Procalcitonin and C-reactive protein as predictors of blood culture positivity among hospitalised children with severe pneumonia in Mozambique

Objectives To evaluate the benefits of using procalcitonin (PCT) and C-reactive protein (CRP) as pre-screening tools to predict blood culture positivity among Mozambican children with clinical severe pneumonia (CSP). Methods 586 children <5years with CSP and no concurrent malaria fulfilled criteria to be included in the study groups. We determined PCT and CRP for all children with positive bacterial culture (BC+ group, n=84) and of a random selection of children with negative bacterial culture (BC- group, n=246). Results PCT and CRP levels were higher in the BC+ group than the BC- one (PCT: median 7.73 versus 0.48ng/ml, P<0.001; CRP: 177.65mg/l vs. 26.5mg/l, P<0.001). In multivariate analysis, PCT was the only independent predictor of the group. To be used as pre-screening tool, PCT presented higher specificities for predetermined sensitivities (≥85%) than CRP. Pursuing a sensitivity of 95%, PCT could reduce the need for bacterial culture by 49% and overall diagnosis costs by 7-35% [assuming variable costs for PCT measurement (ranging from 10 to 30USD) and a fixed cost of 72.5USD per blood culture]. Conclusions Among hospitalised children with CSP and absence of concurrent malaria, PCT pre-screening could help reduce the number of blood cultures and diagnosis costs by specifically targeting patients more likely to yield positive results. © 2012 Blackwell Publishing Ltd.