In this study, a suite of single antigen DNA vaccines, combination DNA vaccines and dual modality vaccines, were developed and evaluated for their potential to induce humoral and cell-mediated immune responses, and protective efficacy against Bordetella pertussis, the aetiological agent of whooping cough, using the mouse respiratory challenge model.

The aim of this study was to determine whether there was an association between a failed test of cough reflex sensitivity and history of chest infection in a general population of rest home residents. One hundred rest home residents from four different levels of care (rest home, hospital, dementia and psycho-geriatric) were recruited and their cough reflex assessed using a solution of 0.6 Mol/L citric acid nebulised and presented via a facemask.Participant’s records were then checked to see if there were any documented episodes of chest infection in the 6 month period prior to cough reflex testing.The results showed that out of 100 participants, 4 failed the cough reflex test. Of the 4 that failed the test, 3 had no documented episodes of chest infections recorded in the 6 month period prior to cough reflex testing. Data was not available for one participant who was deceased by the time of collection of the second data set. As such, there was no direct association demonstrated between a failed cough reflex test and development of chest infection or aspiration pneumonia. The results of the study are unexpected in two ways. Firstly, the relatively low number of participants who failed the cough reflex test is surprising as 72% of the participants for whom a full data set was obtained had neurological conditions that are known predisposing factors for reduced cough reflex sensitivity. Secondly, the finding of no association between a failed cough reflex test and history of recorded chest infection is not consistent with other studies. There is however an established body of research that indicates the causes of aspiration pneumonia are multifactorial and not solely dependent upon aspiration. The characteristics of participants and the implications of the findings are described. The potential use of cough reflex testing as a tool to screen against the risks of silent aspiration in relation to assessment of oro-pharyngeal dysphagia in this frail, elderly population is discussed.

Indoor jets considerably dominate air movement and distribution of temperature and velocity, as well as transport of particles and other pollutants. Indoor air temperature and velocity distribution substantially impact occupants’ thermal comfort and productivity, heat and mass transfer on indoor surfaces. In addition, jets produced by human respiratory activities, such as coughing and sneezing, enhance the spread of particles that might carry bacteria or viruses. Understanding and characterizing indoor jets and their impacts on air distribution, temperature and velocity fields, and particle transport are crucial for advancing heating, ventilation, and air conditioning (HVAC) systems when considering thermal comfort and developing strategies for exposure mitigation. This dissertation contributes to the scientific understanding regarding to indoor air distribution and particle transport associated with indoor air jets. Current HVAC system design defines indoor air distribution related to the selection of diffusers/ grilles that distribute supply air jets, according to the specifics of the space and internal heating and cooling loads. However, current design guidance was developed over 40 years ago. It requires expansion of diffuser/ grille types and the update for air distribution by diffuser/ grille air jets supplying warm air at heating mode. Unlike jets from diffusers/ grilles, jets created by human activities are inherently transient in nature and might perform quite differently from steady-state ones. Understanding the dynamics of unsteady-state jets, such as coughs, enhances the current state of understanding of the mechanisms of respiratory disease transmission, which enables development of exposure reduction measures. The investigations presented in this dissertation extend the state-of-the-art knowledge on indoor jets and analyze the effect of steady-state and unsteady-state jets on particle transport in indoor environments. Figure 1 illustrates the two objectives and six investigations conducted in this dissertation. The first objective includes four investigations that address air distribution and particle transport associated with steady-state jets created by diffusers/ grilles, and the remaining two investigations relate to the second objective on unsteady-state cough jets. The first objective of this dissertation characterizes air distribution and particle transport in a space with steady-state jets created by diffusers/ grilles. One of the major contributions of this objective to the-state-of-the-art knowledge on indoor air distribution is the newly developed method for diffuser performance assessment and design when considering heating mode. It advances the current diffuser/ grille selection guide that was outdated decades ago. Furthermore, based on 650 experimental set-ups this objective provides a systematic analysis of indoor air velocity that can be further used in indoor heat transfer and pollutant emission and transport. The second objective investigates velocity fields in unsteady-state cough jets and transport of coughed particles. This objective provides a theoretical analysis of the dynamics of cough jets and examines how human thermal plume affects the exposure to coughed particles when considering different particle sizes. Ultimately, these investigations fill the knowledge gaps in indoor air distribution and particle transport associated with steady-state and unsteady-state jets in spaces using all-air HVAC systems. The newly developed diffuser guideline will improve HVAC design for both heating and cooling conditions when considering thermal discomfort or air stagnant zones caused by a wrong diffuser selection. In addition, the systematic analysis of indoor air velocity will improve the prediction of indoor heat transfer, mass transfer, particle resuspension rate, pollutant emission rate from the floor and other indoor surfaces. Finally, the theoretical analysis of unsteady-state jets contributes the knowledge for fluid dynamics of unobstructed human coughs and also transport of coughed particles, including the distribution in the vicinity of an exposed person. / text

No description available.

Patients with an impaired reflexive cough response are at increased risk of pneumonia. This study examined the correlation between cough sensitivity to citric acid and radiographic features of airway compromise. Eighty patients referred for a radiographic assessment of swallowing at an acute hospital over an 8-month period participated in the study. Nebulised citric acid diluted in 0.9% sodium chloride was inhaled through a facemask at four concentrations to assess cough sensitivity. These data were then compared to Penetration Aspiration Scale scores based on radiographic swallowing studies. There was a statistically significant correlation between cough response/lack of response and the radiographic features of airway compromise; that is, patients who had a weak or absent response to inhalation of citric acid were also likely to aspirate silently during radiographic assessment. Sensitivity for identifying absent cough was found to be high at all 4 concentrations (0.750, 0.833, 0.941, 1.000), however specificity was consistently quite low (0.344, 0.456, 0.238, 0.078). The significant findings of this research suggest that clinicians adopting cough reflex testing into their clinical practice will have a reliable screen for silent aspiration at bedside. Clinicians will be able to identify patients who require instrumental assessment and are at high risk of pneumonia. This will likely, in turn, decrease length and cost of hospital admissions as well as decrease aspiration pneumonia related morbidities.

Cough reflex testing (CRT) is used to assess the sensory and motor components of a reflexive cough. When used as an adjunct to the clinical swallowing evaluation, it has the potential to identify individuals who are more likely to aspirate silently in the event of aspiration. It is unknown how reliable clinicians are at interpreting cough responses and the factors that influence this reliability. Therefore, this study ascertained the reliability of Speech Language Therapists in interpreting cough responses in CRT and determined how sensory perception and training influence reliability. Additionally, the study determined a relative measure of CRT interpretation validity through a comparison with ‘expert’ consensus ratings. A total of 111 clinicians completed an online survey consisting of ratings of 30 audio-, visual- and audiovisual clips over three sessions, and a final questionnaire. Reliability was substantial (κ=.76) in rating for presence of cough but only fair (κ=.25) in rating for strength of cough. Clinicians used a variety of auditory and visual cues to assist in decision making. Training did not result in higher reliability. Ratings of individual clinicians were significantly associated with consensus ratings for presence of cough (p < 0.001) and strength of cough (p < 0.05). In summary, clinicians could reliably and accurately judge presence of cough response, but were poorer at rating the strength of cough.

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Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains x, 83 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 79-83).

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains viii, 99 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 96-99).

Objective: Describe the prevalence of Bordetella pertussis via PCR in children under 5 years old hospitalized as probable cases of pertussis and report the most common clinical features among them. Results: A positive PCR result for B. pertussis was observed in 20.5% of our samples (18/88), one-third of them were from infants between 2 and 3 months old. The most common symptoms were paroxysms of coughing (88.9%), difficulty breathing (72.2%), cyanosis (77.8%) and fever (50%). The mother was the most common symptomatic carrier (27.8%), followed by uncles/aunts (22.2%) among children with pertussis. / This work was supported by fourth research incentive of the Universidad Peruana de Ciencias Aplicadas (UPC), Lima‑Peru. / Revisión por pares