Bacteria in the urine without symptoms of urinary tract infection or pyelonephritis. This condition may occasionally precede symptomatic urinary tract infection. It is common in elderly women and in patients with indwelling urinary catheters. In children, it may be a sign of underlying urinary tract abnormalities. Screening for asymptomatic bacteriuria is recommended for pregnant women at 12 to 16 weeks’ gestation. Screening school-age children is not beneficial.