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The World Health Organization (WHO) recommends periodic assessment of the therapeutic efficacy of praziquantel (PZQ) to detect reduced efficacy that may arise from drug resistance in schistosomes. In this multi-country study (2014), we assessed the therapeutic efficacy of a single oral dose of PZQ (40 mg/kg) against Schistosoma mansoni (Brazil, Cameroon, Ethiopia, Mali, Madagascar and Tanzania), S. haematobium (Cameroon, Ethiopia, Mali, Tanzania and Zanzibar) and S. japonicum (the Philippines) infections in school-aged children, across a total of 12 different trials. Each trial was performed according to the standardized methodology for evaluating PZQ efficacy as described by the WHO. Overall, therapeutic efficacy, measured as the reduction in arithmetic mean of schistosome egg counts following drug administration (egg reduction rate; ERR), was high for all three schistosome species (S. mansoni: 93.4% (95%CI: 88.8-96.8); S. haematobium: 97.7% (95%CI: 96.5-98.7) and S. japonicum: 90.0% (95%CI: 68.4-99.3). At the trial level, therapeutic efficacy was satisfactory (point estimate ERR ≥90%) for all three Schistosoma species with the exception of S. mansoni in Cameroon where the ERR was 88.5% (95%CI: 79.0-95.1). Furthermore, we observed that in some trials individual drug response could vary significantly (wide 95%CI) and that few non-responsive individuals could significantly impact ERR point estimates. In conclusion, these results do not suggest any established reduced efficacy of the standard PZQ treatment to any of the three schistosome species within these countries. Nevertheless, the substantial degree of variation in individual responses to treatment in some countries underpins the need for future monitoring. The reported ERR values serve as reference values to compare with outcomes of future PZQ efficacy studies to ensure early detection of reduced efficacies that could occur as drug pressure continues increase. Finally, this study highlights that 95%CI should be considered in WHO guidelines to classify the therapeutic efficacy of PZQ.

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INTRODUCTION: This cross-sectional study assessed the prevalence of psychiatric disorders among drivers , as well as the association between recent alcohol and drug use and psychiatric diagnoses using telephone interviews. METHODS: Drivers (n = 1,134) included in a roadside survey from 25 Brazilian state capitals were given a breathalyzer test, and their saliva was tested for psychoactive drugs. A telephone interview was conducted to perform psychiatric disorder evaluations using the MINI. This association was analyzed with a Poisson regression model. RESULTS: The prevalence of any psychiatric disorder was 40.5% among drivers with recent alcohol or drug use, compared with 12.9% among the other drivers. Alcohol/drug-positive drivers reported a higher prevalence of depression (19.4%), mania (6.5%), hypomania (5.4%), post-traumatic stress disorder (8.6%), antisocial personality (7.8%), and substance/alcohol abuse or dependence (48.1%) compared with other drivers (3.5, 2.5, 2.1, 0.5, 1.3 and 18.3% [p < 0.001], respectively). Drivers with recent alcohol or drug use were 2.5 times more likely to have a psychiatric diagnosis (CI: 1.8-3.6, p < 0.001). DISCUSSION: This is the first study in a low-/middle-income country to evaluate psychiatric disorders in drivers with recent alcohol or drug using telephone interviews. Psychiatric disorders were found to be associated with drug and alcohol use. This type of epidemiological information for curtailing related driving problems, as these psychiatric conditions are diagnosable. FINAL REMARKS: The results of this study can aid in the design of interventions, treatment programs and focused psychiatric evaluations, both in Brazil and abroad.

INTRODUÇÃO: Este estudo transversal avaliou a prevalência de transtornos psiquiátricos e a associação entre dirigir alcoolizado e transtornos psiquiátricos entre motoristas por meio de entrevistas telefônicas. MÉTODO: Motoristas (n = 1.134) selecionados a partir de um estudo realizado nas rodovias de 25 capitais brasileiras foram etilometrizados e tiveram sua saliva testada para substâncias psicoativas. Uma entrevista por telefone foi realizada para obter dados sobre transtornos psiquiátricos através do MINI. A associação entre transtornos psiquiátricos e dirigir com uso recente de substâncias foi analisada com um modelo de regressão de Poisson. RESULTADOS: A prevalência de transtornos psiquiátricos foi de 40,5% entre os motoristas que beberam/usaram drogas, em comparação com 12,9% nos demais motoristas. Motoristas que dirigiram com uso recente de substâncias relataram uma maior prevalência de depressão (19,4%), mania (6,5%), hipomania (5,4%), transtorno de estresse póstraumático (8,6%), personalidade antissocial (7,8%), e abuso ou dependência de álcool/drogas (48,1%) quando comparados com os outros motoristas (3,5%, 2,5%, 2,1%, 0,5%, 1,3% e 18,3%, p < 0,001), respectivamente). Motoristas com uso recente de substâncias apresentaram 2,5 mais chance de ter qualquer diagnóstico psiquiátrico (IC: 1,8-3,6, p < 0,001). DISCUSSÃO: Este é o primeiro estudo em países de baixa e média renda cujo objetivo é avaliar transtornos psiquiátricos em motoristas com uso recente de substâncias por meio de entrevistas telefônicas. Transtornos psiquiátricos foram associados com o comportamento de dirigir com uso recente de substâncias. Este tipo de informação epidemiológica é fundamental para estratégias de planejamento que visam enfrentar problemas relacionados com o beber e dirigir, uma vez que estas condições psiquiátricas são diagnosticáveis. OBSERVAÇÕES FINAIS: Os resultados deste estudo podem auxiliar no desenvolvimento de intervenÇÕes, programas de tratamento e avaliação psiquiátrica, tanto no Brasil quanto no exterior.

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INTRODUCTION: This cross-sectional study assessed the prevalence of psychiatric disorders among drivers , as well as the association between recent alcohol and drug use and psychiatric diagnoses using telephone interviews. METHODS: Drivers (n = 1,134) included in a roadside survey from 25 Brazilian state capitals were given a breathalyzer test, and their saliva was tested for psychoactive drugs. A telephone interview was conducted to perform psychiatric disorder evaluations using the MINI. This association was analyzed with a Poisson regression model. RESULTS: The prevalence of any psychiatric disorder was 40.5% among drivers with recent alcohol or drug use, compared with 12.9% among the other drivers. Alcohol/drug-positive drivers reported a higher prevalence of depression (19.4%), mania (6.5%), hypomania (5.4%), post-traumatic stress disorder (8.6%), antisocial personality (7.8%), and substance/alcohol abuse or dependence (48.1%) compared with other drivers (3.5, 2.5, 2.1, 0.5, 1.3 and 18.3% [p < 0.001], respectively). Drivers with recent alcohol or drug use were 2.5 times more likely to have a psychiatric diagnosis (CI: 1.8-3.6, p < 0.001). DISCUSSION: This is the first study in a low-/middle-income country to evaluate psychiatric disorders in drivers with recent alcohol or drug using telephone interviews. Psychiatric disorders were found to be associated with drug and alcohol use. This type of epidemiological information for curtailing related driving problems, as these psychiatric conditions are diagnosable. FINAL REMARKS: The results of this study can aid in the design of interventions, treatment programs and focused psychiatric evaluations, both in Brazil and abroad.

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Mathematical models often propose that within-host competition between parasites can be a major factor in the evolution of increased parasite virulence. Kin selection predicts that as the coefficient of relatedness between infecting parasites decreases, the benefits of competition to individual genotypes increases. Thus where parasites can adjust their behaviour in response to current conditions, higher virulence is predicted in multiple genotype infections. There is limited experimental data, however, regarding the effects of mixed strain infections on host and parasite fitness. We investigated, for a snail-schistosome system, whether a conditional increase in replication rates occurred in mixed genotype infections and resulted in increased virulence. Four groups of Biomphalaria glabrata snails were exposed to 1 or 2 laboratory strains of Schistosoma mansoni. Mixed genotype infections were observed to be more virulent than single genotype infections, in terms of reductions in host reproductive success and survival. Parasite reproductive rate was also increased in mixed strain groups. Reduced host reproductive success was suggested to be directly due to the genetic heterogeneity of the parasitic infections resulting in increased host defence costs. Reduced host survival was consistent with an adaptive conditional parasite response.

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In stark contrast to the huge body of theoretical work on the importance of hosts and parasites as selective agents acting on each other, until recently, little systematic empirical investigation of this issue has been attempted. Research on snail-schistosome interactions have, therefore, the potential for making an important contribution to the study of coevolution or reciprocal adaptation. This may be particularly pertinent since snail-schistosomes represent an indirectly transmitted macroparasite system, so often overlooked amongst both theoretical and empirical studies. Here we review ideas and experiments on snail-schistosome interactions, with particular emphasis on those that may have relevance to the potential coevolution between host resistance and parasite infectivity and virulence. We commence with an introduction and definition of the general concepts, before going into detail of some specific studies to illustrate these: evidence of snail-schistosome coevolutionary process in the field; evidence of coevolutionary processes in the laboratory; a general assessment of the applicability of coevolutionary models in snail-schistosome interactions; and finishing with a section on conclusions and areas for further study.

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