Microbial populations of the upper respiratory tract in mid-aged adults and the elderly differ; it is possible that these differences contribute to the increased risk of respiratory infections experienced by the elderly.

BackgroundWe undertook a 2X2 factorial, randomized controlled trial (RCT) to assess whether vitamin D3 supplementation (10,000 international units per week) versus placebo and gargling versus no gargling could prevent viral, clinical upper respiratory tract infection (URTI) in university students.MethodsWe randomized 600 students into 4 treatment arms: 1) vitamin D3 and gargling, 2) placebo and gargling, 3) vitamin D3 and no gargling, and 4) placebo and no gargling. Students completed weekly electronic surveys and submitted self-collected mid-turbinate nasal flocked swabs during September and October in 2010 or 2011. Symptomatic students also completed an electronic symptom diary. The primary and secondary outcomes were the occurrence of symptomatic clinical URTI and laboratory confirmed URTI respectively.ResultsOf 600 participants, 471 (78.5%) completed all surveys while 43 (7.2%) completed none; 150 (25.0%) reported clinical URTI. Seventy participants (23.3%) randomized to vitamin D3 reported clinical URTI compared to 80 (26.7%) randomized to placebo (RR:0.79, CI95:0.61-1.03, p = 0.09). Eighty-five participants (28.3%) randomized to gargling reported clinical URTI compared to 65 participants (21.7%) randomized to the no gargling arm (RR:1.3, CI95:0.92-1.57, p = 0.19). Laboratory testing identified 70 infections (46.7 per 100 URTIs). Vitamin D3 treatment was associated with a significantly lower risk for laboratory confirmed URTI (RR: 0.54, CI95:0.34-0.84, p = 0.007) and with a significantly lower mean viral load measured as log10 viral copies/mL (mean difference: -0.89, CI95: -1.7, -0.06, p = 0.04). Fewer students assigned to gargling experienced laboratory confirmed URTI, however this was not statistically significant (RR:0.82, CI95:0.53-1.26, p = 0.36).ConclusionsThese results suggest that vitamin D3 is a promising intervention for the prevention of URTI. Vitamin D3 significantly reduced the risk of laboratory confirmed URTI and may reduce the risk of clinical infections.Trial registrationClinical Trials Registration: NCT01158560.

f Two-hundred eighty matched bulk stool and anatomically designed flocked rectal swab samples were collected from children admitted to the hospital with acute diarrhea in Botswana. Their parents were asked about the acceptability of the swab collection method compared with bulk stool sampling. All samples underwent identical testing with a validated 15-target (9 bacterial, 3 viral, and 3 parasite) commercial multiplex PCR assay. The flocked swabs had a 12% higher yield for bacterial pathogen targets (241 versus 212; P ‫؍‬ 0.003) compared with that of stool samples, as well as similar yields for viral targets (110 versus 113; P ‫؍‬ 0.701) and parasite targets (59 versus 65; P ‫؍‬ 0.345). One hundred sixty-four of the flocked swab-stool pairs were also tested with separate laboratory-developed bacterial and viral multiplex assays, and the flocked rectal swabs had a performance that was similar to that seen with commercial assay testing. Almost all parents/guardians found the swabs acceptable. Flocked rectal swabs significantly facilitate the molecular diagnosis of diarrheal disease in children. Diarrheal disease remains a leading cause of global childhood morbidity and mortality, yet access to diagnostic laboratory testing is rarely available in much of the world. One of the barriers to diagnosing diarrheal disease, either for clinical or surveillance purposes, is the difficulty and time delays in obtaining and transporting a bulk stool specimen. Several investigators have sought to overcome this barrier through the use of rectal swab specimens for culture, molecular, and antigen testing, with variable results (1-5). Flocked swabs designed for respiratory and genitourinary sampling have been shown to acquire better samples than those acquired with more traditional spun fiber swabs (6, 7). We used a specially designed flocked rectal swab (FLOQSwabs; Copan Italia, Brescia, Italy) developed specifically for the diagnosis of diarrheal disease in children (Fig. 1) and then compared matched flocked rectal swabs to bulk stool samples in a clinical setting. The samples were collected from children admitted to the hospital in Botswana with severe acute gastroenteritis and tested using a U.S. FDAcleared commercial multiplex PCR assay in order to assess performance across a broad number of bacterial, viral, and parasitic pathogens.(These data were presented in part at the 29th Annual Clinical Virology Symposium, Daytona Beach, FL, 28 April to 1 May 2013, and at the Annual Pediatric Academic Society Meeting, Vancouver, Canada, 5 May 2014.) MATERIALS AND METHODSChildren Ͻ13 years of age who were admitted to the hospital with a diagnosis of acute gastroenteritis were enrolled prospectively at the Princess Marina Hospital in Gaborone, Botswana. Princess Marina Hospital is the largest referral hospital in Botswana.Clinical data were collected, and both the pediatric flocked rectal swab and bulk stool samples were obtained from each child as soon as possible after enrollment. The swab and stool samples were collected simultaneousl...

We developed and evaluated flocked nasal midturbinate swabs obtained from 55 asymptomatic and 108 symptomatic volunteers. Self-collected swabs obtained from asymptomatic volunteers yielded numbers of respiratory epithelial cells comparable to those of staff-collected nasal (n ‫؍‬ 55) or nasopharyngeal (n ‫؍‬ 20) swabs. Specific viruses were detected in swabs self-collected by 42/108 (38.9%) symptomatic volunteers by multiplex PCR.We report herein the design and evaluation of a novel selfcollected nasal midturbinate swab for respiratory virus diagnosis. We previously demonstrated that Copan flocked nasopharyngeal swabs (NPS) collected significantly more respiratory epithelial cells than conventional rayon swabs and improved sample collection for direct fluorescent antibody (DFA) testing of respiratory viruses (2). We observed that the cell yield obtained from sampling the nose using a flocked swab designed for nasopharyngeal sampling was equivalent to that obtained from nasopharyngeal sampling using rayon NPS. This led us to hypothesize that a flocked nasal swab designed to contact a larger nasal surface area would further improve cell sampling and enable self-collection.We measured the nasal passages of adult white cadavers at the Michael G. DeGroote School of Medicine anatomy laboratory, McMaster University, and designed a tapered coneshaped swab with a greater length and diameter of flocked nylon ( Fig. 1). A collar was added at 5.5 cm as a guide to maximum insertion depth for adults. The nasal swab samples a large surface area of respiratory mucosa, covering the inferior and middle turbinate bones, and is now commercially available in pediatric and adult sizes (FLOQSwabs; Copan Italia S.p.A., Brescia, Italy).Our primary study objectives were to determine the feasibility, acceptability, and performance characteristics of selfsampled nasal midturbinate swabs. We tested the adequacy of self-collected flocked nasal swabs, the equivalence of nasal and nasopharyngeal sampling, and the diagnostic yield for specific respiratory viruses by multiplex PCR. The study protocol was approved by the Research Ethics Board at St. Joseph's Healthcare, Hamilton, Ontario, Canada.To examine the adequacy of respiratory specimen self-collection, 55 healthy asymptomatic adult volunteers were recruited from hospital staff and visitors. After providing signed informed consent, volunteers self-collected two flocked nasal swabs by following the printed instructions with illustrations. Each swab was inserted up to 5.5 cm, as tolerated, into the same nostril of their choice. An experienced staff member then collected the following two additional nasal swabs, using the opposite nostril in randomized order: a flocked midturbinate nasal swab and a rayon pernasal swab. A self-administered questionnaire assessed the ease of self-collection, discomfort, and swab preferences.All four nasal swabs were placed into universal transport medium (UTM; Copan Italia S.p.A.) and coded to maintain blinding. Samples were processed identically, according to c...