Chemical composition of urinary calculi in Maiduguri, Nigeria.

Urolithiasis is a common disorder in Maiduguri and constitutes a significant proportion of surgical diseases in Nigerian Hospitals today. Although, the analysis of the stones is an integral part of the assessment of stone formers, earlier report in Maiduguri did not dwell well on it. We therefore, carry out this study to report on the composition of urinary tract calculi removed during surgery at the University of Maiduguri Teaching Hospital and to find out if stone composition in the area changes with time. Fourty-nine urinary tract calculi removed in the surgery unit of the Hospital in 2003 were chemically analyzed in the Department of Chemical Pathology of the same Hospital. We also retrieved results of stones analyzed in 1989 (41) and 1999 (21) and compared the results with the 49 analyzed in 2003. The results showed a male preponderance with male: female ratio 12:1, and the calculi occurred more in the upper part of the tract (70.9%) than the lower part of the tract (29.1%). Calcium containing stones constituted the majority; 76.9%, uric acid/urate was associated with 16.3% of the stones while struvite constitutes 4.3%, xanthine 1.7% and cystine 0.9%. There was subsequent reduction of struvite stones with time. Urinary tract stone is common in Maiduguri. There is need for identification of risk factors of calculi formation in the environment to enable the health care providers plan preventive measures in order to reduce the high incidence in the area.