Resumo A pandemia de COVID-19 tem desafiado pesquisadores e gestores a encontrar medidas de saúde pública que evitem o colapso dos sistemas de saúde e reduzam os óbitos. Esta revisão narrativa buscou sistematizar as evidências sobre o impacto das medidas de distanciamento social na epidemia de COVID-19 e discutir sua implementação no Brasil. Foram triados artigos sobre o efeito do distanciamento social na COVID-19 no PubMed, medRXiv e bioRvix, e analisados atos do poder público nos níveis federal e estadual para sumarizar as estratégias implementadas no Brasil. Os achados sugerem que o distanciamento social adotado por população é efetivo, especialmente quando combinado ao isolamento de casos e à quarentena dos contatos. Recomenda-se a implementação de medidas de distanciamento social e de políticas de proteção social para garantir a sustentabilidade dessas medidas. Para o controle da COVID-19 no Brasil, é imprescindível que essas medidas estejam aliadas ao fortalecimento do sistema de vigilância nos três níveis do SUS, que inclui a avaliação e uso de indicadores adicionais para monitorar a evolução da pandemia e o efeito das medidas de controle, a ampliação da capacidade de testagem, e divulgação ampla e transparente das notificações e de testagem desagregadas.

A literature survey and analysis was conducted to describe the epidemiology of dengue disease in Brazil reported between 2000 and 2010. The protocol was registered on PROSPERO (CRD42011001826: http://www.crd.york.ac.uk/prospero/display_record.asp?ID=CRD42011001826). Between 31 July and 4 August 2011, the published literature was searched for epidemiological studies of dengue disease, using specific search strategies for each electronic database. A total of 714 relevant citations were identified, 51 of which fulfilled the inclusion criteria. The epidemiology of dengue disease in Brazil, in this period, was characterized by increases in the geographical spread and incidence of reported cases. The overall increase in dengue disease was accompanied by a rise in the proportion of severe cases. The epidemiological pattern of dengue disease in Brazil is complex and the changes observed during this review period are likely to have been influenced by multiple factors. Several gaps in epidemiological knowledge regarding dengue disease in Brazil were identified that provide avenues for future research, in particular, studies of regional differences, genotype evolution, and age-stratified seroprevalence. PROSPERO registration number: CRD42011001826. Dengue disease is the most prevalent arthropod-borne viral disease in humans and is a global and national public health concern in Brazil. We conducted this review to consolidate and describe the existing evidence on the epidemiology of dengue disease in Brazil, between 2000 and 2011, to gauge the recent national and regional impact of dengue disease and provide a basis for setting research priorities and prevention efforts. We used well-defined methods to search and identify relevant research, according to predetermined inclusion criteria. Despite control measures, the increased territorial distribution of the mosquito vector and the co-circulation of multiple dengue virus serotypes have resulted in increases in the incidence and distribution of dengue disease. The number of disease-related hospitalizations and deaths has also increased. Efforts to control the increasing disease incidence have been unsuccessful. This review of dengue disease epidemiology will help enhance knowledge and future disease management. Despite the high volume of research retrieved, we have identified several avenues for future research, in particular studies of regional differences, genotype evolution and age-stratified seroprevalence that will improve our knowledge of dengue disease, contribute to a more accurate estimate of global disease incidence, and also inform evidence-based policies for dengue disease prevention.

Summary: Serotypes of dengue DEN‐1 and DEN‐2 have been reported in much of Brazil over the last 15 years, and DEN‐3 serotype was only recently detected. This prospective study was conducted in Salvador, a large city in north‐east Brazil, where two epidemics were previously recorded (DEN‐1 and DEN‐2). We obtained the seroprevalence and 1‐year incidence of dengue infections in the population of 30 sampling areas of Salvador and analysed the relationship between intensity of viral circulation, standard of living and vector density. High seroprevalence (68.7%) and annual incidence (70.6%) of infection for one or both circulating serotypes (DEN‐1 and DEN‐2) were found. High rates of transmission were observed in all studied areas, from the highest to the lowest socio‐economic status. The mean PI (Premise Index) for Aedes aegypti was 7.4% (range 0.27–25.6%). Even in the areas with the lowest PI (≤3%) the observed seroincidence was 54.6%. These findings highlighted the existence of a silent epidemic during a period perceived by the Health Services as of low endemicity, indicating the strength and speed of dengue transmission in the city of Salvador.

This article revisits the epidemiology of dengue in Brazil, 25 years after its reemergence in the country, discussing the main determinants and implications for its control. The authors emphasize the clinical and epidemiological peculiarities of this viral disease in Brazil, which leads the world in both the number of cases reported and risk of occurrence of the disease. The article presents the changes occurring in the dengue epidemiological pattern in recent years, like the sudden age shift in the incidence of dengue hemorrhagic fever, and discusses possible associated factors. The article focuses specifically on the epidemic in Rio de Janeiro in 2008, this episode's impact on the international community, and the fear that the disease could spread to Europe. The authors conclude that the current situation emphasizes the need for the international scientific community to renew its efforts to generate knowledge allowing improvement and progress in the development of new tools and strategies for dengue prevention.

The physiopathology of dengue hemorrhagic fever (DHF), a severe form of Dengue Fever, is poorly understood. We are unable to identify patients likely to progress to DHF for closer monitoring and early intervention during epidemics, so most cases are sent home. This study explored whether patients with selected co-morbidities are at higher risk of developing DHF. A matched case-control study was conducted in a dengue sero-positive population in two Brazilian cities. For each case of DHF, 7 sero-positive controls were selected. Cases and controls were interviewed and information collected on demographic and socio-economic status, reported co-morbidities (diabetes, hypertension, allergy) and use of medication. Conditional logistic regression was used to calculate the strength of the association between the co-morbidities and occurrence of DHF. 170 cases of DHF and 1,175 controls were included. Significant associations were found between DHF and white ethnicity (OR = 4.70; 2.17–10.20), high income (OR = 6.84; 4.09–11.43), high education (OR = 4.67; 2.35–9.27), reported diabetes (OR = 2.75; 1.12–6.73) and reported allergy treated with steroids (OR = 2.94; 1.01–8.54). Black individuals who reported being treated for hypertension had 13 times higher risk of DHF then black individuals reporting no hypertension. This is the first study to find an association between DHF and diabetes, allergy and hypertension. Given the high case fatality rate of DHF (1–5%), we believe that the evidence produced in this study, when confirmed in other studies, suggests that screening criteria might be used to identify adult patients at a greater risk of developing DHF with a recommendation that they remain under observation and monitoring in hospital. Dengue is an arboviral disease that affects large areas of countries in tropical and subtropical regions of the world. Around 500,000 cases and 22,000 deaths of dengue hemorrhagic fever (DHF)/Dengue Shock Syndrome (DSS), the most severe presentations of this disease, occur annually. It is unclear why some cases of dengue fever (0.5% to 4%) progress to DHF/DSS. There is weak evidence that some diseases could have a role in this process, such as diabetes, hypertension, and allergies. In epidemics most dengue fever cases are sent home as there are too many to be kept in observation, but if it were possible to identify those with a higher risk of progression to DHF, they could be kept for observation, for early detection of signs, symptoms and alterations in laboratory tests suggestive of DHF, to enable timely and effective clinical management and early intervention. We study this issue and we believe that the evidence produced in this study, when confirmed in other studies, suggests that screening criteria might be used to identify adult patients at a greater risk of developing DHF with a recommendation that they remain under observation and monitoring in a hospital.