Comparison of the etiologic, microbiologic, clinical and outcome characteristics of febrile vs. non-febrile neutropenia in hospitalized immunocompetent children.

We compared the etiologic, microbiologic, clinical, and outcome picture among febrile and non-febrile immunocompetent children hospitalized during 2013-2015 with acute neutropenia (absolute neutrophil count < 1.5 × 109/L). Serious bacterial infections (SBI) were defined as culture-positive blood, urine, cerebrospinal fluid, articular fluid or stool infections, pneumonia, brucellosis, and rickettsiosis. Overall, 664 children < 18 years of age were enrolled; 407 (62.2%) had fever > 38.0 °C and 247 (37.8%) were non-febrile at admission. There were 425 (64.0%), 125 (18.8%), 48 (7.2%), and 66 (9.9%) patients aged 0-24 months, 2-6, 7-12, and > 12 years, respectively. No differences were recorded in the distribution of febrile vs. non-febrile patients among the age groups nor among the 3 neutropenia severity groups (< 0.5, 0.5-1.0 and 1.0-1.5 × 109/L). SBI infections were diagnosed in 98 (14.8%) patients, with higher rates among febrile patients vs. non-febrile patients (16.8% vs. 11.5%, P = 0.06). Brucellosis and rickettsiosis were diagnosed in 15.4% and 23.1% tests performed, respectively. 295/688 (42.9%) virologic examinations returned positive. Among patients < 24 months, more febrile ones had viral infectious compared with afebrile patients (P = 0.025). Acute leukemia was diagnosed in 6 patients. Neutropenia resolved in 163/323 (50.5%) patients during a 1-month follow-up. No differences were recorded in neutropenia resolution between febrile and non-febrile children among all 3 severity groups. Severe neutropenia was rare and occurred mainly in very young patients. SBIs were more common among febrile patients compared with non-febrile patients, but there was no association between severity of neutropenia or its resolution and the presence or absence of fever at diagnosis.