Prevalence of SARS-CoV-2 IgG antibodies among dental teams in Germany

Objectives During the corona pandemic, dental practices temporarily closed their doors to patients except for emergency treatments. Due to the daily occupational exposure, the risk of SARS-CoV-2 transmission among dentists and their team is presumed to be higher than that in the general population. This study examined this issue among dental teams across Germany. Materials and methods In total, 2784 participants provided usable questionnaires and dry blood samples. Dry blood samples were used to detect IgG antibodies against SARS-CoV-2. The questionnaires were analyzed to investigate demographic data and working conditions during the pandemic. Multivariable logistic mixed-effects models were applied. Results We observed 146 participants with positive SARS-CoV-2 IgG antibodies (5.2%) and 30 subjects with a borderline finding (1.1%). Seventy-four out of the 146 participants with SARS-CoV-2 IgG antibodies did not report a positive SARS-CoV-2 PCR test (50.7%), while 27 participants without SARS-CoV-2 IgG antibodies reported a positive SARS-CoV-2 PCR test (1.1%). Combining the laboratory and self-reported information, the number of participants with a SARS-CoV-2 infection was 179 (6.5%). Though after adjustment for region, mixed-effects models indicated associations of use of rubber dams (OR 1.65; 95% CI: 1.01–2.72) and the number of protective measures (OR 1.16; 95% CI: 1.01–1.34) with increased risk for positive SARS-CoV-2 status, none of those variables was significantly associated with a SARS-CoV-2 status in fully adjusted models. Conclusions The risk of SARS-CoV-2 transmission was not higher among the dental team compared to the general population. Clinical relevance. Following hygienic regulations and infection control measures ensures the safety of the dental team and their patients.

Colours, capsules and concept flavour names on cigarette packs appeal to youth in Mexico

BackgroundFlavoured cigarettes are popular in Mexico. We examined how cigarette packaging design features used to communicate flavour influence perceptions of appeal, harm, perceived interest and pack preference among Mexico City residents.MethodsWe conducted an experimental survey. Participants aged 13–34 years were randomly assigned to one of three conditions, viewed packs with systematically manipulated design features (colour, capsule image and flavour name) and answered questions on appeal, perceived harm, perceived interest and pack preference. Data were analysed using mixed effects and conditional logistic regression.Results1500 adolescents and 950 adults participated. Regardless of flavour, cigarette packs with a background colour and capsule image were more appealing to adolescents (OR=13.19, 95% CI 11.53 to 15.10; OR=1.68, 95% CI 1.45 to 1.88) and adults (OR=4.18, 95% CI 3.73 to 4.69; OR=1.66, 95% CI 1.49 to 1.85) than packs without. Among adolescents, ‘Tropical Burst’ named packs were more appealing (OR=1.43, 95% CI 1.20 to 1.72) than packs without a flavour name and among adults, ‘Arctic Air’ named packs were more appealing (OR=1.20, 95% CI 1.02 to 1.14). Adolescents and adults reported a preference for trying packs that displayed a flavour name, background colour or capsule image (b=0.104, b=0.702, b=1.316, p<0.001 and b=0.126, b=0.619, b=0.775, p<0.001).ConclusionsColours and flavour capsule images appeal to adolescents and adults in Mexico. Mexico should consider adopting plain packaging to reduce appeal and interest.

The Effect of Race and Dementia Prevalence on a COVID-19 Infection Control Intervention in Massachusetts Nursing Homes

Background Nursing home (NH) residents, especially those who were Black or with dementia, had the highest infection rates during the COVID-19 pandemic. A 9-week COVID-19 infection control intervention in 360 Massachusetts NHs showed adherence to an infection control checklist with proper personal protective equipment (PPE) use and cohorting was associated with declines in weekly infection rates. NHs were offered weekly webinars, answers to infection control questions, resources to acquire PPE, backup staff, and SARS-CoV-2 testing. We asked whether the effect of this intervention differed by racial and dementia composition of the NHs. Methods Data were obtained from 4 state audits using infection control checklists, weekly infection rates, and Minimum Data Set variables on race and dementia to determine whether adherence to checklist competencies was associated with decline in average weekly rates of new COVID-19 infections. Results Using a mixed-effects hurdle model, adjusted for county COVID-19 prevalence, we found the overall effect of the intervention did not differ by racial composition, but proper cohorting of residents was associated with a greater reduction in infection rates among facilities with ≥20% non-Whites (n = 83). Facilities in the middle (&gt;50%–62%; n = 121) and upper (&gt;62%; n = 115) tertiles of dementia prevalence had the largest reduction in infection rates as checklist scores improved. Cohorting was associated with greater reductions in infection rates among facilities in the middle and upper tertiles of dementia prevalence. Conclusions Adherence to proper infection control procedures, particularly cohorting of residents, can reduce COVID-19 infections, even in facilities with high percentages of high-risk residents (non-White and dementia).

Genomic Machine Learning Meta-regression: Insights on Associations of Study Features with Reported Model Performance

Background: Many studies have been conducted with the goal of correctly predicting diagnostic status of a disorder using the combination of genetic data and machine learning. The methods of these studies often differ drastically. It is often hard to judge which components of a study led to better results and whether better reported results represent a true improvement or an uncorrected bias inflating performance. Methods: In this systematic review, we extracted information about the methods used and other differentiating features in genomic machine learning models. We used the extracted features in mixed-effects linear regression models predicting model performance. We tested for univariate and multivariate associations as well as interactions between features. Results: In univariate models the number of hyperparameter optimizations reported and data leakage due to feature selection were significantly associated with an increase in reported model performance. In our multivariate model, the number of hyperparameter optimizations, data leakage due to feature selection, and training size were significantly associated with an increase in reported model performance. The interaction between number of hyperparameter optimizations and training size as well as the interaction between data leakage due to optimization and training size were significantly associated reported model performance. Conclusions: Our results suggest that methods susceptible to data leakage are prevalent among genomic machine learning research, which may result in inflated reported performance. The interactions of these features with training size suggest that if data leakage susceptible methods continue to be used, modelling efforts using larger data sets may result in unexpectedly lower results compared to smaller data sets. Best practice guidelines that promote the avoidance and recognition of data leakage may help the field advance and avoid biased results.

Ethiopia prisoner releases will have mixed effects

Headline ETHIOPIA: Prisoner releases will have mixed effects

Growth patterns of infants with in- utero HIV and ARV exposure in Cape Town, South Africa and Lusaka, Zambia

Background Infants born HIV-exposed yet remain uninfected (HEU) are at increased risk of poorer growth and health compared to infants born HIV-unexposed (HU). Whether maternal antiretroviral treatment (ART) in pregnancy ameliorates this risk of poorer growth is not well understood. Furthermore, whether risks are similar across high burden HIV settings has not been extensively explored. Methods We harmonized data from two prospective observational studies conducted in Cape Town, South Africa, and Lusaka, Zambia, to compare weight-for-age (WAZ), length-for-age (LAZ) and weight-for-length (WLZ) Z-scores between infants who were HEU and HU, converting infant anthropometric measures using World Health Organisation Growth Standards adjusted for age and sex. Linear mixed effects models were fit to identify risk factors for differences in anthropometrics at 6–10 weeks and 6 months by infant HIV exposures status and by timing of exposure to maternal ART, either from conception or later in gestation. Results Overall 773 mother-infant pairs were included across two countries: women living with HIV (WLHIV), 51% (n = 395) with 65% on ART at conception and 35% initiating treatment in pregnancy. In linear mixed effects models, WAZ and WLZ at 6–10 weeks were lower among infants who were HEU vs HU [β = − 0.29 (95% CI: − 0.46, − 0.12) and [β = − 0.42 (95% CI: − 0.68, − 0.16)] respectively after adjusting for maternal characteristics and infant feeding with a random intercept for country. At 6 months, LAZ was lower [β = − 0.28 CI: − 0.50, − 0.06)] among infants who were HEU, adjusting for the same variables, with no differences in WAZ and WLZ. Within cohort evaluations identified different results with higher LAZ among infants who were HEU from Zambia at 6–10 weeks, [β = + 0.34 CI: + 0.01, + 0.68)] and lower LAZ among infants who were HEU from South Africa [β = − 0.30 CI: − 0.59, − 0.01)] at 6 months, without other anthropometric differences at either site. Conclusion Infant growth trajectories differed by country, highlighting the importance of studying contextual influences on outcomes of infants who were HEU.