Evaluating evolutionary history in the face of high gene tree discordance in Australian Gehyra (Reptilia: Gekkonidae).

Species tree methods have provided improvements for estimating species relationships and the timing of diversification in recent radiations by allowing for gene tree discordance. Although gene tree discordance is often observed, most discordance is attributed to incomplete lineage sorting rather than other biological phenomena, and the causes of discordance are rarely investigated. We use species trees from multi-locus data to estimate the species relationships, evolutionary history and timing of diversification among Australian Gehyra-a group renowned for taxonomic uncertainty and showing a large degree of gene tree discordance. We find support for a recent Asian origin and two major clades: a tropically adapted clade and an arid adapted clade, with some exceptions, but no support for allopatric speciation driven by chromosomal rearrangement in the group. Bayesian concordance analysis revealed high gene tree discordance and comparisons of Robinson-Foulds distances showed that discordance between gene trees was significantly higher than that generated by topological uncertainty within each gene. Analysis of gene tree discordance and incomplete taxon sampling revealed that gene tree discordance was high whether terminal taxon or gene sampling was maximized, indicating discordance is due to biological processes, which may be important in contributing to gene tree discordance in many recently diversified organisms.

Frequency of percutaneous injuries requiring postexposure prophylaxis for occupational exposure to human immunodeficiency virus.

New recommendations regarding prophylaxis of healthcare workers exposed to human immunodeficiency virus (HIV) prompted us to examine the frequency and nature of percutaneous injuries at this hospital. Four previously defined risk factors for transmission of HIV were evaluated. Between 1993 and 1995, 1,070 percutaneous injuries were reported, including 11 in which the source patient had acquired immunodeficiency syndrome (AIDS). Five of these injuries involved at least one risk factor for transmission. No source patient was found to have AIDS as a result of testing following exposure. We conclude that high-risk injuries are infrequent and that postexposure prophylaxis will not increase costs greatly at this medical center.

Hand hygiene rates unaffected by installation of dispensers of a rapidly acting hand antiseptic.

OBJECTIVE: The objective of the study was to improve health care workers' compliance with hand hygiene after patient contact by use of an alcohol-based hand antiseptic. DESIGN AND METHODS: Six commercially available alcohol-based hand antiseptics were evaluated. The one most pleasing to the evaluators' hands was selected for the study. Baseline handwashing rates were assessed on 2 medical wards. Alcohol dispensers were mounted by every door on the 2 wards. An educational campaign was conducted with 4 weekly visits to these floors to remind and reinstruct staff about the use of the alcohol dispensers and to address questions. After 2 months handwashing rates were reassessed. SETTING: The study was set in a university hospital. RESULTS: The baseline handwashing rate was 60% (76/126). Physicians were most compliant (83%), followed by nurses (60%), technologists (56%), and housekeepers (36%). Two months later overall hand hygiene rates had decreased to 52% (P = .26). Nurses were most compliant (67%), followed by technologists (57%), physicians (29%), and housekeepers (25%). Physician compliance was associated with compliance by attending physicians whose example was usually followed by all other physicians on rounds. CONCLUSIONS: A brief educational campaign and installation of dispensers containing a rapidly acting hand hygiene product near hospital rooms did not affect hand hygiene compliance. The behavior of attending physicians was predictive of handwashing rates for all others in the attending's retinue. Compliance with handwashing after half of all patient contacts was a result of perfect compliance by some and total noncompliance by others being observed.

Glove leakage rates as a function of latex content and brand: caveat emptor.

HYPOTHESIS: That water leakage rates and protection against blood-borne pathogens should not vary as a function of latex content among Food and Drug Administration-approved gloves, allowing avoidance of unnecessary latex exposure. DESIGN AND METHODS: Eighteen different glove types were purchased and tested using the American Society for Testing Methods Standard Test for Detecting Holes in medical gloves, which involves mounting the glove on a plastic tube, pouring a liter of tap water into the glove, and visually inspecting the glove initially and after 2 minutes. Half of the gloves were tested straight from the package and half after a standardized manipulation. SETTING: A university hospital. RESULTS: Eleven sterile glove types (5 high latex content, 4 low latex content, and 2 nonlatex content), and 7 nonsterile examination glove types (2 high latex content, 2 low latex content, and 3 nonlatex content) were tested (total tested, 3720 gloves). Leakage rates were greater for examination than for surgical gloves (relative risk [RR], 1.41, 95% confidence interval [CI], 1.01-1.96), for manipulated than for unused gloves (RR, 2.89, 5% CI, 1.98-4.22), and for low latex content surgical gloves (RR, 2.58, 95% CI, 1.35-4.92) or nonlatex content surgical gloves (RR, 4.93, 95% CI, 2.35-10.32) than for high latex content surgical gloves. Significant differences were observed among low latex content surgical gloves (P