Prospective Study of the Performance of Parent-Collected Nasal and Saliva Swab Samples, Compared with Nurse-Collected Swab Samples, for the Molecular Detection of Respiratory Microorganisms.

Respiratory tract infections (RTIs) are ubiquitous among children in the community. A prospective observational study was performed to evaluate the diagnostic performance and quality of at-home parent-collected (PC) nasal and saliva swab samples, compared to nurse-collected (NC) swab samples, from children with RTI symptoms. Children with RTI symptoms were swabbed at home on the same day by a parent and a nurse. We compared the performance of PC swab samples as the test with NC swab samples as the reference for the detection of respiratory pathogen gene targets by reverse transcriptase PCR, with quality assessment using a human gene. PC and NC paired nasal and saliva swab samples were collected from 91 and 92 children, respectively. Performance and interrater agreement (Cohen's κ) of PC versus NC nasal swab samples for viruses combined showed sensitivity of 91.6% (95% confidence interval [CI], 85.47 to 95.73%) and κ of 0.84 (95% CI, 0.79 to 0.88), respectively; the respective values for bacteria combined were 91.4% (95% CI, 86.85 to 94.87%) and κ of 0.85 (95% CI, 0.80 to 0.89). In saliva samples, viral and bacterial sensitivities were lower at 69.0% (95% CI, 57.47 to 79.76%) and 78.1% (95% CI, 71.60 to 83.76%), as were κ values at 0.64 (95% CI, 0.53 to 0.72) and 0.70 (95% CI, 0.65 to 0.76), respectively. Quality assessment for human biological material (18S rRNA) indicated perfect interrater agreement. At-home PC nasal swab samples performed comparably to NC swab samples, whereas PC saliva swab samples lacked sensitivity for the detection of respiratory microbes. IMPORTANCE RTIs are ubiquitous among children. Diagnosis involves a swab sample being taken by a health professional, which places a considerable burden on community health care systems, given the number of cases involved. The coronavirus disease 2019 (COVID-19) pandemic has seen an increase in the at-home self-collection of upper respiratory tract swab samples without the involvement of health professionals. It is advised that parents conduct or supervise swabbing of children. Surprisingly, few studies have addressed the quality of PC swab samples for subsequent identification of respiratory pathogens. We compared NC and PC nasal and saliva swab samples taken from the same child with RTI symptoms, for detection of respiratory pathogens. The PC nasal swab samples performed comparably to NC samples, whereas saliva swab samples lacked sensitivity for the detection of respiratory microbes. Collection of swab samples by parents would greatly reduce the burden on community nurses without reducing the effectiveness of diagnoses.

Should homes and workplaces purchase portable air filters to reduce the transmission of SARS-CoV-2 and other respiratory infections? A systematic review.

Respiratory infections, including SARS-CoV-2, are spread via inhalation or ingestion of airborne pathogens. Airborne transmission is difficult to control, particularly indoors. Manufacturers of high efficiency particulate air (HEPA) filters claim they remove almost all small particles including airborne bacteria and viruses. This study investigates whether modern portable, commercially available air filters reduce the incidence of respiratory infections and/or remove bacteria and viruses from indoor air. We systematically searched Medline, Embase and Cochrane for studies published between January 2000 and September 2020. Studies were eligible for inclusion if they included a portable, commercially available air filter in any indoor setting including care homes, schools or healthcare settings, investigating either associations with incidence of respiratory infections or removal and/or capture of aerosolised bacteria and viruses from the air within the filters. Dual data screening and extraction with narrative synthesis. No studies were found investigating the effects of air filters on the incidence of respiratory infections. Two studies investigated bacterial capture within filters and bacterial load in indoor air. One reported higher numbers of viable bacteria in the HEPA filter than in floor dust samples. The other reported HEPA filtration combined with ultraviolet light reduced bacterial load in the air by 41% (sampling time not reported). Neither paper investigated effects on viruses. There is an important absence of evidence regarding the effectiveness of a potentially cost-efficient intervention for indoor transmission of respiratory infections, including SARS-CoV-2. Two studies provide 'proof of principle' that air filters can capture airborne bacteria in an indoor setting. Randomised controlled trials are urgently needed to investigate effects of portable HEPA filters on incidence of respiratory infections.

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.

The UK government has called for the introduction of rapid diagnostics to curb overuse of antibiotics for common infections. Multi-viral respiratory 'point-of-care' tests (POCTs) are available but have not been used in UK primary care before. These POCTs use samples from the nose or back of the throat and give results quickly, to see if viruses or bacteria are there. In this study, four GP practices were given POCT machines for 6 weeks to see how they were used. Of the 93 patient samples tested, 3% were inconclusive, 37% tested negative, 58% had at least one virus and only 2% had a bacterial infection. Clinicians were more certain of patient diagnoses after testing especially when a virus or bacterium was detected and they were also less likely to predict the patient would benefit from antibiotics. Clinical diagnoses changed in 20% of patients after testing but less than 10% were contacted to change their treatment plan. During interviews, clinicians revealed they liked the test finding it easy-to-use but wanted faster time-to-results and testing for more bacteria. Clinical trials are needed to see if these POCTs can safely and cost-effectively reduce antibiotic prescribing in primary care.