Tuberculosis still remains a significant global concern despite there is decline of this communicable disease in developed countries. The percentage of tuberculosis patients is more in developing countries. Tuberculosis is caused by bacterium called mycobacterium tuberculosis. Tuberculosis (TB) is a disease primarily affecting the lungs. The germs can then sometime spread to other parts of body through blood and lymph channel. Thus the bacteria can reach to urinary system mainly involving the kidney.
What Causes Urinary Tuberculosis?
Urinary tuberculosis is caused by mycobacterium tuberculosis. It is a type of bacteria belonging to mycobacterium family. The primary site of infection is in the lungs. The bacteria then can spread through blood to the urinary system. Out of all the extra pulmonary tuberculosis, urinary tuberculosis is the most common form. In most cases there is no active pulmonary tuberculosis noted when the symptoms of urinary tuberculosis develop. The involvement of urinary system is usually because of reactivation after a period of dormancy. Tuberculosis usually spreads through droplets released from patient while coughing and through sputum. The germs spread in the air and may enter into the lungs of a healthy person. A person who is exposed to TB germs may not always suffer from tuberculosis. It will depend on his immunity. If his immunity is weak, the germs that have entered into the lungs may cause pulmonary tuberculosis. If the blood vessel of the lung is infiltrated, the bacteria may enter into the blood stream and may lodge into kidney or other organs such as brain, intestine etc. Often kidney tuberculosis occurs months and years after primary lung infection. Once the bacteria get reactivated it starts invading and destroying the structure inside the kidney. As the disease advances it causes scarring of kidney and other urinary structures ultimately leading to kidney dysfunction. In majority of cases only one kidney is affected.
Symptoms of Urinary Tuberculosis
The symptoms of urinary tuberculosis are sudden in onset. However, because the symptoms are similar to several other diseases of urinary tract, it is difficult to pin point the disease. Due to this confusion, many times the disease is not detected in its early stage. The presenting symptoms of urinary tract TB are as follows:
- Red urine due to passage of blood in urine.
- Pain in the renal angle and in lower abdomen.
- Burning in urine with increased frequency
- Weight loss
- Loss of appetite
- Mild fever
- Tiredness all the time
- A cold abscess may develop in thigh. It develops when the infection spreads to the psoas muscle which has its origin in the lower back and its insertion in the thigh region.
Diagnosis and Treatment of Urinary Tuberculosis:
As mentioned earlier, diagnosis of TB initially is difficult because the symptoms are similar to urinary tract infection. However, the gold standard for diagnosis of urinary tract TB is presence of TB bacteria in at least out of 3 to 6 early morning urine specimens. The method used for detection is called Ziehl-Neelson Acid fast staining. Urine PCR for mycobacteria tuberculosis is far more sensitive test used nowadays. Presence of bacteria is known within 48 hours of the test. Urine culture is also useful test to detect the disease. Aside from the urine test, other methods used to determine urinary Tb are sonography of urinary tract, Mantoux test, blood ESR, intravenous pyelography, and CT scan of kidney, ureter and bladder.
Once the disease has been diagnosed, the treatment module is similar to that for pulmonary tuberculosis. Patient is prescribed 3 to 4 anti tuberculosis medicines initially. This medicine has to be continued for at least 6 to 9 months period depending on the severity of disease and response to the drug. After first 3 months, certain medicines are withdrawn out of the 4 and rest important medicines are continued for a period of 6 months. The treatment is discontinued once urine culture is negative after 9 months of treatment. Patient during this period of time is advised to eat healthy food to strengthen the immune system. In addition to the medical therapy, if the kidney is completely damaged and dysfunctional, nephrectomy may be reserved choice. In case if there is several strictures present in ureter, artificial implantation of ureter may be thought of if dilatation is not successful.