We reviewed the incidence of occult bacteremia, to identify the most frequent etiological agents of bacteremias in otherwise healthy children from one month to 10 years old, who had fever of unknown origin attended at the emergency ward of an urban, university-affiliated pediatric referral center. This was a retrospective medical record review, evaluating children with fever. Data were collected from the initial visit, when blood cultures, hematological properties and hemosedimentation rates were examined. Fever was considered as the highest temperature assessed in the hospital or reported by the responsible adult. Occult bacteremia was discovered in 1.4% of the 1,051 children evaluated, and the most common etiologic agent was Streptococcus pneumoniae. Total leukocyte count and blood sedimentation rates greater than 30 mm³ were not predictive factors for occult bacteremia. Fever greater than 39ºC was the most important factor for predicting occult bacteremia (P<0.001). The presence of occult bacteremia was significantly correlated with patient hospitalization.

OBJETIVO: descrever caso clínico de uma criança que desenvolveu septicemia por Salmonella enteritidis, sendo diagnosticada imunodeficiência primária. DESCRIÇÃO: paciente masculino, de um ano e 9 meses, com febre e lesões de pele há 50 dias, internado com lesão perilabial ulcerada com secreção purulenta, lesão ulcerada friável em língua, lesões ulcerocrostosas em membros, pneumonia bilateral com derrame pleural e choque séptico, sendo diagnosticado Salmonella enteritidis como agente etiológico. A identificação desta bactéria direcionou a investigação para a síndrome MIM. O diagnóstico de deficiência do receptor da interleucina-12 (IL-12Rbeta1) foi confirmado através da dosagem de IL-12 e do interferon (IFN)-gama produzido pelas células do paciente em meio de cultura. O resultado demonstrou ausência de produção de IL-12 e do IFN-gama mesmo após estímulo adequado. COMENTÁRIOS: a identificação da Salmonella enteritidis como agente etiológico de septicemia sugere uma disfunção do sistema imunológico. Foi realizada avaliação laboratorial das imunidades humoral, celular e inata. Após avaliação laboratorial direcionada para síndrome MIM, foi confirmada a deficiência do receptor da Interleucina-12 (IL-12Rbeta1). O uso do IFN-gama é recomendado nos casos graves, assim como o tratamento de suporte e o aconselhamento genético.

OBJECTIVE: to present a case report of a child who developed sepsis by Salmonella enteritidis associated with the diagnosis of primary immunodeficiency. DESCRIPTION: a twenty-one months old boy presenting fever and skin lesions, bilateral pneumonia with pleural effusion and septic shock. Salmonella enteritidis was isolated in blood cultures and pleural fluid. The identification of the bacteria suggested the presence of the MIM syndrome. The diagnosis of IL-12Rbeta1 was confirmed after IL-12 and IFN-gamma levels were measured using patient cells in a culture medium. The results showed absence of IL-12 and the IFN-gamma post stimulation using BCG. COMMENTS: a severe infection by Salmonella enteritidis is strongly suggestive of an immune system dysfunction. Laboratory tests for humoral, cellular and innate immunity were performed. Interleukin 12 receptor beta1 (IL-12 Rbeta1) deficiency was confirmed after specific laboratory evaluation. The use of INF-gamma is recommended in severe cases.