Urianry Tuberculosis
The incidence of genito-urinary tuberculosis has markedly decreased in the West but the situation is not altered much in developing countries.

The majority of cases of pulmonary tuberculosis with no clinical evidence of renal involvement reveal bilateral non-progressive microscopic renal cortical foci on careful sectioning at postmortem examination. Slightly over half cases of renal tuberculosis are associated with the evidence of extra renal disease, usually inactive pulmonary lesions, but less than 10% is associated with extra genital disease. It is typically a disease of adults, often middle-aged or older, who are not very sick.

Signs and Symptoms
Even though symptoms are low grade or lacking, the diagnosis can be easily made when considered. Urinary symptoms (dysuria, gross hematuria, and flank pain) are present in 71% of patients, but constitutional symptoms are uncommon, and 20% of patients are entirely asymptomatic. Urinary findings are abnormal in 90% of cases consisting of gross or microscopic hematuria or pyuria. "Sterile pyuria" is said to be typical of renal tuberculosis.

Complications
Tuberculosis affects many sites in urogenital system. Urethral strictures are some of the common presentations but the common site of ureteric stricture is at the uretero vesical junction, but they also occur at the pelviureteric junction, rarely in the middle third of ureter and very occasionally the whole ureter is stenosed, fibrotic and even calcified.

Majority (80%) of advanced cases of renal disease are associated with involvement of female and male genital organs. Male genital tuberculosis may involve the prostrate, the seminal vesicles, the epididymis and testis, in that order. Oligospermia is common and may lead to infertility. Female genital tuberculosis may involve ovary, endosalpinx and rarely cervix, producing granulomatous lesions. The incidence of tuberculosis in India amongst women attending the infertility clinics is as high as 37% (Parikh et al.) which is much higher than the western counterpart. In one study conducted in India it was found that the majority of the patients with genitourinary tuberculosis present with clinical signs and symptoms of infertility, abdominal pain and dysfunctional uterine bleeding, in that order. The diagnosis of male genitourinary tuberculosis is seldom apparent until the disease is far advanced. The earliest clinical symptoms in most cases are epididymitis, dysuria and hematuria. Infertility is an uncommon first sign of male tuberculosis, but may be a clue to early diagnosis. First morning urine sample can be used for the diagnosis of genitourinary tuberculosis in such cases.

Diagnostic Assays
There are a variety of assays available for the diagnosis of TB, all having various advantages and disadvantages.

ZIEHL NEELSEN SMEARS of CSF for acid-fast bacilli (AFB), although virtually diagnostic, are usually positive in less than 10% cases of extra-pulmonary tuberculosis. Also, because of low sensitivity it shows positive result only in the late stages of the disease.

Culture for M. Tuberculosis takes up to 8 weeks and is also often negative. The sensitivity though reported to be higher in the pulmonary samples is as low as 40% in the urinary samples even with the newer rapid culture techniques such as Bactec radiometric culture.

ELISA based method detection is rapid, but its sensitivity at best is not reported to be higher than 55%. Also the biggest drawback is the high rate of false positivity i.e., 20-30%, in both antigen and antibody detection assays in high prevalence regions like India. This makes results of ELISA very difficult to interpret for the physicians.

Polymerase Chain Reaction (PCR): Though there are various methods in molecular diagnostics for the detection of Mycobacterium tuberculosis (PCR, SDA, TMA, NASBA), PCR continues to be most widely accepted test worldwide. It is a very rapid test and the sensitivity is reported to be as high as 94%. Auroprobe Laboratories has made this test highly sensitive and specific by choosing DNA target MPB 64 which is very well represented in the Indian strains of Mycobacterium tuberculosis.

Comparison Of Various Diagnostic Assays For Tuberculosis Infection

Type of Test	Advantage	Disadvantage
ZN SMEAR	Economical, early result, easy availability	Poor sensitivity (<30%)
RADIOMETRIC CULTURE (BACTEC 460 TB SYSTEM)	Differentiation between M.tuberculosis and MOTT, drug sensitivity can be performed	Result in 1 week (Avg), very expensive instrument, not easily available everywhere, low sensitivity (50 -60%)
ELISA	Rapid, gives global diagnosis by antibody detection	High false positive rate in endemic countries, low sensitivity
AUROPROBE TB PCR (ATP 1)	Highly sensitive (up to 95%) and specific (>97%), early result	Needs expertise and elaborate set up including class 100 clean rooms

Information on collection and Transportation of sample

Specimen	Collection	Storage	Transportation
Urinary tract biopsy	In sterile normal saline	*At 40C	**In gel pack box
Urine	1st morning whole sample on 3 consecutive days	*At 40C	**In gel pack box
Semen	In sterile container, to be collected after 3 days of abstinence	*At 40C	**In gel pack box

*	In middle shelf of refrigerator
**	Special transportation box available from Auroprobe Laboratories

References
	Roger M. Mycobacterial Diseases in Principal and practices of Infectious Diseases (Third Ed), Churchil Livingstone. 1990; 229: 1900
	James G Gow. Genitourinary tuberculosis in Walsh, Gittes, Perlmutter, Stamey (Editors): Campbell's Urology; WB Saunders, Philadelphia. 1986; 1 (23): 1037-69