Host-based Immunoassay for Differentiating Bacterial From Viral Infections (Post-marketing Study of ImmunoXpert™ - SPIRIT Study)

Inclusion criteria

• Patients aged 3 month to 18 years that were admitted due to acute febrile illness, and ImmunoDx test was taken as part of their workup.

The febrile illness should also fulfill the following criteria:

• The patient had a peak temperature ≥38°C (AND)
• Symptoms initiated ≤ 7 days before sampling (AND)
• A retrospective diagnosis of bacterial or viral or mixed infection was anonymously determined by a panel of three independent senior pediatricians.

The non-infectious disease control group will include:

• A retrospective diagnosis of a non-infectious disease was anonymously determined by a panel of three independent senior pediatricians physicians.
• Patients with a non-infectious disease ( and ImmunoDx test was wrongly taken)

Exclusion criteria

• Samples from patients who had one or more of the following criteria will be excluded from the study:
• Another infection episode during the last 3 weeks before sampling
• Congenital immune deficiency (CID)
• A proven or suspected HIV-1, HBV, HCV infection
• Active hematological malignancy
• Current treatment with immune-suppressive or immune-modulating therapies including without limitations:
• Use of high dose steroids >1 mg/kg/day prednisone or equivalent in the last two weeks
• Monoclonal antibody administration
• Intravenous immunoglobulin (IVIG)
• Other illnesses that affect life expectancy and/or quality of life
• Suspicion of gastrointestinal infection