An occult bacteremia is the presence of bacteria in the blood feverish, but good-looking children with no apparent focus. The diagnosis is made by blood culture and exclusion of focal infection. The children are treated on an outpatient basis, either in the hospital or with antibiotics; selected children are treated, even if the result of the blood culture is still pending.
The causes, the assessment and treatment of possible occult bacteremia vary depending on the age of the children and immunization status. See also fever in infants and children
An occult bacteremia is the presence of bacteria in the blood feverish, but good-looking children with no apparent focus. The diagnosis is made by blood culture and exclusion of focal infection. The children are treated on an outpatient basis, either in the hospital or with antibiotics; selected children are treated, even if the result of the blood culture is still pending. The causes, the assessment and treatment of possible occult bacteremia vary depending on the age of the children and immunization status. See also fever in infants and children children 3 to 36 months old in the period before the conjugate vaccine had about 3 to 5% of children aged 3 to 36 months (with a febrile illness (Temoeratur ? 39 ° C) and without localized peculiarities ie fever without source) an occult bacteremia. In contrast, children saw> 36 months bacteremia almost always sick and had an identifiable (ie non-occult) infection. The majority (80%) of occult bacteremia before the routine conjugate immunization was caused by Streptococcus pneumoniae. A smaller percentage (10%) was prepared by Haemophilus influenzae type b, and an even smaller proportion (5%) from Neisseria meningitidis caused. Occult bacteremia is a problem because about 5 to 10% of children severe bacterial infections (SBI) develop in-defined usually as sepsis, meningitis and urinary tract infection, but also include septic arthritis and osteomyelitis. Such infections may be minimized by early detection and treatment of bacteremia. The probability that this progresses to a serious illness, hung on the cause from: 7-25% of cases of bacteremia caused by an H. influenzae type b, but in 4-6% of cases of bacteremia were S. pneumoniae caused. Currently, the routine in the US vaccination of infants with polysaccharide conjugate vaccines against S. pneumoniae and H. influenzae type b H. influenzae type B infections removed (> 99%) and invasive S. pneumoniae infections is substantially reduced ( ? 70%). Thus, in this age group, the occult bacteremia has become rare, except for low-immunized or unimmunized children and in children with immune deficiency. Children In contrast, <3 months old febrile infants <3 months continue as older children at increased risk of serious bacterial infection, about 8 to 10%. In the past, SBI were in young infants <3 months of frequent hemolytic streptococcus group B, p. pneumoniae and H. influenzae causes of type B. However, chemoprophylaxis during labor in pregnant women who are colonized with ?-hemolytic streptococcus group B, the early outbreak (infection occurs at the age of <7 days) to a streptococcal disease Group B> reduced 80% did. In addition, the routine conjugate immunization has the colonization of older siblings who are immunized against S. pneumoniae and H. influenzae type b is reduced, so that the rate of SBI, which was caused by these organisms has also reduced (herd immunity ). It is worth noting that late onset (infection occurs when> 7 days old) infection with group B streptococci is not affected by chemoprophylaxis during labor and other serious bacterial diseases such as UTI (most commonly caused by Escherichia coli) and occasionally cases of Salmonella bacteremia remain important causes are <3 months for fever of unknown cause in physical examination in infants. Symptoms and complaints The main symptom of occult bacteremia is fever-temperature ? 39 ° C (? 38 ° C in infants <3 months). By definition, children with an obvious focus (z. B. cough, shortness of breath and rattling noises can to pneumonia, skin redness on a cellulitis or septic arthritis note) excluded (that is, because their disease is not occult). Toxic symptoms (eg. As laxity and indifference, lethargy, signs of poor blood flow, cyanosis and marked hypo- or hyperventilation) are signs of sepsis or septic shock. Bacteremia in such children is not called occult or fever without cause. However, the distinction between an early sepsis and an occult bacteremia can be difficult. Diagnostic blood culture urine culture and urinalysis Complete and differentiated blood count Sometimes other tests depending on age and clinical circumstances The diagnosis of bacteremia requires blood cultures; Ideally, two samples are taken for two different points in order to minimize false positive results, the resulting states of pollutants on the skin. Test results should be within 24 hours are available. The goal is to find the SBI with as few tests. The recommendations regarding the respective investigations are based on the age of the children, the temperature and the clinical appearance children showing signs of focal infection based on history or physical examination, are examined based on these findings. If available, rapid diagnostic tests for enteroviruses, human respiratory syncytial virus and influenza virus in the assessment of children are useful with fever of unknown cause because children whose test results are positive for these viruses probably have a fever due to this virus and only need few or no further testing for SBI. There is also rapid tests for other viruses, but these have not been studied sufficiently enough as it would be justified to use their findings to alter tests for SBI. In children with SBI blood count usually indicates an increase in leukocytes, but only 10% of children with leukocytes> 15,000 / ul have a bacteremia. Specificity is so low. Although acute-phase proteins are used by some physicians (z. B. ESR, CRP, with or without Procalictonin) used, but they contribute only a few additional information. In conjunction with an increased procalcitonin inflammation parameters are already rather an indication of a serious illness. In children <3 months can stab polynuclear leukocytes> 1500 / ul and a low (<5000 / ul) or a high leukocyte count (> 15,000 / ul) indicate a bacteremia. Children 3 to 36 months old, it is important to note that every feverish child, regardless of immunization history that appears seriously ill or toxic, a complete clinical and laboratory evaluation required (blood count with differential, blood cultures, urine cultures, lumbar puncture, and in most cases hospitalization with empirical antimicrobial therapy). Not immunized, too little immunized and immunocompromised febrile children at this age are more prone to SBI than their peers and also require generally the same full clinical and laboratory examination for SBI and empirical antibiotics. In children with dyspnea or lower O2 saturation, a chest X-ray should be performed. In previous immunized febrile children aged 3 and 36 months, which appear healthy (non-toxic), the risk of bacteremia now as low as or even lower than the rate of false positive blood cultures by skin impurities, which many experts brings to to refrain from blood cultures in these children. However, usually a urinalysis with microscopic examination and urine culture is recommended, but no additional laboratory tests (z. B. blood count, chest x-ray). Although the vast majority of these children has a viral infection, a small number of healthy-looking children will have early SBI, so caregivers should be instructed to monitor the symptoms of children to give antipyretics, and h the doctor’s instructions in 24 to 48 to follow (by visit or telephone, depending on the circumstances and the reliability of the support staff). In children whose condition is worsening or that remain feverish, tests should be carried out (eg., Blood count with differential, blood cultures, possibly chest x-ray or lumbar puncture) .Children require <3 months old Toxic appearing or seriously ill appearing Children immediate clinical evaluation and the collection of blood, urine and cultures of spinal fluid and hospitalization for empirical antibiotic therapy. Unlike in older infants, can be among those who are <3 months old and have a non-toxic clinical features, not postpone an investigation routinely. Algorithms were developed to facilitate the evaluation in infants in this age group (for an example, evaluation and treatment of febrile infants aged <3 months.). When using the algorithm many experts consider an age <30 days alone is a criterion for high risk (and therefore routinely further investigations), while others do not, and all children in the age of <90 days, according to the same criteria to treat . This algorithm is sensitive to SBI, but relatively non-specific. So the algorithm has a high negative predictive value (understanding of medical tests and test results: Test characteristics), but a negative positive predictive value, especially given the relatively low incidence of SBI in the group of febrile infants. This makes the identification of children with low risk of infection, which can be treated as a precaution (in case of excluded bacteremia), much more effective than in the identification of children with true SBI or bacteremia. Evaluation and treatment of febrile infants aged <3 months. hpf = field. Treatment Antibiotics (empirically for selected patients with outstanding cultural results as well as for patients with positive cultures) Adequate hydration antipyretics for complaints (because of the increased loss for fever and possible anorexia, oral hydration, if possible, parenteral, if not) Children which are treated with antibiotics before bacteremia was confirmed with a blood culture, seem to have less focal infections. but the data are in any doubt. The overall incidence of bacteremia is low. However, if all children are examined, treated empirically, far too many would receive unnecessary treatment. As mentioned above, the treatment varies according to age and other clinical factors. Regardless of age, all children will be re-examined after 24-48 hours. Children with persistent fever or positive blood or urine cultures that were not treated, get new cultures and to be hospitalized in order to investigate a possible sepsis and initiate parenteral antibiotic treatment. If new signs of focal infection emerge with renewed investigation, evaluation and treatment depend on the findings. Children 3 to 36 months old are antipyretics administered weight-based dosing. Antibiotics are not given unless cultures are positive. At UTI healthy looking children can receive oral antibiotics for UTIs, as well as out-patients; other (eg. as those that appear sicker) can parenteral antibiotics benötigen.Kinder <3 months old A simple system that allows the use of antibiotics in febrile infants in whom a serious bacterial infection is unlikely can be reduced and those with antibiotics are supplied, they also need evaluation and treatment of febrile infants aged <3 months .. If urinalysis and urine cultures indicate a urinary tract infection, appear healthy children can receive oral antibiotics for UTI as outpatients; other (eg. as those that appear sicker) may require parenteral antibiotics. It should be noted that some doctors prefer all febrile children <1 month instruct to perform a complete evaluation with cultures of blood, urine and cerebrospinal fluid, and parenteral antibiotics administered (eg. as ceftriaxone) until the culture results are available, because febrile infants <1 month are the age group with the highest incidence of SBI. Important points Febrile infants and young children <36 months who are immunized appropriately with Hib and pneumococcal conjugate vaccines who look healthy and no obvious sources of infection, it is unlikely that they suffer from occult bacteremia or a severe bacterial infection ( ., for example, sepsis, meningitis); SBI. Use blood cultures (2 samples from two different locations) to diagnose occult bacteremia in febrile children selected. All febrile children <36 months should be tested for UTI with urinalysis and urine culture because UTI is the most common cause of SBI with a fever today. Toxic-appearing children (and perhaps all febrile children <1 month) also require cultures of blood and spinal fluid and hospitalization for an empirical antibiotic therapy. In children aged 3 and 36 months with a temperature ? 39 ° C and immunized appropriately, are among those who appear healthy except urine culture indicated no other tests; others should test based on clinical findings and other circumstances receive (eg. as rapid viral testing for influenza virus, respiratory syncytial virus and enterovirus in the respective seasons). In infants <3 months with a temperature ? 38 ° C a good clinical appearance does not completely a SBI, so further tests are displayed, including urinalysis, complete blood count with differential, blood and urine cultures and - if applicable (depending on the local epidemiology and season) - perhaps a faster viral test for influenza virus, respiratory syncytial virus and enterovirus for all in this age group. Non-toxic, low-risk children require engmachiges follow-up if they are not treated with antibiotics.