Using of Biomarkers and Blood Culture in Early Detection of Systemic Infections

Immunocompromised children with cancer receiving chemotherapy or undergoing hematopoietic stem cell transplant (HSCT) are at high risk of infections. Invasive fungal infection (IFI) is a significant cause of morbidity and mortality. The incidence of IFI from 5.3% to 24% and the mortality rate from 18.6% to 67.6%. Definite diagnosis of fungal infection in immunocompromised patients is particularly challenging. However, the clinical presentation of IFI is not specific, especially in pediatric patients. The culture of blood is the major method to diagnose proven IFI, but the results are mostly negative, and culture is time consuming. New nonculture-based methods, including antigen-based assays, and molecular detection of fungal DNA which may allow early diagnosis and treatment of fungal infection. Molecular techniques, including DNA sequencing and polymerase chain reaction (PCR). These techniques have become more available in many laboratories; however, it lacks methodological standardization, and the results vary widely among laboratories. More attention paid to the biomarkers. 1, 3- β -D- glucan (BDG) is a component of the fungal cell wall and therefore it considered a pan-fungal detection method. Traditional biomarkers as C-reactive protein (CRP) and procalcitonin (PCT) have also been evaluated for their abilities in distinguishing IFI and other infections. In neonates, CRP levels were significantly higher in fungemia than in bacteremia, in adult patients, there was not a significant difference between the candidemia and bacteremia groups. The PCT value was markedly lower in the fungal infection group than in the bacteremia group at the onset of fever.