The Value of Fecal Calprotectin Combined with Procalcitonin in the Differential Diagnosis of Bacterial and Viral Diarrhea in Children

Infectious diarrhea frequently occurs in children, and accurate diagnosis is essential for providing prompt treatment. Fecal calprotectin (FC) and procalcitonin (PCT) are useful in differentiating types of infectious diarrhea. Therefore, this study aims to assess the value of combining FC and PCT in the differential diagnosis of bacterial and viral diarrhea in children. As a retrospective study, convenience sampling was used to include 60 children with acute bacterial diarrhea (bacterial group) and 70 children with acute viral diarrhea (viral group) who were admitted to hospitals in China between October 2019 and October 2021. The demographic characteristics, medical history, and laboratory data of the children were collected and compared. The proportions of children with myocardial and liver damage were lower in the bacterial group than in the viral group, and the proportions of children with bloody stool and purulent stool were higher in the bacterial group than in the viral group (all P <0.001). The levels of FC, PCT, C-reactive protein (CRP), and white blood cells (WBCs) were elevated in patients in the bacterial group compared with those in the viral group (all P <0.05). The FC, PCT, CRP, and WBC count values are valuable in the differential diagnosis of bacterial and viral diarrhea, and the area under the curve of FC combined with PCT for the differential diagnosis was the largest at 0.933, with a 95% CI of 0.856-0.955. Fecal calprotectin is superior to PCT, CRP, and WBC count in terms of guiding the differential diagnosis. The combination of FC and PCT provides better guidance for differential diagnosis than each indicator used individually.