Yellow fever in Africa and the Americas: a historical and epidemiological perspective

Yellow fever was transported during the slave trade in the 15th and 16th centuries from Africa to the Americas where the virus encountered favorable ecological conditions that allowed creation of a sustainable sylvatic cycle. Despite effective vector control and immunization programs for nearly a century, yellow fever epidemics reemerged in many Latin American countries, particularly Brazil. The emergence or reemergence of vector-borne diseases encompasses many intricate factors. Yellow fever outbreaks occur if at least three conditions are fulfilled: the introduction of the virus into a non-immune human community, presence of competent and anthropophilic vectors and insufficiency of prevention and/or adequate management of the growing outbreak. On the other hand, two weapons are available to constrain yellow fever: vector control and immunization. In contrast, yellow fever is absent from Asia and the Pacific despite the presence of the vector and the susceptibility of human populations to the virus. Based on a review of the global history of yellow fever and its epidemiology, the authors deliver some recommendations for improving the prevention of epidemics.(AU)

Yellow fever in Africa and the Americas: a historical and epidemiological perspective

Yellow fever was transported during the slave trade in the 15th and 16th centuries from Africa to the Americas where the virus encountered favorable ecological conditions that allowed creation of a sustainable sylvatic cycle. Despite effective vector control and immunization programs for nearly a century, yellow fever epidemics reemerged in many Latin American countries, particularly Brazil. The emergence or reemergence of vector-borne diseases encompasses many intricate factors. Yellow fever outbreaks occur if at least three conditions are fulfilled: the introduction of the virus into a non-immune human community, presence of competent and anthropophilic vectors and insufficiency of prevention and/or adequate management of the growing outbreak. On the other hand, two weapons are available to constrain yellow fever: vector control and immunization. In contrast, yellow fever is absent from Asia and the Pacific despite the presence of the vector and the susceptibility of human populations to the virus. Based on a review of the global history of yellow fever and its epidemiology, the authors deliver some recommendations for improving the prevention of epidemics.

Efficacy and safety of a four-drug fixed-dose combination regimen versus separate drugs for treatment of pulmonary tuberculosis: a systematic review and meta-analysis

Introduction: Tuberculosis, particularly multi-drug-resistant tuberculosis, is a major cause of morbidity and mortality worldwide. To the best of our knowledge, however, no study to date has assessed the combined use of the four available drugs for tuberculosis treatment, which is an issue of great clinical relevance. Objective: To determine whether the four-drug fixed-dose combination is safer or more effective than separate drugs for treatment of pulmonary tuberculosis. Methods: A systematic review of the literature was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results: In pooled results from five randomized controlled trials with 3502 patients across Africa, Asia, and Latin America, four-drug fixed-dose combination therapy was no better than separate drugs therapy in terms of culture conversion after 2 and 6 months of treatment. There were no significant differences between the groups in overall incidence of adverse effects. However, the meta-analytic measure (log odds ratio) revealed that separate drugs treatment had a 1.65 [exp (0.5) = 1.65] increased chance of gastrointestinal adverse effects compared to four-drug fixed-dose combination treatment. Conclusions: The reviewed studies showed that four-drug fixed-dose combination therapy provides greater patient comfort by reducing the number of pills and the incidence of gastrointestinal adverse effects, as well as simplifying pharmaceutical management at all levels.(AU)

Socio-demographic profile of different samples of Latin American rural extensionists / Perfil sociodemográfico de diferentes amostras de extensionistas rurais da América Latina

In order to design and implement public policies in the context of rural development, information tends to be gathered about family farming in different Latin American countries. In contrast, scarce attention has been given to the description of rural extensionists, who are the ones supporting family farming in the field. A cross-sectional investigation was conducted between 2010 and 2012 including surveys to rural extensions working in 10 different Latin American countries, this allowing for a preliminary description of the socio-demographic profile of the respondents. The samples were incidental ranging from 19 (Bolivia) to 220 (Argentina) subjects, this implying that they were not representative. Significant statistical differences were found with regards to the sex, age, experience, level of education and university degree of the samples pertaining to the different countries. In average, most extensionists are men (70.1%), age 40.3 and have little more than 11 years of experience as extensionists. Brazilian practitioners surveyed are the oldest, most educated and experienced among the different samples. In general, most extensionists have a technical background and are agricultural engineers. The Uruguayan sample showed the highest percentage of extensionists coming from the area of social sciences.(AU)

A fim de elaborar e implementar políticas públicas no contexto do desenvolvimento rural, é muito comum a coleta de informações sobre a distribuição e as características da agricultura familiar. Em contraste, tem sido dada pouca atenção à descrição sociodemográfica dos extensionistas rurais, que são os que apoiam a agricultura familiar no território. Entre 2010 e 2012, foi feita umtrabalho em que foram pesquisados extensionistas rurais que trabalham em 10 países latino-americanos diferentes, permitindo, assim, uma descrição preliminar do perfil sociodemográfico destes extensionistas. As amostras foram incidentais, variando de 19 indivíduos (Bolívia) a 220 (Argentina), implicando que elas não são representativas. Foram encontradas diferenças estatisticamente significativas no sexo, idade, experiência, nível de escolaridade e título academico dos extensionistas das amostras pertencentes aos diferentes países. Em média, a maioria dos extensionistas são homens (70,1%), tem 40,3 anos de idade e tem pouco mais de 11 anos de experiência como extensionistas rurais. Os brasileiros pesquisados são os mais idosos, educados e experientes entre as diferentes amostras. Em geral, a maioria dos extensionistas têm formação técnica e são engenheiros agrícolas. Na amostra uruguaia, pode ser encontrado o maior percentual de extensionistas provenientes da área das ciências sociais.(AU)