Genitourinary TB An Emerging Threat

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If urologists are consulted at the outset, they could treat obstructions and preserve renal function

 

SAN FRANCISCO—Genitourinary tuberculosis (GUTB) cases are on the rise in the United States and globally, but they often are difficult to diagnose, leading to a delay in dialysis that can worsen renal damage, according to a Turkish researcher.

 

Urologists frequently are not consulted early enough in the course of the disease, said Mete Cek, MD, professor of urology at Taksim Teaching Hospital in Istanbul. Consequently, morbidity and mortality rates associated with GUTB may be higher than necessary.

 

“Urologists should be involved from the beginning because there are things we can do to treat obstructions and preserve renal function,” Dr. Cek said here at the 46th annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

 

Dr. Cek estimated that one third of the world's population is infected with the TB bacterium. Although TB is curable, it kills 5,000 people a day (2 million people a year) worldwide. The global incidence is growing at 1% a year. While the problem is worst in Africa and southeast Asia, GUTB cases in the United States are increasing, a trend possibly linked to the growth in global travel, Dr. Cek speculates.

 

Worldwide, 20%-73% of extrapulmonary TB is genitourinary; Mycobacterium tuberculosis is found in the urine of 15%-20% of patients with TB, according to Dr. Cek. Because much of the data on GUTB comes from case reports and retrospective clinical reviews instead of controlled clinical trials, management may have been hindered. Patients considered at highest risk for reactivation of TB infection include those with immunosuppression (such as AIDS patients and transplant recipients), diabetics, patients with chronic renal failure, and IV drug abusers.

 

GUTB often involves the hematogenous spread of bacilli and the lodging of bacteria in the corticomedullary junction, which can lead to scarring and calcification. With kidney involvement, the pathology often causes irregularity of the upper calices, dilatation of the lower calyx, amputation of the middle calyx, and strictures of infundibula, Dr. Cek explained. Extensive parenchymal calcification can show up in the late stages of renal TB. Bladder TB is always secondary to renal TB and starts around the ureteric orifice, with signs of inflammation, fibrosis, and contraction.

 

GUTB manifestations include pyelonephritis, renal colic, stones, sepsis, and renal failure (intrinsic and obstructive). The symptoms are typical of “conventional” bacterial cystitis, with pyuria occurring in the absence of a positive culture, he said. Back, flank, and suprapubic pain often occurs along with hematuria, frequency, and nocturia. Renal colic  is present in fewer than 10% of cases, Dr. Cek noted.

 

“These cases are often overlooked,” said Dr. Cek said. “From a urology point of view, we must be more ag-gressive. The problem is that most of the patients start off with lung disease, and they are not sent for consultation. These patients often just have bladder dysfunction, having to pass water frequently with some pain. Many times the patients are thought to have cancer or just inflammation.”

To diagnose GUTB, urologists should first order a tuberculin test and then perform urinalyses on at least three but preferably five consecutive morning urine specimens. Polymerase chain reaction testing must be combined with culture and/or histopathology. Further investigation may include plain radiographs, intravenous urography, retrograde pyelography, ultrasonography and CT, endoscopy, and bladder biopsy.

 

A six-month course of medication is effective for all forms of TB. The intensive initial phase often requires rifampicin, isoniazid, pyrazinamide, or streptomycin. The continuation phase of treatment requires rifampicin or isoniazid. The World Health Organization guidelines recommend six months of treatment.

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