Urinary tract infection
Summary/Definition
Urinary tract infection is the penetration of microorganisms into the urinary system, including the kidneys, ureters, bladder, urethra and prostate gland, which causes an inflammatory reaction. The type and duration of treatment may vary depending on the presence of concomitant diseases, the body’s ability to excrete urine and the presence of complications associated with urinary tract infection.
Urinary tract infections are divided into lower urinary tract infections and upper urinary tract infections, depending on the place of infection. Lower urinary tract infections develop in the bladder and urethra, while upper urinary tract infections occur in the kidneys and ureters. Infections of the lower urinary tract lead to symptoms associated exclusively with urination, and are not accompanied by systemic manifestations. In turn, upper urinary tract infection is considered a more serious disease compared to lower urinary tract infection, as it is accompanied by systemic symptoms such as fever and nausea, and can lead to severe complications.
A simple urinary tract infection is an infection that develops in the urinary system without the presence of structural abnormalities or violations of the function of the bladder that secretes urine. To describe infections of this system in healthy adult women who are not pregnant, the term “simple urinary tract infection” is sometimes used. In the case of complications such as structural abnormalities of the urinary system, impaired function of the nerves regulating the bladder, urolithiasis and other conditions, such infections are considered complicated urinary tract infections. Complications can also occur in the presence of diseases such as diabetes. It is important to note that the treatment of a urinary tract infection, like a simple infection, may not always lead to a complete recovery in the case of a complicated infection. E. coli is the most common causative agent of urinary tract infections, but it can also be caused by other microorganisms, such as Pneumococcus, proteus and Enterobacteria. Urinary tract infections that develop during hospitalization are more common than those that occur in everyday life, probably due to bacteria that differ from E. coli, or bacteria resistant to antibiotics.
Urinary tract infections may be based on various mechanisms, including the ascending and hematogenic pathway. The ascending path of infection is associated with the penetration of bacteria inhabiting the intestine up the urinary tract. In this case, E. coli and other microorganisms pollute the urethra, then climb up it, which can cause cystitis, and eventually reach the bladder through the ureter, which can lead to the development of pyelonephritis. The hematopoietic mechanism of urinary tract infection is very rare and is associated with the fact that bacteria, for example, Staphylococcus aureus, cause bacteremia, as a result of which blood containing bacteria enters the kidneys and causes infection, for example, pyelonephritis. There is a protective mechanism in the human body that prevents bacteria from sticking to the mucous membrane of the urinary tract, with the exception of the urethral mucosa. The development of urinary tract infection is associated with a violation of this protective mechanism.
Symptoms
Symptoms of lower urinary tract infection include the following manifestations: discomfort in the pubic bone, pain when urinating, a feeling of irritation, an urgent need to urinate, residual urination, enuresis (involuntary urination), cloudy urine and hematuria (an admixture of blood in the urine). However, in this case, there are no systemic symptoms. Symptoms of upper urinary tract infection include the following: systemic manifestations, such as fever, chills, pain in the side of the abdomen (or pain in the side), back pain, headache, nausea, vomiting and abdominal pain. At the same time, symptoms associated with urination may be absent.
Diagnostics
During physical examination, soreness over the pubic bone (pressing pain) is assessed, and in the case of pyelonephritis, soreness in the costo–vertebral angle. To determine the presence of pyuria or bacteriuria, a urine test is performed using diagnostic sticks or microscopy. Culture culture of urine can be useful in identifying the sensitivity of bacteria to antibiotics, as it allows you to determine the number of cultivated bacteria and identify the causative agents of infection. If a complicated urinary tract infection is suspected, imaging studies are performed.
Treatment and course of the disease
Urinary tract infections are common bacterial infections, with manifestations ranging from asymptomatic bacteriuria to septic shock. The right choice of antibiotics plays a critical role in the treatment of serious infections and in preventing excessive use of antibiotics. Since antibiotic resistance of common pathogen bacteria varies depending on the region, it is important to take into account local treatment recommendations when choosing an antibiotic. In the case of asymptomatic bacteriuria in women in the early stages of pregnancy and in anticipation of procedures with a potential risk to the mucous membranes, examination and treatment should be carried out before intervention. For uncomplicated cystitis, antibiotics such as nitrofurantoin, fosfomycin, pivmecillin, oral fluoroquinolones and oral cephalosporins of the 2nd and 3rd generations are usually recommended and prescribed. The duration of treatment depends on the specific antibiotic and can range from a single dose to 5 days or more. In uncomplicated acute pyelonephritis, one of the injectable fluoroquinolones, ceftriaxone or amikacin, is administered once, followed by oral fluoroquinolones. Depending on the results of sowing, you can switch to the appropriate oral antibacterial drug. Usually, treatment is carried out with oral antibiotics, to which the patient’s body is sensitive, for 7-14 days.
