Retrospective review of serious bacterial infections in infants who are 0 to 36 months of age and have influenza A infection

The Impact of Respiratory Symptoms on the Risk of Serious Bacterial Infection in Febrile Infants < 60 Days Old

OBJECTIVES

We aimed to evaluate the impact of respiratory symptoms and positive viral testing on the risk of serious bacterial infections (SBIs).

METHODS

A retrospective study was conducted that included infants (0-60 days) presenting with a fever between 2001 and 2022 at a tertiary hospital in northern Israel. Demographic, clinical, and laboratory parameters were collected, and risk factors for SBIs were analyzed.

RESULTS

Data from a total of 3106 infants, including data from blood, urine, and CSF cultures, were obtained in 96.6%, 89%, and 29% of cases, respectively. A fever without respiratory symptoms (fever only) was present in 1312 infants, while 1794 had a fever and respiratory symptoms-427 were positive for a respiratory virus (virus+), 759 tested negative (virus-), and 608 were not tested. The SBI rate was 5.1% vs. 7.5% in the fever-and-respiratory group vs. the fever-only group (p = 0.004, OR = 0.65 (95% CI = 0.49-0.88)) and 2.8% vs. 7% in the virus+ vs. virus- group (p = 0.002, OR = 0.385, (95% CI = 0.203-0.728)). The male gender, an age < 1 month, leukocytosis > 15 × 10⁹/L, or a CRP > 2 mg/dL increased the risk of SBIs. Respiratory symptoms or a confirmed viral infection reduced the risk of SBIs in the presence of the above risk factors.

CONCLUSIONS

Respiratory symptoms and a positive viral test decreased the risk of SBIs. Combining rapid viral testing with clinical variables may identify low-risk infants. Despite the relatively low risk of SBIs in individuals with viral infections, conducting prospective studies remains essential for accurately predicting the occurrence of these potentially life-threatening infections.

Viremia as a predictor of absence of serious bacterial infection in children with fever without source

Most children with fever without source (FWS) require diagnostic laboratory tests to exclude a serious bacterial infection (SBI), often followed by admission and empirical antibiotics. As febrile children with a viral infection are less likely to have a SBI, identifying patients with systemic viral infection could contribute to exclude SBI. We evaluated whether the presence of virus in the blood could be used as a biomarker to rule out SBI. Children < 3 years old with FWS were prospectively enrolled and had real-time (reverse-transcription) PCR performed on the blood for adenovirus, enterovirus, parechovirus, and HHV6. 20/135 patients had SBI, and in 47/135, at least one virus was detected in the blood. Viremia had a higher sensitivity and negative predictive value (90% and 96%) to rule out SBI compared to CRP (65% and 93%) and PCT (55% and 90%). The odds ratio (OR) for the presence of SBI among non-viremic patients was 5.8 (p = 0.0225), compared to 5.5 for CRP ≥ 40 mg/l (p = 0.0009) and 3.7 for PCT ≥ 0.5 ng/mL (0.0093). This remained significant after adjusting for CRP and PCT (OR 5.6 and 5.9, respectively; p = 0.03 for both). Area under the ROC curve for CRP and PCT were 0.754 and 0.779, respectively, but increased to 0.803 and 0.832, respectively, when combined with viremia.

CONCLUSION

The presence of viremia had a better performance than commonly used biomarkers to rule-out SBI and could potentially be used in conjunction with CRP and/or PCT in the evaluation of children with FWS. Larger studies should evaluate the role of point-of-care testing of viruses by (revere-transcription) PCR in the plasma in management algorithms of children with FWS.

WHAT IS KNOWN

• Most children with FWS have a viral infection, but up to 15% have a SBI; most require laboratory tests, and many admission and empirical antibiotics. • Children with a viral infection are less likely to have a SBI.

WHAT IS NEW

• Children with a systemic viral infection are less likely to have an SBI. • Viremia is a better predictor of absence of SBI than commonly used biomarkers and could potentially be used in conjunction with CRP and/or PCT in the evaluation of children with FWS.

Diagnostic Stewardship—The Impact of Rapid Diagnostic Testing for Paediatric Respiratory Presentations in the Emergency Setting: A Systematic Review

Antimicrobial resistance is a growing public health crisis, propelled by inappropriate antibiotic prescription, in particular the over-prescription of antibiotics, prolonged duration of antibiotic therapy and the overuse of broad-spectrum antibiotics. The paediatric population, in particular, those presenting to emergency settings with respiratory symptoms, have been associated with a high rate of antibiotic prescription rates. Further research has now shown that many of these antibiotic prescriptions may have been avoided, with more targeted diagnostic methods to identify underlying aetiologies. The purpose of this systematic review was to assess the impact of rapid diagnostic testing, for paediatric respiratory presentations in the emergency setting, on antibiotic prescription rates. To review the relevant history, a comprehensive search of Medline, EMBASE and Cochrane Database of Systematic Reviews was performed. Eighteen studies were included in the review, and these studies assessed a variety of rapid diagnostic testing tools and outcome measures. Overall, rapid diagnostic testing was found to be an effective method of diagnostic antibiotic stewardship with great promise in improving antibiotic prescribing behaviours. Further studies are required to evaluate the use of rapid diagnostic testing with other methods of antibiotics stewardship, including clinical decisions aids and to increase the specificity of interventions following diagnosis to further reduce rates of antibiotic prescription.

Rapid Viral Testing and Antibiotic Prescription in Febrile Children With Respiratory Symptoms Visiting Emergency Departments in Europe

BACKGROUND

Inappropriate antibiotic prescribing often occurs in children with self-limiting respiratory tract infections, contributing to antimicrobial resistance. It has been suggested that rapid viral testing can reduce inappropriate antibiotic prescribing. We aimed to assess the association between rapid viral testing at the Emergency Department (ED) and antibiotic prescription in febrile children.

METHODS

This study is part of the MOFICHE study, which is an observational multicenter study including routine data of febrile children (0-18 years) attending 12 European EDs. In children with respiratory symptoms visiting 6 EDs equipped with rapid viral testing, we performed multivariable logistic regression analysis regarding rapid viral testing and antibiotic prescription adjusted for patient characteristics, disease severity, diagnostic tests, focus of infection, admission, and ED.

RESULTS

A rapid viral test was performed in 1061 children (8%) and not performed in 11,463 children. Rapid viral test usage was not associated with antibiotic prescription (aOR 0.9, 95% CI: 0.8-1.1). A positive rapid viral test was associated with less antibiotic prescription compared with children without test performed (aOR 0.6, 95% CI: 0.5-0.8), which remained significant after adjustment for CRP and chest radiograph result. Twenty percent of the positively tested children received antibiotics. A negative rapid viral test was not associated with antibiotic prescription (aOR 1.2, 95% CI: 1.0-1.4).

CONCLUSIONS

Rapid viral test usage did not reduce overall antibiotic prescription, whereas a positive rapid viral test did reduce antibiotic prescription at the ED. Implementation of rapid viral testing in routine emergency care and compliance to the rapid viral test outcome will reduce inappropriate antibiotic prescribing at the ED.

Frequency of serious bacterial infections in young infants with and without viral respiratory infections

BACKGROUND

The goal of our investigation was to describe the incidence of serious bacterial infection (SBI, defined as bacteremia, urinary tract infection (UTI), or meningitis) in young infants with and without documented viral pathogens.

METHODS

This was a retrospective cross-sectional study (1/2016-12/2017) in 3 emergency departments (EDs). Previously healthy 0-60-day-old infants were included if at least respiratory viral testing and a blood culture was obtained. The frequency of SBI, the primary outcome, was compared among infants with/without respiratory viral infections using the Pearson Chi-square test (or Fisher's Exact Test) and unadjusted odds ratios (OR).

RESULTS

The median age of the 597-infant cohort was 32 days (interquartile range: 20-45 days); 42% were female. Eighty-three percent were well appearing in the ED and 72% were admitted. ED triage vitals commonly revealed tachypnea (68%), pyrexia (45%), and tachycardia (28%); hypoxemia (5%) was uncommon. Twenty-eight percent had positive viral testing, most commonly RSV (93/169, 55%), parainfluenza (29, 17%), and influenza A (23, 14%). Eighty-three infants (13.9%) had SBI: 8.4% (n = 50) had UTI alone, 2.8% (n = 17) had bacteremia alone, 1.2% (n = 7) had bacteremia + UTI, 1.0% (n = 6) had bacteremia + meningitis, and 0.5% (n = 3) had meningitis alone. Infants with documented respiratory viral pathogens were less likely to have any SBI (OR: 0.23; 95% CI: 0.11-0.50), UTI (OR 0.22, 95% CI: 0.09-0.56), or bacteremia (OR 0.27, 95% CI: 0.08-0.9) than infants with negative viral testing. There was no difference in meningitis frequency based on viral status (OR: 0.13, 95% CI: 0.008-2.25).

CONCLUSIONS

The frequency of bacteremia and UTI was lower in young infants with respiratory viral infections compared to infants with negative respiratory viral testing.

Fever Without Source in Unvaccinated Children Aged 3 to 24 Months: What Workup Is Recommended?

ABSTRACT

Fever is the most common complaint for infants and children brought to the emergency department. Most febrile children younger than 3 years will have a clinically apparent source of infection. However, in approximately 20% of these children, a source cannot be identified by history and physical examination alone. The recommended diagnostic approach to children younger than 3 years presenting with fever without source (FWS) has changed dramatically over the past 30 years because of the widespread use of the Haemophilus influenza type b and polyvalent pneumococcal vaccines. The percentage of children in the United States unvaccinated at 24 months is now over 1% and seems to be increasing. This article will review what is currently known about FWS in children aged 3 to 24 months in the modern era and how it pertains to unvaccinated children treated in the emergency department. An algorithm for the treatment of unvaccinated young children presenting with FWS is proposed.

Febrile infants without respiratory symptoms or sick contacts: are chest radiographs or RSV/influenza testing indicated?

Background

Serious bacterial infection rates in febrile infants < 60 days are about 8–11%. Less than 1% of febrile infants with no respiratory symptoms will have pneumonia however, chest radiography (CXR) rates remain between 30 and 60%. Rapid Respiratory Syncytial Virus (RSV) and influenza (flu) testing is common, however, there is not enough data to determine if febrile infants without any respiratory symptoms should be tested. The goal of this study is to determine the rate of positive CXR and RSV/flu results in febrile infants with no respiratory symptoms and no sick contacts.

Methods

Well-appearing febrile infants between 7 and 60 days of age who presented to the pediatric emergency department (PED) from September 1st, 2015 through October 30th, 2017 were enrolled. Demographic data, respiratory symptoms, CXR findings and RSV/flu results were collected. SAS statistical software was used for analysis.

Results

129 infants met enrollment criteria. Of the 129 infants, 58 (45.0%) had no respiratory symptoms and no sick contacts. Of these 58, 36 (62.1%) received a CXR and none of them had any abnormal findings, 48 (82.8%) had RSV/flu testing, no patients tested positive for RSV and only one patient tested positive for flu. Costs of CXR and RSV/flu testing for this cohort was $19,788.

Conclusion

The absence of positive CXRs in this patient population reinforces the current recommendations that CXR is not indicated. The low incidence of RSV/flu indicate that routine testing may not be necessary in this population especially outside of the flu season. Reduced testing could decrease overall costs to the healthcare system as well as radiation exposure to this population.

Enterovirus, parechovirus, adenovirus and herpes virus type 6 viraemia in fever without source

OBJECTIVES

To evaluate the potential associations between fever without a source (FWS) in children and detection of human enterovirus (HEV), human parechovirus (HPeV), adenovirus (AdV) and human herpesvirus type 6 (HHV-6) in the plasma; and to assess whether the detection of viruses in the plasma is associated with a reduced risk of serious bacterial infection (SBI) and antibiotic use.

DESIGN AND SETTING

Between November 2015 and December 2017, this prospective, single-centre, diagnostic study tested the plasma of children <3 years old with FWS. Real-time (reverse-transcription) PCR for HEV, HPeV, AdV and HHV-6 was used in addition to the standardised institutional work-up. A control cohort was also tested for the presence of viruses in their blood.

RESULTS

HEV, HPeV, AdV and HHV-6 were tested for in the plasma of 135 patients of median age 2.4 months old. At least one virus was detected in 47 of 135 (34.8%): HEV in 14.1%, HHV-6 in 11.1%, HPeV in 5.9% and AdV in 5.2%. There was no difference in antibiotic use between patients with or without virus detected, despite a relative risk of 0.2 for an SBI among patients with viraemia. Controls were less frequently viraemic than children with FWS (6.0% vs 34.8%; p<0.001).

CONCLUSIONS

HEV, HPeV, AdV and HHV-6 are frequently detected in the plasma of children with FWS. Antibiotic use was similar between viraemic and non-viraemic patients despite a lower risk of SBI among patients with viraemia. Point-of-care viral PCR testing of plasma might reduce antibiotic use and possibly investigations and admission rates in patients with FWS.

TRIAL REGISTRATION NUMBER

NCT03224026.

Testing for Urinary Tract Infection in the Influenza/Respiratory Syncytial Virus-Positive Febrile Infant Aged 2 to 12 Months

OBJECTIVE

Infants 12 months or younger with influenza and respiratory syncytial virus (RSV) commonly present to the emergency department (ED) with fever. Previous publications have recommended that these patients have a urinalysis and urine culture performed. We aimed to assess the prevalence of urinary tract infection (UTI) in febrile RSV/influenza positive infants aged 2 to 12 months presenting to the ED. We also examined whether the 2011 American Academy of Pediatrics (AAP) UTI clinical practice guidelines could be used to identify patients at lower risk of UTI.

METHODS

This was a retrospective chart review examining all infants aged 2 to 12 months with a documented fever of higher than 38°C who presented to our ED from 2009 to 2013 and tested positive for influenza and/or RSV.

RESULTS

One thousand seven hundred twenty-four patients were found to meet our inclusion criteria. Of these, 98 were excluded because of known urinary tract anomaly or systemic antibiotic use in the 24 hours preceding evaluation. Of those patients remaining, 10 (0.62%) of 1626 had positive urine cultures (95% confidence interval, 0.3%-1.1%), and 8 (0.49%) of 1626 (95% confidence interval, 0.2%-0.97%) had positive urine cultures with positive urinalyses as defined in the 2011 AAP UTI clinical practice guidelines. All subjects with positive urine cultures as defined by the AAP had risk factors for UTI that placed their risk for UTI above 1%.

CONCLUSIONS

Our population of 2- to 12-month-old febrile infants with positive influenza/RSV testing, who did not have risk factors to make their risk of UTI higher than 1%, may not have required evaluation with urinalysis or urine culture.

The Risk of Serious Bacterial Infection in Febrile Infants 0-90 Days of Life With a Respiratory Viral Infection

BACKGROUND

Molecular diagnostic methods enhance the sensitivity and broaden the spectrum of detectable respiratory viruses in febrile infants ≤90 days of life. We describe the occurrence of respiratory viruses in this population, as well as the rates of serious bacterial infection (SBI) and respiratory viral coinfection with regard to viral characteristics.

METHODS

This was a prospective observational cohort study performed in the emergency department that included previously healthy febrile infants ≤90 days of life. Clinical and historical characteristics were documented, and a respiratory nasal wash specimen was obtained from each patient. This sample was tested for 17 common respiratory pathogens, and a chart review was conducted to ascertain whether the infant was diagnosed with an SBI.

RESULTS

In a 12-month period, 67% of the 104 recruited febrile infants were positive for a respiratory virus. The most commonly detected viruses were rhinovirus, respiratory syncytial virus, enterovirus and influenza. The rate of respiratory viral and SBI coinfection was 9% overall, and infants with either a systemic respiratory virus or negative viral testing were 3 times more likely to have an SBI than those with viruses typically restricted to the respiratory mucosa (95% confidence interval: 1.1, 9.7).

CONCLUSIONS

Respiratory viruses are readily detectable via nasopharyngeal wash in febrile infants ≤90 days of life. With the enhanced sensitivity of molecular respiratory diagnostics, rates of coinfection of respiratory viruses and SBI may be higher than previously thought. Further investigation utilizing molecular diagnostics is needed to guide usage in febrile infants ≤90 days.

Epidemiology of human respiratory viruses in children with acute respiratory tract infection in a 3-year hospital-based survey in Northern Italy

Acute respiratory tract infections (ARTIs) are among the leading causes of morbidity and mortality in children. The viral etiology of ARTIs was investigated over 3 years (October 2012–September 2015) in 2575 children in Parma, Italy, using indirect immunofluorescent staining of respiratory samples for viral antigens, cell culture, and molecular assays. Respiratory viruses were detected in 1299 cases (50.44%); 1037 (79.83%) were single infections and 262 (20.17%) mixed infections. The highest infection incidence was in children aged >6 months to ≤3 years (57.36%). Human respiratory syncytial virus (27.12%) and human adenovirus (23.58%) were the most common viruses identified. The virus detection rate decreased significantly between the first and third epidemic season (53.9% vs. 43.05%, P < 0.0001). The simultaneous use of different diagnostic tools allowed us to identify a putative viral etiology in half the children examined and to provide an estimate of the epidemiology and seasonality of respiratory viruses associated with ARTIs.

•

Respiratory viruses were assessed in children from October 2012 to September 2015.

•

Viruses were detected using antigen and molecular assays, and cell culture.

•

Respiratory syncytial virus and adenovirus were the most common viruses detected.

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Influenza virus and respiratory syncytial virus detection showed seasonal variation.

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Respiratory virus detection was highest in children aged >6 months to ≤3 years.

Risk of Bacterial Coinfections in Febrile Infants 60 Days Old and Younger with Documented Viral Infections

OBJECTIVE

To determine the risk of serious bacterial infections (SBIs) in young febrile infants with and without viral infections.

STUDY DESIGN

Planned secondary analyses of a prospective observational study of febrile infants 60 days of age or younger evaluated at 1 of 26 emergency departments who did not have clinical sepsis or an identifiable site of bacterial infection. We compared patient demographics, clinical, and laboratory findings, and prevalence of SBIs between virus-positive and virus-negative infants.

RESULTS

Of the 4778 enrolled infants, 2945 (61.6%) had viral testing performed, of whom 1200 (48.1%) were virus positive; 44 of the 1200 had SBIs (3.7%; 95% CI, 2.7%-4.9%). Of the 1745 virus-negative infants, 222 had SBIs (12.7%; 95% CI, 11.2%-14.4%). Rates of specific SBIs in the virus-positive group vs the virus-negative group were: UTIs (33 of 1200 [2.8%; 95% CI, 1.9%-3.8%] vs 186 of 1745 [10.7%; 95% CI, 9.2%-12.2%]) and bacteremia (9 of 1199 [0.8%; 95% CI, 0.3%-1.4%] vs 50 of 1743 [2.9%; 95% CI, 2.1%-3.8%]). The rate of bacterial meningitis tended to be lower in the virus-positive group (0.4%) than in the viral-negative group (0.8%); the difference was not statistically significant. Negative viral status (aOR, 3.2; 95% CI, 2.3-4.6), was significantly associated with SBI in multivariable analysis.

CONCLUSIONS

Febrile infants ≤60 days of age with viral infections are at significantly lower, but non-negligible risk for SBIs, including bacteremia and bacterial meningitis.

Impact of Rapid Molecular Respiratory Virus Testing on Real-Time Decision Making in a Pediatric Emergency Department

Acute respiratory illnesses (ARIs) are usually viral [influenza, respiratory syncytial virus (RSV)] and account for 25% of emergency department (ED) peak-season visits. Laboratory PCR testing is accurate albeit slow, whereas rapid antigen testing is inaccurate. We determined the impact of bedside PCR (molecular point-of-care test; mPOCT) on pediatric ARI management. This was a prospective cohort study of consecutive pediatric patients with ED-ordered respiratory PCR test, enrolled over 9 weeks during peak flu season. On ordering, ED physicians were interviewed to ascertain real-time plans if given immediate influenza/RSV PCR results for the current patient. Two groups were compared: actual management and management adjusted for mPOCT results. We compared ED length of stay (LOS), tests ordered, and antibiotic/antiviral ordering. One-hundred thirty-six respiratory PCR panels were ordered, 71 by admitting team, 61 for ED management. Of 61 ED-initiated tests, physicians indicated in 39 cases (64%) they would change patient management were bedside viral results available. Physicians would have decreased ED LOS by 33 minutes, ordered fewer tests (18%; P < 0.001) with average patient charge savings of $669, fewer antibiotics among discharged patients (17%; P = 0.043), and increased appropriate antiviral use (13%; P = 0.023). Rapid bedside ARI mPOCT PCR has the potential to decrease ED LOS, reduce diagnostic tests and patient charges, and increase appropriate use of antibiotics and antiviral agents.

Utility of early influenza diagnosis through point-of-care testing in children presenting to an emergency department

AIM

Influenza causes a large burden of disease in children. Point-of-care testing (POCT) can rapidly diagnose influenza with the potential to reduce investigation and hospital admission rates, but information on its use in an Australian setting is limited.

METHODS

Through a retrospective review of laboratory-confirmed influenza cases presenting at a paediatric emergency department (ED) in 2009, we evaluated children diagnosed by POCT versus standard testing (direct fluorescent antibody, polymerase chain reaction or viral culture) and assessed differences in investigations, admission requirements, length-of-stay (LOS) in ED/hospital and antibiotic/antiviral prescription. The rate of serious bacterial infection was examined.

RESULTS

Compared with standard testing (n = 65), children diagnosed by positive POCT (n = 236) had a shorter median hospital LOS by 1 day (P = 0.006), increased antiviral prescription (odds ratio 3.31, P < 0.001) and a reduction in the time to influenza diagnosis (2.4 vs. 24.4 h, P < 0.001); however, a negative POCT result (n = 63) resulted in delayed diagnosis (44.0 h, P = 0.001). POCT did not decrease LOS in ED. Interpretation of reductions in admission and investigations with POCT may be limited by possible confounding. Approximately 4% of influenza patients had a serious bacterial infection; urinary tract infections were commonest (2.7%), but no cerebrospinal fluid cultures were positive. A single positive blood culture was seen among 332 immunocompetent influenza patients.

CONCLUSIONS

Influenza diagnosis by POCT was quicker and reduced LOS of hospitalised children, whereas negative results delayed diagnosis. Negative POCT should not alter usual investigations if influenza remains suspected. A controlled prospective study during the influenza season is needed to clarify the direct benefits of POCT.

Fever phobia: a comparison survey between caregivers in the inpatient ward and caregivers at the outpatient department in a children's hospital in China

BACKGROUND

Fever in children is one of the most common clinical symptoms and a chief complaint and a main reason that caregivers took the children to the outpatient service or admitted to hospital. Studies have found that the majority of parents surveyed at a hospital pediatric clinic held unrealistic and unwarranted concerns about fevers, first termed as 'fever phobia' by Schmitt in 1980. In the present study, we explore whether 'fever phobia' exists in Chinese caregivers and investigate whether such phobia is alleviated when admitted to hospital after propaganda of fever related knowledge by doctors and nurses.

METHODS

A questionnaire was distributed to caregivers of children who visited the pediatric outpatient department and those with caregivers in the wards between June 2012 and Feb 2013 in Wenzhou, China.

RESULTS

Data were obtained from 621 caregivers, 305(49%) from the OPD and 316(51%) from the ward. Most caregivers of the two groups (OPD vs. ward group, 75.1 vs. 74.4%) believed fever could cause brain damage. 77.7% (76.0 vs. 81.3%) caregivers were very worried when their children had fever and 12.8% (14.1 vs. 11.4%) caregivers would check the temperature within 30 min. Moreover, 68.0% (63.0 vs. 72.8%, P < 0.05) caregivers would give their children antipyretics during sleep and 39.9% (40.3 vs. 39.6%) would administrate antipyretics when temperature was above 38 °C. After admitted to hospital, 83.9% caregivers stated to have received education about fever and 96.5% felt relieved. Less caregivers (ward group vs. OPD, 42.4 vs. 46.9%, P < 0.05) from ward group would give antipyretics with a temperature under 38.5 °C and less (0.6 vs. 4.9%, P < 0.05) preferred cold sponging as physical cooling method compared to the OPD caregivers. Alarmingly, more caregivers (42.7 vs. 34.3%, P < 0.05) in the ward group believed fever could lead to death or/and deafness (17.4 vs. 10.5%, P < 0.05) and even 0.6% caregivers in the ward group chose aspirin when the children had fever.

CONCLUSION

'Fever phobia' also exists in Chinese caregivers. Fever related knowledge propaganda after admitted to hospital did not work effectively to improve the caregivers' understanding and management of fever and an effective way to alleviate 'Fever phobia'.

Risk of urinary tract infection in infants and children with acute bronchiolitis

OBJECTIVES:

To estimate the prevalence of urinary tract infection in infants and children with bronchiolitis.

METHODS:

A retrospective cross-sectional study involving patients zero to 24 months of age who were hospitalized with acute bronchiolitis was conducted.

RESULTS:

A total of 835 paediatric patients with acute bronchiolitis were admitted to the paediatric ward between January 2010 and December 2012. The mean (± SD) age at diagnosis was 3.47±2.99 months. There were 325 (39%) girls and 510 (61%) boys. For the purpose of data analysis, the patient population was divided into three groups: group 1 included children hospitalized with respiratory syncytial virus (RSV) bronchiolitis; group 2 included children hospitalized with clinical bronchiolitis with no virus detected; and group 3 included children hospitalized with clinical bronchiolitis due to a respiratory virus other than RSV. Results revealed that urinary tract infection was present in 10% of patients, and was most common in group 3 (13.4%) followed by group 2 (9.7%), and was least common in group 1 (6%) (P=0.030).

CONCLUSIONS:

The possibility of a urinary tract infection should be considered in a febrile child with a diagnosis of bronchiolitis, particularly if the trigger is a respiratory virus other than RSV.

Respiratory virus infections in febrile children presenting to a general practice out-of-hours service

BACKGROUND

Fever is common in young children and is assumed to be frequently caused by viral infections.

OBJECTIVES

To document respiratory viruses in children with fever presenting at a general practice out-of-hours service (OHS), evaluate presenting symptoms in febrile children with a virus infection, and examine the association between antibiotic prescription and the presence of a viral infection.

METHODS

Nasopharyngeal swabs were obtained to detect respiratory viruses in non-hospitalized children aged ≥ three months to six years presenting with fever at an OHS. Symptoms were assessed using physical examinations and questionnaires. Logistic regression analysis was used to reveal associations between symptoms or diagnoses, and the presence of at least one virus

RESULTS

In total 257 nasopharyngeal swabs were obtained in 306 eligible children; 53% of these children were infected by at least one virus. The most frequently detected viruses were adenovirus (10.9%), RSV type A (10.5%) and PIV type 1 (8.6%). Cough (OR 2.6; 95% CI: 1.4-4.6) and temperature ≥ 38.0°C (OR 2.1; 95% CI: 1.3-3.5) were independent predictors of the presence of a virus, but the discriminative ability was low (AUC 0.64; 95% CI: 0.58-0.71). Antibiotic prescription rate was 37.3%. In 57.4% of children with an antibiotic prescription, a virus was found.

CONCLUSION

In over 50% of all febrile children presenting at an OHS, a virus was found. Antibiotic prescription rate was high and not associated to the outcome of viral testing.

Evaluation of child with fever without source: review of literature and update

Fever is one of the most common reasons for a visit to the primary care provider or the emergency department. Traditionally, clinicians have used various risk-stratification strategies to identify serious bacterial infections (SBI) without an obvious source in febrile children, because missed bacterial infections in such children can result in meningitis, sepsis, and death; therefore, early and accurate identification of SBIs is critical. Infants aged less than 60 to 90 days are at greatest risk of SBI. The epidemiology of SBI continues to evolve, especially after the successful introduction of conjugate vaccines against Streptococcus pneumoniae and Haemophilus influenzae.

Impact of the availability of an influenza virus rapid antigen test on diagnostic decision making in a pediatric emergency department

OBJECTIVES

Fever is one of the most commonly seen symptoms in the pediatric emergency department. The objective of this study was to observe how the rapid testing for influenza virus impacts on the management of children with fever.

METHODS

We performed a review of our pediatric emergency department records during the 2008/2009 annual influenza season. The BinaxNow Influenza A+B test was performed on patients with the following criteria: age 1.0 to 16.0 years, fever greater than 38.5 °C, fever of less than 96 hours' duration after the onset of clinical illness, clinical signs compatible with acute influenza, and nontoxic appearance. Additional laboratory tests were performed at the treating physician's discretion.

RESULTS

The influenza rapid antigen test was performed in 192 children. One hundred nine (57%) were influenza positive, with the largest fraction (101 patients) positive for influenza A. The age distribution did not differ between children with negative and positive test results (mean, 5.3 vs. 5.1 years, not statistically significant). A larger number of diagnostic tests were performed in the group of influenza-negative patients. Twice as many complete blood counts, C-reactive protein determinations, lumbar punctures, and urinalyses were ordered in the latter group.

CONCLUSIONS

Rapid diagnosis of influenza in the pediatric emergency department affects the management of febrile children as the confirmation of influenza virus infection decreases additional diagnostic tests ordered.

Comparing the use of, and considering the need for, lumbar puncture in children with influenza or other respiratory virus infections

BACKGROUND

The clinical presentation of influenza in infancy may be similar to serious bacterial infection and be investigated with invasive procedures like lumbar puncture (LP), despite very limited evidence that influenza occurs concomitantly with bacterial meningitis, perhaps because the diagnosis of influenza is very often not established when the decision to perform LP is being considered.

METHODS

A retrospective medical record review was undertaken in all children presenting to the Children's Hospital at Westmead, Sydney, Australia, in one winter season with laboratory-confirmed influenza or other respiratory virus infections (ORVIs) but excluding respiratory syncytial virus, to compare the use of, and reflect on the need for, the performance of invasive diagnostic procedures, principally LP, but also blood culture, in influenza and non-influenza cases. We also determined the rate of concomitant bacterial meningitis or bacteraemia.

FINDINGS

Of 294 children, 51% had laboratory-confirmed influenza and 49% had ORVIs such as parainfluenza viruses (34%) and adenoviruses (15%). Of those with influenza, 18% had a LP and 71% had a blood culture performed compared with 6·3% and 55·5% in the ORVI group (for both P<0·01). In multivariate analysis, diagnosis of influenza was a strong independent predictor of both LP (P=0·02) and blood culture (P=0·05) being performed, and, in comparison with ORVIs, influenza cases were almost three times more likely to have a LP performed on presentation to hospital. One child with influenza (0·9%) had bacteraemia and none had meningitis.

INTERPRETATION

Children with influenza were more likely to undergo LP on presentation to hospital compared with those presenting with ORVIs. If influenza is confirmed on admission by near-patient testing, clinicians may be reassured and less inclined to perform LP, although if meningitis is clinically suspected, the clinician should act accordingly. We found that the risk of bacterial meningitis and bacteraemia was very low in hospitalised children with influenza and ORVIs. A systematic review should be performed to investigate this across a large number of settings.

Pediatric urinary tract infections

Urinary tract infections (UTIs) in children are commonly seen in the emergency department and pose several challenges to establishing the proper diagnosis and determining management. This article reviews pediatric UTI and addresses epidemiology, diagnosis, treatment, and imaging, and their importance to the practicing emergency medicine provider. Accurate and timely diagnosis of pediatric UTI can prevent short-term complications, such as severe pyelonephritis or sepsis, and long-term sequelae including scarring of the kidneys, hypertension, and ultimately chronic renal insufficiency and need for transplant.

Interaction between influenza virus and Streptococcus pneumoniae in severe pneumonia

The contribution of bacterial superinfection to influenza-associated pneumonia morbidity and mortality is evident from the 1918 and 1957 influenza pandemics, and is supported by a number of murine model studies. Murine model studies have also assisted in helping to expand our understanding of the pathogenesis of the interaction between the influenza virus and subsequent susceptibility to pneumococcal superinfections. The purported impact that the pneumococcal conjugate vaccine has had on reducing the burden of confirmed influenza-associated pneumonia, as well as upon all-cause clinical pneumonia, provides additional clinical evidence of the role of superimposed pneumococcal infections as a cause of severe pneumonia in children. Using this information together with the evidence for the effectiveness of influenza vaccination against influenza-associated pneumonia, it is imperative that preventive strategies for future influenza pandemic preparedness include broad-based vaccination against pneumococci, as well as ensuring that adequate antimicrobials are available for the early treatment of influenza virus, in addition to pneumococcal and other bacterial infections.

Performance of a rapid influenza test in children during the H1N1 2009 influenza a outbreak

OBJECTIVE

To evaluate the performance of a rapid influenza diagnostic test (RIDT) in detecting H1N1 2009 influenza A virus in respiratory samples from pediatric patients in comparison to that of real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) and viral culture. Methodology. This was a cross-sectional diagnostic-accuracy study conducted at a tertiary care children's hospital. Patients for whom the RIDT (BinaxNOW [Binax, Inc, Portland, ME]), viral culture, and rRT-PCR results were known were included. Sensitivity, specificity, and likelihood ratios (LRs) were calculated.

RESULTS

A total of 3030 specimens had RIDT results paired with both rRT-PCR and viral culture results. With rRT-PCR as the reference, overall test sensitivity was 45% (95% confidence interval [CI]: 43.3%-46.3%) and specificity was 98.6% (95% CI: 98.1%-99%). Positive and negative LRs were 32.9 (95% CI: 22.9-45.4) and 0.56 (95% CI: 0.54-0.58), respectively. RIDT sensitivity was significantly higher in young infants and children younger than 2 years than in older children. Using viral culture as the reference standard, RIDT sensitivity was 55.5% (95% CI: 51.9%-95.6%) and specificity was 95.6% (95% CI: 95%-96.1%). The positive and negative LRs were 12.6 and 0.47, respectively.

CONCLUSIONS

The RIDT had relatively poor sensitivity but excellent specificity in this consecutive series of respiratory specimens obtained from pediatric patients. Although a positive RIDT result was highly accurate in predicting infection with influenza type A H1N1 2009 in children, a negative RIDT result did not preclude a child having H1N1. Therefore, for children at high risk with influenza-like illnesses during high-prevalence periods of influenza, empiric initiation of antiviral therapy should be considered for patients with a negative RIDT result.

Antigen-based assays for the identification of influenza virus and respiratory syncytial virus: why and how to use them in pediatric practice

This article describes the clinical and socioeconomic relevance of influenza (IV) and respiratory syncytial virus (RSV) in pediatrics, the characteristics and limitations of currently available assays, and the impact of rapid diagnostic tests. This article shows that rapid tests for the detection and identification of IV and RSV in the respiratory secretions of infants and children are useful in the diagnosis of common, and possibly severe diseases, such as influenza and bronchiolitis. The tests' specificity and sensitivity make them most reliable when the prevalence of influenza or RSV infection is high, which suggests that their routine use should be restricted to the peak periods of viral circulation. The most recently marketed tests are similarly effective in identifying viruses, and so pediatricians should choose those that are less expensive, less time consuming, and easier to perform and to interpret.

Comparison of polyurethane foam to nylon flocked swabs for collection of secretions from the anterior nares in performance of a rapid influenza virus antigen test in a pediatric emergency department

Rapid antigen testing of upper respiratory secretions collected with various swab types is often utilized for laboratory diagnoses of influenza virus infection. There are limited data on the effects of swab composition on test performance. This study compared the performance of the Quidel QuickVue Influenza A+B test on secretions from the anterior nares when a polyurethane foam swab was used for collection to that when a nylon flocked swab was used for collection. One hundred subjects who presented to a pediatric emergency department with symptoms suggestive of an influenza virus infection were recruited for the study. Foam and flocked swabs of the anterior nares were obtained from separate nares of each subject before a posterior nasopharyngeal swab was collected and placed into viral transport medium. The QuickVue test was performed directly on each swab type, and the results were compared to the results of reverse transcription-PCR (RT-PCR), direct fluorescent antibody (DFA) test, and viral culture performed on the transport medium. RT-PCR alone and DFA combined with culture were utilized as separate gold standards. There were 56 cases of influenza detected by RT-PCR; the QuickVue test was positive for 40 foam and 30 flocked swabs, for sensitivities of 71% and 54%, respectively (P = 0.01). Similarly, there were 49 influenza cases detected by DFA and/or culture; the QuickVue test was positive for 38 foam and 30 flocked swabs, for sensitivities of 78% and 61%, respectively (P = 0.13). This study suggests that polyurethane foam swabs perform better than nylon flocked swabs for the collection of secretions from anterior nares in the Quidel QuickVue Influenza A+B test.

Influenza virus infection in infants less than three months of age

OBJECTIVE

We evaluated the presentation, outcomes, and the risk of serious bacterial infection (SBI) in infants <3 months old with influenza virus infection.

PATIENTS AND METHODS

We identified demographic, hospitalization, and microbiologic data from computerized medical records for all infants and children <24 months of age, with laboratory confirmed influenza infection cared for at a tertiary care children's hospital during 4 winter seasons (2004-2008). We compared those <3 months of age with older groups.

RESULTS

We identified 833 children <24 months of age with laboratory-confirmed influenza. Of those, 218 were <3 months old. Influenza accounted for 3.6% of all evaluations of febrile infants and 12% of febrile infant encounters during winter. Infants <3 months of age were less likely to have a high risk chronic medical condition, but were more likely to be hospitalized than children 3 to <24 months old (P < 0.005). Infants <3 months with influenza had fewer prolonged hospital stays than those 3 to <6 months old [P = 0.056; OR: 0.5 (0.24-1.0)] and 6 to <12 months old [P = 0.011; OR: 0.43 (0.24-0.83)]. Five (2.3%) infants <3 months old had SBI.

CONCLUSIONS

Infants <3 months of age with influenza virus infection often present with fever alone. Although they are more likely to be hospitalized than those 3 to <24 months old, hospital stays are short and outcomes generally good. Infants with influenza virus infection have a low risk of concomitant SBI.

Rapid influenza test in young febrile infants for the identification of low-risk patients

We included 381 febrile infants less than 3 months with a blood culture and a rapid influenza test done as part of study of fever. The prevalence of serious bacterial infections was significantly lower in patients in the positive rapid influenza test (RIT) group (3/113; 2.65%; 95% CI: 0-5.6) than in patients in the negative RIT group (47/268; 17.5%; 95% CI: 13-22.0). No patient with a positive RIT had a positive blood culture (vs. 8 in the negative RIT group, 2.98%, 95% CI: 0.9-5.0) The cerebrospinal fluid culture was positive in 5; all of them had a negative RIT. The use of RIT in the Emergency Department on previously well-appearing febrile young infants without a known source during influenza seasons can help to identify infants with a lower risk of developing serious bacterial infections. Routine blood culture may be no longer necessary in infants with a positive RIT.

Influenza virus infection and the risk of serious bacterial infections in young febrile infants

OBJECTIVE

We aimed to determine the risk of SBIs in febrile infants with influenza virus infections and compare this risk with that of febrile infants without influenza infections.

PATIENTS AND METHODS

We conducted a multicenter, prospective, cross-sectional study during 3 consecutive influenza seasons. All febrile infants <or=60 days of age evaluated at any of 5 participating pediatric EDs between October and March of 1998 through 2001 were eligible. We determined influenza virus status by rapid antigen detection. We evaluated infants with blood, urine, cerebrospinal fluid, and stool cultures. Urinary tract infection (UTI) was defined by single-pathogen growth of either >or=5 x 10(4) colony-forming units per mL or >or=10(4) colony-forming units per mL in association with a positive urinalysis. Bacteremia, bacterial meningitis, and bacterial enteritis were defined by growth of a known bacterial pathogen. SBI was defined as any of the 4 above-mentioned bacterial infections.

RESULTS

During the 3-year study period, 1091 infants were enrolled. A total of 844 (77.4%) infants were tested for the influenza virus, of whom 123 (14.3%) tested positive. SBI status was determined in 809 (95.9%) of the 844 infants. Overall, 95 (11.7%) of the 809 infants tested for influenza virus had an SBI. Infants with influenza infections had a significantly lower prevalence of SBI (2.5%) and UTI (2.4%) when compared with infants who tested negative for the influenza virus. Although there were no cases of bacteremia, meningitis, or enteritis in the influenza-positive group, the differences between the 2 groups for these individual infections were not statistically significant.

CONCLUSIONS

Febrile infants <or=60 days of age with influenza infections are at significantly lower risk of SBIs than febrile infants who are influenza-negative. Nevertheless, the rate of UTI remains appreciable in febrile, influenza-positive infants.

A randomized, controlled trial of the impact of early and rapid diagnosis of viral infections in children brought to an emergency department with febrile respiratory tract illnesses

OBJECTIVES

Acute respiratory tract infections represent a significant burden on pediatric emergency departments (ED) and families. We hypothesized that early and rapid diagnosis of a viral infection alleviates the need for ancillary testing and antibiotic treatment.

STUDY DESIGN

We conducted a randomized, controlled trial of children 3 to 36 months of age with febrile acute respiratory tract infections at a pediatric ED. Two hundred four subjects were randomly assigned to receive rapid respiratory viral testing on admission or a routine ED admission protocol. Outcome measures were: mean length of visits, rate of ancillary tests, and antibiotic prescription in the ED. A follow-up call was made to all study subjects to inquire about further healthcare visits, ancillary testing, and antibiotic prescription after ED discharge.

RESULTS

We did not find a statistically significant difference in ED length of visits, rate of ancillary testing, or antibiotic prescription rate in the ED between the study groups. There was, however, a significant reduction in antibiotic prescription after ED discharge (in the group who had rapid viral testing RR = 0.36; 95% CI = 0.14, 0.95).

CONCLUSIONS

Rapid multi-viral testing in the ED did not significantly affect ED patient treatment but may reduce antibiotic prescription in the community after discharge from the ED, suggesting a novel strategy to alter community physician antibiotic prescription patterns.

The evolving approach to the young child who has fever and no obvious source

Fever is a common complaint of young children who seek care in the emergency department. Recent advances, such as universal vaccination with the pneumococcal conjugate vaccine, require the review of traditional approaches to these patients. This article discusses newer strategies in the evaluation and management of the young child with fever, incorporating changes based on the shifting epidemiology of bacterial infection.

Sudden death in toddlers with viral meningitis, massive cerebral edema, and neurogenic pulmonary edema and hemorrhage: report of two cases

Viral (lymphocytic) meningitis typically does not cause sudden death, especially in the absence of severe inflammation in the brain or other organs. We report 2 toddlers with clinical evidence of a viral infection who died unexpectedly and were found at autopsy to have lymphocytic meningitis associated with severe brain edema, transtentorial herniation, neurogenic pulmonary edema and hemorrhage, and cardiomegaly. Influenza A virus, demonstrated in tracheal epithelium by immunocytochemistry, is the presumed cause of the mild meningitis in 1 case; adenovirus was cultured from swabs of the brain and anus in the 2nd case. Current concepts of neurogenic pulmonary edema and acute cardiac dysfunction associated with intracranial disease are discussed in considering the mechanism of sudden death in these toddlers. These cases emphasize the possibility that mild intracranial viral infections may be a rare cause of sudden death via lethal cardiopulmonary complications. They also underscore the importance of a comprehensive autopsy, including detailed neuropathologic examination and viral testing, in determining of the cause of unexpected death in toddlers.

Respiratory infections for which general practitioners consider prescribing an antibiotic: a prospective study

OBJECTIVE

To determine the viral aetiology of respiratory infections in children presenting to primary care with "more than a simple cold".

DESIGN

Observational study in 18 Oxfordshire general practices over four winters (2000-01 to 2003-04).

PATIENTS

425 children aged 6 months to 12 years with cough and fever for whom general practitioners considered prescribing an antibiotic.

METHODS

Nasopharyngeal aspirate obtained from 408 (96%) children was subjected to PCR for respiratory viruses. Parents completed an illness diary for the duration of illness.

RESULTS

A viral cause of infection was detected in most (77%) children. Clinical symptoms correctly identified the infecting virus in 45% of cases. The duration of illness was short and the time course was very similar for all infecting viruses. One third of children were prescribed an antibiotic (34%), but this made no difference to the rate of parent-assessed recovery (Kruskal-Wallis, p = 0.67). About one in five children with influenza who did not receive an antibiotic had persistent fever on day 7 compared to no children receiving antibiotics (p = 0.02); this difference remained after adjustment for severity and other factors and was not seen with other viruses.

CONCLUSIONS

Most children receiving antibiotics for respiratory symptoms in general practice have an identifiable viral illness. In routine clinical practice, neither the specific infecting virus nor the use of antibiotics has a significant effect on the time course of illness. Antibiotics may reduce the duration of fever in children with influenza which could reflect an increased risk of secondary bacterial infection for such children.

Impact des tests de diagnostic rapide en ville dans la prise en charge des enfants en période de grippe

Several studies in children showed at the paediatric emergency hospital the interest of influenza rapid diagnostic tests (IRDT) in this disease for which the clinical diagnosis is difficult in children. The purpose of this prospective study carried out in ambulatory paediatric setting was to evaluate impact of the IRDT in the assumption of responsibility of children suspected of Influenza infection. Thirty paediatricians (14 without IRDT, 16 with IRDT) included 602 children between 2004 and 2005. The influenza was confirmed by IRDT in 54% of the cases. Among the 13 symptoms or signs recorded, only 4 - chills (61.6 vs 48.4%), cough (89.8 vs 71.1%), rhinorrhea (97.9 vs 86.2%), and anorexia (50.3 vs 34.8%) - were significantly more frequent (P </= 0.01) for patients avec with positive IRDT. However, the difference is not sufficient to be contributive. The paediatricians using IRDT prescribed with positive test more oseltamivir (68.5 vs 1.9%, P < 0.0001). The antibiotic prescription was overall low (9.5% with IRDT vs 3.9% without IRDT, P = 0,008), and primarily when the result of IRDT was negative (15.7% if IRDT(-) vs 4.3% if IRDT(+), P = 0.0003). This study confirms the difficulty of clinical diagnosis, and shows the interest of IRDT for the diagnosis of influenza and consequently to improve the management of influenza in children in ambulatory paediatric setting.

Leukocyte counts in urine reflect the risk of concomitant sepsis in bacteriuric infants: a retrospective cohort study

BACKGROUND

When urine infections are missed in febrile young infants with normal urinalysis, clinicians may worry about the risk--hitherto unverified--of concomitant invasion of blood and cerebrospinal fluid by uropathogens. In this study, we determine the extent of this risk.

METHODS

In a retrospective cohort study of febrile 0-89 day old infants evaluated for sepsis in an urban academic pediatric emergency department (1993-1999), we estimated rates of bacteriuric sepsis (urinary tract infections complicated by sepsis) after stratifying infants by urine leukocyte counts higher, or lower than 10 cells/hpf. We compared the global accuracy of leukocytes in urine, leukocytes in peripheral blood, body temperature, and age for predicting bacteruric sepsis. The global accuracy of each test was estimated by calculating the area under its receiver operating characteristic curve (AUC). Chi-square and Fisher exact tests compared count data. Medians for data not normally distributed were compared by the Kruskal-Wallis test.

RESULTS

Two thousand two hundred forty-nine young infants had a normal screening dipstick. None of these developed bacteremia or meningitis despite positive urine culture in 41 (1.8%). Of 1516 additional urine specimens sent for formal urinalysis, 1279 had 0-9 leukocytes/hpf. Urine pathogens were isolated less commonly (6% vs. 76%) and at lower concentrations in infants with few, compared to many urine leukocytes. Urine leukocytes (AUC: 0.94) were the most accurate predictors of bacteruric sepsis. Infants with urinary leukocytes < 10 cells/hpf were significantly less likely (0%; CI:0-0.3%) than those with higher leukocyte counts (5%; CI:2.6-8.7%) to have urinary tract infections complicated by bacteremia (N = 11) or bacterial meningitis (N = 1)--relative risk, 0 (CI:0-0.06) [RR, 0 (CI: 0-0.02), when including infants with negative dipstick]. Bands in peripheral blood had modest value for detecting bacteriuric sepsis (AUC: 0.78). Cases of sepsis without concomitant bacteriuria were comparatively rare (0.8%) and equally common in febrile young infants with low and high concentrations of urine leukocytes.

CONCLUSION

In young infants evaluated for fever, leukocytes in urine reflect the likelihood of bacteriuric sepsis. Infants with urinary tract infections missed because of few leukocytes in urine are at relatively low risk of invasive bacterial sepsis by pathogens isolated from urine.

Accuracy and interpretation of rapid influenza tests in children

BACKGROUND

Influenza rapid antigen detection (rapid tests) can provide timely identification of infection and aid in clinical decision-making. Although the interpretation of test results depends on test characteristics and influenza prevalence, this information is limited in routine clinical practice.

OBJECTIVE

We sought to assess the times at which rapid tests are most predictive of influenza infection.

METHODS

The New Vaccine Surveillance Network enrolled children aged < 5 years who were hospitalized with respiratory symptoms or fever from October 2000 through September 2004. Nasal and throat swabs were obtained, and influenza virus was detected by culture and reverse-transcription polymerase chain reaction. Provider-ordered rapid influenza tests were compared with the criterion standard (culture and reverse-transcription polymerase chain reaction) to determine their sensitivity and specificity. The New Vaccine Surveillance Network also enrolled children in outpatient settings during the 2002-2003 and 2003-2004 influenza seasons and determined the weekly influenza prevalence among symptomatic children. Trends in weekly predictive values of the rapid tests were estimated over the influenza seasons.

RESULTS

Rapid influenza tests had an overall sensitivity of 63% and specificity of 97%. In 2002-2003, the prevalence of influenza in symptomatic outpatient children peaked at 21% and stayed above 10% for approximately 4 weeks. In contrast, in 2003-2004, influenza prevalence peaked at 60% and remained above 20% for approximately 6 weeks. The positive predictive value of the rapid tests approached 80% when influenza prevalence was > or = 15% but decreased to < 70% when influenza prevalence was < 10%.

CONCLUSIONS

Influenza prevalence varies between and within seasons. On the basis of our estimates, rapid tests are of limited use when prevalence is < 10%. The appropriate interpretation of rapid influenza tests requires local influenza surveillance and timely communication of this information to the practitioners.

Impact of rapid viral testing for influenza A and B viruses on management of febrile infants without signs of focal infection

BACKGROUND

The objective of this study was to assess the effect of rapid testing for influenza virus on management of febrile young infants.

METHODS

During 2 influenza seasons (November to December 2003 and December 2004 to February 2005), we studied prospectively infants who were 0 to 36 months of age who presented to the emergency department (ED) with fever in the absence of signs of focal infection. The Directigen Flu A+B test was used to determine infection with influenza virus types A or B. Confirmatory viral cultures were not done.

RESULTS

Rapid influenza testing was performed in 206 infants and 84 (40.7%) of them were influenza-positive. Infants with a positive and a negative influenza test showed a similar mean (standard deviation) age (6.86 [6.3] versus 6.55 [6.8] months) and mean temperature (39.38 degrees C [0.6] versus 39.32 degrees C [0.8]), but there were significant differences (P < 0.01) in the percentage of patients undergoing blood tests (33.3% versus 100%), urinalysis (80.9% versus 100%), chest roentgenogram (14.2% versus 32%), cerebrospinal fluid analysis (1.33% versus 21.3%), mean length of stay in the ED (116.2 [75.5] versus 192.9 [76.3] minutes), admission to the ED observation ward (8.3% versus 21.3%), inpatient care (2.3% versus 16.4%) and antibiotic treatment (0% versus 38.5%). All positive bacterial cultures occurred among influenza-negative patients.

CONCLUSIONS

The inclusion of rapid influenza testing for the evaluation of febrile young infants without signs of focal infection during influenza season decreases the need for additional studies and reduces the length of stay in the ED, the use of antibiotic treatment and unnecessary hospitalizations.

Effect of point-of-care influenza testing on management of febrile children

OBJECTIVES

To determine the effect of point-of-care testing (POCT) for influenza on the physician management of febrile children who are at risk for serious bacterial illness (SBI) on the basis of age and temperature and who are presenting to a pediatric emergency department (ED) during an influenza outbreak.

METHODS

Patients 2-3 months of age with temperature of > or = 38 degrees C and patients 3-24 months of age with temperature of > or = 39 degrees C who were presenting to a pediatric ED during an influenza outbreak were enrolled into a prospective, quasi-randomized, controlled trial. Influenza testing was performed on enrolled patients by either the POCT or the standard-testing (ST) methods. The two groups were compared in terms of laboratory testing, chest radiography, antibiotic use, visit-associated costs, pediatric ED lengths of stay, inpatient admission, and return visits to the pediatric ED. Similar analyses also were performed on the resulting subgroups of patients on the basis of method of testing (POCT or ST) and test result (positive or negative).

RESULTS

Of 767 eligible patients, 700 (91%) completed the study. No significant differences were demonstrated between the POCT and ST groups with respect to laboratory tests ordered, chest radiographs obtained, antibiotic administration, inpatient admission, return visits to the pediatric ED, lengths of stay, or visit-associated costs. In the subgroup analysis, the adjusted odds ratios (ORs) for blood culture in influenza test-positive to -negative patients were 0.59 and 0.71 in the POCT and ST groups, respectively (p = 0.088). The adjusted ORs for urine culture in influenza test-positive to -negative patients were 0.46 and 0.67 in the POCT and ST groups, respectively (p = 0.005).

CONCLUSIONS

When using a strategy of performing influenza testing on all patients at risk for SBI who presented to a pediatric ED during an influenza outbreak, the method of testing (POCT or ST) did not appear to significantly alter physician management, cost, or length of stay in the pediatric ED. However, if the interaction of the method of testing and the test result (positive or negative) were considered, a positive POCT for influenza was associated with a significant reduction in orders for urinalyses and urine cultures.

Prospective evaluation of the risk of serious bacterial infection in children who present to the emergency department with hyperpyrexia (temperature of 106 degrees F or higher)

BACKGROUND

Previous studies of children with temperatures > or = 106 degrees F (hyperpyrexia) disagree as to whether hyperpyrexia confers a high risk of serious bacterial infection.

OBJECTIVES

The purpose of this study was to determine (1) the risk of serious bacterial infection in children with hyperpyrexia and (2) whether clinical presentation can identify hyperpyrexic patients at risk for serious bacterial infection.

METHODS

Data were collected prospectively on all children <18 years of age presenting to a pediatric emergency department during a 2-year period with rectal temperatures of > or = 106 degrees F. History, physical examination, complete blood cell counts, blood cultures, and nasopharyngeal viral cultures were obtained on all of the patients.

RESULTS

Of 130828 visits, 103 children had hyperpyrexia (1 per 1270 patient visits). Of the 103 subjects, 20 had serious bacterial infection, and 22 had laboratory-proven viral illness (including 1 subject with bacterial/viral coinfection). The presence of a chronic underlying illness was associated with an increased risk of serious bacterial infection. The presence of rhinorrhea or any viral symptom was associated with a decreased risk of serious bacterial infection, although diarrhea itself was associated with an increased risk of serious bacterial infection. Age, maximum temperature, and total white blood cell count were not predictive of either bacterial or viral illness.

CONCLUSIONS

Children with hyperpyrexia are at equally high risk for serious bacterial infection and for viral illness. Bacterial and viral coinfection also occurs. No aspect of the clinical presentation reliably distinguishes between bacterial and viral illness. We recommend consideration of antibiotic treatment for all children presenting to the emergency department with hyperpyrexia without confirmed viral illness.

Fever without source in children 0 to 36 months of age

Although fever in the young child (0-36 months) is a common clinical problem, the evaluation and treatment of febrile children remain controversial. Furthermore, universal vaccination with the heptavalent pneumococcal conjugate vaccine (PCV7) has changed the epidemiology of invasive bacterial disease in young children. This article addresses the approach to febrile neonates (0-28 days old), young infants (1-3 months old), and older infants and toddlers (3-36 months old) in the PCV7 era.

Performance characteristics of a rapid immunochromatographic assay for detection of influenza virus in children during the 2003 to 2004 influenza season

STUDY OBJECTIVE

We evaluate the performance of a rapid assay (Binax NOW) for the detection of influenza A virus in children.

METHODS

The performance of an in vitro rapid immunochromatographic assay for detection of influenza A virus was compared to viral culture in 4,383 consecutive respiratory specimens received during the 2003 to 2004 season, which included an influenza A epidemic in October and November of 2003.

RESULTS

The overall test sensitivity was 61.6% (95% confidence interval [CI] 60.3% to 63.2%) and specificity was 95.8% (95% CI 95.1% to 96.3%). In preplanned subset analyses, we found the test more sensitive in infants aged 90 days or younger (sensitivity 70.3%; specificity 96.6%) and less specific during the epidemic (sensitivity 61.7%; specificity 90.4%).

CONCLUSION

This rapid assay was highly specific for detecting influenza A in children and thus appears useful for confirming this infection. Because of its limited sensitivity, however, a negative test cannot rule out influenza A.

Rapid viral testing in the evaluation of the febrile infant and child

PURPOSE OF REVIEW

This review focuses on rapid viral testing in the febrile infant and child. Recent literature is reviewed regarding physician decision making, antibiotic use, ancillary testing use, and rate of serious bacterial infections concurrent with viral disease.

RECENT FINDINGS

Two recent studies detail the use of rapid testing of influenza. The impact on the use of ancillary testing and antibiotic prescribing practices based on the knowledge provided by rapid viral testing has been evaluated. Physician awareness of a rapid diagnosis of influenza significantly reduced the number of laboratory tests and radiographs ordered and their associated charges, decreased antibiotic use, increased antiviral use, and decreased length of time to discharge. The rate of serious bacterial infections coexisting with influenza illness has also been studied. Researchers concluded that the prevalence of serious bacterial infections is lower in febrile children with influenza A infection. Another two studies evaluated respiratory syncytial virus-positive febrile infants and their risk of serious bacterial infection. Both studies independently noted that febrile infants with respiratory syncytial virus infections are at significantly lower risk of serious bacterial infection than febrile infants without respiratory syncytial virus infection. The rate of urinary tract infections remained significant in febrile respiratory syncytial virus-positive infants, however.

SUMMARY

Various studies have documented the impact of rapid viral testing in the evaluation and management of febrile infants and children. There is insufficient evidence to change current clinical practice algorithms for young febrile infants and children. Continued research will affect future guidelines and algorithms in the management of febrile infants and children.