INCLINE VALLEY, NEV. — Urinary tract infection is so common in children younger than age 2 years that a physician should almost always get a urine culture when working up a fever in a child that age, Dr. Nathan Kuppermann said at an emergency medicine conference sponsored by the University of California, Davis.
That includes getting a urine culture for febrile children younger than age 2 years who have a clinically documented viral infection, he said.
“Urinary tract infections in young febrile infants, particularly, are very common, and these viral infections are very common, so overlap occurs not infrequently,” said Dr. Kuppermann, professor of emergency medicine and pediatrics and chair of the department of emergency medicine at the university.
Studies have looked at concurrence of bacterial infection and viral croup, varicella, stomatitis, bronchiolitis, and influenza infection, and they suggest that a urinary tract infection can also be present about 3% of the time, he said.
Urinary tract infection (UTI) is probably the most important bacterial infection in children 0–3 months of age, because it is so common and because of its serious consequences. Urinary tract infection occurs in 5%–10% of children aged 0–3 months who have a fever above 38° C.
About half the time, the normal routine urinalysis performed for a child of that age will be normal even when there is an infection, Dr. Kuppermann noted. So, one should have a culture done, with Gram staining.
In children younger than age 3 months, UTI is more common in boys than girls. It only switches when they get older. In children younger than age 2 years overall, UTI accounts for 7%–8% of infections in girls with a temperature of 39° C or higher, and 2%–3% of boys with a temperature of 39° C or higher. Most of those boys, however, are uncircumcised. The rate among circumcised boys is 0.2%–0.4%, Dr. Kuppermann said.
The reason for the UTI vigilance is that the kidney is so much more susceptible to damage in the young. It is estimated that most UTIs that lead to renal damage occur in children younger than age 4 years, and especially in those younger than 1 year.
Approximately 13%–15% of end-stage renal disease may be related to an unrecognized, and untreated, UTI in early childhood, Dr. Kuppermann said.