Urinary TB, or Urinary Tract Tuberculosis (UTTB), is a specific form of tuberculosis that affects the urinary system. It is an infectious-allergic inflammation of various parts of the urinary tract, including the calyces, renal pelvis, and the upper and lower urinary pathways. This condition is primarily caused by Mycobacterium tuberculosis (Mtb) or, less commonly, by Mycobacterium bovis.
Understanding Urinary Tract Tuberculosis (UTTB)
UTTB develops when Mycobacterium bacteria, typically originating from a primary site of infection elsewhere in the body (most often the lungs), spread through the bloodstream to the kidneys. While the initial infection might be silent for years, the bacteria can establish a foothold in the urinary system, leading to inflammation and damage.
Key aspects of UTTB include:
- Causative Agents: The most common pathogen is Mycobacterium tuberculosis, the same bacterium responsible for pulmonary TB. Mycobacterium bovis, which can be acquired from contaminated dairy products, is another less frequent cause.
- Pathogenesis: The bacteria usually reach the kidneys via hematogenous spread (through the bloodstream). Initial lesions often form in the renal cortex, gradually progressing downwards to affect the renal pelvis, ureters, bladder, and even the urethra. This can lead to various complications, including strictures, hydronephrosis (swelling of the kidney due to urine backup), and in severe long-standing cases, even a non-functional, shrunken kidney, sometimes referred to as "auto-nephrectomy."
- Symptoms: Symptoms of urinary TB can be vague and non-specific, often mimicking common urinary tract infections (UTIs). This can lead to diagnostic delays. Common symptoms include:
- Frequent urination (frequency)
- Pain or burning sensation during urination (dysuria)
- Blood in the urine (hematuria), which may be microscopic or visible
- Persistent pus in the urine without common bacterial infection (known as sterile pyuria) – a key diagnostic clue
- Flank pain or tenderness over the kidney area
- Systemic symptoms of tuberculosis like fatigue, fever, night sweats, and weight loss.
Broader Scope: Generalized Urogenital Tuberculosis (gUGTB)
While UTTB specifically refers to the urinary tract, tuberculosis can affect the entire urogenital system. Generalized Urogenital Tuberculosis (gUGTB) describes a broader condition where TB affects not only the kidneys but also the genital tract in both males and females.
| Aspect | Urinary Tract Tuberculosis (UTTB) | Generalized Urogenital Tuberculosis (gUGTB) |
|---|---|---|
| Definition | Infectious-allergic inflammation of the urinary system (calyx, pelvis, upper/lower tract). | TB of the kidney and the genital tract (male or female). |
| Primary Focus | Primarily affects the kidneys, ureters, bladder, and urethra. | Involves the urinary system and reproductive organs (e.g., epididymis, seminal vesicles, prostate in males; fallopian tubes, ovaries, uterus in females). |
| Common Causes | M. tuberculosis or M. bovis. | M. tuberculosis or M. bovis. |
| Clinical Picture | Symptoms often related to urinary dysfunction and inflammation. | Broader range of symptoms, including infertility, pelvic pain, or scrotal swelling, in addition to urinary symptoms. |
Diagnosis and Treatment
Diagnosing urinary TB can be challenging due to its non-specific symptoms and the slow-growing nature of Mycobacterium. Key diagnostic methods include:
- Urine Analysis and Culture: Multiple morning urine samples are collected for acid-fast bacilli (AFB) smear and culture. Culture remains the gold standard but can take weeks. Molecular tests like PCR (Polymerase Chain Reaction) can provide faster results.
- Imaging Studies:
- Ultrasound: Can reveal structural changes like hydronephrosis or bladder thickening.
- CT Scan (Computed Tomography): Provides detailed images, showing calcifications, strictures, or abscesses in the urinary tract.
- Intravenous Urography (IVU): Though less common now, it can show specific deformities and strictures within the urinary system.
- Biopsy: In some cases, a biopsy of the affected urinary tissue (e.g., bladder or kidney) may be necessary for definitive diagnosis.
Treatment for urinary TB involves a multi-drug anti-tubercular therapy (ATT) regimen, similar to that used for pulmonary TB. However, the duration of treatment for urinary TB is often longer, typically ranging from 6 to 12 months, depending on the severity and response to treatment. Surgical intervention may be required to address complications such as urinary tract obstruction, strictures, or to remove severely damaged, non-functional kidneys.
Early diagnosis and consistent adherence to the full course of treatment are crucial to prevent irreversible kidney damage and other complications.
