Fever in the first six months of life: risks of underlying serious infection

Managing Febrile Infants

The authors hypothesized that sepsis workup recommendations are associated with practice recommendations published during the physician’s residency. The first published recommendations suggesting sepsis workups for nontoxic, young, febrile infants appeared in pediatric journals from 1975-1980 and in family practice journals from 1981-1987. Data are from the Community Tracking Study (3,272 pediatricians and 2,432 family physicians). “Percentage of sepsis workups recommended” was defined by response to a vignette about the percentage of well-appearing 6-week-old children with a fever of 101°F for whom the physician would recommend a sepsis workup. Multivariable regression with piecewise linear functions evaluated workup recommendations by timing of literature recommendations during residency. Pediatricians recommended sepsis workups 81.6% of the time and family physicians 67.7% (p < .001). Increased recommendations occurred among pediatricians who completed residency from 1975-1980 (p < .05) and among family physicians who completed residency from 1981-1987 (p < .005), when specialty-specific journals published recommendations for sepsis workups for febrile infants. The association between publication of sepsis workup recommendations during a physician’s residency and increased sepsis workup recommendations suggests an unrecognized and enduring impact of such publications.

Predictors of bacteremia in infants with diarrhea and systemic inflammatory response syndrome attending an urban diarrheal treatment center in a developing country

OBJECTIVES

To identify clinical and laboratory predictors of bacteremia in infants with diarrhea and systemic inflammatory response syndrome and to analyze their outcome.

STUDY DESIGN

Retrospective, case-control study.

SETTING

The Special Care Ward of the Dhaka Hospital of the International Centre for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh.

PATIENTS

All the infants (n = 90) admitted to the Special Care Ward between May 2005 and April 2006 who had a blood culture, full peripheral blood count, and serum C-reactive protein performed were included in the study. Infant with systemic inflammatory response syndrome with confirmed bacteremia (n = 18) constituted cases, and those with systemic inflammatory response syndrome but negative blood culture (n = 72) constituted the controls.

RESULTS

The following features were analyzed by comparing the two groups: absent or uncountable peripheral pulses, hypothermia, sclerema, altered mental status, white blood cell count, serum C-reactive protein, total protein concentrations, and outcome. The case-fatality rate was significantly higher among bacteremic infants compared with those without bacteremia (33% vs. 6%, p < .01). In the univariate model, sclerema (56% vs. 28%, p = .05), hyperglycemia (28% vs. 6%, p < .01), immature neutrophils [3.5 (00, 6.5) vs. 0.0 (0.0, 3.25); p = .02], higher C-reactive protein [2.7 (1.2, 7.4) vs. 1.8 (0.5, 4.2); p = .02], and lower serum total protein (51.1 +/- 14.1 vs. 57.6 +/- 12.2; p = .05) were identified as potential predictors of bacteremia. However, in the logistic regression analysis, after adjusting for confounders, only hypothermia (odds ratio = 6.4, 95% confidence Interval, 1.6-25.9; p = .01) and absent or uncountable peripheral pulse (odds ratio, 12.4, 95% confidence interval, 1.9-83.4; p < .01) remained significant independent predictors of bacteremia.

CONCLUSIONS

Our data suggest that, in infants presenting with diarrhea and systemic inflammatory response syndrome, coexistence of hypothermia and absent or uncountable peripheral pulse is strongly associated with bacteremia. Bacteremia in this patient group is associated with high case-fatality rates.

Bedside procalcitonin and C-reactive protein tests in children with fever without localizing signs of infection seen in a referral center

OBJECTIVE

To assess the value of bedside tests for predicting the occurrence of severe bacterial infections (SBIs) in children with fever without source.

METHODS

We conducted a prospective study of 99 children, aged 7 days to 36 months, who were seen for fever >38 degrees C and no localizing sign of infection at the emergency department of the University Children's Hospital of Geneva. Blood procalcitonin (PCT), C-reactive protein (CRP), and interleukin-6 (IL-6) values were determined using rapid tests and were compared with the total white blood cell (WBC) count with differential and clinical score. Specificity, sensitivity, predictive values, and multilevel likelihood ratios (LRs) with posttest probabilities of disease were calculated.

RESULTS

Twenty-nine (29%) children received a diagnosis of having an SBI. PCT had the best sensitivity (93%) and negative predictive value (96%). Band count had the best specificity (93%), but its positive predictive value was only 38%. Multilevel LRs revealed that a PCT concentration <0.5 ng/mL (LR: 0.093) almost ruled out SBI (posttest probability of disease: 3.7%) in 54 (54%) subjects, whereas a value >2 ng/mL (LR: 5.2) increased the probability of SBI to 68% in 19 (19%) children. For CRP, values <40 mg/L (LR: 0.263) and >100 mg/L (LR: 14.483) generated posttest probabilities for SBI of 9.7% (61 subjects) and 86.5% (14 subjects), respectively. For WBC count, the posttest probabilities of SBI were modestly changed from the pretest prevalence.

CONCLUSIONS

PCT and CRP performed better than IL-6, WBC, and/or band count in predicting the occurrence of SBI. PCT and CRP bedside tests may be useful tools for emergency and private practice doctors and should be considered in the initial work-up of children with fever without source.

Predictive model for serious bacterial infections among infants younger than 3 months of age

OBJECTIVE

To develop a data-derived model for predicting serious bacterial infection (SBI) among febrile infants <3 months old.

METHODS

All infants </=90 days old with a temperature >/=38.0 degrees C seen in an urban emergency department (ED) were retrospectively identified. SBI was defined as a positive culture of urine, blood, or cerebrospinal fluid. Tree-structured analysis via recursive partitioning was used to develop the model. SBI or No-SBI was the dichotomous outcome variable, and age, temperature, urinalysis (UA), white blood cell (WBC) count, absolute neutrophil count, and cerebrospinal fluid WBC were entered as potential predictors. The model was tested by V-fold cross-validation.

RESULTS

Of 5279 febrile infants studied, SBI was diagnosed in 373 patients (7%): 316 urinary tract infections (UTIs), 17 meningitis, and 59 bacteremia (8 with meningitis, 11 with UTIs). The model sequentially used 4 clinical parameters to define high-risk patients: positive UA, WBC count >/=20 000/mm(3) or </=4100/mm(3), temperature >/=39.6 degrees C, and age <13 days. The sensitivity of the model for SBI is 82% (95% confidence interval [CI]: 78%-86%) and the negative predictive value is 98.3% (95% CI: 97.8%-98.7%). The negative predictive value for bacteremia or meningitis is 99.6% (95% CI: 99.4%-99.8%). The relative risk between high- and low-risk groups is 12.1 (95% CI: 9.3-15.6). Sixty-six SBI patients (18%) were misclassified into the lower risk group: 51 UTIs, 14 with bacteremia, and 1 with meningitis.

CONCLUSIONS

Decision-tree analysis using common clinical variables can reasonably predict febrile infants at high-risk for SBI. Sequential use of UA, WBC count, temperature, and age can identify infants who are at high risk of SBI with a relative risk of 12.1 compared with lower-risk infants.

Evaluation of the infant with fever without source: an evidence based approach

The infant with fever without an obvious source upon physical examination offers a challenging clinical problem. A combination of detailed history, physical examination, and selected laboratory tests allows the clinician to discern which infants are at lower risk for bacterial illness. Implications for management and future research are discussed herein.

Presenting features of bacterial meningitis in young infants

More guidance is required in the management of acutely ill, febrile young infants. Of 94 young infants undergoing lumbar puncture (LP) as part of their management, 26 of the 60 (43.3%) presenting with seizures and fever and six of the 34 (17.7%) without seizures had bacterial meningitis (BM) (relative risk (95% confidence interval) = 2.46 (1.12, 5.37), p = 0.012). Except for the presence of a bulging fontanelle and focal seizures, no other presenting signs or symptoms were significantly associated with BM; seven of the 26 infants with BM who presented with seizures and two of the six without seizures lacked a bulging fontanelle. Overall, the ratio of BM to other illnesses was 1:1.94; of those with BM, 13 of the 32 (40.6%) had co-existing acute respiratory infections and four of the 32 (12.5%) had asexual malaria parasitaemia. Seizures with fever are an important presenting feature of BM in young infants and a screening LP should be considered mandatory to confirm or exclude BM in febrile young infants with seizures, unless certain contraindications apply.

What is fever? Normal temperature in infants less than 3 months old

To determine the normal temperature of healthy infants, we studied 691 infants less than 3 months of age being seen for regularly scheduled well-baby visits. All temperatures were taken rectally with an electronic thermometer. The mean temperature was 37.5 degrees C +/- 0.3 degrees C. Using a cutoff of 2 standard deviations (SD) above the mean, fever would be defined as a temperature > or = 38.1 degrees C. The 95th percentile was 38.0 degrees C, and > or = 38.1 degrees C would correspond to values above the 95th percentile. The most widely used definition of fever at present is a temperature > or = 38.0 degrees C; by this definition, 6.5% of these well infants would be considered to have a fever. A significant rise in temperature with age was noted. For infants from birth to 30 days old, 2 SD above the mean was 38.0 degrees C; for those 31 to 60 days old, it was 38.1 degrees C; and for those 61 to 91 days old, it was 38.2 degrees C. Similarly, the 95th percentile was 37.9 degrees C, 38.0 degrees C, and 38.1 degrees C, respectively. Temperature also varied significantly with the season of the year, being higher in the summer (2 SD above a mean = 38.3 degrees C) than in the winter (2 SD above a mean = 38.0 degrees C). Fever should be defined as a temperature > or = 38.0 degrees C in infants less than 30 days of age, > or = 38.1 degrees C in 1-month-olds, and > or = 38.2 degrees C in 2-month-olds.

Management of feverish children at home

OBJECTIVES

To compare the acceptability and effects on temperature of advice to unwrap children and give paracetamol or warm sponging treatments in the management of feverish illness at home.

DESIGN

A randomised, open, parallel group study using factorial design comparison of unwrapping, warm sponging plus unwrapping, paracetamol plus unwrapping, and paracetamol and warm sponging plus unwrapping.

SETTING

Homes of willing families with a feverish child recruited after consulting one of 21 participating general practitioners in Southampton.

SUBJECTS

52 children aged from 3 months to 5 years with axillary temperatures before treatment of > or = 37.8 degrees C and < 40 degrees C.

MAIN OUTCOME MEASURES

Response to advice assessed over four hours; temperature assessed by continuous data logging from an axillary thermistor; acceptability of treatment to child and parent scored on Likert scales immediately after treatment and on return to health.

RESULTS

Response to treatment advice varied; unwrapping alone had little effect on temperature. Paracetamol increased the time below 37.2 degrees C in four hours by 109 (95% confidence interval 74 to 145) minutes compared with unwrapping; warm sponging caused the fastest reduction in temperature. Parents discriminated between treatments, preferring paracetamol.

CONCLUSION

Advice to give paracetamol is more effective than sponging or unwrapping in controlling temperature in children at home and is more acceptable to parents. Warm sponging has an additive effect and reduces fever more quickly than paracetamol.

Delayed diagnosis of infantile meningitis. Medical and legal outcomes

While the diagnosis of meningitis in the infant can be difficult due to the lack of definitive signs, a delay in the diagnosis can markedly increase morbidity and mortality. Eighteen cases of meningitis that were reported to a malpractice carrier over 75 months were evaluated for medical and legal outcome. Fourteen had a delay in diagnosis that was judged to have occurred due to substandard care. All had a poor outcome; one half died and the other half had neurologic complications. Four cases resulted in payment to the patient. Median payment was $1,100,000. When care was standard, no payment or legal action occurred.

Overwhelming infections in infants and children

Infections in children may present with nonspecific findings, requiring early recognition and stabilization. Age, etiology, immunocompetency, and duration of illness should all be considered in the initial assessment. Antibiotics and aggressive support are mandatory to avoid deterioration and severe morbidity or death.

Febrile infants less than eight weeks old. Predictors of infection

Febrile infants less than eight weeks old frequently are admitted and receive parenteral antibiotics for treatment of possible sepsis. The authors assess 52 infants less than eight weeks old with a rectal temperature of 38.1 degrees C or higher as having either a readily identifiable focus of infection by physical examination, appearing "toxic" without a focus, or appearing well. The authors screened patients by using white blood cell (WBC) counts, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and chest radiographs in addition to blood, cerebrospinal fluid and urine cultures. The authors found a 9.6% incidence of bacteria in the 52 infants evaluated, with a 4.3% incidence in those febrile infants who appeared well. Five patients had positive blood cultures with Group B B Hemolytic streptococcus (four patients), and Viridans streptococcus (one patient). A clinical assessment of toxicity and a total band count greater than or equal to 0.5 x 10(3) cells/uL together were sensitive indicators of bacteremia, as were toxicity and a positive CRP. A "toxic" appearance, a WBC count greater than or equal to 15 x 10(3) cells/uL and an ESR greater than 30 were specific indicators of bacteria. Based on these data, identification of bacteremia in febrile infants may be possible with clinical assessment and screening laboratory tests. Because of the relatively small sampling size of this study, the authors feel that evaluation of a larger number of patients is warranted to evaluate these sensitivities in a more diffuse patient population.

Parents' vs physicians' utilities (values) for clinical outcomes in potentially bacteremic children

Our previous analyses of decision strategies in children 3-24 months with acute-onset fever greater than or equal to 39 degrees C and no evident bacterial focus of infection indicated that the risks of routine blood cultures (the unnecessary hospitalization and treatment of children who clear their bacteremia spontaneously) outweigh its benefits (the prevention of a few cases with major infectious sequelae). Because those analyses were based on parents' values for beneficial and adverse clinical outcomes, we wished to examine whether those values differed in physicians and, if so, whether the differences were sufficient to change the results of the decision analysis. Using a pre-tested linear analog utility (value) scale, we evaluated eight potential clinical outcomes in potentially bacteremic children by surveying 121 parents of healthy 3-24-month-old children attending a private pediatric group practice and 57 attending physicians of a tertiary-care children's hospital emergency room. Utilities were based on a 0-1 normalization, where 0 is the utility of the worst outcome (meningitis or other major bacterial infection, plus venipuncture), and 1 the utility of the best outcome (complete recovery without venipuncture or hospitalization), and were analyzed using a recently developed statistical model of utility. The majority of parents and physicians combined the imputed components of the outcomes (disease, pain of venipuncture, and stress of hospitalization) in a nonlinear fashion. Parents assigned substantially lower utility (i.e. greater disutility) to venipuncture, minor infection, and hospitalization than did physicians, and these utilities were even lower in parents with other children at home.(ABSTRACT TRUNCATED AT 250 WORDS)

Variability in the management of the febrile infant under 2 months of age

The management in the emergency department of febrile infants less than 2 months of age is influenced by the standard of practice in the community. We sought to determine if uniform practices existed across the United States. Individual academically based faculty from 154 (61%) United States pediatric residency programs responding to a questionnaire on the emergency department management of febrile infants less than 2 months of age showed great variability. Twenty-nine respondents reported written policies and 103 reported informal but defined guidelines for the evaluation and management of infants seen at their institutions. There was little consensus among the respondents as to the definition of fever in this age group. Those at institutions with formal policies reported using more laboratory tests in the evaluation. Respondents differed on the number and types of tests used and on antibiotic administration. University affiliation, type of population served, or presence of advanced training programs in ambulatory pediatrics were not related to the type of policy. The care of the young febrile infant varies greatly.

Evaluation of the febrile child under 2 years of age

Unlike older children and adults, fever in young children may reflect serious underlying disease despite the lack of associated findings on physical examination. Laboratory examinations may provide important information in the management of these children. The recent literature suggests a systematic approach to the evaluation and management of the young febrile child.

Febrile infants: predictors of bacteremia

One hundred and seventy-five infants less than 8 weeks of age, presenting to the pediatric emergency room of the Bronx Municipal Hospital Center with rectal temperature greater than or equal to 38 degrees C (100.4 degrees F), were studied. House officers recorded their impressions of the infants on a number of variables prior to performing a lumbar puncture and obtaining laboratory data. All infants were admitted for parenteral antibiotic therapy pending culture results. Culture-positive bacterial infections occurred in 6.3% (n = 11); the incidence of bacteremia was 3.4% (n = 6). Of special concern were the 134 infants who had no visible source for their fever during the first examination. A major goal was to determine whether there were any early predictors of bacteremia in this group. The individual variables of white blood cell count greater than or equal to 15,000/mm3, band count greater than or equal to 500/mm3, temperature, impression of irritability, tone, cry, and activity level were not related to the presence of bacteremia. An erythrocyte sedimentation rate greater than or equal to 30 and the examiner's impression of sepsis were significantly associated with bacteremia but did not correctly identify all cases. However, the combination of impression of sepsis, white blood count greater than or equal to 15,000/mm3, and erythrocyte sedimentation rate greater than or equal to 30 identified all infants with bacteremia and excluded 82% of the infants who were eventually shown not to have bacteremia.

Management of febrile outpatient neonates

To determine whether all febrile outpatients below the age of two months should be routinely hospitalized and given parenteral antibiotics because of the possibility of occult sepsis or meningitis, 147 such admissions were reviewed over four years. None of the neonates had occult bacterial meningitis, while one may have had occult sepsis. Because serious infections may have been missed in outpatients not hospitalized, the outcome of all such illnesses seen in the clinic during a subsequent six months was monitored; none of 17 hospitalized or 20 followed as outpatients experienced sepsis or meningitis. If our findings are confirmed in other studies, febrile outpatient neonates with a well appearance, normal cerebrospinal fluid and physical examination, and dependable follow-up may not require universal hospitalization and antibiotics.