[Children less than 3 months hospitalised due to acute febrile syndrome. 5 years clinical experience]. / Lactantes menores de 3 meses hospitalizados por síndrome febril agudo. Experiencia clínica de 5 años.

INTRODUCTION: Acute fever of unknown origin (AFUO) is established when the anamnesis and physical examination cannot identify the cause. In infants less than 3 months-old this is situation for concern, due to the risk of a serious bacterial infection. OBJECTIVE: To describe the clinical and laboratory variable of patients with AFUO, in order to look for clues in order to base studies on the decisions arising drom this problem. PATIENTS AND METHODS: A report is presented on a retrospective study conducted on a cohort of children less than three months-old admitted to the Hospital Roberto del Río (2007-2011) due to an AFUO. Clinical histories were reviewed and the patients were grouped, according to the severity of the admission diagnosis, into severe and non-severe. They were compared in strata determined by the variables of clinical interest. RESULTADOS: A total of 550 children were admitted with AFUO during the study period. There was low agreement between the severity on admission and at discharge (kappa=0.079; P=.26). There were 23.8% of children in the severe group and 76.2% in the non-severe group. Urinary tract infection predominated in the severe group (68.7%) and 40.7% with acute febrile syndrome in the non-severe group. The cut-off levels for C-reactive protein, white cells, and neutrophils per mm(3), to calculate the fixed and variable indices, only showed negative predictive values of some use for ruling out serious bacterial infection. The ROC curves with white cell and neutrophil counts and C-reactive protein, did not provide andy fixed indices of clinical use. More than one-third (34.6%) of lumbar punctures were traumatic or failures. CONCLUSIONS: According to the results of this study, there is an obvious excess of hospital admissions, little usefulness in the examinations to identify serious bacterial infection, a high percentage lumbar punctures traumatic and lumbar punctures failures, and an excess of antibiotic treatments. A review of clinical criteria and procedures is needed.