Survival of Staphylococcus aureus on sampling swabs stored at different temperatures

Aims

To understand the impact of storage temperature on recovery of Staphylococcus aureus on sampling swabs. Staphylococcus aureus is a common cause of skin and soft tissue infections, but also causes a variety of life‐threatening diseases. With a large pool of asymptomatic carriers and transmission that can occur even through indirect contact, mitigation efforts have had limited success. Swab sampling, followed by culturing, is a cornerstone of epidemiological studies, however, S. aureus viability on swabs stored at different temperatures has not been characterized.

Methods and Results

We determined survival rates on swabs stored at five different temperatures. Samples stored at −70°C had no decay over time while samples stored at higher temperatures showed an exponential decay in viability. Mortality rates were greatest for swabs stored at 37°C. Survival at intermediate temperatures (−20 to 20·5°C) did not differ significantly, however, we observed more variation at higher temperatures.

Conclusions

To maximize recovery of S. aureus cells, samples should be stored at −70°C or processed for culturing without delay.

Significance and Impact of the Study

Epidemiological studies of bacterial diseases are typically limited to determination of pathogen presence/absence, yet quantitative assessments of pathogen load and genetic diversity can provide insights into disease progression and severity, likelihood of transmission and adaptive evolutionary potential. For studies of S. aureus where time or access to a microbiology laboratory may delay culturing, deep freezing or timely culturing will maximize the degree to which sampling results reflect source status.

Atrial fibrillation and stroke outcomes in Scotland: real-world evidence from a contemporary, national dataset

Introduction

Atrial Fibrillation (AF) is an important cause of mortality and morbidity. The major risk of AF is stroke, which can be reduced through anticoagulation. The burden of stroke, and AF-related stroke, is particularly high in Scotland. It is often reported that AF-related stroke is associated with poorer outcomes than other stroke types, it is also thought to lead to an increased institutionalisation. Data supporting these observations are historic, but major advances in AF assessment and treatment could have changed outcome patterns. Real world evidence on outcomes, collected at scale, can give a useful measure of contemporary AF stroke outcomes.

Purpose

To assess whether stroke patients, with and without AF on admission, differ in terms of al-cause mortality, recurrence of stroke, and care home admission using contemporary large-scale observational data.

Methods

A retrospective cohort study linking national hospital, prescribing, care home and stroke audit data was conducted. The cohort, comprising patients ≥18 years of age with incident ischemic stroke between 2009 and 2017, was divided into three groups: AF-related stroke prescribed oral anticoagulant (OAC) pre-stroke event (AF-OAC Group); AF-related stroke not prescribed anticoagulant pre-stroke event (AF-noOAC Group); stroke with no prevalent or incident AF and no anticoagulation (comparator) (noAF-noOAC Group). Time-to-event analyses (adjusted for demographic and clinical characteristics) were conducted to estimate hazard ratios for recurrent stroke, all-cause mortality, and care-home admission with a follow-up time of two years.

Results

From a cohort of 64,159 incident ischemic strokes, 4,418 and 15,124 patients with AF were identified for groups AF-OAC and AF-noOAC, respectively. The remaining 44,617 patients belonged to group noAF-noOAC. An increasing number of incident strokes was observed with increasing age in each group up to 80–84 years. The risk of recurrent stroke was significantly greater in groups AF-OAC (HR 1.12 [95% CI 1.08,1.17]) and AF-noOAC (HR 1.05 [95% CI 1.03,1.08]) compared to noAF-noOAC group. An increased risk of all-cause mortality was observed in groups AF-OAC (HR 1.52 [95% CI 1.39,1.66]) and AF-noOAC (HR 1.59 [95% CI 1.51,1.68]) compared to the noAF-noOAC group. Patients in group AF-noOAC were more likely to be discharged to a care home following stroke (HR 1.37 [95% CI 1.23,1.52]) compared to patients in the other groups.

Conclusion

AF-related stroke is associated with poor outcomes, with significantly higher risks of recurrent stroke and all-cause mortality for patients with AF compared to non-AF stroke. Despite advances in AF care, our data suggest there is still potential to prevent a substantial proportion of disabling strokes through better identification and treatment of AF. These results must be interpreted with caution, as data take no account of treatment adherence, dosing or rationale for individual patient level prescribing decisions.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Bristol-Myers Squibb Research and Development

Developmental trajectories of maladaptive perfectionism among African American adolescents

This study examined the developmental trajectories of maladaptive perfectionism over a 7-year period among African American youth living in an urban setting (N = 547). In particular, the study attempted to determine whether two maladaptive aspects of perfectionism (socially prescribed and self-critical) changed over time and could be distinguished by variables in 6th and 12th grades (Mage at study entry [first grade] was 6.22 years [SD = 0.34]). Four classes best described the developmental trajectories on both measures of maladaptive perfectionism: high, low, increasing, and decreasing. Sixth- and 12th-grade correlates, including measures of internalizing symptoms, mostly confirmed the distinctiveness of these classes. Parallel process analyses suggested that the two processes are complementary, yet distinct. Implications regarding the prevention of maladaptive perfectionism are discussed.

Developmental origins of perfectionism among African American youth

The present study used a person-centered latent variable approach to classify types of perfectionism among 6th-grade African American children living in an urban setting. In particular, the authors were interested in determining whether an adaptive subtype could be found and validated against external criteria. The authors also attempted to identify any developmental precursors that could reliably differentiate the perfectionist subtypes. A social learning and competence framework was used to select potential 1st-grade risk and protective factors for future perfectionism profiles. Four classes best described the children's perfectionism scores in 6th grade. Three of these classes resembled the profiles most commonly seen in prior perfectionism research (Non-Critical/Adaptive, Critical/Maladaptive, and Non-Perfectionist). The fourth class, Non-Striving, was characterized by extremely low levels of reported personal standards. Sixth-grade correlates confirmed the distinctiveness of these classes. In particular, the Critical/Maladaptive and Non-Striving classes had higher rates of internalizing symptoms and disorders. Additionally, several 1st-grade predictors suggested unique developmental origins of these classes. The Critical/Maladaptive class was characterized by lower academic skills and elevated teacher-rated attention problems, hyperactivity, shyness, and peer rejection. The Non-Striving class had higher rates of family alcohol problems and lower levels of parent praise. Implications regarding the universal and culture-specific origins and effects of perfectionism are discussed.

Perceived condom norms and HIV risks among social and sexual networks of young African American men who have sex with men

The association between condom norms and unprotected sexual intercourse was examined within social and sexual networks of young African American men who have sex with men (MSM) in an HIV epicenter of the southern United States. We used a chain-link design to recruit 158 young African American men: 95 initial participants, 56 contacts of participants (alters) and 7 contacts of alters. Men in the high-risk group, compared with those in the no-risk group, perceived significantly lower approval concerning condom use in their social and sexual networks. Also, 100 participants could be connected to each other in 86 dyads of social and sexual networks. Within these dyads, men perceived that their friends and acquaintances approved for them to use condoms but that their friends and acquaintances did not use condoms themselves. Low HIV risk behavior appears associated with perceived social norms that support one's use of condoms, even when perceived norms do not support condom use by network members themselves.

Unemployment, drug use, and HIV risk among American Indian and Alaska Native drug users

American Indians and Alaska Natives have had low employment in recent history. Drug users also have low employment due to cycles of drug use and relapse,and the impact of the type of drug abused on levels of functioning. Drug use is associated with increased HIV risk through injection drug use, frequency of injection, and needle sharing. Data from three sites of the NIDA Cooperative Agreement for Community Based-Outreach/Intervention Research were analyzed to determine the relationship among race/ethnicity, age, and level of educational attainment on employment and unemployment at intake interview and six-month follow-up. HIV risk for those employed and unemployed was then assessed. American Indian and Alaska Native drug users were younger, less educated, and less likely to have a paid job at both intake and follow-up than non-Native drug users. Those participants who were unemployed at baseline interview who were American Indian/Alaska Native were less likely to transition to employment at six-month follow-up than other race/ethnicity groups in the cohort. However, all participants showed low levels of employment at follow-up. Individuals who were employed at baseline and those who transitioned to employment had lower levels of injection drug use and needle sharing than those who were unemployed at both baseline and follow-up. American Indian and Alaska Native drug users may be at risk for acquisition of HIV due to drug risk behaviors that appear to be associated with unemployment.

The risk environment for HIV transmission: results from the Atlanta and Flagstaff network studies

The purpose of this study was to investigate the hypothesis that human immunodeficiency virus (HIV) transmission may be facilitated or obstructed by network structure, incorporating a measure of risk that combines true risk and surrogates. Persons at presumed high risk for HIV were enrolled in long-term follow-up studies of urban and rural networks in Atlanta, Georgia, and Flagstaff, Arizona. We focused on respondents who were also contacts to evaluate information on both sides of the observed dyads and constructed a Risk Indicator, based on a four-digit binary number, that permitted assessment and visualization of the overall risk environment. We constructed graphs that provided visualization of the level of risk, the types of relationships, and the actual network. Although some of the findings conform to the hypotheses relating network structure to transmission, there were several anomalies. In Atlanta, HIV prevalence was most strongly related to men with a male sexual orientation, despite the widespread use of injectable drugs. In Flagstaff, an area of very low prevalence and no transmission, the risk environment appeared more intense, and the frequency of microstructures was as great or greater than representative areas in Atlanta. The network hypothesis is not yet sufficiently developed to account for empirical observations that demonstrate the presence of intense, interactive networks in the absence of transmission of HIV.

Multiple-informant ranking of the disabling effects of different health conditions in 14 countries. WHO/NIH Joint Project CAR Study Group

BACKGROUND

The Global Burden of Disease study provided international statistics on the burden of diseases, combining mortality and disability, that can be used for priority setting and policy making. However, there are concerns about the universality of the disability weights used. We undertook a study to investigate the stability of such weighting in different countries and informant groups.

METHODS

241 key informants (health professionals, policy makers, people with disabilities, and their carers) from 14 countries were asked to rank 17 health conditions from most disabling to least disabling. Kruskal-Wallis ANOVA was used to test for differences in ranking between countries or informant groups and Kendall tau-B correlations to measure association between different rank orders.

FINDINGS

For 13 of 17 health conditions, there were significant (p<0.05) differences in ranking between countries; in the comparison of informant groups, there were significant differences for five of the 17 health conditions. The overall rank order in the present study was, however, almost identical to the ranking of the Global Burden of Disease study, which used a different method. Most of the rank correlations between countries were between 0.50 and 0.70 (average 0.61 [95% CI 0.59-0.64]). The average correlation of rank orders between different informant groups was 0.76.

INTERPRETATION

Rank order of disabling effects of health conditions is relatively stable across countries, informant groups, and methods. However, the differences are large enough to cast doubt on the assumption of universality of experts' judgments about disability weights. Further studies are needed because disability weights are central to the calculation of disability-adjusted life years.

HIV risk behaviors associated with the injection process: multiperson use of drug injection equipment and paraphernalia in injection drug user networks

This study examines drug acquisition and multiperson use of paraphernalia, drugs, and needles/syringes. Ethnographers observed 54 injection episodes in which IDUs were linked by HIV risk behaviors, and developed a typology of higher-risk, lower-risk, and nonsharing-risk networks. Multiperson use of injection paraphernalia or drug solution occurred in most injection events (94%). Serial use of syringes/needles occurred infrequently (14%) relative to "backloading" (37%) and reuse of paraphernalia (cookers 84%, cotton 77%, water 77%). Higher-risk injection networks were characterized by larger size and pooling of resources for drugs. Prevention messages must include avoiding reuse of injection paraphernalia and transfer of drug solution.

HIV risk in intravenous drug users and crack cocaine smokers: predicting stage of change for condom use

This study examined the utility of the Transtheoretical Model of Change and the AIDS Risk Reduction Model for predicting condom use with not-in-treatment crack cocaine smokers and intravenous drug users. The sample included 265 participants; 99 reported having casual partners and 166 reported having main partners. All participants must have used drugs in the preceding 48 hr and received no drug treatment for at least 1 year. Participants were grouped into 3 stages of change; precontemplation, contemplation, and action. Logistic regression analyses indicated that both the benefits of change and condom assertiveness varied across the stages of change for main and casual partners, whereas the costs of change were important for predicting stage only with main partners. Age was a significant predictor of stage with casual partners, whereas ethnicity and nonherpes sexually transmitted diseases significantly predicted stage with main partners. The utility of the stages of change for choosing intervention strategies and the need for more qualitative and longitudinal research to determine additional predictors of intention to use condoms are discussed.

HIV risk in intravenous drug users and crack cocaine smokers: predicting stage of change for condom use

This study examined the utility of the Transtheoretical Model of Change and the AIDS Risk Reduction Model for predicting condom use with not-in-treatment crack cocaine smokers and intravenous drug users. The sample included 265 participants; 99 reported having casual partners and 166 reported having main partners. All participants must have used drugs in the preceding 48 hr and received no drug treatment for at least 1 year. Participants were grouped into 3 stages of change; precontemplation, contemplation, and action. Logistic regression analyses indicated that both the benefits of change and condom assertiveness varied across the stages of change for main and casual partners, whereas the costs of change were important for predicting stage only with main partners. Age was a significant predictor of stage with casual partners, whereas ethnicity and nonherpes sexually transmitted diseases significantly predicted stage with main partners. The utility of the stages of change for choosing intervention strategies and the need for more qualitative and longitudinal research to determine additional predictors of intention to use condoms are discussed.

Head and neck tumors after energetic proton irradiation in rats

This is a two-year progress report on a life span dose-response study of brain tumor risk at moderate to high doses of energetic protons. It was initiated because a joint NASA/USAF life span study of rhesus monkeys that were irradiated with 55-MeV protons (average surface dose, 3.5 Gy) indicated that the incidence of brain tumors per unit surface absorbed dose was over 19 times that of the human tinea capitis patients whose heads were exposed to 100 kv x-rays. Examination of those rats that died in the two-year interval after irradiation of the head revealed a linear dose-response for total head and neck tumor incidence in the dose range of 0-8.5 Gy. The exposed rats had a greater incidence of pituitary chromophobe adenomas, epithelial and mesothelial cell tumors than the unexposed controls but the excessive occurrence of malignant gliomas that was observed in the monkeys was absent in the rats. The estimated dose required to double the number of all types of head and neck tumors was 5.2 Gy. The highest dose, 18 Gy, resulted in high mortality due to obstructive squamous metaplasia at less than 50 weeks, prompting a new study of the relative biological effectiveness of high energy protons in producing this lesion.

Experimental Rift Valley fever in rhesus macaques

Rift Valley fever (RVF) is a major cause of human morbidity and mortality in endemic areas of sub-Saharan Africa and has the potential to cause epidemic disease in receptive areas world-wide. In this study, a RVF viral isolate from the 1977 Egyptian epidemic (ZH-501) inoculated intravenously into rhesus macaques caused a benign viremic infection in most, but resulted in the hemorrhagic fever syndrome in 20 per cent (3 of 15). Serious disease of this type has not previously been observed in nonhuman primates inoculated with RVF virus and may be a consequence of the viral strain used or the route of inoculation. Severe disease was accompanied by extensive liver necrosis, disseminated intravascular coagulation, and microangiopathic hemolytic anemia. We also attempted to prevent RVF by passive transfer of serum from vaccinated rhesus monkeys (plaque-reduction neutralization test titer 1:2,560). As little as 0.025 ml/kg prevented the development of viremia in naive rhesus monkeys after subcutaneous inoculation of virus. The monkey model should be helpful in understanding the pathogenesis and prevention of human RVF.

Disablement and helping

This study investigated the effect of apparent disablement and sex differences on helping behaviour. Women received more help than men but the presence of a wheelchair did not decrease the amount of help offered. It is suggested that the presence of a wheelchair may cause less embarrassment to the help-giver than other more disfiguring handicaps.