SALIVARY AND BLOOD DIAGNOSTIC TESTS BASED ON HOST BIOMARKERS TO DISTINGUISH BETWEEN BACTERIAL AND VIRAL INFECTIONS IN FEBRILE CHILDREN

Purpose and aims: In a primary care setting, we aim finding host RNA and protein biomarkers that reliably distinguish bacterial from viral causes of acute fever in children.

Project organization: In two cohorts of febrile children, aged 3 months to 5-years, we will examine how well the host immune signatures RNA transcripts FAM89A and IFI44L, in blood and saliva, perform as biomarkers in distinguishing between viral and bacterial infections.

We will also assess if blood and/or salivary protein levels of CRP, procalcitonin, IL-6, IL-8 and IP-10 can discriminate between viral and bacterial infection.

Finally, we will explore the cellular source behind the RNA and protein biomarkers by analyzing their relationship with blood monocyte and T-cell phenotypes in these children.Time plan and scientific methods: Patient recruitment will be carried out at 2 units within Norrtälje, Vårdbolaget Tiohundra.

We will recruit 70 children in each cohort during the first 12-15 months and 70 children will be recruited as controls.

Blood, saliva and NP samples, and convalescence samples will be taken for research purposes and chart review will be performed.

During the 2nd and 3rd year we will perform PCR for biomarkers FAM89A and IFI44L; ELISA for conventional biomarkers and flow cytometry for monocytes and T-cells.

Significance: A simple test for discrimination between bacterial and viral infections in febrile children would improve patient management and limit antibiotic over-use