The etiologic, microbiologic, clinical and outcome characteristics of immunocompetent young children 2?years of age hospitalized with acute neutropenia

摘要

Background To describe the etiologic, microbiologic, clinical and outcome characteristics of acute neutropenia (absolute neutrophil count, ANC, 1.5?×?10sup9/sup/L) in hospitalized immunocompetent children. Methods Serious bacterial infections (SBI) were defined as culture-positive blood, urine, cerebrospinal fluid, articular fluid or stool infections, alveolar pneumonia, Brucellosis and Rickettsiosis. Results 431/671 (64.2%) healthy infants and children hospitalized with acute neutropenia were 2 years of age; 176 (40.8%), 167 (38.8%) and 88 (20.4%) patients were aged 0–3, 4–12 and 13–24 months, respectively. There were 19 (4.4%), 53 (12.3%), 140 (32.5%) and 209 (50.8%) patients with ANC count 200, 200–500, 501–1000 and 1001–1500?×?10sup9/sup?cells/L, respectively. Severe neutropenia (500?×?10sup9/sup/L) was recorded in 72 (16.7%) patients. Fever 38?°C was present in 208/431 (48.3%) patients. Blood cultures were positive in 10 (2.3%), with Brucella melitensis , Staphylococcus aureus and Enterobacter spp. identified in 4, 3 and 2 patients, respectively; 5/10 patients with positive blood cultures were 3 months of age. Overall, 55/431 (12.7%) and 65/431 (15.1%) patients were diagnosed with SBIs and bacterial infections, respectively. Nasal washings-PCR for respiratory viruses was positive in 139/293 (47.4%) patients tested. An infectious etiology (bacterial and/or viral) was diagnosed in 190/431 (44.1%) patients. Three patients were diagnosed with acute lymphocytic leukemia. Resolution of neutropenia was achieved in 111/208 (53.4%) evaluable patients (63%, 50.6% and 48% of patients aged 0–3, 4–12 and 12 months, respectively and 56.8%, 53.5% and 52% of patients with severe, moderate and mild neutropenia, respectively). Conclusion Acute neutropenia is common in immunocompetent children 2 years of age and is frequently associated with viral infections. We showed a substantial involvement of bacterial infections and particularly SBIs in the etiology of acute neutropenia. After a 1-month follow-up, resolution of neutropenia occurred in half of the patients, without association with age subgroups and with neutropenia severity.