Diagnostic Accuracy of a Real-Time Host-Protein Test for Infection

OBJECTIVE

Determining infection etiology can be difficult because viral and bacterial diseases often manifest similarly. A host protein test that computationally integrates the circulating levels of TNF-related apoptosis-induced ligand, interferon γ-induced protein-10, and C-reactive protein to differentiate between bacterial and viral infection (called MMBV) demonstrated high performance in multiple prospective clinical validation studies. Here, MMBV's diagnostic accuracy is evaluated in febrile children for whom physicians were uncertain about etiology when applied at the physician's discretion.

METHODS

Patients aged 3 months to 18 years were retrospectively recruited (NCT03075111; SPIRIT study; 2014-2017). Emergency department physician's etiological suspicion and certainty level were recorded in a questionnaire at blood-draw. MMBV results are based on predefined score thresholds: viral/non-bacterial etiology (0 ≤ score <35), equivocal (35 ≤ score ≤65), and bacterial or coinfection (65 < score ≤100). Reference standard etiology (bacterial/viral/indeterminate) was adjudicated by 3 independent experts based on all available patient data. Experts were blinded to MMBV. MMBV and physician's etiological suspicion were assessed against the reference standard.

RESULTS

Of 3003 potentially eligible patients, the physicians were uncertain about infection etiology for 736 of the cases assigned a reference standard (128 bacterial, 608 viral). MMBV performed with sensitivity 89.7% (96/107; 95% confidence interval 82.4-94.3) and specificity 92.6% (498/538; 95% confidence interval 90.0-94.5), significantly outperforming physician's etiological suspicion (sensitivity 49/74 = 66.2%, specificity 265/368 = 72.0%; P < .0001). MMBV equivocal rate was 12.4% (91/736).

CONCLUSIONS

MMBV was more accurate in determining etiology compared with physician's suspicion and had high sensitivity and specificity according to the reference standard.

Paediatric hospital visit with laboratory-confirmed influenza improved family members' influenza vaccination

OBJECTIVES

Vaccination is the primary intervention to prevent influenza infection, yet vaccine uptake remains low among children and other at-risk patients. The aim of the study is to investigate the impact of a paediatric hospital visit with laboratory-confirmed influenza on the influenza vaccination behaviour of participants and their family members in the subsequent influenza season.

METHODS

This study compared the influenza vaccination coverage for participants < 18 years of age with a clinical suspicion of influenza in 2017-2018 during a hospital visit, in two subsequent influenza seasons. Data was retrieved from the hospital electronic medical record and a follow-up questionnaire (2018-2019) to ascertain the common reason(s) that families did not vaccinate their children the following year (2018-2019). The children were distributed into positive- (antigen and/or PCR) and negative-influenza groups.

RESULTS

A total of 133 children were enrolled in our study. Participants' mean age was 4.6 years and 74 (55.6%) were males. Overall, 47 (35.3%) had confirmed influenza virus. A significant increase in influenza immunization was found among both positive- and negative-influenza participants between 2017-2018 and 2018-2019 (6.4% vs. 27.7%, p < 0.001; 8.1% vs. 29.1%, p < 0.001, respectively), as well as among family members of positive-influenza participants - siblings and parents (6.4% vs. 19.6%, p = 0.003; 0% vs. 17%, p < 0.001, respectively). Common reasons for failure to vaccinate included doubt in vaccine effectiveness, unlikely to get "flu", busy, and side effects.

CONCLUSIONS

Our findings suggest that a paediatric hospital visit with laboratory-confirmed influenza increases vaccine uptake among families. Future studies should aim to evaluate evidence-based interventions to improve influenza vaccine uptake among children.

Association of viral load with TRAIL, IP-10, CRP biomarker signature and disease severity in children with respiratory tract infection or fever without source: A prospective, multicentre cohort study

BACKGROUND

To investigate the association of viral load (VL) with (i) tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), interferon gamma-induced protein-10, C-reactive protein, and a combinatorial score (BV score), and (ii) clinical severity.

STUDY DESIGN

In this prospective, multicentre cohort substudy, children with respiratory tract infection or fever without source were enrolled. VL for influenza virus, rhinovirus, respiratory syncytial virus, and adenovirus was measured from nasopharyngeal swabs. The reference standard diagnosis was established based on expert panel adjudication.

RESULTS

Of 1140 recruited patients, 333 had a virus monodetection. VL for the aggregated data set correlated with TRAIL and IP-10 levels, with the length of oxygen therapy, and inversely with the BV score. At a single viral level, only the influenza VL yielded a correlation with TRAIL, IP-10 levels, and the BV score. Children with a viral reference standard diagnosis had significantly higher VL than those with bacterial infection (p = 0.0005). Low TRAIL (incidence rate ratio [IRR] 0.6, 95% confidence interval [CI] 0.39-0.91) and young age (IRR 0.62, 95% CI 0.49-0.79) were associated with a longer hospital stay, while young age (IRR 0.33, 95% CI 0.18-0.61), low TRAIL (IRR 0.25, 95% CI 0.08-0.76), and high VL (IRR 1.16, 95% CI 1.00-1.33) were predictive of longer oxygen therapy.

CONCLUSION

These findings indicate that VL correlates with biomarkers and may serve as a complementary tool pertaining to disease severity.

Impact of rotavirus vaccine implementation on Israeli children: a comparison between pre- and post-vaccination era

BACKGROUND

Worldwide rotavirus vaccination has resulted in a substantial decrease in rotavirus-induced severe gastroenteritis and related hospitalizations among children. Still, the characterization of patients warranting hospitalization needs to be further elucidated. The purpose of the study is to compare the clinical and laboratory features of children hospitalized with acute rotavirus infection before and after the introduction of routine vaccination.

METHODS

This is a retrospective observational study. Participants were pediatric patients who presented to the Bnai Zion Medical Center pediatric emergency department and were diagnosed with rotavirus acute gastroenteritis between 2017 and 2019.

RESULTS

During the pre-vaccination period (2007-2009), 114 infants and young children (median age: 14 months, range: 1-72 months; 59 male, 55 female) were hospitalized for rotavirus-induced acute gastroenteritis with a rate of 11.71 positive rotavirus tests per 1000 emergency room visits. In the post-vaccination period (2012-2019), 168 infants and young children (median age: 17 months, range: 0-84 months; 90 male, 78 female) were hospitalized with a rate of 4.18 positive rotavirus tests per 1000 emergency room visits. There were no statistical differences between the two groups in gender, breast-feeding rates and sibling(s). The proportion of cases with moderate-to-severe dehydration was higher in the post-vaccination children than in the pre-vaccination children.

CONCLUSIONS

Rates of rotavirus-attributed acute gastroenteritis hospitalizations declined from the pre- to the post-vaccination period. Higher rates of dehydration were found in the post-vaccination children. Ongoing surveillance is warranted to better understand the implications of the vaccine.

The diagnostic value of nasal microbiota and clinical parameters in a multi-parametric prediction model to differentiate bacterial versus viral infections in lower respiratory tract infections

Background

The ability to accurately distinguish bacterial from viral infection would help clinicians better target antimicrobial therapy during suspected lower respiratory tract infections (LRTI). Although technological developments make it feasible to rapidly generate patient-specific microbiota profiles, evidence is required to show the clinical value of using microbiota data for infection diagnosis. In this study, we investigated whether adding nasal cavity microbiota profiles to readily available clinical information could improve machine learning classifiers to distinguish bacterial from viral infection in patients with LRTI.

Results

Various multi-parametric Random Forests classifiers were evaluated on the clinical and microbiota data of 293 LRTI patients for their prediction accuracies to differentiate bacterial from viral infection. The most predictive variable was C-reactive protein (CRP). We observed a marginal prediction improvement when 7 most prevalent nasal microbiota genera were added to the CRP model. In contrast, adding three clinical variables, absolute neutrophil count, consolidation on X-ray, and age group to the CRP model significantly improved the prediction. The best model correctly predicted 85% of the ‘bacterial’ patients and 82% of the ‘viral’ patients using 13 clinical and 3 nasal cavity microbiota genera (Staphylococcus, Moraxella, and Streptococcus).

Conclusions

We developed high-accuracy multi-parametric machine learning classifiers to differentiate bacterial from viral infections in LRTI patients of various ages. We demonstrated the predictive value of four easy-to-collect clinical variables which facilitate personalized and accurate clinical decision-making. We observed that nasal cavity microbiota correlate with the clinical variables and thus may not add significant value to diagnostic algorithms that aim to differentiate bacterial from viral infections.

BV score differentiates viral from bacterial-viral co-infection in adenovirus PCR positive children

BACKGROUND AND OBJECTIVES

Adenovirus causes acute respiratory illness that can mimic bacterial infection, making it challenging to differentiate adenoviral infection from adenoviral-bacterial co-infection. A host-protein score (BV score) for differentiating bacterial from viral infection that combines the expression levels of TNF-related apoptosis-induced ligand, interferon gamma-induced protein-10, and C-reactive protein exhibited a negative predictive value (NPV) of 98% in prior studies. Here we evaluate BV score's diagnostic accuracy in pediatrics with adenovirus PCR detection.

METHODS

This is a sub-analysis of children aged 3 months to 20 years with adenovirus PCR-positive infection recruited prospectively in two previous cohort studies. Reference standard diagnosis (bacterial, viral or indeterminate) was based on expert adjudication. BV score ranges from 0 to 100 and provides three results based on predefined cutoffs: viral or other non-bacterial etiology (0 ≤ score < 35), equivocal (35 ≤ score ≤ 65), and bacterial or co-infection (65 < score ≤ 100). Experts were blinded to BV results.

RESULTS

Out of 1,779 children, 142 had an adenovirus PCR-positive nasopharyngeal swab. Median age was 1.2 years (interquartile range 0.6-1.8), 50.7% were male and 52.8% were hospitalized. 12 cases were reference standard bacterial, 115 reference standard viral and 15 were indeterminate. BV score attained sensitivity of 100.0% (no false negatives), specificity of 89.5% (95% confidence interval: 83.2-95.8), and NPV of 100.0% (92.6-100.0). Equivocal rate was 19.7%.

CONCLUSIONS

BV score accurately differentiated between adenoviral and bacterial-adenoviral co-infection in this cohort of children with PCR-positive adenovirus detection. This performance supports a potential to improve appropriate antibiotic use.

A host signature based on TRAIL, IP-10, and CRP for reducing antibiotic overuse in children by differentiating bacterial from viral infections: a prospective, multicentre cohort study

OBJECTIVES

Identifying infection aetiology is essential for appropriate antibiotic use. Previous studies have shown that a host-protein signature consisting of TNF-related apoptosis-induced ligand (TRAIL), interferon-γ-induced protein-10 (IP-10), and C-reactive protein (CRP) can accurately differentiate bacterial from viral infections.

METHODS

This prospective, multicentre cohort study, entitled AutoPilot-Dx, aimed to validate signature performance and to estimate its potential impact on antibiotic use across a broad paediatric population (>90 days to 18 years) with respiratory tract infections, or fever without source, at emergency departments and wards in Italy and Germany. Infection aetiology was adjudicated by experts based on clinical and laboratory investigations, including multiplex PCR and follow-up data.

RESULTS

In total, 1140 patients were recruited (February 2017-December 2018), of which 1008 met the eligibility criteria (mean age 3.5 years, 41.9% female). Viral and bacterial infections were adjudicated for 628 (85.8%) and 104 (14.2%) children, respectively; 276 patients were assigned an indeterminate reference standard outcome. For the 732 children with reference standard aetiology, the signature discriminated bacterial from viral infections with a sensitivity of 93.7% (95%CI 88.7-98.7), a specificity of 94.2% (92.2-96.1), positive predictive value of 73.0% (65.0-81.0), and negative predictive value of 98.9% (98.0-99.8); in 9.8% the test results were equivocal. The signature performed consistently across different patient subgroups and detected bacterial immune responses in viral PCR-positive patients.

CONCLUSIONS

The findings validate the high diagnostic performance of the TRAIL/IP-10/CRP signature in a broad paediatric cohort, and support its potential to reduce antibiotic overuse in children with viral infections.

Evaluation of Israeli healthcare workers knowledge and attitudes toward the COVID-19 vaccine

Objectives

Healthcare workers (HCWs) are considered an important target group for the COVID‐19 vaccines. The current study assesses the knowledge and attitudes of Israeli HCWs regarding COVID‐19 immunization, and how various occupational and demographic factors may underlie COVID‐related knowledge and attitudes differences.

Methods

Following a pre‐test to validate measures, a cross‐sectional online anonymous survey was distributed to HCWs using a snowball sampling method.

Results

The survey was completed by 714 participants (mean age 39.9; range 18–74; 447 female), 52% doctors, 32% nurses, and the remainder by paramedical staff. Of the respondents, 553 (77.4%) answered the question are you in favor of getting the COVID‐19 vaccine, 105 (14.7%) were not sure, and 56 (7.8%) were not in favor. Doctors had higher odds of agreement as compared to both nurses (p < .025) and paramedical staff (p < .001). Multivariate logistic regression analysis revealed that increased age (OR: 1.075; 95% CI: 1.04–1.11, p < .001), profession (physician vs. nurse; OR: 2.73; 95% CI: 1.32–5.65; p < .007), and getting the current influenza vaccine (OR: 4.96; 95% CI: 2.47–9.95) were significant predictors of agreement.

Conclusions

A high level of HCWs knowledge and in favor attitudes were observed. Yet negative attitudes were also noted, particularly among nurses, paramedical staff, and young employees.

Outcomes of Migraine and Tension-Type Headache in Children and Adolescents

The aim of our study was to evaluate the long-term outcomes of pediatric migraine and TTH in a clinical setting. We conducted a cohort study. Pediatric patients who visited the pediatric neurology clinic due to diagnoses of migraine or TTH were contacted by phone 8–10 years after their initial diagnosis and interviewed about their outcomes. Of 147 children, we were able to reach 120 (81%) patients. Of these 120 patients, 59 were seen initially due to migraine and 61 due to TTH. For the migraine patients, headaches improved in 48 (81.4%) and worsened in four (6.8%). Regarding diagnosis at follow-up, 59% still had migraine, 17% had TTH, and 23% were headache-free. Aura and photophobia were significantly associated with persistence of a migraine diagnosis. For the TTH patients, headaches improved in 49 (81.7%) and worsened in nine (15.0%). Regarding diagnosis at follow-up, 36.7% still had TTH, 18.3% had migraine, and 45% were headache-free. Of the patients with TTH, 36.7% retained their initial diagnosis compared to 59.3% among the migraine patients. Most pediatric patients presenting with migraine or TTH will experience a favorable outcome over 10 years, with TTH patients having twice the chance of complete resolution.

COVID-19 in a Subset of Hospitalized Children in Israel

BACKGROUND

Most pediatric coronavirus disease 2019 (COVID-19) is mild. We assessed nationally severe COVID-19, including pediatric inflammatory multisystem syndrome (PIMS), in hospitalized children.

METHODS

An ongoing, prospective, national surveillance was conducted from March 2020 through March 2021, at 20 hospitals treating children <18 years across Israel (~75% of Israeli hospitals).

RESULTS

Overall, 1007 cases (439 outpatients and 568 hospitalized) identified represent 0.35% of pediatric COVID-19 nationwide (n = 291 628). Of hospitalized cases, 464 (82%), 48 (8%), and 56 (10%) had mild, moderate/severe, and PIMS disease, respectively. The mean ± SD age was 5.6 ± 6.4 years. In mild, moderate/severe, and PIMS disease, 55%, 23%, and 4% of patients were <1 year old, respectively. Obesity was reported in 1%, 4%, and 13% of patients, respectively (P < .001). The most common symptom was fever in 67%, 60%, and 100%, respectively, whereas respiratory symptoms were documented in 33%, 41%, and 38% of patients, respectively. Lymphopenia was recorded in 25%, 60%, and 86% of cases, respectively. PIMS diagnosis was mainly serology-based (in 59%). Gastrointestinal symptoms, cardiovascular involvement, rash, and conjunctivitis were noted in 82%, 61%, 57%, and 34% of PIMS episodes, respectively. Elevated C-reactive protein (100%), ferritin, troponin, D-dimer, low albumin, and thrombocytopenia were common in PIMS. Echocardiography revealed pathological findings in 33% of patients. PIMS mainstay treatment included corticosteroids (77%) and intravenous immunoglobulin (53%). No mortality was recorded.

CONCLUSIONS

At a national level, pediatric COVID-19 is mild, even in hospitalized cases, with only a third presenting with respiratory involvement. PIMS is rare, but necessitates a high index of suspicion, and with suitable treatment prognosis is favorable.

Pooled saliva CMV DNA detection: A viable laboratory technique for universal CMV screening of healthy newborns

BACKGROUND

Most infants with congenital cytomegalovirus (cCMV) have no overt manifestations at birth, yet may later develop CMV-related sensorineural hearing loss (SNHL). With targeted screening, many asymptomatic neonates are missed and lose the opportunity for timely anti-viral treatment to ameliorate SNHL. Saliva is the preferred screening specimen given its ease of collection.

OBJECTIVES

Assess a pooled saliva CMV DNA detection technique for cCMV screening of healthy full-term neonates.

STUDY DESIGN

We conducted a prospective laboratory CMV PCR screening study in a secondary hospital from March-June 2019. Saliva specimens were obtained from 1000 newborns two-four hours after birth. Specimens were analyzed for CMV DNA with a real-time PCR platform (Altona) in pools of 10 and individually (40 μL and 400 μL, respectively). Neonates with positive saliva CMV DNA detection required urine CMV PCR testing to confirm cCMV diagnosis.

RESULTS

From the 1000 saliva samples, there were 6 urine-confirmed cCMV cases, yielding a prevalence rate of 0.6 %. The specificity was high for both pooled and individual saliva sampling (99.9 % and 98.1 %, respectively). The positive predictive value of the pooled sample was 85.7 %, compared to 24.0 % for a single saliva sample.

CONCLUSIONS

Pooling saliva of healthy newborns appears to be a reliable method to identify asymptomatic cCMV infection when positive results are confirmed by urine CMV DNA. Pooling in sizes appropriate to the cCMV prevalence rate may improve the laboratory workflow and decrease costs. Further studies should evaluate the clinical implications of this widespread cCMV pooled screening technique.

A Retrospective Study of the Impact of Pneumococcal Conjugate Vaccine-13 Immunization in a Northern Israel Hospital

BACKGROUND

The introduction of pneumococcal conjugate vaccine-13 (PCV-13) has reduced the burden of invasive pneumococcal disease.

OBJECTIVES

To characterize true positive blood cultures of children who presented to our hospital following implementation of the PCV-13 vaccine.

METHODS

A retrospective study was conducted on positive blood cultures of children presenting with fever from 2010-2017. Subjects were divided into two age groups: a younger group 3-36 months and an older group 3-18 years. Patients were classified as either having or not having a focus of infection at the time of their bacteremia. Pneumococcal isolates were typed at Israel's Streptococcal Reference Laboratory.

RESULTS

The samples included 94 true positive blood cultures. Focal infection with concomitant bacteremia was more common than bacteremia without a focus both overall: 67/94 (71%) vs. 27/94 (28.7%), P <0.001 as well as in the two groups: 32/48 (66%) vs. 16/48 (33%), P = 0.02 in the younger group and 35/46 (76%) vs. 11/46 (24%), P = 0.001 in the older group. Streptococcus pneumoniae was the most common pathogen overall, 27/94 (29%), and in the younger group, 21/48 (44%), but rare in the older group, 6/46 (13%). In the latter, Brucella species predominated, 12/46 (26%), along with Staphylococcus aureus 12/46 (26%).

CONCLUSIONS

Our findings are consistent with other studies reporting decreased pneumococcal bacteremia, bacteremia primarily accompanying focal infection, and changing etiological agents among PCV-13-vaccinated children. Brucella species was prominent in older children with osteoarticular infections. Ongoing surveillance is warranted to better understand the implications of PCV-13.

2624. Viral Pneumonia in Children: Facing the Challenge Using the Host Response

Background

Diagnosing viral pneumonia in children is challenging. Chest radiographic imaging and clinical findings cannot reliably distinguish viral from bacterial pneumonia. Furthermore, pathogen-based diagnosis is limited by inaccessible site of infection and high asymptomatic detection rates. The objectives of this analysis were twofold: first, to establish pneumonia etiology by applying a rigorous expert panel process, and second, to evaluate whether a novel host-immune signature that integrates viral induced proteins TRAIL and IP-10 together with bacterial CRP, can accurately differentiate viral from bacterial pneumonia.

Methods

This analysis included 1025 febrile children enrolled in two multi-center clinical studies that evaluated the host-immune signature performance: ‘Curiosity’ study (Oved et al., PLoS One 2015) and ‘Pathfinder’ study (Srugo et al., Pediatrics 2017). Pneumonia etiology – viral or bacterial – was determined by a panel of 3 independent experts, after reviewing patients’ clinical, laboratory, microbiological, and radiological data. Only cases with majority panel assignment were included. The host-signature generated one of the three results: viral, equivocal or bacterial, based on predetermined cut-offs.

Results

A total of 709 children were eligible for analysis and had an expert panel etiology determination. Of them, 114 were diagnosed with pneumonia: 51 assigned viral and 63 assigned bacterial (Figure 1). The signature separated viral from bacterial pneumonia with a sensitivity of 94% (95% CI: 85%–99%) and specificity of 95% (85%–99%) with 14% equivocal test results. Out of the 51 children diagnosed with viral pneumonia by the expert panel, 40 (78%) were given antibiotics, and 43 (83%) underwent chest x-ray evaluation. The signature correctly classified 42 of these 51 viral children, indicating its potential to reduce antibiotic overuse rates by 4.4-fold (from 78% to 18%; P < 0.001) and chest x-ray examination by 4.8-fold (from 83% to 18%; P < 0.001).

Conclusion

The TRAIL/IP-10/CRP signature exhibits high accuracy for diagnosing viral pneumonia in children. The signature’s potential to safely decrease unnecessary antibiotics and chest radiographic imaging should be examined in future utility studies.

Disclosures

All authors: No reported disclosures.

Expressions of Gratitude and Medical Team Performance

BACKGROUND AND OBJECTIVES

Exposure to negative social interactions (such as rudeness) has robust adverse implications on medical team performance. However, little is known regarding the effects of positive social interactions. We hypothesized that expressions of gratitude, a prototype of positive social interaction, would enhance medical teams' effectiveness. Our objective was to study the performance of NICU teams after exposure to expressions of gratitude from alternative sources.

METHODS

Forty-three NICU teams (comprising 2 physicians and 2 nurses) participated in training workshops of acute care simulations. Teams were randomly assigned to 1 of 4 conditions: (1) maternal gratitude (in which the mother of a preterm infant expressed gratitude to NICU teams, such as the one that treated her child), (2) expert gratitude (in which a physician expert expressed gratitude to teams for participating in the training), (3) combined maternal and expert gratitude, or (4) control (same agents communicated neutral statements). The simulations were evaluated (5-point Likert scale: 1 = failed and 5 = excellent) by independent judges (blind to team exposure) using structured questionnaires.

RESULTS

Maternal gratitude positively affected teams' performances (3.9 ± 0.9 vs 3.6 ± 1.0; P = .04), with most of this effect explained by the positive impact of gratitude on team information sharing (4.3 ± 0.8 vs 4.0 ± 0.8; P = .03). Forty percent of the variance in team information sharing was explained by maternal gratitude. Information sharing predicted team performance outcomes, explaining 33% of the variance in diagnostic performance and 41% of the variance in therapeutic performance.

CONCLUSIONS

Patient-expressed gratitude significantly enhances medical team performance, with much of this effect explained by enhanced information sharing.

Antibiotic misuse in respiratory tract infections in children and adults-a prospective, multicentre study (TAILORED Treatment)

Respiratory tract infections (RTI) are more commonly caused by viral pathogens in children than in adults. Surprisingly, little is known about antibiotic use in children as compared to adults with RTI. This prospective study aimed to determine antibiotic misuse in children and adults with RTI, using an expert panel reference standard, in order to prioritise the target age population for antibiotic stewardship interventions. We recruited children and adults who presented at the emergency department or were hospitalised with clinical presentation of RTI in The Netherlands and Israel. A panel of three experienced physicians adjudicated a reference standard diagnosis (i.e. bacterial or viral infection) for all the patients using all available clinical and laboratory information, including a 28-day follow-up assessment. The cohort included 284 children and 232 adults with RTI (median age, 1.3 years and 64.5 years, respectively). The proportion of viral infections was larger in children than in adults (209(74%) versus 89(38%), p < 0.001). In case of viral RTI, antibiotics were prescribed (i.e. overuse) less frequently in children than in adults (77/209 (37%) versus 74/89 (83%), p < 0.001). One (1%) child and three (2%) adults with bacterial infection were not treated with antibiotics (i.e. underuse); all were mild cases. This international, prospective study confirms major antibiotic overuse in patients with RTI. Viral infection is more common in children, but antibiotic overuse is more frequent in adults with viral RTI. Together, these findings support the need for effective interventions to decrease antibiotic overuse in RTI patients of all ages.

873. Using the Host Immune Response to Identify Viral-Bacterial Coinfection in Children With Respiratory Syncytial Virus Infection

Background

A major challenge in the effective management of children with RSV infection is the clinical difficulty of distinguishing a simple viral from viral–bacterial coinfections. As a result, despite the low rates of viral–bacterial coinfection, RSV patients are often prescribed antibiotics with recent reports demonstrating more than 60% antibiotic overuse rates (Van Houten et al. 2018). Here, we examined whether a host-immune signature combining the viral-induced proteins TRAIL and IP-10 with the bacterial-induced protein CRP (ImmunoXpert; Oved et al. 2015) can distinguish simple viral from viral–bacterial coinfection in RSV patients.

Methods

We studied 402 febrile children enrolled as part of “Curiosity,” a prospective study designed to develop and validate the host-immune signature. Infection etiology—viral or viral-bacterial coinfection—was determined by a panel of experts following a review of patients’ clinical, laboratory, radiological, microbiological, and follow-up data. RSV strains were detected using a respiratory multiplex PCR applied to nasal swabs (Seeplex-RV15).

Results

Out of the 402 children with suspected acute infection 29 had a positive RSV detection (Figure 1); of them, 27 had a unanimous expert panel etiology determination: 24 viral and 3 viral–bacterial coinfections. Out of the 24 patients unanimously assigned viral by the expert panel, 13 were given antibiotics, indicating a 54% antibiotic overuse rate. The host-immune signature correctly identified all 3 viral-bacterial coinfection cases, as well as 22 out of the 24 (92%) simple viral patients. This finding supports that the signature has the potential to reduce antibiotic overuse by 6.5-fold (from an overuse of 13/24 = 54% to 2/24 = 8%, P < 0.001).

Conclusion

Our results demonstrate high antibiotic overuse rates for RSV patients, consistent with previous reports. The host-immune signature correctly distinguished simple viral from viral–bacterial coinfection and therefore may have the potential to aid physicians in the correct management of children with RSV infection. Implementation studies are required to evaluate its utility in safely decreasing unnecessary antibiotic use for RSV patients.

Disclosures

N. Mastboim, MeMed Diagnostics: Employee, Salary. K. Oved, MeMed Diagnostics: Board Member, Employee and Shareholder, Salary. T. Gottlieb, MeMed Diagnostics: Employee, Salary. A. Cohen, MeMed Diagnostics: Employee, Salary. R. Navon, MeMed Diagnostics: Employee, Salary. M. Paz, MeMed Diagnostics: Employee, Salary. E. Bamberger, MeMed Diagnostics: Employee, Salary. T. Friedman, MeMed Diagnostics: Employee, Salary. L. Etshtein, MeMed Diagnostics: Employee, Salary. O. Boico, MeMed Diagnostics: Employee, Salary. I. Potasman, MeMed Diagnostics: Holding stock options, Stock options. E. Eden, MeMed Diagnostics: Board Member, Employee and Shareholder, Salary. L. Shani, MeMed Diagnostics: Employee, Salary.

1948. A Host-Response Assay Distinguishes Between Simple Influenza Patients and Influenza Patients With Bacterial Coinfection

Background

Identifying bacterial coinfection in influenza patients can be difficult as the symptoms of simple influenza vs. mixed infections are often similar, leading to antibiotic overuse. A new host-response assay (ImmunoXpert™) that integrates the levels of three proteins (TRAIL, IP-10, and CRP) was shown to exhibit high performance in distinguishing between bacterial and viral disease in two double-blind validation studies. Here we sought to evaluate its ability to differentiate between simple influenza and influenza with bacterial coinfection.

Methods

The study population included 653 febrile pediatric and adult patients prospectively recruited in the “Curiosity” study. Patient etiology (simple viral vs. mixed infection) was determined by unanimous expert adjudication based on comprehensive clinical, laboratory and radiological assessment. Influenza strains (A or B) were detected using multiplex PCR applied to nasal swabs (Seeplex-RV15). We compared the expert panel diagnosis with the assay that gives three possible outcomes: viral, bacterial (including viral with bacterial coinfection) or equivocal. An equivocal outcome does not provide diagnostic information and is observed in ~10% of cases.

Results

Out of 653 patients, 51 had positive influenza detection and unanimous expert diagnosis: 44 simple viral infections and seven influenza with bacterial coinfections (Figure 1). Antibiotics were prescribed to all seven cases of influenza with bacterial coinfection and to 20/44 cases adjudicated as simple viral infections, indicating an overuse rate of 45%. The assay correctly classified 40 of the 44 simple viral cases (out of the remaining four, two were assigned viral with bacterial coinfection, and two received equivocal outcomes) as well as five of the seven viral with bacterial coinfection cases (the remaining two received equivocal outcomes) supporting the assay’s potential to reduce antibiotic overuse 5-fold (from 45% to 4/44 = 9%, P < 0.001).

Conclusion

The host–response assay can differentiate between simple influenza and influenza patients with bacterial coinfection, with potential to reduce antibiotic overuse. Utility studies are warranted to demonstrate that the assay can safely assist physicians in correct management of influenza patients.

Disclosures

M. Paz, MeMed Diagnostics: Employee, Salary. K. Oved, MeMed Diagnostics: Board Member, Employee and Shareholder, Salary. T. Gottlieb, MeMed Diagnostics: Employee, Salary. A. Cohen, MeMed Diagnostics: Employee, Salary. R. Navon, MeMed Diagnostics: Employee, Salary. N. Mastboim, MeMed Diagnostics: Employee, Salary. E. Bamberger, MeMed Diagnostics: Employee, Salary. T. Friedman, MeMed Diagnostics: Employee, Salary. L. Etshtein, MeMed Diagnostics: Employee, Salary. O. Boico, MeMed Diagnostics: Employee, Salary. I. Potasman, MeMed Diagnostics: Holding stock options, Stock options. E. Eden, MeMed Diagnostics: Board Member, Employee and Shareholder, Salary. L. Shani, MeMed Diagnostics: Employee, Salary.

A novel host-protein assay outperforms routine parameters for distinguishing between bacterial and viral lower respiratory tract infections

Bacterial and viral lower respiratory tract infections (LRTIs) are often clinically indistinguishable, leading to antibiotic overuse. We compared the diagnostic accuracy of a new assay that combines 3 host-biomarkers (TRAIL, IP-10, CRP) with parameters in routine use to distinguish bacterial from viral LRTIs. Study cohort included 184 potentially eligible pediatric and adult patients. Reference standard diagnosis was based on adjudication by an expert panel following comprehensive clinical and laboratory investigation (including respiratory PCRs). Experts were blinded to assay results and assay performers were blinded to reference standard outcomes. Evaluated cohort included 88 bacterial and 36 viral patients (23 did not fulfill inclusion criteria; 37 had indeterminate reference standard outcome). Assay distinguished bacterial from viral LRTI patients with sensitivity of 0.93±0.06 and specificity of 0.91±0.09, outperforming routine parameters, including WBC, CRP and chest x-ray signs. These findings support the assay's potential to help clinicians avoid missing bacterial LRTIs or overusing antibiotics.

A Novel Host-protein Assay Accurately Distinguishes Bacterial From Viral Upper Respiratory Tract Infections

Background

Bacterial and viral infections are often clinically indistinguishable, particularly in upper respiratory tract infections (URTI), which leads to antibiotic misuse. A novel assay (ImmunoXpert™) that integrates measurements of three host-response proteins (TRAIL, IP-10, CRP) was recently developed to assist in differentiation between bacterial and viral etiologies. We evaluated the assay performance in URTI patients and compared it with standard laboratory measures.

Methods

We performed a sub-analysis of 464 patients with clinical suspicion of URTI enrolled in three previously conducted multi-center clinical studies that evaluated the assay performance in patients with acute infections: ‘Curiosity’ study (NCT01917461), ‘Opportunity’ study (NCT01931254), and ‘Pathfinder’ study (NCT01911143). Comparator method was predetermined criteria combined with expert panel adjudication, which was blinded to the test results. Diagnostic performance was evaluated by comparing test and comparator method outcomes.

Results

A unanimous panel adjudication was attained for 61 bacterial (13%) and 241 viral (52%) patients (162 patients (35%) had an indeterminate diagnosis). The assay distinguished between bacterial and viral infected patients with a sensitivity of 92% (95% CI: 82%- 98%) and specificity of 93% (88%-96%) with 11% equivocal test results. Overall the assay outperformed other routine laboratory tests (FIG 1), including: white blood cell count (WBC; cutoff 15,000 cells/µL, sensitivity 48% (35%-60%), P < 10^-−6; specificity 85% (80%-90%), P < 0.05); CRP (cutoff 40 mg/L, sensitivity 82% (72%–92%), P = 0.16, specificity 79% (74%–84%), P < 10^-4); Procalcitonin (PCT; cutoff 0.5 ng/mL, sensitivity 22% (11%–32%), P < 10^–14, specificity 80% (74%–85%), P < 0.001); absolute neutrophil count (ANC; cutoff 10,000 cells/µL, sensitivity 58% (45%–71%), P < 10^-−4, specificity 94% (91%–97%), P = 0.7).

Conclusion

The novel assay demonstrated superior performance compared with routine laboratory tests (WBC, ANC) and biomarkers (CRP, PCT), in distinguishing bacterial from viral etiologies in patients with URTI. It has the potential to help clinicians avoid missing bacterial infections or prescribing unwarranted antibiotics for viral URTIs.

Disclosures

K. Oved, MeMed Diagnostics: Board Member, Employee and Shareholder, Salary E. Eden, MeMed Diagnostics: Board Member, Employee and Shareholder, Salary T. Gottlieb, MeMed Diagnostics: Employee, Salary R. Navon, MeMed Diagnostics: Employee, Salary A. Cohen, MeMed Diagnostics: Employee, Salary O. Boico, MeMed Diagnostics: Employee, Salary M. Paz, MeMed Diagnostics: Employee, Salary L. Etshtein, MeMed Diagnostics: Employee, Salary G. Kronenfeld, MeMed Diagnostics: Employee, Salary T. Friedman, MeMed Diagnostics: Employee, Salary E. Bamberger, MeMed Diagnostics: Employee, Salary I. Chistyakov, MeMed Diagnostics: Consultant, Consulting fee I. Potasman, MeMed Diagnostics: Holding stock options, stock options

Validation of a Novel Assay to Distinguish Bacterial and Viral Infections

BACKGROUND

Reliably distinguishing bacterial from viral infections is often challenging, leading to antibiotic misuse. A novel assay that integrates measurements of blood-borne host-proteins (tumor necrosis factor-related apoptosis-inducing ligand, interferon γ-induced protein-10, and C-reactive protein [CRP]) was developed to assist in differentiation between bacterial and viral disease.

METHODS

We performed double-blind, multicenter assay evaluation using serum remnants collected at 5 pediatric emergency departments and 2 wards from children ≥3 months to ≤18 years without (n = 68) and with (n = 529) suspicion of acute infection. Infectious cohort inclusion criteria were fever ≥38°C and symptom duration ≤7 days. The reference standard diagnosis was based on predetermined criteria plus adjudication by experts blinded to assay results. Assay performers were blinded to the reference standard. Assay cutoffs were predefined.

RESULTS

Of 529 potentially eligible patients with suspected acute infection, 100 did not fulfill infectious inclusion criteria and 68 had insufficient serum. The resulting cohort included 361 patients, with 239 viral, 68 bacterial, and 54 indeterminate reference standard diagnoses. The assay distinguished between bacterial and viral patients with 93.8% sensitivity (95% confidence interval: 87.8%-99.8%) and 89.8% specificity (85.6%-94.0%); 11.7% had an equivocal assay outcome. The assay outperformed CRP (cutoff 40 mg/L; sensitivity 88.2% [80.4%-96.1%], specificity 73.2% [67.6%-78.9%]) and procalcitonin testing (cutoff 0.5 ng/mL; sensitivity 63.1% [51.0%-75.1%], specificity 82.3% [77.1%-87.5%]).

CONCLUSIONS

Double-blinded evaluation confirmed high assay performance in febrile children. Assay was significantly more accurate than CRP, procalcitonin, and routine laboratory parameters. Additional studies are warranted to support its potential to improve antimicrobial treatment decisions.

A pilot study of an emotional intelligence training intervention for a paediatric team

OBJECTIVE

Emotional intelligence (EI) is the individual's ability to perceive, understand and manage emotion and to understand and relate effectively to others. We examined the degree to which EI training may be associated with a change in EI among different medical personnel and patient satisfaction.

DESIGN, SETTING AND PARTICIPANTS

The EI of 17 physicians and 10 nurses in paediatric ward was prospectively evaluated with Bar-On's EI at baseline and after 18 months. 11 physicians who did not undergo the intervention served as controls.

INTERVENTIONS

The intervention consisted of a training programme comprising group discussions, simulations and case studies.

MAIN OUTCOMES AND MEASURES

Pre-emotional quotient inventory (EQ-i) and post-EQ-i scores and patient satisfaction surveys of nurse and physicians pre-intervention and post-intervention were analysed.

RESULTS

The mean overall EI score of the study sample rose from 99.0±9.6 (both plus and minus mathematical operations standing for SD) at baseline to 105.4±10 (p<0.000) after 18 months, with the most robust increase (nearly 6%; p<0.003) manifested among physicians. In contrast, the control group's EI scores did not change over this period. Within the intervention group, physicians displayed a statistically significant increase in three of the five EI dimensions, compared with only one of the five EI dimensions for nurses. Patient satisfaction scores relating to physician care rose from 4.4 pre-intervention to 4.7 post-intervention (p=0.03).

CONCLUSION

An EI intervention led to an overall increase in EI scores, with a significant improvement in patient satisfaction. These findings suggest important potential benefits for both staff and their patients.

Adult Pertussis Is Hazardous for the Newborn

We report 4 cases involving the likely transmission of pertussis from parents to newborns in a hospital setting. The adoption of proper infection control measures and targeted screening of parents may reduce the potential for such transmission.

The Decline of Pertussis-Specific Antibodies After Tetanus, Diphtheria, and Acellular Pertussis Immunization in Late Pregnancy

We prospectively measured pertussis-specific antibodies 9-15 months after delivery in women immunized with tetanus, diphtheria, and acellular pertussis (Tdap) after the 20th week of their recent pregnancy. The Tdap-immunized women (n = 38) exhibited a decline in geometric mean concentrations between their peripartum and follow-up levels for immunoglobulin G to pertussis toxin (21.48 [95% confidence interval, 12.51-36.89] vs 11.72 [7.09-19.37] IU/mL];); filamentous hemagglutinin (185.95 [157.93-218.94] vs 140.33 IU/mL [113.46-173.57] IU/mL); and pertactin (171.52 [120.73-243.67] vs 83.74 [60.58-115.75] IU/mL) (all P < .001). For women immunized with Tdap during late pregnancy, pertussis-specific immunoglobulin G levels decreased significantly 9-15 months after delivery.

The significance of allergic contact urticaria to milk in children with cow's milk allergy

BACKGROUND

Cow's milk allergy (CMA) is the most common food allergy in infancy. Food allergy is generally triggered through ingestion, but can also be triggered through skin contact. We investigated the incidence and the clinical significance of cow's milk protein (CMP)-induced contact urticaria in individuals with CMA with and without atopic dermatitis (AD).

METHODS

A total of 157 children of whom 133 were diagnosed with CMA were participated. The study was based on observational data gathered in the course of patient care, including a skin prick test and a 'finger test', in which cow's milk is applied on the cheek by a physician's finger to detect contact urticaria.

RESULTS

Eighty nine of 133 patients (66.9%) had IgE-mediated CMA. Forty of these 89 (44.9%) tested positive in the finger test. Family atopy was higher in those with positive contact urticaria [21/40 (52.5%) vs. 14/49 (28.5%), p = 0.029]. Patients with positive vs. negative CMP contact urticaria had higher incidence of multiple food allergies [20 of 40 (50%) vs. 7/49 (14.3%), p < 0.004]. IgE-mediated CMA patients with AD had statistically higher CMP allergic contact urticaria compared to patients without AD [71% (15/21) vs. 37% (25/68), p = 0.0064]. Children with non-IgE milk allergy and healthy control group did not have contact urticaria to CMP.

CONCLUSION

CMP contact urticaria exists only in patients with IgE-mediated CMA. A 'finger test' to CMP should be part of the evaluation of CMA patients, and positivity suggests the potential for multiple food allergies, especially to sesame and egg.

Immunization of pregnant women against pertussis: the effect of timing on antibody avidity

BACKGROUND

The Centers for Disease Control and Prevention recommend tetanus-diphteria-acellular pertussis (Tdap) immunization during pregnancy, preferably at 27-36 weeks gestation.

AIMS

First, to assess the relative avidity index (RAI) of umbilical cord immunoglobulin G (IgG) to pertussis toxin (PT) for newborns of women immunized with Tdap during late pregnancy as compared to unimmunized women. Second, to assess whether there is a preferential period of gestational Tdap immunization that provides the highest RAI of umbilical cord IgG to PT.

METHODS

RAI of IgG to PT was assessed via an adapted ELISA using NH4SCN as a dissociating agent.

RESULTS

We found that newborns of women immunized with Tdap during late pregnancy (n=52) had higher mean RAI of umbilical cord IgG to PT than those of unimmunized women (n=8), 73.77%±12.08 (95% CI, 70.41-77.13) vs. 50.23%±21.32 (95% CI, 32.41-68.06), p<0.001. Further, the RAI of umbilical cord IgG to PT was significantly higher in newborns of women immunized at 27-30(+6) weeks gestation (n=20) when compared with newborns of women immunized at 31-36 weeks (n=22) and >36 weeks (n=7), 79.53%±5.61 (95% CI, 76.91-82.16) vs. 71.56%±12.58 (95% CI, 65.98-77.14) vs. 63.93%±17.98 (95% CI, 47.31-80.56), p<0.03.

CONCLUSION

Gestational Tdap immunization between 27 and 30(+6) weeks resulted in the highest avidity of IgG to PT conveyed at delivery as compared with immunization beyond 31 weeks gestation. Future studies should be conducted to confirm our findings to optimize pertussis-controlling strategies.

The effect of timing of maternal tetanus, diphtheria, and acellular pertussis (Tdap) immunization during pregnancy on newborn pertussis antibody levels - a prospective study

BACKGROUND

The Centers for Disease Control and Prevention recommend Tdap immunization during pregnancy, preferably at 27-36 weeks.

AIM

To ascertain whether there is a preferential period of maternal Tdap immunization during pregnancy that provides the highest concentration of pertussis-specific antibodies to the newborn.

METHODS

This prospective study measured pertussis-specific antibodies in paired maternal-cord sera of women immunized with Tdap after the 20th week of their pregnancy (n=61).

RESULTS

The geometric mean concentrations (GMCs) of Immunoglobulin G (IgG) to pertussis toxin (PT) were higher in the newborns' cord sera when women were immunized at 27-30(+6) weeks (n=21) compared with 31-36 weeks (n=30) and >36 weeks (n=7), 46.04 international units/milliliter (IU/mL) (95% CI, 24.29-87.30) vs. 8.69IU/mL (95% CI, 3.66-20.63) and 21.12IU/mL (95% CI, 7.93-56.22), p<0.02, respectively. The umbilical cord GMCs of IgG to filamentous hemagglutinin (FHA) were higher in the newborns' cord sera when women were immunized at 27-30(+6) weeks compared with 31-36 weeks and >36 weeks, 225.86IU/mL (95% CI, 182.34-279.76) vs. 178.31IU/mL (95% CI, 134.59-237.03) and 138.03IU/mL (95% CI, 97.61-195.16), p<0.02, respectively.

CONCLUSIONS

Immunization of pregnant women with Tdap between 27-30(+6) weeks was associated with the highest umbilical cord GMCs of IgG to PT and FHA compared with immunization beyond 31 weeks gestation. Further research should be conducted to reaffirm these finding in order to promote an optimal pertussis controlling policy.

The induction of breast milk pertussis specific antibodies following gestational tetanus-diphtheria-acellular pertussis vaccination

BACKGROUND

Center for Disease Control and Prevention recommends vaccination of pregnant women with tetanus-diphtheria-acellular pertussis (Tdap).

AIM

To measure pertussis specific antibodies, total protein and their ratio in breast milk following gestational Tdap vaccination.

METHODS

Women who received Tdap after the 20th week of pregnancy were recruited and unvaccinated women served as controls. Breast milk total protein, immunoglobulin A (IgA) to pertussis toxin (PT), filamentous hemagglutinin (FHA) and immunoglobulin G (IgG) to PT, FHA and pertactin (PRN) were measured. To overcome the dilution that occurs in the transition from colostrum to mature breast milk, we calculated pertussis specific antibody to total protein ratio.

RESULTS

Pertussis specific IgA was the predominant pertussis immunoglobulin in the colostrum of Tdap vaccinated women with the geometric mean concentrations (GMCs) of IgA to FHA higher than for IgA to PT, 24.12 ELISA units/milliliter (EU/mL) vs. 8.18EU/mL, respectively, p<0.004. There were differences between the vaccinated women and controls in the GMCs of IgA to FHA and IgG to PRN in the colostrum, 24.12EU/mL vs. 6.52EU/mL, p=0.01 and 2.46EU/mL vs. <0.6EU/mL, p=0.03, respectively. The GMCs of total protein showed significant decline over 8 weeks in the vaccinated women and controls, p<0.004. Among vaccinated women, there was significant decline in the GMCs of IgA to PT and FHA over 8 weeks, p<0.001. The geometric mean ratio of IgA to FHA to total protein also declined significantly over 8 weeks in the vaccinated women, p<0.01, demonstrating a true decrease, however, pertussis IgA was measurable at 8 weeks.

CONCLUSIONS

Select colostrum pertussis antibody levels were significantly higher among women vaccinated with Tdap during pregnancy compared with unvaccinated women. Among vaccinated women, maximal levels of pertussis specific IgA were in the colostrum but still detected at 8 weeks. Lactation may augment infant's protection against pertussis.

Legionella pneumophila and Pneumocystis jirovecii coinfection in an infant treated with adrenocorticotropic hormone for infantile spasm: case report and literature review

We describe an 8-month-old infant with infantile spasms treated with adrenocorticotropic hormone (ACTH) who presented with fatal Legionella pneumophila and Pneumocystis jirovecii infection. Emphasis is placed on the ensuing immunosuppression and infectious sequelae of ACTH therapy. Given that ACTH therapy may increase the risk of fatal infection, patients undergoing such treatment should be closely monitored, with particular attention paid to the functioning of the immune system.

[Genital ulcers--what's new?]

The most common infectious causes of genital ulcers are herpes simplex virus and syphilis. However, mixed infections can occur and genital ulcer may increase the risk of acquiring human immunodeficiency virus. Although the history and physical examination can narrow the differential diagnosis, there is a need for initial routine laboratory testing for the most common pathogens that includes: for syphilis: serologic screening and dark field examination of the lesion; for herpes simplex virus: serology, vial culture and/or polymerase chain reaction. Human immunodeficiency testing is mandatory. Recently, some clinical laboratories adapted the reverse screening algorithm for syphilis (initial treponemal test, and, if positive, followed by non-treponemal test) that may potentially lead to overtreatment. Early and prompt therapy may decrease the risk of transmission of the infectious agent to others. This article reviews the infectious pathogens causing genital ulcers, their unique clinical manifestation, diagnosis and treatment.

Beyond "safe sex"--can we fight adolescent pelvic inflammatory disease?

Pelvic inflammatory disease (PID) is a common disorder affecting sexually active adolescents. The Centers for Disease Control and Prevention (CDC) and European CDC report Chlamydia trachomatis as the most common sexually transmitted infection and one of the main etiological agents causing PID. C. trachomatis' and PID's high prevalence may be attributed to multiple factors including high-risk sexual behaviors, sensitive laboratory diagnostics (polymerase chain reaction), and the introduction of chlamydia screening programs. The pathogenesis of C. trachomatis infection is complex with recent data highlighting the role of toll-like receptor 2 and four in the mediation of the inflammatory cascade. The authors review the etiology of the disease, explore its pathogenesis, and discuss a variety of strategies that may be implemented to reduce the prevalence of C. trachomatis including: (a) behavioral risk reduction, (b) effective screening of asymptomatic females, (c) targeted male screening, (d) implementation of a sensitive, rapid, self-administered point-of-care testing, and (e) development of an effective vaccine.

Toll-like receptor-4 expression in infants with pertussis infection

PURPOSE

Our aim was to evaluate the expression of Toll-like receptor-4 (TLR-4) and the level of interferon-gamma (IFN-γ) and interleukin-10 (IL-10) in young infants infected by Bordetella pertussis and B. parapertussis.

METHODS

Twenty-two infants under the age of 3.5 months with the clinical suspicion of pertussis were enrolled in the study. Nasopharyngeal secretions were obtained for laboratory testing, and blood samples were obtained for flow cytometry and cytokine level analysis.

RESULTS

Six infants had positive PCR results for pertussis; the other 16 infants had infections attributable to another causal agent and were used as the control group. The mean fluorescence index, used as a measure of TLR-4 expression by monocytes, was significantly lower in infants with pertussis than in the control group infants (34.32 ± 18.58 vs. 63.14 ± 28, respectively; p = 0.041). The serum IFN-γ level was also significantly lower in infants with pertussis than in the control group patients (0.41 ± 0.58 vs. 1.36 ± 1.87, respectively; p = 0.04). No differences were found in the levels of IL-10.

CONCLUSIONS

Based on these results, we suggest that TL4 expression by monocytes and serum INF-γ levels are lower in infants with positive PCR results for pertussis than in infants with a non-pertussis upper respiratory tract infection.

Elevated serum total IgE--a potential marker for severe chronic urticaria

BACKGROUND

Elevated IgE levels in patients with chronic urticaria have been noted previously, but the significance of these findings has not been appreciated.

OBJECTIVE

To measure the IgE levels in such patients and to examine the relationship between these levels and urticarial severity, autologous serum skin test, anti-thyroid antibodies and duration.

METHODS

Serum total IgE levels from 203 patients with chronic urticaria were measured and compared with nonatopic individuals. Additionally, patients were assessed for urticarial severity, the presence of autologous serum skin test and anti-thyroid antibodies.

RESULTS

Of the chronic urticaria patients, 47 (23.2%) were classified as mild, whereas 67 (33%) were classified as having moderate and 89 (43.8%) as having severe chronic urticaria. Total IgE levels were elevated, above 175 U/ml, in 69/203 (34%) of patients, compared with 7/81 (8.6%) of healthy controls (p < 0.001). A significant association between increased total IgE and chronic urticaria severity was found. Whereas 93% of patients with increased level of total IgE suffered from moderate-to-severe chronic urticaria, this was observed in only 69% of patients with normal IgE (p < 0.0001). Autologous serum skin test and anti-thyroid antibodies were positive in 59/163 (36%) and 28/189 (15%) patients, respectively. A significant association between increased total IgE levels and the presence of autologous serum skin test, anti-thyroid antibodies and urticarial duration lasting more than 25 months (p < 0.0001, p < 0.0001 and p = 0.021, respectively) was also detected.

CONCLUSIONS

Total serum IgE levels are frequently elevated in patients with chronic urticaria and these are associated with disease severity and duration.

[Adult pertussis poses a severe risk for infants]

In Israel, there have been increasing reports of Bordetella pertussis infection among adolescents and adults, but the peak incidence and highest mortality occur among infants. The authors report four cases involving the likely transmission of pertussis from parents to their offspring in two hospitals in Israel. The adoption of proper infection control measures and targeted screening of parents may reduce the potential risk for such transmission.

The role of T regulatory cells in human sepsis

It is well-known that septic shock undermines immune homeostasis by inducing an initial intense systemic inflammatory response that is rapidly followed by a negative feedback of anti-inflammatory process. This secondary immunoparalysis state is characterized by decreased phagocytic cells, T cells, natural killer cells and B cells function and proinflammatory cytokine release. This persistence of immunoparalysis increased the risk for fatal outcome. In recent studies it was found that following the onset of septic shock, a relative increase in T regulatory cells number and suppressive function appears and makes them an important participant in the inhibition of immune responsiveness during sepsis. Consequently, a question emerging from these findings concerns the degree to which the manipulation of T regulatory cells might improve the outcome of patients with sepsis. Preliminary studies in animal models suggest that more work is needed to understand the conditions under which such a therapy may be effective.

Abnormal spirometry in children with persistent allergic rhinitis due to mite sensitization: the benefit of nasal corticosteroids

Inflammatory processes affecting nasal and bronchial mucosa are similar in nature. The purpose of this study was to examine whether children with perennial allergic rhinitis, without underlying asthma, have impaired pulmonary function. We also investigated whether nasal corticosteroids and loratidine would improve the pulmonary function tests of those children with impaired lung function. Fifty subjects with moderate/severe persistent allergic rhinitis due to exclusively dust mite sensitization and no past medical history suggestive of asthma were assessed. The control group consisted of 26 matched healthy subjects. Subjects with airway obstruction, as detected by forced expiratory volume/1 s (FEV1) or forced expiratory flow from 25/% to 75% (FEF(25-75)) values <80% of those predicted, were treated with loratidine, once a day for 10 days, and daily nasal budesonide for 3 months. We found that 11 of 50 patients (22%) with perennial allergic rhinitis had impaired pulmonary function (FEF(25-75) values <80%), compared to 1/26 (3.8%) of the control group (p < or = 0.05). Reversibility was observed in 9/11 (81.8%), mean 24.7% +/- 10.3%. Within 3 months of treatment, 7/10 had FEF(25-75) > 80% of their predicted values as well as significant improvements in their FEV1 (p = 0.04), and FEV1/FVC (p = 0.04). We conclude that a substantial proportion of children with perennial allergic rhinitis have diminished FEF (25-75) values and reversible airway obstruction. Nasal corticosteroids improve the pulmonary function tests of these children with impaired lung function.

Pertussis is under diagnosed in infants hospitalized with lower respiratory tract infection in the pediatric intensive care unit

BACKGROUND

To determine the rate of pertussis in infants aged <1 year hospitalized at the pediatric intensive care unit (PICU) with lower respiratory tract infection (LRTI) and to characterize the clinical aspects of these patients.

MATERIAL/METHODS

Infants <12 months hospitalized with LRTI in the PICU were identified retrospectively. Demographic, clinical and laboratory data were obtained. Stored nasopharyngeal washes (NPW) were tested by polymerase chain reaction (PCR) for the pertussis toxin gene (ptxA) and insertion element IS481 sequences.

RESULTS

Eleven of seventy-four (15%) NPW were positive for pertussis, none of them was clinically suspected. Of the positive patients, 82% suffered from paroxysmal cough vs. 32% of the negative patients and from prolonged cough, 45.5% vs. 8%, respectively (P<0.01). Thirty (41%) patients needed mechanical ventilation with no differences between positive and negative pertussis patients. Infiltrates in x-rays were more common among pertussis negative than among pertussis positive patients, 29% vs. 0% (P=0.05).

CONCLUSIONS

Lower respiratory tract infections caused by pertussis are a more frequent cause of admission to the PICU than generally recognized. Patient's history with paroxysmal cough suggests the possibility of pertussis and the lack of whooping cough does not rule out pertussis. Pediatricians should be aware of the limitations of their diagnostic tools when ruling out pertussis especially in infants with a diagnosis of bronchiolitis. Using new diagnostic methods add considerably to the sensitivity of pertussis diagnosis in PICU and PCR techniques should be used routinely, at least in a PICU setting.

Increased susceptibility of cord blood B lymphocytes to undergo spontaneous apoptosis

In this study, we compared the rate of spontaneous apoptosis of B cells from umbilical cord blood with adult B cells and assessed the role of Bcl-2, CD5, interleukin (IL)-4 and B cell-activating factor in B cell spontaneous apoptosis. We found that spontaneous apoptosis of cultured B cells, as assessed by utilizing annexin-V binding, was significantly higher in cord blood than in healthy adult individuals (77.5; 95 CI, 73.5-81.5 versus 59.2; 95 CI, 54-64, respectively, P < 0.0001) and further confirmed by 4' 6-diamidino-2-phenylindole, dihydrochloride (DAPI) staining. Whereas the expression of B cell-activating factor from the tumour necrosis factor family (BAFF) receptor mRNA was similar in B cells from adults and cord blood, we detected lower levels of circulating BAFF in the serum of cord blood (0.68 +/- 0.13 ng versus 1.83 +/- 0.54 ng, P = 0.01). The latter may explain, in part, our observation of lower levels of mean fluorescence intensity of Bcl-2 in cord B cells compared with adults (1.6 +/- 0.9 versus 2.85 +/- 1.3, P = 0.033). CD19(+) CD5(+) B cells from cord blood underwent a lower rate of apoptosis in comparison to CD19(+) CD5(-) B cells (25.1 +/- 9.3%versus 58.5 +/- 12.5%, P < 0.0001). This pattern of sensitivity was comparable in adult blood (15 +/- 5.5%versus 22.7 +/- 9.3%, P = 0.01). Nevertheless, the rate of apoptosis was higher in CD19(+) CD5(+) from cord blood compared to CD19(+) CD5(+) from adults (25.1 +/- 9.3%versus 15 +/- 5.5%, P = 0.0013). The addition of rIL-4 (10 u/ml) to cultured cells decreased B cell apoptosis in a similar fashion in both cord and adults blood. This rescue was strengthened when BAFF (100 microg/ml) was further added. Thus, alterations in Bcl-2 or serum BAFF level may explain the increased rate of cord blood B cell apoptosis.

The return of pertussis: who is responsible? What can be done?

The Israel Ministry of Health's epidemiology department reported a record number of 1564 new pertussis cases in 2004. This brings the incidence rate to 23 per 100,000 population, indicating a marked increase in the prevalence of pertussis, from 1-3/100,000 in 1998, 9 in 2001, to 14 in 2003. The rate of atypical pertussis presentations in vaccinated patients, the decline in pertussis immunity post-vaccination, and the decreased awareness of potential infections in the adult population make the diagnosis of pertussis difficult and contribute to the rising incidence. In this article we review the current literature in order to increase awareness of the occurrence of pertussis in children as well as adults, discuss the laboratory diagnostic methods being used, and report the currently recommended means of treating the disease.