Stochastic lattice model describing a vector-borne disease

We employ the approach of stochastic dynamics to describe the dissemination of vector-borne diseases such as\ud dengue, and we focus our attention on the characterization of the threshold of the epidemic. The coexistence\ud space comprises two representative spatial structures for both human and mosquito populations. The human\ud population has its evolution described by a process that is similar to the Susceptible-Infected-Recovered (SIR)\ud dynamics. The population of mosquitoes follows a dynamic of the type of the Susceptible Infected-Susceptible\ud (SIS) model. The coexistence space is a bipartite lattice constituted by two structures representing the human\ud and mosquito populations. We develop a truncation scheme to solve the evolution equations for the densities and\ud the two-site correlations from which we get the threshold of the disease and the reproductive ratio. We present\ud a precise deØnition of the reproductive ratio which reveals the importance of the correlations developed in the\ud early stage of the disease. According to our deØnition, the reproductive rate is directed related to the conditional\ud probability of the occurrence of a susceptible human (mosquito) given the presence in the neighborhood of an\ud infected mosquito (human). The threshold of the epidemic as well as the phase transition between the epidemic\ud and the non-epidemic states are also obtained by performing Monte Carlo simulations.\ud References: [1] David R. de Souza, T^ania Tom∂e, , Suani R. T. Pinho, Florisneide R. Barreto and M∂ario J. de\ud Oliveira, Phys. Rev. E 87, 012709 (2013). [2] D. R. de Souza, T. Tom∂e and R. M. ZiÆ, J. Stat. Mech. P03006\ud (2011)

The achievements of the SUS in tackling the communicable diseases

Apresenta-se a evolução da situação epidemiológica de algumas das principais Doenças transmissíveis (DT) no Brasil, assinalando as intervenções proporcionadas pelo SUS e outras políticas sociais. Dados e informações foram levantados do Datasus e Boletins epidemiológicos do Ministério da Saúde e de artigos científicos sobre o tema. A universalização, a descentralização e a ampliação das ações de vigilância, controle e prevenção de DT produziram impacto sobre a morbimortalidade dessas doenças, principalmente das imunopreveníveis. A emergência e reemergência de três arboviroses, para as quais não se dispõe de instrumentos de controle efetivos, interromperam a evolução decrescente no perfil de morbidade das DT no Brasil. Outros programas sociais e econômicos, voltados para a população brasileira mais carente, também contribuíram para a melhoria dos indicadores de saúde analisados. Contudo, a universalização do acesso aos serviços de atenção à saúde, ao lado do aperfeiçoamento do escopo de atuação da vigilância sobre doenças e riscos à saúde, vem desempenhando papel fundamental na melhoria das condições de saúde e qualidade de vida da população, bem como contribuindo para o processo de democratização do país.This article presents the development of the epidemiological situation of some of the major communicable diseases (CD) in Brazil, with emphasis on the interventions by the SUS and other social policies. The data and information were collected from Datasus, epidemiological newsletters from the Brazilian Ministry of Health, and scientific articles on the issue. The universalization, decentralization and expansion of the surveillance, control and prevention of CD has produced an impact on the morbidity and mortality of these diseases, mainly those which are vaccine-preventable. The emergence and re-emergence of three arboviruses, for which there are no effective control instruments, interrupted the downward trend in the morbidity profile of CD in Brazil. Other social and economic programs, which are geared to the needier sectors of the Brazilian population, have also contributed to the improvement of the analyzed health indicators. However, the universalization of access to healthcare services, as well as improvements in the scope of the surveillance of diseases and health risks, has played a key role in improving the health and quality of life of the population, as well as contributing to the process of the democratization of Brazil

The need for fast-track, high-quality and low-cost studies about the role of the BCG vaccine in the fight against COVID-19.

Bacillus Calmette-Guérin (BCG) vaccination is routine and near-universal in many low- and middle-income countries (LMIC). It has been suggested that BCG can have a protective effect on COVID-19 morbidity and mortality. This commentary discusses the limitations of the evidence around BCG and COVID-19. We argue that higher-quality evidence is necessary to understand the protective effect of the BCG vaccine from existing, secondary data, while we await results from clinical trials currently conducted in different settings

Repercussões da emergência do vírus Zika na saúde da população do estado do Tocantins, 2015 e 2016: estudo descritivo

Objective. To describe the occurrence of Zika and its complications in the state of Tocantins and in its capital, the city of Palmas. Methods. Descriptive study using data from Official Information Systems. Results. The incidence of reported cases of Zika in 2015 and 2016 was 295.2/100,000 and 411.1/100,000 inhabitants, respectively and 5.9/1000 and 27.8/1000 NV in pregnant women. Higher risks occurred in women, age 20-39 years, municipalities in the central and northwestern regions and hotter months (February and March). The incidence of Zika-related microcephaly at pregnancy was 0.06/1000 NV. One case of Guillain Barré Syndrome resulting from Zika virus infection has been confirmed. Conclusion. Zika virus fever has hit Tocantins intensely. However, their adverse outcomes have been less frequent than in others states.Objetivo. Descrever a ocorrência da febre pelo vírus Zika (ZIKV) e suas complicações no estado do Tocantins e em sua capital, Palmas. Métodos. Estudo descritivo, utilizando dados dos sistemas de informações em saúde. Resultados. A incidência de casos notificados de febre pelo ZIKV, em 2015 e 2016, foi de 295,2/100 mil e 411,1/100 mil habitantes na população geral, e de 5,9/1000 e 27,8/1000 nascidos vivos em gestantes, respectivamente. Maiores riscos ocorreram em mulheres, nas idades de 20-39 anos, nos municípios das regiões central e noroeste do estado, durante os meses mais quentes (fevereiro e março). A incidência de microcefalia relacionada à infecção pelo ZIKV na gestação foi de 0,06/1000 nascidos vivos. Foi confirmado um caso de síndrome de Guillain-Barré decorrente da infecção pelo ZIKV. Conclusão. A febre pelo ZIKV atingiu o Tocantins intensamente, embora seus desfechos adversos tenham sido menos frequentes que em outros estados

Seroprevalence of Chikungunya Virus after Its Emergence in Brazil.

Chikungunya has had a substantial impact on public health because of the magnitude of its epidemics and its highly debilitating symptoms. We estimated the seroprevalence, proportion of symptomatic cases, and proportion of chronic form of disease after introduction of chikungunya virus (CHIKV) in 2 cities in Brazil. We conducted the population-based study through household interviews and serologic surveys during October-December 2015. In Feira de Santana, we conducted a serologic survey of 385 persons; 57.1% were CHIKV-positive. Among them, 32.7% reported symptoms, and 68.1% contracted chronic chikungunya disease. A similar survey in Riachão do Jacuípe included 446 persons; 45.7% were CHIKV-positive, 41.2% reported symptoms, and 75.0% contracted the chronic form. Our data confirm intense CHIKV transmission during the continuing epidemic. Chronic pain developed in a high proportion of patients. We recommend training health professionals in management of chronic pain, which will improve the quality of life of chikungunya-affected persons

Previous BCG vaccination is associated with less severe clinical progression of COVID-19

Background: BCG vaccination, originally used to prevent tuberculosis, is known to “train” the immune system to improve defence against viral respiratory infections. We investigated whether a previous BCG vaccination is associated with less severe clinical progression of COVID-19./ Methods: A case-control study comparing the proportion with a BCG vaccine scar (indicating previous vaccination) in cases and controls presenting with COVID-19 to health units in Brazil. Cases were subjects with severe COVID-19 (O2 saturation < 90%, severe respiratory effort, severe pneumonia, severe acute respiratory syndrome, sepsis, and septic shock). Controls had COVID-19 not meeting the definition of “severe” above. Unconditional regression was used to estimate vaccine protection against clinical progression to severe disease, with strict control for age, comorbidity, sex, educational level, race/colour, and municipality. Internal matching and conditional regression were used for sensitivity analysis./ Results: BCG was associated with high protection against COVID-19 clinical progression, over 87% (95% CI 74–93%) in subjects aged 60 or less and 35% (95% CI − 44–71%) in older subjects./ Conclusions: This protection may be relevant for public health in settings where COVID-19 vaccine coverage is still low and may have implications for research to identify vaccine candidates for COVID-19 that are broadly protective against mortality from future variants. Further research into the immunomodulatory effects of BCG may inform COVID-19 therapeutic research.

Case Fatality Rate Related to Microcephaly Congenital Zika Syndrome and Associated Factors: A Nationwide Retrospective Study in Brazil †.

BACKGROUND: The clinical manifestations of microcephaly/congenital Zika syndrome (microcephaly/CZS) have harmful consequences on the child's health, increasing vulnerability to childhood morbidity and mortality. This study analyzes the case fatality rate and child-maternal characteristics of cases and deaths related to microcephaly/CZS in Brazil, 2015-2017. METHODS: Population-based study developed by linkage of three information systems. We estimate frequencies of cases, deaths, case fatality rate related to microcephaly/CZS according to child and maternal characteristics and causes of death. Multivariate logistic regression models were applied. RESULTS: The microcephaly/CZS case fatality rate was 10% (95% CI 9.2-10.7). Death related to microcephaly/CZS was associated to moderate (OR = 2.15; 95% CI 1.63-2.83), and very low birth weight (OR = 3.77; 95% CI 2.20-6.46); late preterm births (OR = 1.65; 95% CI 1.21-2.23), Apgar < 7 at 1st (OR = 5.98; 95% CI 4.46-8.02) and 5th minutes (OR = 4.13; 95% CI 2.78-6.13), among others. CONCLUSIONS: A high microcephaly/CZS case fatality rate and important factors associated with deaths related to this syndrome were observed. These results can alert health teams to these problems and increase awareness about the factors that may be associated with worse outcomes

Seroprevalence of Chikungunya virus and living conditions in Feira de Santana, Bahia-Brazil.

BACKGROUND: Chikungunya is an arbovirus, transmitted by Aedes mosquitoes, which emerged in the Americas in 2013 and spread rapidly to almost every country on this continent. In Brazil, where the first cases were detected in 2014, it currently has reached all regions of this country and more than 900,000 cases were reported. The clinical spectrum of chikungunya ranges from an acute self-limiting form to disabling chronic forms. The purpose of this study was to estimate the seroprevalence of chikungunya infection in a large Brazilian city and investigate the association between viral circulation and living condition. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a population-based ecological study in selected Sentinel Areas (SA) through household interviews and a serologic survey in 2016/2017. The sample was of 1,981 individuals randomly selected. The CHIKV seroprevalence was 22.1% (17.1 IgG, 2.3 IgM, and 1.4 IgG and IgM) and varied between SA from 2.0% to 70.5%. The seroprevalence was significantly lower in SA with high living conditions compared to SA with low living condition. There was a positive association between CHIKV seroprevalence and population density (r = 0.2389; p = 0.02033). CONCLUSIONS/SIGNIFICANCE: The seroprevalence in this city was 2.6 times lower than the 57% observed in a study conducted in the epicentre of the CHIKV epidemic of this same urban centre. So, the herd immunity in this general population, after four years of circulation of this agent is relatively low. It indicates that CHIKV transmission may persist in that city, either in endemic form or in the form of a new epidemic, because the vector infestation is persistent. Besides, the significantly lower seroprevalences in SA of higher Living Condition suggest that beyond the surveillance of the disease, vector control and specific actions of basic sanitation, the reduction of the incidence of this infection also depends on the improvement of the general living conditions of the population

Previous BCG vaccination is associated with less severe clinical progression of COVID-19

BACKGROUND: BCG vaccination, originally used to prevent tuberculosis, is known to "train" the immune system to improve defence against viral respiratory infections. We investigated whether a previous BCG vaccination is associated with less severe clinical progression of COVID-19 METHODS: A case-control study comparing the proportion with a BCG vaccine scar (indicating previous vaccination) in cases and controls presenting with COVID-19 to health units in Brazil. Cases were subjects with severe COVID-19 (O2 saturation < 90%, severe respiratory effort, severe pneumonia, severe acute respiratory syndrome, sepsis, and septic shock). Controls had COVID-19 not meeting the definition of "severe" above. Unconditional regression was used to estimate vaccine protection against clinical progression to severe disease, with strict control for age, comorbidity, sex, educational level, race/colour, and municipality. Internal matching and conditional regression were used for sensitivity analysis. RESULTS: BCG was associated with high protection against COVID-19 clinical progression, over 87% (95% CI 74-93%) in subjects aged 60 or less and 35% (95% CI - 44-71%) in older subjects. CONCLUSIONS: This protection may be relevant for public health in settings where COVID-19 vaccine coverage is still low and may have implications for research to identify vaccine candidates for COVID-19 that are broadly protective against mortality from future variants. Further research into the immunomodulatory effects of BCG may inform COVID-19 therapeutic research

Cadernos de Saúde Pública

p. 7-18This 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