Impact of PCR for respiratory viruses on antibiotic use: theory and practice

Optimizing the Use of Antibiotic Agents in the Pediatric Intensive Care Unit: A Narrative Review

Antibiotics are one of the most prescribed drug classes in the pediatric intensive care unit, yet the incidence of inappropriate antibiotic prescribing remains high in critically ill children. Optimizing the use of antibiotics in this population is imperative to guarantee adequate treatment, avoid toxicity and the occurrence of antibiotic resistance, both on a patient level and on a population level. Antibiotic stewardship encompasses all initiatives to promote responsible antibiotic usage and the PICU represents a major target environment for antibiotic stewardship programs. This narrative review provides a summary of the available knowledge on the optimal selection, duration, dosage, and route of administration of antibiotic treatment in critically ill children. Overall, more scientific evidence on how to optimize antibiotic treatment is warranted in this population. We also give our personal expert opinion on research priorities.

Impact of respiratory viral polymerase chain reaction testing on de-escalation of antibiotic therapy in children who require chronic positive pressure ventilation

BACKGROUND

Children who require chronic positive pressure ventilation (CPPV) are frequently hospitalized with acute respiratory infections. Although respiratory viral testing is often performed, it is unclear how positive results impact antibiotic use. We sought to assess the impact of respiratory viral testing on antibiotic use in hospitalized children on CPPV.

METHODS

This retrospective cohort study included hospitalized children on CPPV who had respiratory viral polymerase chain reaction (RVP) testing on admission. Primary exposure was a positive RVP result; primary outcome was antibiotic de-escalation, defined as discontinuation of antibiotics or narrowing of antimicrobial spectra. To determine the independent association of positive RVP and antibiotic de-escalation, a generalized linear mixed effect model was used to account for within patient clustering and confounders defined a priori (blood and respiratory cultures, leukocytosis, bandemia, chest radiograph findings, aspiration risk, and recent admission).

RESULTS

A total of 200 admissions representing 118 patients were included. A viral pathogen was identified in 46.5% (93/200) of admissions; rhinovirus was most frequently identified (61.5% of positive RVPs). Antibiotic de-escalation occurred in 33% of admissions (35.5% of RVP-positive admissions vs 30.8% of RVP-negative admissions; P = .49). In adjusted analysis, there was no association between positive RVP and antibiotics de-escalation (adjusted OR: 0.86; 95% confidence interval: 0.32-2.26).

CONCLUSION

This single center cohort study suggests that respiratory viral testing may not impact antibiotic prescribing for hospitalized children on CPPV. There is need for improved stewardship of both diagnostic testing and antimicrobial use in this population.

Epidemiology and Phylogenetic Analysis of Viral Respiratory Infections in Vietnam

Acute respiratory infections (ARIs) impose a major public health burden on fragile healthcare systems of developing Southeast Asian countries such as Vietnam. The epidemiology, genetic diversity and transmission patterns of respiratory viral pathogens that circulate in this region are not well characterized. We used RT-PCR to screen for 14 common respiratory viruses in nasal/throat samples from 4326 ARI patients from 5 sites in Vietnam during 2012-2016. 64% of patients tested positive for viruses; 14% tested positive multiple co-infecting viruses. The most frequently detected viruses were Respiratory syncytial virus (RSV, 23%), Human Rhinovirus (HRV, 13%), Influenza A virus (IAV, 11%) and Human Bocavirus (HBoV, 7%). RSV infections peaked in July to October, were relatively more common in children <1 year and in the northernmost hospital. IAV infections peaked in December to February and were relatively more common in patients >5 years in the central region. Coinfection with IAV or RSV was associated with increased disease severity compared with patients only infected with HBoV or HRV. Over a hundred genomes belonging to 13 families and 24 genera were obtained via metagenomic sequencing, including novel viruses and viruses less commonly associated with ARIs. Phylogenetic and phylogeographic analyses further indicated that neighboring countries were the most likely source of many virus lineages causing ARIs in Vietnam and estimated the period that specific lineages have been circulating. Our study illustrates the value of applying the state-of-the-art virus diagnostic methods (multiplex RT-PCR and metagenomic sequencing) and phylodynamic analyses at a national level to generate an integrated picture of viral ARI epidemiology.

The Clinical Utility of Respiratory Viral Testing in Hospitalized Children: A Meta-analysis

CONTEXT

Respiratory virus (RV) detection tests are commonly used in hospitalized children to diagnose viral acute respiratory infection (ARI), but their clinical utility is uncertain.

OBJECTIVES

To systematically review and meta-analyze the impact of RV test results on antibiotic consumption, ancillary testing, hospital length of stay, and antiviral use in children hospitalized with severe ARI.

DATA SOURCES

Seven medical literature databases from 1985 through January 2018 were analyzed.

STUDY SELECTION

Studies in children <18 years old hospitalized for severe ARI in which the clinical impact of a positive versus negative RV test result or RV testing versus no testing are compared.

DATA EXTRACTION

Two reviewers independently screened titles, abstracts, and full texts; extracted data; and assessed study quality.

RESULTS

We included 23 studies. High heterogeneity did not permit an overall meta-analysis. Subgroup analyses by age, RV test type, and viral target showed no difference in the proportion of patients receiving antibiotics between those with positive versus negative test results. Stratification by study design revealed that RV testing decreased antibiotic use in prospective cohort studies (odds ratio = 0.58; 95% confidence interval: 0.45-0.75). Pooled results revealed no conclusive impact on chest radiograph use (odds ratio = 0.71; 95% confidence interval: 0.48-1.04). Results of most studies found that positive RV test results did not impact median hospital length of stay, but they may decrease antibiotic duration. Nineteen (83%) studies were at serious risk of bias.

LIMITATIONS

Low-quality studies and high clinical and statistical heterogeneity were among the limitations.

CONCLUSIONS

Higher-quality prospective studies are needed to determine the impact of RV testing on antibiotic use in children hospitalized with severe ARI.

Impact of viral multiplex real-time PCR on management of respiratory tract infection: a retrospective cohort study

Background

Significance and clinical utility of multiple virus detection by multiplex real-time polymerase chain reaction (rtPCR) in respiratory tract infection remain unclear.

Methods

This retrospective cohort study analyzed how virus detection affected clinical management. During a 27-month period, clinical and laboratory information was collected from all children and adults in two Swiss tertiary centres whose respiratory samples were tested for respiratory viruses with a 16-plex rtPCR test.

Results

Pathogens were identified in 140 of 254 patients (55%); of those patients, there was ≥1 virus in 91 (65%), ≥ 1 bacterium in 53 (38%), and ≥1 virus and bacterium in 11 (8%). Of 80 patients with viral infection, 59 (74%) received antibiotics. Virus detection was associated with discontinuation of antibiotics in 2 of 20 adults (10%) and 6 of 14 children (43%). Overall 12 adults (34%) and 18 children (67%) were managed correctly without antibiotics after virus detection (p = 0.01). When taking biomarkers, radiologic presentations, and antibiotic pre-treatment into account, the impact of rtPCR and appropriateness of therapy for clinically viral infections increased to 100% in children and 62% in adults.

Conclusions

A substantial reduction of unnecessary antibiotic prescriptions seems possible. Appropriate application of rtPCR results in respiratory tract infections should be encouraged.

Utilization of viral molecular diagnostics among children hospitalized with community acquired pneumonia

OBJECTIVE

To examine whether results of a polymerase chain reaction-based respiratory viral panel (RVP) are associated with changes in antibiotic use or differential clinical outcomes among children hospitalized with pneumonia.

METHODS

We retrospectively identified otherwise healthy children hospitalized over a 3-year period at a single institution with community-acquired pneumonia who had an RVP performed within 24 hours of admission. We examined associations between RVP results and clinical outcomes as well as management decisions including initiation and duration of intravenous antibiotics.

RESULTS

Among 202 children, a positive RVP (n = 127, 63%) was associated with a more complicated clinical course, although this was due largely to more severe disease seen in younger children and those with respiratory syncytial virus (n = 38, 30% of positive detections). Detection of a virus did not influence antibiotic therapy. Included children were younger and had more severe illness than children hospitalized with pneumonia at the same institution without an RVP obtained.

CONCLUSIONS

In our study, only respiratory syncytial virus was associated with a more severe clinical course compared with RVP-negative children. Regardless of the virus detected, RVP positivity did not influence antibiotic usage. However, RVP use focused primarily on children with severe pneumonia. Whether similar testing influences management decisions among children with less severe illness deserves further study.

Role of a respiratory viral panel in the clinical management of pediatric inpatients

BACKGROUND

Respiratory viral panels (RVPs) able to detect multiple pathogens are increasingly used in the management of pediatric inpatients. Despite this, few studies have examined whether the results of these tests are associated with clinically significant changes in medical management.

METHODS

In this retrospective cohort study, we identified pediatric inpatients between August 2009 and December 2010 for whom an RVP was ordered within 24 hours of admission to a large, tertiary-care children's hospital. We used linear regression to determine whether RVP was associated with length of stay (LOS), duration of antibiotics and the number of diagnostic microbiology tests ordered, adjusting for potential confounders.

RESULTS

We found that the association between results of the RVP and LOS was dependent on a patient's admission service, specifically admission to the hematology/oncology service. We also found that patients with a positive RVP had a shorter duration of intravenous antibiotic administration (P = 0.03; 42% reduction in the geometric mean), but that this was influenced by the primary admission service. We also found that positive results of the RVP were associated with decreased LOS and shorter duration of antibiotics in patients with some common respiratory diagnoses.

CONCLUSIONS

This study lacked sufficient evidence to claim an association between a positive RVP and LOS in pediatric patients, adjusting for their underlying diagnosis. However, we found that a positive RVP was associated with a shorter duration of intravenous antibiotic administration in certain groups of patients and those with some common respiratory diagnoses. These findings help clarify the utility of rapid viral testing in the management of hospitalized pediatric patients.