Genitourinary Tuberculosis (G-UTB) is a form of tuberculosis that develops outside of the lungs, specifically targeting the urinary tract and reproductive organs. G-UTB is one of the most common forms of extrapulmonary tuberculosis. It involves organs like the kidneys, ureters, bladder, and the male and female reproductive organs. The disease often progresses without clear or specific symptoms, which frequently leads to a delayed diagnosis.
The Source and Spread of Infection
The cause of Genitourinary Tuberculosis is the bacterium Mycobacterium tuberculosis. G-UTB almost always represents a secondary infection, resulting from a previous infection, most commonly in the lungs. The infection can remain dormant for a significant period, with latency periods spanning anywhere from 5 to over 40 years before symptoms appear in the genitourinary tract.
The bacteria spread through the bloodstream via hematogenous dissemination from the initial site of infection. Due to their high blood flow, the kidneys are typically the first organs in the genitourinary system to be seeded. The bacteria colonize the renal cortex and can remain inactive for decades before reactivating and multiplying.
Reactivated bacilli spread from the kidneys in a descending pattern, eroding into the collecting system. The infection travels down to the renal pelvis, ureters, and the bladder. From the urinary tract, the infection can spread to male reproductive organs (epididymis, prostate, and seminal vesicles) or to female reproductive organs, including the fallopian tubes.
Recognizing the Clinical Signs
The symptoms of Genitourinary Tuberculosis are often vague and chronic, leading to a common delay in diagnosis. Patients may experience symptoms mimicking a persistent or recurrent urinary tract infection (UTI) that fails to improve with standard antibiotic treatment. Common complaints relate to bladder irritation, including increased frequency of urination, urgency, and pain while passing urine (dysuria).
A defining characteristic of G-UTB is “sterile pyuria,” which refers to the presence of pus cells, or white blood cells, in the urine despite standard bacterial cultures showing no growth. This finding should raise suspicion for G-UTB, particularly in individuals with a history of tuberculosis exposure or those who have had pulmonary TB. Other urinary tract symptoms may include flank or abdominal pain, especially if there is blockage of the ureters, and the presence of blood in the urine (hematuria).
In men, the infection may present as a painful or painless swelling in the scrotum, most commonly affecting the epididymis. The vas deferens, the tube that carries sperm, may also feel thickened or nodular upon physical examination. Involvement of the prostate or seminal vesicles can lead to symptoms such as perineal pain or even male factor infertility due to obstruction of the ejaculatory ducts.
Female genital tract involvement often presents subtly and is frequently discovered during an investigation for infertility. The infection most commonly targets the fallopian tubes, which can lead to scarring and obstruction. Other symptoms in women may include chronic pelvic pain, irregular or heavy menstrual bleeding, or abnormal vaginal discharge.
Confirming the Diagnosis
The diagnosis of Genitourinary Tuberculosis is challenging due to the slow-growing nature of the causative organism. The initial step is a urinalysis confirming the presence of sterile pyuria, which signals inflammation without a typical bacterial infection. Clinicians must then pursue specialized testing to identify Mycobacterium tuberculosis in the urine.
The traditional “gold standard” for diagnosis is the culture of urine samples for acid-fast bacilli (AFB), as the bacteria retain a stain even after acid washing. This test usually requires collecting multiple first-morning urine samples, typically three to six, because the bacteria are shed intermittently. The main drawback of this method is the long waiting period, as the mycobacteria can take up to eight weeks to grow in culture.
To achieve a quicker diagnosis, Nucleic Acid Amplification Tests (NAATs), such as Polymerase Chain Reaction (PCR), are utilized. These tests detect the genetic material of the bacteria and can provide results within hours or days, offering high sensitivity and specificity for G-UTB. The Xpert MTB/RIF assay is a specific NAAT that simultaneously detects the presence of M. tuberculosis and tests for resistance to the common drug Rifampicin.
Imaging techniques assess the extent of damage the disease has caused to the genitourinary system. Intravenous pyelography (IVP) and Computed Tomography (CT) scans are commonly used to look for characteristic changes like calcifications in the kidney, which occur in about 50% of patients. Imaging can also reveal narrowing or strictures of the ureters, which leads to swelling of the kidney, known as hydronephrosis, or a small, scarred “thimble bladder” from severe bladder wall fibrosis. In cases where other tests are inconclusive, a biopsy of the bladder, prostate, or other affected tissue may be performed. Histological examination of the biopsy tissue can confirm the diagnosis by showing the characteristic granulomatous inflammation associated with tuberculosis.
Standard Treatment Protocols
Treatment for Genitourinary Tuberculosis follows the same multi-drug regimen used for pulmonary tuberculosis, but the duration is extended due to the extent of tissue damage. The standard approach involves a combination of four antibiotics: Rifampicin, Isoniazid, Pyrazinamide, and Ethambutol. This intensive phase typically lasts for the first two months of treatment.
Following the initial intensive phase, the treatment transitions to a continuation phase involving only two drugs: Rifampicin and Isoniazid. The total duration of therapy for G-UTB is commonly six to nine months, though some cases require a longer course. The poor blood supply to scarred and damaged tissues in the genitourinary tract necessitates this prolonged treatment to ensure complete eradication of the bacteria.
Patient adherence to the medication schedule is necessary throughout the course of treatment to prevent the development of drug-resistant tuberculosis. Directly observed therapy (DOT), where a healthcare worker watches the patient take every dose, is recommended to ensure adherence. The successful cure rate for G-UTB is high when the appropriate regimen is completed fully and without interruption.
In addition to antibiotic therapy, surgical intervention is sometimes required for complications resulting from the disease’s destructive nature. Surgery may be needed to address severe ureteral strictures that cause significant obstruction and hydronephrosis, or to manage a severely contracted bladder that can no longer hold an adequate volume of urine. In advanced cases, surgical removal of a non-functioning kidney may be necessary to resolve persistent infection or high blood pressure caused by the damaged organ.