Characteristics of autism

The purpose of this research paper was to delineate the characteristics of autism and to investigate what techniques can be used successfully to help autistic children achieve their potential

Analysis of HIV pre-exposure prophylaxis (PrEP) needs and PrEP use in Germany among men who have sex with men

Aims: We aim to estimate the number of HIV pre-exposure prophylaxis (PrEP) users among men having sex with men (MSM) in Germany from 2017 through 2020, and analyse if PrEP needs expressed in 2017 might have been met by the expansion of PrEP until 2020. Subject and methods: We estimated the number of PrEP users by using drug prescription data and information on on-demand/intermittent PrEP use from online surveys to determine the proportion of on-demand/intermittent and daily PrEP use as well as the average number of PrEP pills used. The number of MSM in need of PrEP in 2017 was estimated based on four groups defined among respondents to a large online survey, combining respondents with PrEP use intention and respondents indicating substantial sexual risks. The size of each group was estimated based on self-selection biases. MSM with PrEP need in 2017 were compared with the estimated number of persons taking PrEP by June 2020. Results: We estimated a total of 15,600 to 21,600 PrEP users in Germany by the end of June 2020, corresponding to 40–55% of men with PrEP use intention in 2017. A correlation between the regional distribution of PrEP use intention in 11/2017 and actual PrEP use by 06/2020 suggested an unequal regional distribution of unsatisfied needs. The number of men with unmet PrEP needs ranged between 27,500 and 93,000 in 06/2020. Conclusion: PrEP use in Germany has increased considerably between 10/2017 and 06/2020, but large regional inequalities persist. PrEP is not yet readily accessible, and there is a need to expand services and encourage uptake.Peer Reviewe

Blood donor deferral policies across Europe and characteristics of men whohave sex with men screened for human immunodeficiency virus in bloodestablishments: data from the European Men-who-have-sex-with-men Internet Survey (EMIS).

BACKGROUND: The predominant mode of transmission of human immunodeficiency virus (HIV) in Europe is male-to-male transmission. Men who have sex with men (MSM) are deferred from donating blood in many countries, but nevertheless do donate blood. Based on data from 34 countries, we estimated the proportion of MSM screened for HIV in the context of a blood donation and identified individual factors associated with this HIV screening in order to propose possible public health interventions. MATERIALS AND METHODS: In 2010, the first European MSM Internet Survey (EMIS) collected self-reported data on HIV testing from >180,000 MSM in 38 European countries. Using logistic regression, demographic and behavioural factors associated with screening for HIV in blood establishments were identified. Stratified by European sub-region, we analysed the proportion of MSM screening in blood establishments by time elapsed since last negative HIV test. RESULTS: Donor eligibility criteria for MSM vary across Europe with most countries using permanent deferral. The Western region had the lowest (2%) proportion of MSM screened in blood establishments and the Northeastern region had the highest (14%). Being <25 years old, not disclosing sexual attraction to men, never having had anal intercourse with a man, having a female partner, living in a rural area, and certain European sub-regions or countries of residence increased the likelihood of being screened in blood establishments. DISCUSSION: In spite of deferral policies, MSM are screened for HIV in the context of blood donations. Gay-friendly testing services are rare in rural areas, and young men might be reluctant to disclose their sexual orientation. Recent developments, such as home sampling, might offer new testing possibilities for those not reached by established services yet wishing to know their HIV status. Donor selection procedures should be improved. Both interventions might help to further reduce the risk of transfusion-transmitted infections

Metabolic modeling of a mutualistic microbial community

The rate of production of methane in many environments depends upon mutualistic interactions between sulfate-reducing bacteria and methanogens. To enhance our understanding of these relationships, we took advantage of the fully sequenced genomes of Desulfovibrio vulgaris and Methanococcus maripaludis to produce and analyze the first multispecies stoichiometric metabolic model. Model results were compared to data on growth of the co-culture on lactate in the absence of sulfate. The model accurately predicted several ecologically relevant characteristics, including the flux of metabolites and the ratio of D. vulgaris to M. maripaludis cells during growth. In addition, the model and our data suggested that it was possible to eliminate formate as an interspecies electron shuttle, but hydrogen transfer was essential for syntrophic growth. Our work demonstrated that reconstructed metabolic networks and stoichiometric models can serve not only to predict metabolic fluxes and growth phenotypes of single organisms, but also to capture growth parameters and community composition of simple bacterial communities

Association of internalised homonegativity with partner notifcation after diagnosis of syphilis or gonorrhoea among men having sex with men in 49 countries across four continents

Background: Partner notifcation (PN) after a sexually transmitted infection (STI) diagnosis is being promoted as a means to interrupt transmission chains. We investigated whether Internalised Homonegativity (IH) is associated with PN among men having sex with men (MSM). Methods: PN, defned as notifying at least one partner after diagnosis of syphilis and gonorrhoea, was queried in two internet-based self-completion surveys conducted between Oct 2017 and May 2018 in 68 countries in Europe, Latin America, Canada, and the Philippines. IH is defned by a man’s level of agreement or disagreement with negative social beliefs about male homosexuality. Covariates included in a multivariate regression model with a random intercept at country level were age, HIV diagnosis, partnership status, sexual self-efcacy, HIV serostatus communication during last sex with a non-steady partner, place where this partner was met, and PN-related socio-historical background of the country of residence. We grouped countries in three areas: North- and Central-Western European countries plus Canada, former socialist countries, and Latin-American/Mediterranean countries plus the Philippines. In each of the three areas individuals were assigned to 4 subgroups based on IH quartiles and PN rates were determined for each subgroup. Results: PN rates were calculated for 49 countries (excluding countries with less than 10 diagnoses). Mean proportions of MSM notifying their partners were 68.1% and 72.9% after syphilis and gonorrhoea diagnoses, respectively. PN rates were lower in Latin American countries and the Philippines compared to European countries. Within Europe, a North–South divide with lower PN rates in Mediterranean countries was observed. In each of the three regions we mostly observed a stepwise increase of PN rates with decreasing IH. Regression analysis showed lower IH scores associated with higher PN rates. Higher perceived self-efcacy, living in a partnership, and HIV status communication were positively associated with PN. Men who had met their last partner in a gay social venue were more likely to have notifed their partners of a syphilis diagnosis compared to men who had met this partner online. Men with diagnosed HIV were less likely to report PN. Conclusions: We could demonstrate that IH was associated with PN among MSM across all countries included in our analysis. Reducing cultural homophobia and ensuring inclusive policies may contribute to STI prevention and control

Microbial catabolic activities are naturally selected by metabolic energy harvest rate

The fundamental trade-off between yield and rate of energy harvest per unit of substrate has been largely discussed as a main characteristic for microbial established cooperation or competition. In this study, this point is addressed by developing a generalized model that simulates competition between existing and not experimentally reported microbial catabolic activities defined only based on well-known biochemical pathways. No specific microbial physiological adaptations are considered, growth yield is calculated coupled to catabolism energetics and a common maximum biomass-specific catabolism rate (expressed as electron transfer rate) is assumed for all microbial groups. Under this approach, successful microbial metabolisms are predicted in line with experimental observations under the hypothesis of maximum energy harvest rate. Two microbial ecosystems, typically found in wastewater treatment plants, are simulated, namely: (i) the anaerobic fermentation of glucose and (ii) the oxidation and reduction of nitrogen under aerobic autotrophic (nitrification) and anoxic heterotrophic and autotrophic (denitrification) conditions. The experimentally observed cross feeding in glucose fermentation, through multiple intermediate fermentation pathways, towards ultimately methane and carbon dioxide is predicted. Analogously, two-stage nitrification (by ammonium and nitrite oxidizers) is predicted as prevailing over nitrification in one stage. Conversely, denitrification is predicted in one stage (by denitrifiers) as well as anammox (anaerobic ammonium oxidation). The model results suggest that these observations are a direct consequence of the different energy yields per electron transferred at the different steps of the pathways. Overall, our results theoretically support the hypothesis that successful microbial catabolic activities are selected by an overall maximum energy harvest rate

Changes in the prevalence of self-reported sexually transmitted bacterial infections from 2010 and 2017 in two large European samples of men having sex with men-is it time to re-evaluate STI-screening as a control strategy?

BACKGROUND/OBJECTIVES: Many European countries reported increased numbers of syphilis, gonorrhoea and chlamydia diagnoses among men who have sex with men (MSM) in recent years. Behaviour changes and increased testing are thought to drive these increases. METHODS: In 2010 and 2017, two large online surveys for MSM in Europe (EMIS-2010, EMIS-2017) collected self-reported data on STI diagnoses in the previous 12 months, diagnostic procedures, STI symptoms when testing, number of sexual partners, and sexual behaviours such as condom use during the last intercourse with a non-steady partner in 46 European countries. Multivariate regression models were used to analyse factors associated with diagnoses of syphilis, gonorrhoea/chlamydia, and respective diagnoses classified as symptomatic and asymptomatic. If applicable, they included country-level screening rates. RESULTS: Questions on STI diagnoses and sexual behaviours were answered by 156,018 (2010) and 125,837 (2017) participants. Between 2010 and 2017, overall diagnoses with gonorrhoea/chlamydia and syphilis increased by 76% and 83% across countries. Increases were more pronounced for asymptomatic compared to symptomatic infections. The proportion of respondents screened and the frequency of screening grew considerably. Condomless anal intercourse with the last non-steady partner rose by 62%; self-reported partner numbers grew. Increased syphilis diagnoses were largely explained by behavioural changes (including more frequent screening). Gonorrhoea/chlamydia increases were mainly explained by more screening and a change in testing performance. A country variable representing the proportion of men screened for asymptomatic infection was positively associated with reporting symptomatic gonorrhoea/chlamydia, but not syphilis. DISCUSSION/CONCLUSION: The positive association of country-level screening rates with the proportion of symptomatic infections with gonorrhoea/chlamydia may indicate a paradoxical effect of screening on incidence of symptomatic infections. Treatment of asymptomatic men might render them more susceptible to new infections, while spontaneous clearance may result in reduced susceptibility. Before expanding screening programmes, evidence of the effects of screening and treatment is warranted

Population Dynamics Constrain the Cooperative Evolution of Cross-Feeding

Cross-feeding is the exchange of nutrients among species of microbes. It has two potential evolutionary origins, one as an exchange of metabolic wastes or byproducts among species, the other as a form of cooperation known as reciprocal altruism. This paper explores the conditions favoring the origin of cooperative cross-feeding between two species. There is an extensive literature on the evolution of cooperation, and some of the requirements for the evolution of cooperative cross-feeding follow from this prior work–specifically the requirement that interactions be limited to small groups of individuals, such as colonies in a spatially structured environment. Evolution of cooperative cross-feeding by a species also requires that cross-feeding from the partner species already exists, so that the cooperating mutant will automatically be reciprocated for its actions. Beyond these considerations, some unintuitive dynamical constraints apply. In particular, the benefit of cooperative cross-feeding applies only in the range of intermediate cell densities. At low density, resource concentrations are too low to offset the cost of cooperation. At high density, resources shared by both species become limiting, and the two species become competitors. These considerations suggest that the evolution of cooperative cross-feeding in nature may be more challenging than for other types of cooperation. However, the principles identified here may enable the experimental evolution of cross-feeding, as born out by a recent study

Sulfur-mediated electron shuttling during bacterial iron reduction

Microbial reduction of ferric iron [Fe(III)] is an important biogeochemical process in anoxic aquifers. Depending on groundwater pH, dissimilatory metal-reducing bacteria can also respire alternative electron acceptors to survive, including elemental sulfur (S0). To understand the interplay of Fe/S cycling under alkaline conditions, we combined thermodynamic geochemical modeling with bioreactor experiments using Shewanella oneidensis MR-1. Under these conditions, S. oneidensis can enzymatically reduce S0 but not goethite (α-FeOOH). The HS– produced subsequently reduces goethite abiotically. Because of the prevalence of alkaline conditions in many aquifers, Fe(III) reduction may thus proceed via S0-mediated electron-shuttling pathways