Use of diagnostic algorithms and new technologies to study the incidence and prevalence of viral upper respiratory tract infections and their complications in high risk populations

The impact of exercise training on the lipid peroxidation metabolomic profile and respiratory infection risk in older adults

Aging is associated with oxidative stress that may increase susceptibility to respiratory infections (RIs). We aimed to assess the impact of exercise training on the risk of RIs in older adults and on a targeted metabolomic profile of stress oxidative lipid peroxidation-related metabolites.

METHODS

In an 8-month clinical trial, 38 participants over 60 years of age were allocated to an exercise group (EG), in which participants underwent 90-min training sessions three times/week(n = 20), or a control group (CG), in which participants maintained daily physical activities(n = 18). Daily respiratory symptoms and RIs number and severity were collected. Serum by-products were assessed by comprehensive two-dimensional gas chromatography coupled to mass spectrometry with time of flight analyzer. Serum metabolomic profiling comprised 76 metabolites (alcohols, aldehydes, alkanes, and ketones). Principal components analysis and ANOVA-simultaneous component analysis were used to evaluate the metabolomic profile change.

RESULTS

The odds ratio of RIs for the EG was 2.0 CI 95% [0.2;25]. The incidence of RIs was 47% [23;70] in the EG vs. 44%[12;77] in the CG. The metabolomic profiling showed that alkanes and aldehydes classes differed between the EG and the CG before and after intervention. A calibration model showed a relation between the metabolites from four main classes (ketones, alcohols, alkanes and aldehydes) and the prediction of the number of RIs.

CONCLUSION

Moderate exercise training, in older adults, compared with no exercise in controls, did not show a difference in the risk of RIs. A pattern of lipid peroxidation was associated with the number of RIs.

Family environments and leukocyte transcriptome indicators of a proinflammatory phenotype in children and parents

High conflict and low warmth in families may contribute to immune cells developing a tendency to respond to threats with exaggerated inflammation that is insensitive to inhibitory signaling. We tested associations between family environments and expression of genes bearing response elements for transcription factors that regulate inflammation: nuclear factor kappa B (NF-κB) and glucocorticoid receptor. The overall sample (47 families) completed interviews, questionnaires, and 8-week daily diary assessments of conflict and warmth, which were used to create composite family conflict and warmth scores. The diaries assessed upper respiratory infection (URI) symptoms, and URI episodes were clinically verified. Leukocyte RNA was extracted from whole blood samples provided by a subsample of 42 children (8-13 years of age) and 73 parents. In children, higher conflict and lower warmth were related to greater expression of genes bearing response elements for the proinflammatory transcription factor NF-κB, and more severe URI symptoms. In parents, higher conflict and lower warmth were also related to greater NF-κB-associated gene expression. Monocytes and dendritic cells were implicated as primary cellular sources of differential gene expression in the sample. Consistent with existing conceptual frameworks, stressful family environments were related to a proinflammatory phenotype at the level of the circulating leukocyte transcriptome.

Pressure chamber tests of eustachian tube function document lower efficiency in adults with colds when compared to without colds

CONCLUSIONS

Fractional gradient equilibrated (FGE) for ears with applied positive but not negative middle ear (ME)-ambient pressure gradients is highly sensitive to a cold-like illness (CLI).

OBJECTIVE

The sequential development of eustachian tube (ET) dysfunction, ME under-pressure, and otitis media (OM) characterizes many children during a CLI. If linked, OM burden would be lessened by interventions that promote/preserve good ET function during a CLI. Evaluating this requires a quantitative ET function test for MEs with an intact tympanic membrane responsive to a CLI.

METHODS

Pressure chamber testing of ET function was performed at +200 and -200 daPa in 3 groups of adults: group I, 21 subjects with an extant CLI and groups II and III, 14 and 57 adults, respectively, without a CLI. ME-chamber pressure gradient was recorded by tympanometry before and after the subject swallowed twice. ET functional efficiency was quantified as the FGE, which was then compared among groups using a Mann-Whitney U test.

RESULTS

At chamber pressures of 200 daPa, the ME-chamber pressure gradient was negative, and FGE was low and not different among groups. At chamber pressures of -200 daPa that gradient was positive, and FGE was significantly higher in groups II and III when compared with group I.

Evaluation of a multiplexed PCR assay for detection of respiratory viral pathogens in a public health laboratory setting

There are numerous viral and bacterial causes of respiratory disease. To enable rapid and sensitive detection of even the most prevalent causes, there is a need for more-simplified testing systems that enable researchers and clinicians to perform multiplexed molecular diagnostics quickly and easily. To this end, a new multiplexed molecular test called the MultiCode-PLx respiratory virus panel (PLx-RVP) was developed and then implemented in a public health laboratory setting. A total of 687 respiratory samples were analyzed for the presence of 17 viruses that commonly cause respiratory disease. As a comparator, the samples were also tested using a standard testing algorithm that included the use of a real-time influenza virus A and B reverse transcription-PCR test and routine viral culture identification. The standard testing algorithm identified 503 (73%) samples as positive and 184 as negative. Analyzing the same 687 samples, the PLx-RVP assay detected one or more targets in 528 (77%) samples and found 159 samples negative for all targets. There were 25 discordant results between the two systems; 14 samples were positive for viruses not routinely tested for by the Wisconsin State Laboratory of Hygiene, and 13 of these were confirmed by real-time PCR. When the results of the standard testing algorithm were considered "true positives," the PLx-RVP assay showed an overall sensitivity of 99% and an overall specificity of 87%. In total, the PLx-RVP assay detected an additional 40 viral infections, of which 11 were mixed infections.

Temporal relationships for cold-like illnesses and otitis media in sibling pairs

BACKGROUND

New otitis media (OM) episodes are most frequently a complication of cold-like illnesses (CLIs) which are often virus infections that can be exchanged within the family unit. Interference with intrafamily CLI transmission may present a strategy for OM prophylaxis in high risk children. This study estimated factors relevant to strategy efficiency.

METHODS

Two siblings (ages, 1.0-4.3 and 1.7-6.1 years) from 69 families were followed for 193 days beginning in October using daily parental diaries focused on CLI signs and weekly pneumatic otoscopy to diagnose OM presence/absence. An algorithm converted the signs to presence/absence of a cold-day; cold-days were grouped into CLI episodes, and episodes were examined for intersib transmission and OM complications.

RESULTS

We identified 267 CLIs in the younger siblings and 221 in the older siblings. Twenty-seven percent of the CLI episodes in one sibling occurred after CLI onset in the other with a median interval of 3 days. Sixty-two percent of newly diagnosed OM episodes occurred during a CLI and 27% of CLIs were complicated by OM. Analysis of factors that could affect CLI incidence documented significant contributions of gender, age, daily environment and the CLI burden in the sibling with expected directionalities.

CONCLUSION

The results document intrafamily transmission of CLIs that is often associated with the development of OM as a complication. These observations and the measured interval between primary and secondary CLI onsets support the possibility of preventing OM by strategies that target intrafamily CLI transmission.

Temporal relationships between colds, upper respiratory viruses detected by polymerase chain reaction, and otitis media in young children followed through a typical cold season

INTRODUCTION

Otitis media is a frequent complication of a viral upper respiratory tract infection, and the reported co-incidence of those diseases increases with assay sensitivity and sampling density. We determined the incidence of otitis-media complications in young children when referenced to cold-like illnesses and to concurrent virus recovery from the nasopharynx.

METHODS

A total of 60 children from 24 families were followed from October 2003 through April 30, 2004, by daily parental recording of illness signs, weekly pneumatic otoscopic examinations, and periodic polymerase chain reaction assay of collected nasal fluids for common viruses.

RESULTS

One hundred ninety-nine cold-like illnesses were observed, but a sample for virus assay was not collected concurrent with 71 episodes. Of the remainder, 73% of cold-like illnesses were temporally related to recovery of 1 or a combination of the assayed viruses, with rhinovirus predominating. For non-cold-like illness periods, 54 (18%) of 297 assays were positive for virus, and the virus frequency distribution was similar to that for cold-like illnesses. There were 93 diagnosed otitis-media episodes; 65 (70%) of these occurred during a cold-like illness. For the 79 otitis-media episodes with available nasal samples, 61 (77%) were associated with a positive virus result. In this population, the otitis-media complication rate for a cold-like illness was 33%.

CONCLUSIONS

A cold-like illness was not a prerequisite for polymerase chain reaction detection of viruses in the nose and nasopharynx of young children. Viral detection by polymerase chain reaction in the absence of a cold-like illness is associated with complications in some subjects. Otitis media is a complication of viral infection both with and without concurrent cold-like illnesses, thus downwardly biasing coincidence estimates that use cold-based illnesses as the denominator.