Throat swabs in children with respiratory tract infection: associations with clinical presentation and potential targets for point-of-care testing

Rapid respiratory microbiological point-of-care-testing and antibiotic prescribing in primary care: Protocol for the RAPID-TEST randomised controlled trial

BACKGROUND

Antibiotics are prescribed for over 50% of respiratory tract infections in primary care, despite good evidence of there being no benefit to the patient, and evidence of over prescribing driving microbial resistance. The high treatment rates are attributed to uncertainty regarding microbiological cause and clinical prognosis. Point-of-care-tests have been proposed as potential antibiotic stewardship tools, with some providing microbiological results in 15 minutes. However, there is little research on their impact on antibiotic use and clinical outcomes in primary care.

METHODS

This is a multi-centre, individually randomised controlled trial with mixed-methods investigation of microbial, behavioural and antibiotic mechanisms on outcomes in patients aged 12 months and over presenting to primary care in the UK with a suspected respiratory tract infection, where the clinician and/or patient thinks antibiotic treatment may be, or is, necessary. Once consented, all participants are asked to provide a combined nose and throat swab sample and randomised to have a rapid microbiological point-of-care-test or no point-of-care-test. For intervention patients, clinicians review the result of the test, before contacting the patient to finalise treatment. Treatment decisions are made as per usual care in control group patients. The primary outcome is whether an antibiotic is prescribed at this point. All swab samples are sent to the central laboratory for further testing. Patients are asked to complete a diary to record the severity and duration of symptoms until resolution or day 28, and questionnaires at 2 months about their beliefs and intention to consult for similar future illnesses. Primary care medical records are also reviewed at 6-months to collect further infection consultations, antibiotic prescribing and hospital admissions. The trial aims to recruit 514 patients to achieve 90% power with 5% significance to detect a 15% absolute reduction in antibiotic prescribing. Qualitative interviews are being conducted with approximately 20 clinicians and 30 participants to understand any changes in beliefs and behaviour resulting from the point-of-care-test and generate attributes for clinician and patient discrete choice experiments.

DISCUSSION

This trial will provide evidence of efficacy, acceptability and mechanisms of action of a rapid microbiological point-of-care test on antibiotic prescribing and patient symptoms in primary care.

TRIAL REGISTRATION

ISRCTN16039192, prospectively registered on 08/11/2022.

Asymptomatic viruses detectable in saliva in the first year of life: a narrative review

Viral infections are common in children. Many can be asymptomatic or have delayed health consequences. In view of increasing availability of point-of-care viral detection technologies, with possible application in newborn screening, this review aimed to (1) identify potentially asymptomatic viruses detectable in infants under one year old, via saliva/nasopharyngeal swab, and (2) describe associations between viruses and long-term health conditions. We systematically searched Embase(Ovid), Medline(Ovid) and PubMed, then further searched the literature in a tiered approach. From the 143 articles included, 28 potentially asymptomatic viruses were identified. Our second search revealed associations with a range of delayed health conditions, with most related to the severity of initial symptoms. Many respiratory viruses were linked with development of recurrent wheeze or asthma. Of note, some potentially asymptomatic viruses are linked with later non-communicable diseases: adenovirus serotype 36 and obesity, Enterovirus-A71 associated Hand, Foot, Mouth Disease and Attention-Deficit Hyperactivity Disorder, Ebstein Barr Virus (EBV) and malignancy, EBV and multiple sclerosis, HHV-6 and epilepsy, HBoV-1 and lung fibrosis and Norovirus and functional gastrointestinal disorders. Our review identified many potentially asymptomatic viruses, detectable in early life with potential delayed health consequences, that could be important to screen for in the future using rapid point-of-care viral detection methods. IMPACT: Novel point-of-care viral detection technologies enable rapid detection of viruses, both old and emerging. In view of increasing capability to screen for viruses, this is the first review to explore which potentially asymptomatic viruses, that are detectable using saliva and/or nasopharyngeal swabs in infants less than one year of age, are associated with delayed adverse health conditions. Further research into detecting such viruses in early life and their delayed health outcomes may pave new ways to prevent non-communicable diseases in the future.

Positive and negative viral associations in patients with acute respiratory tract infections in primary care: the ECOVIR study

Introduction

Acute respiratory infections (ARIs) are the most common viral infections encountered in primary care settings. The identification of causal viruses is still not available in routine practice. Although new strategies of prevention are being identified, knowledge of the relationships between respiratory viruses remains limited.

Materials and methods

ECOVIR was a multicentric prospective study in primary care, which took place during two pre-pandemic seasons (2018-2019 and 2019-2020). Patients presenting to their General practitioner (GP) with ARIs were included, without selecting for age or clinical conditions. Viruses were detected on nasal swab samples using a multiplex Polymerase Chain Reaction test focused on 17 viruses [Respiratory Syncytial Virus-A (RSV-A), RSV-B, Rhinovirus/Enterovirus (HRV), human Metapneumovirus (hMPV), Adenovirus (ADV), Coronaviruses (CoV) HKU1, NL63, 229E, OC43, Influenza virus (H1 and H3 subtypes), Influenza virus B, Para-Influenza viruses (PIVs) 1-4, and Bocavirus (BoV)].

Results

Among the 668 analyzed samples, 66% were positive for at least one virus, of which 7.9% were viral codetections. The viral detection was negatively associated with the age of patients. BoV, ADV, and HRV occurred more significantly in younger patients than the other viruses (p < 0.05). Codetections were significantly associated with RSV, HRV, BoV, hMPV, and ADV and not associated with influenza viruses, CoV, and PIVs. HRV and influenza viruses were negatively associated with all the viruses. Conversely, a positive association was found between ADV and BoV and between PIVs and BoV.

Conclusion

Our study provides additional information on the relationships between respiratory viruses, which remains limited in primary care.

Antibiotics for lower respiratory tract infection in children presenting in primary care: ARTIC-PC RCT

Background

Antimicrobial resistance is a global health threat. Antibiotics are commonly prescribed for children with uncomplicated lower respiratory tract infections, but there is little randomised evidence to support the effectiveness of antibiotics in treating these infections, either overall or relating to key clinical subgroups in which antibiotic prescribing is common (chest signs; fever; physician rating of unwell; sputum/rattly chest; shortness of breath).

Objectives

To estimate the clinical effectiveness and cost-effectiveness of amoxicillin for uncomplicated lower respiratory tract infections in children both overall and in clinical subgroups.

Design

Placebo-controlled trial with qualitative, observational and cost-effectiveness studies.

Setting

UK general practices.

Participants

Children aged 1-12 years with acute uncomplicated lower respiratory tract infections.

Outcomes

The primary outcome was the duration in days of symptoms rated moderately bad or worse (measured using a validated diary). Secondary outcomes were symptom severity on days 2-4 (0 = no problem to 6 = as bad as it could be); symptom duration until very little/no problem; reconsultations for new or worsening symptoms; complications; side effects; and resource use.

Methods

Children were randomised to receive 50 mg/kg/day of oral amoxicillin in divided doses for 7 days, or placebo using pre-prepared packs, using computer-generated random numbers by an independent statistician. Children who were not randomised could participate in a parallel observational study. Semistructured telephone interviews explored the views of 16 parents and 14 clinicians, and the data were analysed using thematic analysis. Throat swabs were analysed using multiplex polymerase chain reaction.

Results

A total of 432 children were randomised (antibiotics, n = 221; placebo, n = 211). The primary analysis imputed missing data for 115 children. The duration of moderately bad symptoms was similar in the antibiotic and placebo groups overall (median of 5 and 6 days, respectively; hazard ratio 1.13, 95% confidence interval 0.90 to 1.42), with similar results for subgroups, and when including antibiotic prescription data from the 326 children in the observational study. Reconsultations for new or worsening symptoms (29.7% and 38.2%, respectively; risk ratio 0.80, 95% confidence interval 0.58 to 1.05), illness progression requiring hospital assessment or admission (2.4% vs. 2.0%) and side effects (38% vs. 34%) were similar in the two groups. Complete-case (n = 317) and per-protocol (n = 185) analyses were similar, and the presence of bacteria did not mediate antibiotic effectiveness. NHS costs per child were slightly higher (antibiotics, £29; placebo, £26), with no difference in non-NHS costs (antibiotics, £33; placebo, £33). A model predicting complications (with seven variables: baseline severity, difference in respiratory rate from normal for age, duration of prior illness, oxygen saturation, sputum/rattly chest, passing urine less often, and diarrhoea) had good discrimination (bootstrapped area under the receiver operator curve 0.83) and calibration. Parents found it difficult to interpret symptoms and signs, used the sounds of the child's cough to judge the severity of illness, and commonly consulted to receive a clinical examination and reassurance. Parents acknowledged that antibiotics should be used only when 'necessary', and clinicians noted a reduction in parents' expectations for antibiotics.

Limitations

The study was underpowered to detect small benefits in key subgroups.

Conclusion

Amoxicillin for uncomplicated lower respiratory tract infections in children is unlikely to be clinically effective or to reduce health or societal costs. Parents need better access to information, as well as clear communication about the self-management of their child's illness and safety-netting.

Future work

The data can be incorporated in the Cochrane review and individual patient data meta-analysis.

Trial registration

This trial is registered as ISRCTN79914298.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 9. See the NIHR Journals Library website for further project information.

Antibiotics for lower respiratory tract infection in children presenting in primary care (ARTIC-PC): the predictive value of molecular testing

OBJECTIVES

This study aimed to assess whether the presence of bacteria or viruses in the upper airway of children presenting with uncomplicated lower respiratory tract infection (LRTI) predicts the benefit of antibiotics.

METHODS

Children between 6 months and 12 years presenting to UK general practices with an acute LRTI were randomized to receive amoxicillin 50 mg/kg/d for 7 days or placebo. Children not randomized (ineligible or clinician/parental choice) could participate in a parallel observational study. The primary outcome was the duration of symptoms rated moderately bad or worse. Throat swabs were taken and analyzed for the presence of bacteria and viruses by multiplex PCR.

RESULTS

Swab results were available for most participants in the trial (306 of 432; 71%) and in the observational (182 of 326; 59%) studies. Bacterial pathogens potentially sensitive to amoxicillin (Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae) were detected among 51% of the trial placebo group and 49% of the trial antibiotic group. The median difference in the duration of symptoms rated moderately bad or worse between antibiotic and placebo was similar when potentially antibiotic-susceptible bacteria were present (median: -1 day; 99% CI, -12.3 to 10.3) or not present (median: -1 day; 99% CI, -4.5 to 2.5). Furthermore, bacterial genome copy number did not predict benefit. There were similar findings for all secondary outcomes and when including the data from the observational study.

DISCUSSION

There was no clear evidence that antibiotics improved clinical outcomes conditional on the presence or concentration of bacteria or viruses in the upper airway. Before deploying microbiologic point-of-care tests for children with uncomplicated LRTI in primary care, rigorous validating trials are needed.

Prognostic value of upper respiratory tract microbes in children presenting to primary care with respiratory infections: A prospective cohort study

Background

The association between upper respiratory tract microbial positivity and illness prognosis in children is unclear. This impedes clinical decision-making and means the utility of upper respiratory tract microbial point-of-care tests remains unknown. We investigated for relationships between pharyngeal microbes and symptom severity in children with suspected respiratory tract infection (RTI).

Methods

Baseline characteristics and pharyngeal swabs were collected from 2,296 children presenting to 58 general practices in Bristol, UK with acute cough and suspected RTI between 2011–2013. Post-consultation, parents recorded the severity of six RTI symptoms on a 0–6 scale daily for ≤28 days. We used multivariable hurdle regression, adjusting for clinical characteristics, antibiotics and other microbes, to investigate associations between respiratory microbes and mean symptom severity on days 2–4 post-presentation.

Results

Overall, 1,317 (57%) children with complete baseline, microbiological and symptom data were included. Baseline characteristics were similar in included participants and those lacking microbiological data. At least one virus was detected in 869 (66%) children, and at least one bacterium in 783 (60%). Compared to children with no virus detected (mean symptom severity score 1.52), adjusted mean symptom severity was 0.26 points higher in those testing positive for at least one virus (95% CI 0.15 to 0.38, p<0.001); and was also higher in those with detected Influenza B (0.44, 0.15 to 0.72, p = 0.003); RSV (0.41, 0.20 to 0.60, p<0.001); and Influenza A (0.25, -0.01 to 0.51, p = 0.059). Children positive for Enterovirus had a lower adjusted mean symptom severity (-0.24, -0.43 to -0.05, p = 0.013). Children with detected Bordetella pertussis (0.40, 0.00 to 0.79, p = 0.049) and those with detected Moraxella catarrhalis (-0.76, -1.06 to -0.45, p<0.001) respectively had higher and lower mean symptom severity compared to children without these bacteria.

Conclusions

There is a potential role for upper respiratory tract microbiological point-of-care tests in determining the prognosis of childhood RTIs.

Antibiotics for lower respiratory tract infection in children presenting in primary care in England (ARTIC PC): a double-blind, randomised, placebo-controlled trial

BACKGROUND

Antibiotic resistance is a global public health threat. Antibiotics are very commonly prescribed for children presenting with uncomplicated lower respiratory tract infections (LRTIs), but there is little evidence from randomised controlled trials of the effectiveness of antibiotics, both overall or among key clinical subgroups. In ARTIC PC, we assessed whether amoxicillin reduces the duration of moderately bad symptoms in children presenting with uncomplicated (non-pneumonic) LRTI in primary care, overall and in key clinical subgroups.

METHODS

ARTIC PC was a double-blind, randomised, placebo-controlled trial done at 56 general practices in England. Eligible children were those aged 6 months to 12 years presenting in primary care with acute uncomplicated LRTI judged to be infective in origin, where pneumonia was not suspected clinically, with symptoms for less than 21 days. Patients were randomly assigned in a 1:1 ratio to receive amoxicillin 50 mg/kg per day or placebo oral suspension, in three divided doses orally for 7 days. Patients and investigators were masked to treatment assignment. The primary outcome was the duration of symptoms rated moderately bad or worse (measured using a validated diary) for up to 28 days or until symptoms resolved. The primary outcome and safety were assessed in the intention-to-treat population. The trial is registered with the ISRCTN Registry (ISRCTN79914298).

FINDINGS

Between Nov 9, 2016, and March 17, 2020, 432 children (not including six who withdrew permission for use of their data after randomisation) were randomly assigned to the antibiotics group (n=221) or the placebo group (n=211). Complete data for symptom duration were available for 317 (73%) patients; missing data were imputed for the primary analysis. Median durations of moderately bad or worse symptoms were similar between the groups (5 days [IQR 4-11] in the antibiotics group vs 6 days [4-15] in the placebo group; hazard ratio [HR] 1·13 [95% CI 0·90-1·42]). No differences were seen for the primary outcome between the treatment groups in the five prespecified clinical subgroups (patients with chest signs, fever, physician rating of unwell, sputum or chest rattle, and short of breath). Estimates from complete-case analysis and a per-protocol analysis were similar to the imputed data analysis.

INTERPRETATION

Amoxicillin for uncomplicated chest infections in children is unlikely to be clinically effective either overall or for key subgroups in whom antibiotics are commonly prescribed. Unless pneumonia is suspected, clinicians should provide safety-netting advice but not prescribe antibiotics for most children presenting with chest infections.

FUNDING

National Institute for Health Research.

Novel multi-virus rapid respiratory microbiological point-of-care testing in primary care: a mixed-methods feasibility evaluation

BACKGROUND AND OBJECTIVES

Rapid multi-viral respiratory microbiological point-of-care tests (POCTs) have not been evaluated in UK primary care. The aim of this study was to evaluate the use of a multi-viral microbiological POCT for suspected respiratory tract infections (RTIs).

METHODS

In this observational, mixed-methods feasibility study practices were provided with a POCT machine for any patient aged ≥3 months with suspected RTI. Dual throat/nose swabs tested for 17 respiratory viruses and three atypical bacteria, 65 minutes per sample.

RESULTS

Twenty clinicians recruited 93 patients (estimated 1:3 of all RTI cases). Patient's median age was 29, 57% female, and 44% with co-morbidities. Pre-test diagnoses: upper RTI (48%); lower RTI (30%); viral/influenza-like illness (18%); other (4%). Median set-up time was 2.72 minutes, with 72% swabs processed <4 hours, 90% <24 hours. Tests detected ≥1 virus in 58%, no pathogen 37% and atypical bacteria 2% (3% inconclusive). Antibiotics were prescribed pre-test to 35% of patients with no pathogen detected and 25% with a virus. Post-test diagnoses changed in 20%, and diagnostic certainty increased (P = 0.02), more so when the test was positive rather than negative (P < 0.001). Clinicians predicted decreased antibiotic benefit post-test (P = 0.02). Interviews revealed the POCT has clear potential, was easy to use and well-liked, but limited by time-to-result and the absence of testing for typical respiratory bacteria.

CONCLUSIONS

This POCT was acceptable and appeared to influence clinical reasoning. Clinicians wanted faster time-to-results and more information about bacteria. Randomized trials are needed to understand the safety, efficacy and patient perceptions of these POCTs.

Prevalence of antimicrobial-resistant Streptococcus species among respiratory patients and meat products, and antibacterial effects of oregano oil nanoemulsion

Background and Aim: Antimicrobial-resistant Streptococcus species causes several diseases in humans with infection recurrence in some cases. Handling of food under unhygienic conditions resulted in transmission of pathogens to food leading to risks for consumers' health. This work studies the possible role of humans in transmission of human pathogens to food products. In this study, we focused on the presence of antimicrobial resistance Streptococcus pyogenes, Streptococcus mitis, and Streptococcus pneumoniae found in respiratory patients and in some meat products. We detected the risk factors for patient's infection and examined the antibacterial effect of oregano oil nanoemulsion (ONE) at different concentrations against the multi-drug resistance strains of streptococci. Materials and Methods: Microbiological culture and polymerase chain reaction were used to identify S. pyogenes, S. mitis, and S. pneumoniae in 120 throat swab samples and 200 meat products. The disk diffusion method was used for investigating the prevalence of resistance against 10 antimicrobials that are commonly used in the treatment of humans and animals. ONE at four concentrations (0.5%, 1.0%, 2.0%, and 3.0%) with an average particle size of 45.4 nm was identified using transmission electron microscopy. The effect of ONE on Streptococcus species isolates was examined using the well diffusion method. Risk factors for human infection were detected using statistical analysis. Results: S. pyogenes, S. mitis, and S. pneumoniae were detected in 14 (11.7%), 9 (7.5%), and 7 (5.8%), respectively, of 120 throat swabs of patients. These bacteria were also detected in 11 (5.5%), 8 (4%), and 6 (3%), respectively, of 200 meat products samples. Beef luncheon had the highest infection rate for the three species of streptococci. The majority of these isolates showed resistance to antimicrobials such as tetracycline and amoxicillin/clavulanic acid. ONE had an inhibitory effect on the growth of S. pyogenes, S. mitis, and S. pneumoniae, and its effect was significantly increased at a high concentration (3%), with a mean inhibition zone of 36.45±0.302 mm. Very young and old patients, those with chronic diseases, and those exposed to the infection several times were most susceptible to infection. Conclusion: ONE may be used as a therapeutic agent at safe and specific doses, and also in the food industry, to prevent the spoilage of food and protect human health.

Relationship between microbiology of throat swab and clinical course among primary care patients with acute cough: a prospective cohort study

BACKGROUND

Acute lower respiratory tract infections (ALRTIs) account for most antibiotics prescribed in primary care despite lack of efficacy, partly due to clinician uncertainty about aetiology and patient concerns about illness course. Nucleic acid amplification tests could assist antibiotic targeting.

METHODS

In this prospective cohort study, 645 patients presenting to primary care with acute cough and suspected ALRTI, provided throat swabs at baseline. These were tested for respiratory pathogens by real-time polymerase chain reaction and classified as having a respiratory virus, bacteria, both or neither. Three hundred fifty-four participants scored the symptoms severity daily for 1 week in a diary (0 = absent to 4 = severe problem).

RESULTS

Organisms were identified in 346/645 (53.6%) participants. There were differences in the prevalence of seven symptoms between the organism groups at baseline. Those with a virus alone, and those with both virus and bacteria, had higher average severity scores of all symptoms combined during the week of follow-up than those in whom no organisms were detected [adjusted mean differences 0.204 (95% confidence interval 0.010 to 0.398) and 0.348 (0.098 to 0.598), respectively]. There were no differences in the duration of symptoms rated as moderate or severe between organism groups.

CONCLUSIONS

Differences in presenting symptoms and symptoms severity can be identified between patients with viruses and bacteria identified on throat swabs. The magnitude of these differences is unlikely to influence management. Most patients had mild symptoms at 7 days regardless of aetiology, which could inform patients about likely symptom duration.

Efficacy and safety of rapid tests to guide antibiotic prescriptions for sore throat

BACKGROUND

Sore throat is a common condition caused by viruses or bacteria, and is a leading cause of antibiotic prescription in primary care. The most common bacterial species is group A streptococcus ('strep throat'). Between 50% to 70% of pharyngitis cases are treated with antibiotics, despite the majority of cases being viral in origin. One strategy to reduce antibiotics is to use rapid tests for group A streptococcus to guide antibiotic prescriptions. Rapid tests can be used alone or in combination with a clinical scoring system.

OBJECTIVES

To assess the efficacy and safety of strategies based on rapid tests to guide antibiotic prescriptions for sore throat in primary care settings.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, Web of Science, and LILACS, as well as the trial registries ClinicalTrials.gov and the WHO ICTRP on 5 June 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing rapid tests with management based on clinical grounds to guide the prescription of antibiotics for people with a sore throat in ambulatory care settings. We included trials that randomised individuals, as well as cluster-RCTs in which individual practitioners (or practices) or emergency departments were randomised.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data on the primary outcomes (number of participants provided with an antibiotic prescription; number of participants with an antibiotic dispensed) and secondary outcomes (duration of sore throat symptoms; duration of other symptoms; quality of life measures; number of participants with a complication attributed to the index infection; number of participants in need of re-consultation by the end of follow-up; number of participants in need of hospital admission by the end of follow-up; number of satisfied participants; number of participants with an adverse event attributed to the rapid test). We assessed the risk of bias of all included trials and used GRADE to assess the certainty of the evidence. We performed meta-analyses and sensitivity analyses when feasible.

MAIN RESULTS

We included five trials (2891 children and adult participants in total; 2545 participants after adjusting for clustering). Management in the intervention group was as follows: in three trials rapid tests were used in combination with a clinical scoring system; in one trial, some physicians were asked to use rapid tests alone, while others were asked to use rapid tests in combination with a clinical scoring system; in one trial, rapid tests were used alone. Based on data from five trials (2545 participants), a large reduction in prescribed antibiotics was found in the rapid test group (481/1197) versus management based on clinical grounds (865/1348), for a summary risk difference (RD) of -25%, 95% confidence interval (CI) -31% to -18%; I² = 62%; moderate-certainty evidence. Estimates of effect on antibiotic prescription rates were stable in various sensitivity analyses. Based on data from two trials (900 people) originating from the same overarching study, the evidence suggests that rapid tests may not reduce dispensed antibiotic treatments: rapid test group (156/445) versus management based on clinical grounds (197/455); summary RD -7%, 95% CI -17% to 2%; I² = 53%; low-certainty evidence. Four trials (2075 participants) reported data on the number of participants with a complication attributed to the index infection; the summary odds ratio (OR) was 0.85, 95% CI 0.03 to 26.65; P = 0.93; I² = 62%; very low-certainty evidence, which means that people in the rapid testing group were less likely to develop complications of the index infection, but the evidence is very uncertain. Two trials (1161 participants) reported on the number of participants in need of re-consultation by the end of follow-up; the summary OR was 1.12, 95% CI 0.57 to 2.21; P = 0.74; I² = 59%; low-certainty evidence, which means that participants in the rapid testing group were more likely to be in need of re-consultation by the end of the study follow-up, but the evidence is uncertain. Lack of data impeded assessment of other secondary outcomes (including safety outcomes) and of sources of heterogeneity.  AUTHORS' CONCLUSIONS: Rapid testing to guide antibiotic treatment for sore throat in primary care probably reduces antibiotic prescription rates by 25% (absolute risk difference), but may have little or no impact on antibiotic dispensing. More studies are needed to assess the efficacy and safety of rapid test-guided antibiotic prescribing, notably to evaluate patient-centred outcomes and variability across subgroups (e.g. adults versus children).

Ongoing strategies to improve the management of upper respiratory tract infections and reduce inappropriate antibiotic use particularly among lower and middle-income countries: findings and implications for the future

Introduction: Antibiotics are indispensable to maintaining human health; however, their overuse has resulted in resistant organisms, increasing morbidity, mortality and costs. Increasing antimicrobial resistance (AMR) is a major public health threat, resulting in multiple campaigns across countries to improve appropriate antimicrobial use. This includes addressing the overuse of antimicrobials for self-limiting infections, such as upper respiratory tract infections (URTIs), particularly in lower- and middle-income countries (LMICs) where there is the greatest inappropriate use and where antibiotic utilization has increased the most in recent years. Consequently, there is a need to document current practices and successful initiatives in LMICs to improve future antimicrobial use.Methodology: Documentation of current epidemiology and management of URTIs, particularly in LMICs, as well as campaigns to improve future antimicrobial use and their influence where known.Results: Much concern remains regarding the prescribing and dispensing of antibiotics for URTIs among LMICs. This includes considerable self-purchasing, up to 100% of pharmacies in some LMICs. However, multiple activities are now ongoing to improve future use. These incorporate educational initiatives among all key stakeholder groups, as well as legislation and other activities to reduce self-purchasing as part of National Action Plans (NAPs). Further activities are still needed however. These include increased physician and pharmacist education, starting in medical and pharmacy schools; greater monitoring of prescribing and dispensing practices, including the development of pertinent quality indicators; and targeted patient information and health education campaigns. It is recognized that such activities are more challenging in LMICs given more limited resources and a lack of healthcare professionals.Conclusion: Initiatives will grow across LMICs to reduce inappropriate prescribing and dispensing of antimicrobials for URTIs as part of NAPs and other activities, and these will be monitored.

Assessing the potential of upper respiratory tract point-of-care testing: a systematic review of the prognostic significance of upper respiratory tract microbes

OBJECTIVES

Microbial point-of-care testing (POCT) has potential to revolutionize clinical care. Understanding the prognostic value of microbes identified from the upper respiratory tract (a convenient sampling site) is a necessary first step to understand potential for upper respiratory tract POCTs in assisting antimicrobial treatment decisions for respiratory infections (RTIs). The aim was to investigate the relationship between upper respiratory tract microbial detection and disease prognosis, including effects of antimicrobial use.

METHODS

Data sources were the MEDLINE and Embase databases. Study eligibility criteria consisted of quantitative studies reporting microbiological and prognostic data from patients of all age groups presenting with RTI. Patients presenting to healthcare or research settings with RTI participated. Interventions included upper respiratory tract swab. The methods used were systematic review and meta-analysis.

RESULTS

Searches identified 5156 articles, of which 754 were duplicates and 4258 excluded on title or abstract. A total of 144 full texts were screened; 21 articles were retained. Studies reported data for 15 microbes and 26 prognostic measures (390 potential associations). One hundred and seven (27%) associations were investigated statistically, of which 38 (36%) were significant. Most studies reported only prognostic value of test positive results. Meta-analyses suggested hospitalization duration was longer for patients with respiratory syncytial virus than adenovirus and influenza, but significant heterogeneity was observed between studies.

CONCLUSIONS

A quarter of potential prognostic associations have been investigated. Of these, a third were significant, suggesting considerable potential for POCT. Future research should investigate prognostic value of positive and negative tests, and interactions between test results, use of antimicrobials and microbial resistance.

Adenoviral detection by recombinase polymerase amplification and vertical flow paper microarray

Respiratory viral infections often mimic the symptoms of infections caused by bacteria; however, restricted and targeted administration of antibiotics is needed to combat growing antimicrobial resistance. This is particularly relevant in low-income settings. In this work, we describe the use of isothermal amplification of viral DNA at 37 °C coupled to a paper-based vertical flow microarray (VFM) setup that utilizes a colorimetric detection of amplicons using functionalized gold nanoparticles. Two oligonucleotide probes, one in-house designed and one known adenoviral probe were tested and validated for microarray detection down to 50 nM using a synthetic target template. Furthermore, primers were shown to function in a recombinase polymerase amplification reaction using both synthetic template and viral DNA. As a proof-of-concept, we demonstrate adenoviral detection with four different adenoviral species associated with respiratory infections using the paper-based VFM format. The presented assay was validated with selected adenoviral species using the in-house probe, enabling detection at 1 ng of starting material with intra- and inter-assay %CV of ≤ 9% and ≤ 13%. Finally, we validate our overall method using clinical samples. Based on the results, the combination of recombinase polymerase amplification, paper microarray analysis, and nanoparticle-based colorimetric detection could thus be a useful strategy towards rapid and affordable multiplexed viral diagnostics.

Bacterial pathogens were detected from human exhaled breath using a novel protocol

It is generally believed that influenza outbreak is associated with breath-borne transmission of viruses, however relevant evidence is little for that of respiratory bacterial infections. On another front, point-of-care infection diagnostic methods at the bedside are significantly lacking. Here, we used a newly developed protocol of integrating an exhaled breath condensate (EBC) collection device (PKU BioScreen) and Loop Mediated Isothermal Amplification (LAMP) to investigate what bacterial pathogens can be directly exhaled out from humans. Exhaled breath condensates were collected from human subjects with respiratory infection symptoms at Peking University 3rd hospital using the BioScreen. The screened bacterial pathogens included Streptococcus pneumoniae, Staphylococcus aureus, Methicillin-resistant Stphylococcus aureus (MRSA), Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia, Haemophilus influenzae, Legionella pneumophila, Mycoplasma Pneumonia, Chlamydia pneumonia, and Mycobacterium tuberculosis. The results were further compared and validated using throat swabs from the same patients by a PCR method. Here, human bacterial pathogens such as H. influenzae, P. aeruginosa, E. coli, S. aureus and MRSA were detected in exhaled breath using the developed protocol that integrates the EBC collection and LAMP. For the patients recruited from the hospital, seven types of pathogens were detected from 36.5% of them, and for the remaining subjects none of those screened bacterial pathogens was detected. Importantly, some super resistant bacteria such as MRSA were detected from the exhaled breath, suggesting that breathing might be also an important bacterial transmission route. Results from throat swabs showed that 36.2% of the subjects were found to be infected with H. influenzae, P. aeruginosa, E. coli, S. maltophilia, S. aureus and MRSA. For the EBC samples, 33.3% were found to be infected with MRSA, E. coli and P. aeruginosa. Depending on the initial pathogen load in the sample, the entire protocol (EBC-LAMP) only takes 20-60 min to complete for a respiratory infection diagnosis. For different detection methods and pathogens, the agreements between the EBC and throat swabs from the same patients were found to range from 35% to 65%. Here, we have detected several bacterial pathogens including MRSA from exhaled breath, and the developed protocol could be very useful for the bedside pathogen screening particularly in remote areas where resources are significantly limited or prohibited.

Parent views on the content and potential impact of respiratory tract infection surveillance information: semistructured interviews to inform future research

OBJECTIVES

This study explored the potential value of real-time information regarding respiratory tract infections (RTIs) circulating in the community by eliciting parent views on illustrative surveillance information and its possible impact on primary care consultations.

DESIGN

Semistructured interviews were conducted with parents of children (>3 months-15 years). Participants were presented with example information on circulating viruses, symptoms and symptom duration and asked about its potential impact on perceptions of child illness and management practices. Interviews were analysed using the framework method.

SETTING

Parents participating in a cohort study were selected purposefully using index of multiple deprivation and child age.

PARTICIPANTS

30 mothers of children (>3 months-15years).

RESULTS

Parents anticipated using the information to inform lay diagnoses particularly when child symptoms were severe and thought normal symptom duration awareness might extend the time prior to seeking medical advice, but it also may encourage consultations when symptoms exceed the given duration. The information was not expected to change consultation behaviour if parents felt their child needed a medical evaluation and they felt unable to manage the symptoms. Most parents felt that the information could provide reassurance that could reduce intention to consult, but some felt it could raise concerns, by heightening awareness of circulating viruses. Lastly, parents wanted advice about protecting children from circulating viruses and felt that general practitioners using the information to diagnose child RTIs with greater certainty was acceptable.

CONCLUSIONS

Diverse responses to the surveillance information were elicited, and there was some support for the intended outcomes. This study has important implications for the design of interventions to modify consulting behaviour. Future piloting to measure behaviour change in response to infection surveillance information are needed.