Introduction

Something wasn’t right!

She sighed as she walked out of the restroom again. This was the fourth time in the last hour, but the discomfort just wouldn’t go away. 

Each trip to the restroom ended with a burning sensation, and the urge to go never really stopped.

She had initially ignored it, thinking, “Maybe I should drink more water.” But now, a dull ache was creeping in and extending up her back, and she was starting to feel feverish.

What could this be? A urinary tract infection(UTI)?

If you feel this way, you might be dealing with UTI.

In this article, we’ll talk about pyuria and pyelonephritis, how they relate to upper urinary tract infections and why early treatment matters. Let’s dive in!

What is a Urinary Tract Infection (UTI)?

A urinary tract infection (UTI) is an infection affecting the urinary tract, which is very common. The most common type of infection is bacterial infection, the most common bacteria causing it being Escherichia coli (E.coli). It affects 45% of women at some point in their lives.^1,2

It is a significant problem worldwide. However, it mainly becomes a challenge when it becomes recurrent; 25% of women with a UTI will have a repeat one within the first 6 months of the initial infection, and 25% of those who had a second will also have a 3rd infection or more.¹ 1- 2% and 5% of school-age girls and women, respectively, have asymptomatic bacteriuria, which is when there are bacteria in the urine without causing symptoms of an infection. UTIs are very rare in males. As people age, the prevalence of UTIs increases; 21% and 12% of women and men over the age of 65 years, respectively, have bacteria present in their urine.

The commonest type of symptomatic UTI is acute cystitis, which is an infection of the bladder. It affects about 15% and 40% of women yearly or at some point in their lifetime, respectively (30% of these have recurrent infections).²

UTIs can be classified based on location:

• Upper urinary tract infections, e.g., pyelonephritis
• Lower urinary tract infection, e.g., Cystitis, Urethritis

Based on the presence of complications:^2,3

• An uncomplicated UTI occurs when there is no abnormality of structure or function of the individual’s urinary tract
• A complicated UTI occurs when abnormalities in the structure and/or function of the urinary tract are present, or other risk factors that increase UTI are present

What are the symptoms of a UTI?

UTIs can occur with or without symptoms. Symptoms may include:^4,5

• A very strong urge to pass urine, which doesn't leave after urinating
• Smelly urine
• Discomfort in the lower abdomen
• Burning feeling when passing urine
• Cloudy urine

What risk factors contribute to a UTI?

The normal defence system of the urinary tract can be disturbed by improper urine flow or the presence of a foreign body in the urinary tract, which can increase the risk of infection.²

Here are some risk factors associated with UTI:^4,5

• Being female: the female urinary system structure includes a shorter urethra than men, making infection easier as bacteria don’t have as far to go to cause an infection
• Sexual activities: being sexually active increases the risk
• Menopause: After menopause, the level of oestrogen circulating in the body causes some changes in the urinary system, which increase the risk of UTI
• The use of contractive (birth control) methods like the diaphragm increases the risk of UTI

Other risk factors include⁴

• Kidney stones or blockages
• Catheter use
• Pregnancy
• Older age (frailty)
• Diabetes mellitus

What is pyuria?

The presence of white blood cells (WBCs) in urine is called pyuria. It can be caused by:

• Infectious causes (Bacterial UTIs, Tuberculosis)
• Non-infectious causes (Kidney stones, Interstitial nephritis)

Symptoms associated with pyuria include:

• Cloudy urine
• Burning sensation
• Increased urinary Frequency

What is pyelonephritis?

Pyelonephritis is the infection of the kidney due to bacteria travelling up the urinary tract from the urethra and bladder to the kidneys. It can be acute or chronic.

Symptoms associated with Pyelonephritis include⁴

• Fever
• Chills
• Nausea
• Vomiting
• Flank pain
• Frequent and painful urination

What is the relationship between pyuria and pyelonephritis?

Pyuria serves as a marker of infection and can commonly occur in pyelonephritis, and is part of the response of your immune system to infection. Pyuria doesn’t always mean there is definitely an infection, though. Pyelonephritis is a serious infection that requires immediate treatment, and pyuria is a warning sign of infection that should be investigated further.

What are the complications of a UTI?

Here are some complications that can occur in patients with UTI:⁵

• Recurrent UTI
• Permanent damage to the kidneys
• Narrowing of the urethra, especially in men
• Delivering babies who have low birth weight or are premature if it occurs in a pregnant woman
• Sepsis: a life-threatening infection that affects the blood

How are UTIs diagnosed? 

Diagnosis of a UTI involves:

• A thorough history and examination by a doctor to check for signs and symptoms.
• Laboratory investigations such as³

• Urinalysis, which will show the presence of infection markers in the urine
• Imaging such as ultrasound and CT scan can be used in complicated cases
• Urine culture to identify the pathogen (specific bacteria)

The gold standard for diagnosis of UTI is based on the detection of bacteria in the urine culture, most commonly, Escherichia coli, Proteus mirabilis, Klebsiella spp. In pregnant women, Group B Streptococcus (GBS) is also associated with UTI.³

How are UTIs treated?

Treatment of UTI is dependent on whether it is uncomplicated or complicated.^3,4 For individuals with an uncomplicated UTI, treatment can be done on an outpatient basis, whereas complicated UTIs are treated as inpatients with a hospital stay.

• Supportive care: Hydration, pain management, and drugs that reduce vomiting (antiemetics) should be given appropriately to all individuals with UTIs who require them.
• Antibiotics: Broad-spectrum IV antibiotics are used for severe/complicated cases, and oral (taken by mouth) antibiotics are used for mild-moderate cases.
• Hospitalisation is important in severe/ complicated cases.

How can you prevent a UTI?

UTIs can be prevented by:^3,5

• Drinking ots of water to help dilute the urine and increase urination to flush out any infectious agents
• Practising proper hygiene, such as washing hands with water after passing stool or, if using toilet tissue, wiping from front to back
• Treating lower UTIs promptly
• Emptying the bladder immediately after having sex
• Avoiding unnecessary catheter use
• Changing birth control methods, like using diaphragms and condoms

Special considerations

When dealing with UTIs, some special groups must be considered. They include Individuals with urologic abnormalities and pregnant women.^4,5

Individuals with urologic abnormalities

• Patients with urologic obstruction or abnormalities in their urinary tract structure need longer antibiotic treatment for UTIs
• Patients with a catheter for 2 weeks or more should have it removed and/or changed

Pregnant patients

• Pyelonephritis occurs in about 2% of pregnant women, usually in the second and third trimesters
• Due to the risk of complications, a pregnant woman with pyelonephritis requires hospital admission
• Due to pregnancy, treatment options are limited, since some antibiotics are contraindicated in pregnancy

FAQs

Is it possible to have pyuria without an infection?

Yes, pyuria can be found in individuals with kidney stones, interstitial nephritis, or tuberculosis. This type of pyuria is called sterile pyuria.

How do I know if it's pyelonephritis or a UTI that I have?

The presence of fever, chills, lower back pain (flank pain), nausea, or vomiting, alongside urinary symptoms like increased frequency, pain on urination, may indicate pyelonephritis. At that point, you should seek medical care immediately.

What is the best treatment for pyelonephritis?

Antibiotics are the main choice of medications. Oral antibiotics can be used in mild to moderate infections, while IV antibiotics are used for severe/complicated infections. However, there is a place for supportive care, like hydration and pain management, as well.

How long does it take to recover from pyelonephritis?

Mild/uncomplicated UTIs will usually improve within a few days of antibiotic treatment, but full recovery may take 7-14 days. Severe/complicated infections may require hospitalisation and longer treatment.

Can pyelonephritis be prevented?

Yes. Drinking enough water, practising good hygiene, treating UTIs early, and avoiding unnecessary catheter use can help prevent pyelonephritis.

Summary

A UTI is an infection that affects the urinary tract. It can be upper (pyelonephritis affecting the kidney) or lower (cystitis affecting the bladder) urinary tract infection.

Pyelonephritis is a serious kidney infection which commonly develops from untreated lower UTIs and pyuria, which is the presence of white blood cells in urine.

Pyuria may be commonly seen in pyelonephritis, but not all pyuria is caused by infection.

To prevent complications, early detection and treatment are required.

Preventive measures like proper hydration, good hygiene, and prompt treatment of UTIs can help reduce the risk of upper urinary tract infections.