder offers the perfect environment for them to multiply and cause an infection.
5. Improper toilet hygiene
People who are in the habit of wiping their nether region from back to front after defecating are more at risk of reinfection. The bacteria around the anus are brought to the urethral opening, which is an entry point into the urinary tract.
People who use contraceptives such as spermicides and diaphragms often suffer from repetitive bouts of UTI.
Risk Factors for Urinary Tract Infections
While almost anyone can be down with a UTI, some people are more likely than others to contract this infection. These groups include:
- People who have diabetes
- Infants with a congenital abnormality in the urinary tract
- Women, especially those on birth control or who are sexually active
- People who are overweight
- Men who have trouble with urination or bladder emptying
- People who are using urinary catheters
- People who have a history of spinal cord injuries
- Uncircumcised males
Complications of Urinary Tract Infections
Untreated and recurrent UTIs can lead to the following problems:
1. Kidney damage
An untreated case of lower UTI can spread to the kidneys and result in pyelonephritis, a severe form of UTI that is associated with several serious complications, including kidney damage.
2. Struvite stones
The UTI-causing bacteria break down urea into ammonia and produce a mineral by-product in the process called struvite, which crystallizes to form struvite stones.
If left untreated, these stones can grow large enough to block your kidney, bladder, or ureter. People who are prone to UTIs are more likely to develop struvite stones.
When to See a Doctor
If you suspect a UTI, immediately seek medical help to prevent the condition from worsening. Proper and timely treatment is needed to avoid complications.
Consult a doctor if you experience any of these symptoms:
- Blood in the urine
- Incessant pain and burning sensation during urination
- Fever and chills
Expert Answers (Q&A)
Answered by Dr. Dana C. Rice, MD (Urologist)
Urinary tract infection is a catchall phrase that is used loosely in many different ways. Ureaplasma infections are sexually transmitted infections (STI) that can lead to urinary symptoms.
However, not all bacterial infections in the bladder are sexually transmitted. In fact, most bacterial cystitis infections (bladder infections) are not sexually transmitted.
There are also upper urinary tract infections (kidney infections) that are not sexually transmitted and are often called UTIs, instead of pyelonephritis. In addition, many “UTIs” are not infections at all but rather urethral irritation or pain.
Symptoms of a UTI can pass without treatment. If a true bacterial infection is documented, it is possible that it may flush out on its own. It is also possible to be colonized with bacteria, meaning there will always be bacteria in the urine, but it does not cause symptoms for the patient.
Bladder analgesics such as phenazopyridine (Pyridium, AZO, etc.) would provide most patients relief from the dysuria and urinary frequency. It is not an antibiotic, however, so it will not treat a bacterial infection.
D-Mannose is a supplement that has been shown to prevent UTIs and is also widely available. Patients with E. coli infections can take D-Mannose and AZO to avoid antibiotic treatment for UTIs.
UTIs can be managed by practicing proper personal hygiene and taking doctor-prescribed medications. Treating these infections early can prevent bladder lining irritation and inflammation, ascending infections (pyelonephritis), and sepsis.
Hormones, sexual acts, hydration status, time of and position when voiding, and bowel movements play roles in UTI prevention. Drinking plenty of water, lubrication during sexual intercourse, and timed voiding are the most effective ways to avoid recurrent UTIs across all age groups.