ANATOMY OF URINARY TRACT INFECTIONS
The urinary tract, simply put, is the bodies system of drainage through which excess water and wastes are removed from the body. It is a multi-organ system consisting of the two kidneys, two ureters, the bladder and the urethra.
The kidneys are small organs that assume the shape of a bean and are equivalently the size of a normal human fist. They are located below the rib cage, each of them on either side of the spine. Wastewater (urine) moves from the kidneys downwards through two narrow tubes known as ureters, and it is then stored in the bladder, a balloon shaped organ designed so for this function. When the sphincter muscles in the bladder relax, the urine leaves the body through the urethra, a tube connected to it.
A urinary tract infection is, therefore, an infection of this system or any organ that is part of the system. UTIs are the second most common type of infection, whose major causative agent is bacteria although viruses and other microbes can also cause the infections. The infections are common in females especially young ones because they have a shorter urethra compared to the male counterparts, this means that bacteria can easily enter their bodies through the vagina and get access to the bladder, where most infections take place. A different cause of this is the fact that the openings of urethras are near the main sources of bacteria in women i.e. the vagina and anus. At least half the women develop a single episode or more of the infection during their lifetime. While they are not common in men, more so young men, they can cause serious problems when they occur. It should also be noted that the symptoms observed in men suffering from UTIs are completely different from those observed in women. The age of an individual also dictates which symptoms will be observed in the course of the infection. Normal or infection free urinary tracts are characterized and maintained by enough amounts of urine during bladder emptying, full emptying of the bladder, urine free flow from the kidneys through the whole system, normal or near normal acidic levels in the urine, increased pressure between the vessels to prevent any urine from flowing back into the system, peristaltic function of the ureters and efficient junction between the ureters and the vesicles, and in males, the antibacterial effect of zinc ions in the prostatic fluid.
The infections generally fall into two: lower urinary tract infections that include cystitis, urethritis and prostatitis; and upper urinary tract infection which is majorly pyelonephritis, a condition where the kidneys and renal pelvis are inflamed.
CAUSES OF URINARY TRACT INFECTIONS
While other microbes may be involved in infecting the urinary tract, bacterial infections are the ones most commonly reported by a majority of the population. The two most common agents responsible for this are Escherichia coli and Staphylococcus saprophyticus. E. coli are gram-negative bacteria that are commonly found in the lower intestines of warm-blooded organisms where they play beneficial roles thus help keep the organisms healthy. However, some strains of the bacteria are harmful to the organisms and one of them is the major causative agent of UTIs and accounts for most acquired infections in society. On the other hand, S. saprophyticus is a gram-positive bacterium also found normally existing in the genital tract of females, it also has been found to occur in vegetables, meat, cheese, and gastrointestinal tracts of animals. It is known to cause about 10 t0 15% of all the reported cases and it’s usually associated with sexual intercourse which displaces it from the normal flora of the vagina into the urethra where it can be harmful. Most symptoms of infection with S. saprophyticus appear twenty-four hours after sex. This is the reason why an infection due to this agent is sometimes referred to as honeymoon cystitis.
The third and less common causative agents are Klebsiella, Seratia, Proteus, and Pseudomonas bacteria known to cause what is clinically called catheter-associated urinary tract infections. These infections, according to Golden and Hopkins (37), are UTIs associated with the use of a urinary catheter that has been connected to the body for evacuation of urine from the system (indwelling urethral catheter). The use of catheters usually is recommended for the short term as long term usage exposes an individual to such infections as these. It is worth noting, however, that most of the UTIs associated with urinary catheters are asymptomatic while just a few cases are symptomatic. The risk of acquiring a UTI is 3 to 36 times more with an individual using an indwelling catheter than one who doesn’t.
PATHOGENESIS OF URINARY TRACT INFECTIONS
The infections kick off when disease-causing micro-organisms present in the gastrointestinal tract contaminate the periurethral region and colonize the urethra. They then migrate to the bladder where they grow attachment pili and adhesins which help them colonize and invade superficial umbrella cells in the bladder. The host’s immune response then begins to clear these foreign molecules by neutrophil infiltration. However, some pathogens manage to evade the clearance via morphological change and host cell invasion which earns them resistance to the host cell immune responses. The resistant bacteria will then multiply and form biofilms in the host system, produce proteases and toxic substances that damage the cell to release important nutrients needed by the microbes for survival and entry into the kidneys. Once inside the kidneys, the bacteria colonize the kidney cells leading to the production of toxins and damage of the host tissue. If the infection is not discovered and treated, it will cause the presence of bacteria in blood, bacteremia, that is normally a sterile environment in which detection of bacteria should be an alarm raising alert. The pathogenesis described here is that of uncomplicated urinary tract infections only. Complicated UTIs follow somehow the same route with a few differences to advance their attack on the system (Niall and Hugh n.p). Catheter-associated UTIs also follow a similar route only that there is the presence of fibrinogen on the catheter which then promotes the attachment of the uropathogens which produce proteins that bind onto fibrinogen. (Flores-Mireles et al. 269).
RISK FACTORS ASSOCIATED WITH URINARY TRACT INFECTIONS
Age – as someone grows old, they become susceptible to many ailments due to a debilitated immune system. According to Stavridis (n.p), as women advance in age especially after menopause, the tissue lining in the genitalia may weaken and become more fragile due to atrophic vaginitis, a condition that causes an increased number of urine infections. In aged men, an enlarged prostate blocks the bladder from emptying all its contents leading to retention of some urine. Microbes are likely to multiply and colonize the bladder in such a situation causing the infection. (Harding n.p)
Underlying health conditions – if a person suffers from another health condition, it may be responsible for the development of these infections. Diabetes is a classic example of an underlying medical condition that can cause urine infections. A generally weak or inefficient immune system may also expose one to many infections, UTIs being among them.
Constipation- when the free movement of bowel is impeded, the lower gut may become full and press onto the bladder, which may stop proper emptying of urine and thus providing the conducive environment for the growth and multiplication of the bacteria that would ultimately cause urinary tract infections.
Catheters – these are thin, hollow and flexible tubes that are fixed on some individuals to drain urine due to lack of efficiency of urine expulsion by the individuals. Catheters may cause catheter-associated urinary tract infections as discussed above (Damani and Nizam 261).
Contraceptives – sometimes the use of contraceptives to prevent unwanted pregnancies carries with it negative news in the name of UTIs. These drugs may alter the composition of normal bacterial flora in the vagina and perineal tissues, creating an easy target for entry and attack by other microbes.
SYMPTOMS OF URINARY TRACT INFECTIONS
The major symptoms associated with these infections depend on where the infection has occurred i.e cystitis (infection of the bladder) or infection of the kidney. Cystitis is mostly associated with pain when passing urine. There may also be a pain in the lower abdomen, urine may start to look cloudy and bloody or it may develop some unpleasant smell. Fevers are also associated with cystitis in some cases. For infections in the kidneys, an individual may generally feel unwell, they may feel back pain in the area around the loin where the kidneys are situated, and vomiting may also be a symptom to look out for.
In some patients, however, the only sign of an infection may an onset of confusion or the general feeling of being unwell. The confusion can be attributed to fevers or deficiency of fluids in the body due to the frequent passing of urine associated with these infections.
MANAGEMENT OF URINARY TRACT INFECTIONS
In most cases of the infection, the symptoms may be obvious that there may not be a need for any test to be done. Urine tests can, however, confirm this and point out what pathogen is responsible for the infection. Dipstick tests provide enough evidence in most cases but further examination under microscopes is sometimes advised to single out the causative agent.
Treatment of these infections involve prescription of a regimen of antibiotics that are supposed to clear out the infection in a short time; paracetamol or ibuprofen are given together with the antibiotics to relieve the patient of any pain, fever or discomfort.
PREVENTION OF UTIS
There are a few ways that have been proven to prevent urine infections and include: avoiding constipation by consuming a lot of fibers and drinking enough fluids, Hormone replacement in older women who are affected by vaginal atrophy, treatment of underlying medical conditions that may expose the patient to the UTI or weaken their immune response, consumption of lots of vitamin C which acidifies urine and therefore inhibiting the growth of microbes in the urinary tract. (Flores-Mireles et al. 269).
Some foods are also known to irritate the bladder when one is suffering from a UTI making it hard to heal and include alcohol, nicotine, spiced foods, caffeine and artificial sweeteners. These foods should be avoided when one has a UTI and replaced with healthier ones which have a lot of fibers. Lifestyle changes have also been suggested to prevent recurrence of the infections like putting on loose cotton underwear and clothing, wiping oneself from front to back and stopping smoking.
Works Cited
Damani and Nizam. "Catheter-associated urinary tract infections." Manual of Infection Prevention and Control (2011): 261-271. Print.
Niall and Hugh. "The Pathogenesis of Urinary Tract Infections." Clinical Management of Complicated Urinary Tract Infection (2011): n. pag. Print.
Flores-Mireles, Ana L., Jennifer N. Walker, Michael Caparon, and Scott J. Hultgren. "Urinary tract infections: epidemiology, mechanisms of infection and treatment options." Nature Reviews Microbiology 13.5 (2015): 269-284. Print.
Golden, William E., and Robert H. Hopkins. "Catheter-Associated Urinary Tract Infections." Internal Medicine News 43.20 (2010): 37. Print.
Harding, M. (2016, March 24). Urine Infection in Older People. Patient Magazine. 2016: Print.
Stavridis, Sotir. "Urinary tract infections in postmenopausal women." CEJU 66.03 (2013): n. pag. Print.
