Human Occupancy as a Source of Indoor Airborne Bacteria

Exposure to specific airborne bacteria indoors is linked to infectious and noninfectious adverse health outcomes. However, the sources and origins of bacteria suspended in indoor air are not well understood. This study presents evidence for elevated concentrations of indoor airborne bacteria due to human occupancy, and investigates the sources of these bacteria. Samples were collected in a university classroom while occupied and when vacant. The total particle mass concentration, bacterial genome concentration, and bacterial phylogenetic populations were characterized in indoor, outdoor, and ventilation duct supply air, as well as in the dust of ventilation system filters and in floor dust. Occupancy increased the total aerosol mass and bacterial genome concentration in indoor air PM10 and PM2.5 size fractions, with an increase of nearly two orders of magnitude in airborne bacterial genome concentration in PM10. On a per mass basis, floor dust was enriched in bacterial genomes compared to airborne particles. Quantitative comparisons between bacterial populations in indoor air and potential sources suggest that resuspended floor dust is an important contributor to bacterial aerosol populations during occupancy. Experiments that controlled for resuspension from the floor implies that direct human shedding may also significantly impact the concentration of indoor airborne particles. The high content of bacteria specific to the skin, nostrils, and hair of humans found in indoor air and in floor dust indicates that floors are an important reservoir of human-associated bacteria, and that the direct particle shedding of desquamated skin cells and their subsequent resuspension strongly influenced the airborne bacteria population structure in this human-occupied environment. Inhalation exposure to microbes shed by other current or previous human occupants may occur in communal indoor environments

Toward a model of the legal doctrine of informed consent

The authors draw together the disparate scholarly and judicial commentaries on consent to medical treatment to develop a model of the components in the decision-making process regarding consent to or refusal of psychiatric treatment. The components consist of the precondition of voluntariness, the provision of information, the patient\u27s competency and understanding, and, finally, consent or refusal. They offer two models of valid consent: the objective model, which focuses on the congruence or lack of it between the patient and a reasonable person, and the subjective model, which focuses entirely on the patient\u27s actual understanding

Tests of competency to consent to treatment

The authors describe the various tests of competency to consent to treatment used today, which include the following: 1)evidencing a choice, 2) reasonable outcome of choice, 3)choice based on rational reasons, 4)ability to understand, and 5)actual understanding. They analyze the applicability of these tests to patients\u27 decisions to accept or refuse psychiatric treatment and illustrate the problems of ap-lying these tests by citing clinical case examples. They find that the circumstances in which competency becomes an issue determine which elements of which tests are stressed and which are underplayed

Dimensional approach to delusions: comparison across types and diagnoses

OBJECTIVE: A dimensional approach to the characterization of delusions was used to examine the use of non-content-related descriptors of delusions in revealing differences across diagnostic categories and delusion types. METHOD: Interviews with 1,136 acutely hospitalized psychiatric patients identified subjects as definitely or possibly delusional on the basis of screening questions derived from the Diagnostic Interview Schedule. Subjects with delusions were given the MacArthur-Maudsley Delusions Assessment Schedule, which generates scores on six dimensions of delusions. Delusions were classified by type, and diagnoses were assigned by using the DSM-III-R checklist. RESULTS: A total of 328 subjects (29%) were rated as definitely or possibly delusional. Their ratings on dimensions of the MacArthur-Maudsley Delusions Assessment Schedule were significantly but modestly intercorrelated. Subjects with schizophrenia generally had more intense delusions than those in other diagnostic categories. Grandiose and religious delusions were held with the greatest conviction, whereas persecutory delusions were marked by strong negative affect and a propensity to act. Factor analysis of the dimensions revealed a consistent two factor solution- intensity and scope and affect and action -regardless of the diagnosis or delusion type. CONCLUSIONS: The stability of the dimensional structure of delusions across diagnoses and delusion types suggests that even seemingly diverse delusions are more like than unlike each other; this is consistent with common etiologic mechanisms. The utility of a dimensional approach is indicated, in addition, by the ability to characterize delusions of different types and diagnoses so as to highlight therapeutic and other implications

Informed consent in psychiatric research: Preliminary findings from an ongoing investigation

Preliminary findings from an investigation of informed consent processes in four psychiatric research projects (two being carried out at a university medical center and two at a public psychiatric hospital) are reported. Study methods include the systematic observation of investigator/subject information disclosure sessions using audio and videotape, as well as the use of standardized interaction rating forms and subject understanding interviews. In an attempt to determine if subjects' understanding of research can be improved through increased subject education, several modes of information disclosure are compared. Partial results from the public psychiatric hospital portion of the investigation suggest low subject understanding in many areas with subjects often demonstrating difficulty differentiating between treatment and biomedical research. Subjects' problematic understanding of research purposes and methodology was compounded by investigator disclosures which often emphasized the therapeutic, personalistic and nonresearch-oriented aspects of the project. Nevertheless, even when information disclosures were significantly improved, subject understanding in many cases continued to be low-- suggesting that additional factors aside from the quality of investigator disclosure are involved in psychiatric subjects' comprehension and understanding of research. The implication of these findings for informed consent, regulation of biomedical research and the protection of human subjects are discussed.

Confidentiality in psychiatry: a study of the patient\u27s view

The views of patients on the degree of confidentiality that is necessary for effective psychiatric care have not been empirically investigated, despite their potential importance to the debate. This study examines the views of 30 psychiatric inpatients on issues related to confidentiality. Patients were found to value confidentiality highly and to be concerned about the possibility of unauthorized disclosures but to have little knowledge of their legal rights or recourses should breaches of confidentiality occur. The data support contentions about the importance of confidentiality and suggest the need for further patient education