Bacteria: Bacteria accounts for more than 80% of urinary tract infections, with Escherichia coli (E. coli) being the most common cause. Other bacteria associated with cystitis, urethritis, or kidney infections include Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus saprophyticus, and Enterococcus faecalis.
Viruses: Viral infections may damage the lining of the urinary tract and impair urinary system function, leading to symptoms such as blood in the urine or painful urination.
- Adenovirus can cause hemorrhagic cystitis.
- BK polyomavirus is commonly associated with urinary tract complications in kidney transplant recipients.
- Cytomegalovirus (CMV) may also affect the urinary tract.
Fungi: The most common fungal pathogen is the Candida albicans. Fungal urinary tract infections are more frequently seen in people with weakened immune systems, including individuals with diabetes, those taking long-term antibiotics, or people with long-term urinary catheters. Common symptoms may include painful urination or blood in the urine.
Parasites: One of the most notable causes is Schistosoma haematobium, which causes urinary schistosomiasis. This parasite is associated with contaminated freshwater exposure and can lead to chronic urinary tract inflammation and an increased risk of bladder cancer.
Yes. Urinary tract infections can recur, particularly in individuals with certain risk factors or when the initial infection is not fully resolved. Recurrence may occur when bacteria from a previous infection are not completely eliminated or when new bacteria enter the urinary tract.
Women are particularly prone to recurrent urinary tract infections because the female urethra is shorter and located closer to the anus, making it easier for bacteria to enter the urinary tract.
Pregnant women are at increased risk of urinary tract infections due to physiological and hormonal changes during pregnancy. Increased progesterone levels relax the smooth muscles of the urinary tract, slowing urine flow, and creating favorable conditions for bacterial growth.
As the uterus enlarges, it can also place pressure on the bladder and ureters, further restricting urine flow and increasing the risk of infection. In addition, pregnancy involves changes in immune function that may reduce the body’s ability to respond to certain infections.
If not detected and treated promptly, urinary tract infections during pregnancy can lead to serious complications. The infection may progress to pyelonephritis and is associated with an increased risk of preterm birth, low birth weight, and other adverse pregnancy outcomes.
Therefore, testing is important for early detection and treatment of urinary tract infections to help protect both maternal and fetal health. Pregnant women should generally undergo urine culture screening between 12 and 16 weeks of pregnancy or at the first prenatal visit, even if they have no symptoms. If bacteriuria is detected, treatment should be guided by antibiotic susceptibility testing.
Young children should be evaluated for a urinary tract infection if they develop suspicious symptoms such as unexplained fever, painful or frequent urination, cloudy or unusually strong-smelling urine, abdominal or flank pain, poor feeding, or vomiting.
Symptoms of urinary tract infections in children may be less specific than those in adults and can easily be mistaken for other illnesses, making appropriate testing important when an infection is suspected.
- Wiping from back to front after using the toilet, which may transfer bacteria from the anal area to the urethra, particularly in women
- Inadequate hygiene after urination or bowel movements
- Holding urine for prolonged periods, allowing bacteria more time to multiply in the bladder
- Not drinking enough fluids, which may reduce the body’s ability to flush bacteria from the urinary tract
- Sexual activity that may facilitate the entry of bacteria into the urethra
- Long-term use of a urinary catheter
- Wearing tight or poorly ventilated clothing that creates a warm, moist environment favorable for bacterial growth
- Using bathtubs or public bathing facilities where water hygiene may be inadequate.




