What is a urinary tract infection (UTI)?
The urinary tract is comprised of the kidneys, ureters, bladder, and urethra. A urinary tract infection (UTI) is an infection caused by pathogenic organisms (for example, bacteria, fungi, or parasites) in any of the structures that comprise the urinary tract. However, this is the broad definition of urinary tract infections; many authors prefer to use more specific terms that localize the urinary tract infection to the major structural segment involved such as urethritis(urethral infection), cystitis(bladder infection), ureter infection, and pyelonephritis. Other structures that eventually connect to or share close anatomic proximity to the urinary tract (for example, prostate, epididymis, and vagina) are sometimes included in the discussion of UTIs because they may either cause or be caused by UTIs. …show more content…
Technically, they are not UTIs and will be only briefly mentioned in this article.
UTIs are common, more common in women than men, leading to approximately 8.3 million doctor visits per year. Although some infections go unnoticed, UTIs can cause problems that range from dysuria (pain and/or burning when urinating) to organ damage and even death. The kidneys are the active organs that, during their average production of about 1.5 quarts of urine per day, function to help keep electrolytes and fluids (for example, potassium, sodium, water) in balance, assist removal of waste products (urea), and produce a hormone that aids to form red blood cells. If kidneys are injured or destroyed by infection, these vital functions can be damaged or lost.
While some investigators state that UTIs are not transmitted from person to person, other investigators dispute this and say UTIs may be contagious and recommend that sex partners avoid relations until the UTI has cleared. There is no dispute about UTIs caused by sexually transmitted disease(STD) organisms; these infections (gonorrhea, Chlamydia) are easily transmitted between sex partners and are very contagious.
ETIOLOGIC FACTORS
What causes a UTI?
The most common causes of UTI infections (about 80%) are Escherichia coli bacterial strains that usually inhabit the colon. However, many other bacteria can occasionally cause an infection (for example, Klebsiella, Pseudomonas, Enterobacter, Proteus, Staphylococcus, Mycoplasma, Chlamydia, Serratia and Neisseria spp) but are far less frequent causes than E. coli. In addition, fungi (Candida and Cryptococcusspp) and some parasites (Trichomonas, Schistosoma) also may cause UTIs;Schistosoma causes other problems, withbladder infections as only a part of its complicated infectious process. In the U.S., most infections are due to Gram-negative bacteria with E. coli causing the majority of infections.
What are UTI risk factors? * any interruption or impedance of the usual flow of urine (about 50 cc per hour in normal adults) is a risk factor for a UTI. * People who require catheters have an increased risk (about 30% of patients with indwelling catheters get UTIs) as the catheter has none of the protective immune systems to eliminate bacteria and offers a direct connection to the bladder. * women who use a diaphragm or who have partners that use condoms with spermicidal foam are at increased risk for UTIs * females who become sexually active seem to have a higher risk of UTI; some investigators term these UTIs as "honeymoon cystitis." * Men over 60 have a higher risk for UTIs because many men at or above that age develop enlarged prostates that may cause slow and incomplete bladder emptying.
Stages of urinary tract infection: * the urethra can become infected. This urinary tract infection is more commonly with sexually transmitted diseases. * the bladder can become infected and, commonly, that's where most of the urinary tract infections occur. * urinary infections can ascend up into the kidneys, causing an issue with kidney infections.
Types of urinary tract infection: * acute urinary tract infections * Chronic urinary tract infections * Types of UTI by location of infection: 1. Nephritis 2. Pyelonephritis 3. Cystitis 4. Urethritis * Urinary tract infections (child)
Classification of urinary tract infection:
1) First or simple urinary tract infection
2) Recurrent urinary tract infection owing to unresolved bacteriuria during treatment
3) Recurrent urinary tract infection owing to bacterial persistence
4) Recurrent urinary tract infection owing to reinfection.
What are UTI symptoms and signs in women, men, and children? * The UTI symptoms and signs may vary according to age, sex, and location of the infection in the tract. Some individuals will have no symptoms or mild symptoms and may clear the infection in about two to five days. * Many people will not spontaneously clear the infection; some of the most frequent signs and symptoms experienced by most patients is a frequent urge to urinate, accompanied by pain or burning on urination. * Urine often appears cloudy and occasionally reddish if blood is present. * Urine may develop an unpleasant odor. * Women often have lower abdominal discomfort or feel bloated and experience sensations like their bladder is full. * Women may also complain of a vaginal discharge, especially if their urethra is infected, or if they have an STD. * Men may complain of dysuria, frequency, and urgency, other symptoms may include rectal, testicular, penile, or abdominal pain. * Men with a urethral infection, especially if it is caused by an STD may have a pus-like drip or discharge from their penis. * Toddlers and children with UTIs often show blood in the urine, abdominal pain, fever, and vomiting along with pain and urgency with urination. * Newborns and infants may develop fever or hypothermia, poor feeding, jaundice, vomiting, and diarrhea. Unfortunately, the elderly often have mild symptoms or no symptoms of a UTI until they become weak, lethargic, or confused * Location of the infection in the urinary tract usually gives certain symptoms. Urethral infections usually have dysuria (pain or discomfort when urinating). * STD infections may cause a pus-like fluid to drain or drip from the urethra. * Cystitis (bladder infection) symptoms include suprapubic pain, usually without fever and flank pain. Ureter and kidney infections often have flank pain and fever as symptoms.
What are possible complications of a urinary tract infection? * Chronic infections may result in urinary strictures, abscesses, fistulas, and kidney damage. * Rapid advancement of UTIs can lead to dehydration, kidney failure,sepsis, and death. * Pregnant females with untreated UTIs may develop premature delivery and a low birth weight for the infant and run the risks of rapid advancement of the infection. * Renal hypertension * Sepsis
ANATOMY AND PHYSIOLOGY
THE NORMAL ANATOMY AND PHYSIOLOGY: Anatomy of the Urinary System |
How do the kidneys and urinary system work?
The body takes nutrients from food and converts them to energy. After the body has taken the food that it needs, waste products are left behind in the bowel and in the blood.
The kidney and urinary systems keep chemicals, such as potassium and sodium, and water in balance and remove a type of waste, called urea, from the blood. Urea is produced when foods containing protein, such as meat, poultry, and certain vegetables, are broken down in the body. Urea is carried in the bloodstream to the kidneys.
Other important functions of the kidneys include blood pressure regulation and the production of erythropoietin, which controls red blood cell production in the bone marrow.
Kidney and urinary system parts and their functions: * Two kidneys - a pair of purplish-brown organs located below the ribs toward the middle of the back. Their function is to remove liquid waste from the blood in the form of urine; keep a stable balance of salts and other substances in the blood; and produce erythropoietin, a hormone that aids the formation of red blood cells.
The kidneys remove urea from the blood through tiny filtering units called nephrons. Each nephron consists of a ball formed of small blood capillaries, called a glomerulus, and a small tube called a renal tubule. Urea, together with water and other waste substances, forms the urine as it passes through the nephrons and down the renal tubules of the kidney. * Two ureters - narrow tubes that carry urine from the kidneys to the bladder. Muscles in the ureter walls continually tighten and relax forcing urine downward, away from the kidneys. If urine backs up, or is allowed to stand still, a kidney infection can develop. About every 10 to 15 seconds, small amounts of urine are emptied into the bladder from the ureters. * Bladder - a triangle-shaped, hollow organ located in the lower abdomen.
It is held in place by ligaments that are attached to other organs and the pelvic bones. The bladder's walls relax and expand to store urine, and contract and flatten to empty urine through the urethra. The typical healthy adult bladder can store up to two cups of urine for two to five hours. * Two sphincter muscles - circular muscles that help keep urine from leaking by closing tightly like a rubber band around the opening of the bladder. * Nerves in the bladder - alert a person when it is time to urinate, or empty the bladder. * Urethra - the tube that allows urine to pass outside the body. The brain signals the bladder muscles to tighten, which squeezes urine out of the bladder. At the same time, the brain signals the sphincter muscles to relax to let urine exit the bladder through the urethra. When all the signals occur in the correct order, normal urination occurs.
Facts about urine: * Adults pass about a quart and a half of urine each day, depending on the fluids and foods
consumed. * The volume of urine formed at night is about half that formed in the daytime. * Normal urine is sterile. It contains fluids, salts and waste products, but it is free of bacteria, viruses and fungi. * The tissues of the bladder are isolated from urine and toxic substances by a coating that discourages bacteria from attaching and growing on the bladder wall.
Urinary tract infections: Diagnostic Tests
The list of diagnostic tests mentioned in various sources as used in the diagnosis of Urinary tract infections includes: * Urine tests * Urinalysis * Intravenous pyelogram (IVP) * Cystoscopy
Medical management of UTI:
Treatments and drugs
Antibiotics are typically used to treat urinary tract infections. Which drugs are prescribed and for how long depend on your health condition and the type of bacterium found in your urine. * Simple infection
Drugs commonly recommended for simple urinary tract infections include:
1. Sulfamethoxazole-trimethoprim (Bactrim, Septra, others)
2. Amoxicillin (Larotid, Moxatag, others)
3. Nitrofurantoin (Furadantin, Macrodantin, others)
4. Ampicillin
5. Ciprofloxacin (Cipro)
6. Levofloxacin (Levaquin) * Frequent infections
If you experience frequent urinary tract infections, your doctor may recommend a longer course of antibiotic treatment or a program with short courses of antibiotics at the outset of your urinary symptoms. * Severe infection
For severe urinary tract infections, hospitalization and treatment with intravenous antibiotics may be necessary