Detection of by Real-time PCR in Young Children Does Not Predict Disease.

Objectives: Diagnosing infections in young children with high asymptomatic colonization is challenging. We compared the frequency of detection by polymerase chain reaction (PCR) in healthy control (HC) children with those with acute gastroenteritis (AGE) and evaluated fecal-lactoferrin and organism load as possible indicators of true infection disease.

Methods: Stool was collected from children <2 years old with AGE and from HCs. was detected by real-time PCR, and lactoferrin was measured by enzyme-linked immunosorbent assay. Clinical data were obtained via interviews and chart review. Mann-Whitney test and χ tests were used for group comparisons.

Results: Of 524 stools collected from 524 children (250 with AGE, 274 HCs), was detected less in children with AGE (14%, 36 of 250) than in HCs (28%, 76 of 274) stools ( < .0001). Among infants <1 year old ( = 297), was detected in 18% of children with AGE versus 32% of HCs ( < .005), and among children 1 to 2 years old ( = 227), was detected in 10% of children with AGE versus 21% of HCs ( < .02). There was no significant difference in PCR cycle threshold values between children with AGE and HCs or lactoferrin levels in PCR-positive versus -negative stools.

Conclusions: HC children <2 years of age had higher rates of detection by PCR than children with AGE; detection by real-time PCR alone is not a reliable means to diagnose disease in children <2 years old.