BackgroundSevere dengue virus (DENV) disease is associated with extensive immune activation, characterized by a cytokine storm. Previously, elevated lipopolysaccharide (LPS) levels in dengue were found to correlate with clinical disease severity. In the present cross-sectional study we identified markers of microbial translocation and immune activation, which are associated with severe manifestations of DENV infection.MethodsSerum samples from DENV-infected patients were collected during the outbreak in 2010 in the State of São Paulo, Brazil. Levels of LPS, lipopolysaccharide binding protein (LBP), soluble CD14 (sCD14) and IgM and IgG endotoxin core antibodies were determined by ELISA. Thirty cytokines were quantified using a multiplex luminex system. Patients were classified according to the 2009 WHO classification and the occurrence of plasma leakage/shock and hemorrhage. Moreover, a (non-supervised) cluster analysis based on the expression of the quantified cytokines was applied to identify groups of patients with similar cytokine profiles. Markers of microbial translocation were linked to groups with similar clinical disease severity and clusters with similar cytokine profiles.ResultsCluster analysis indicated that LPS levels were significantly increased in patients with a profound pro-inflammatory cytokine profile. LBP and sCD14 showed significantly increased levels in patients with severe disease in the clinical classification and in patients with severe inflammation in the cluster analysis. With both the clinical classification and the cluster analysis, levels of IL-6, IL-8, sIL-2R, MCP-1, RANTES, HGF, G-CSF and EGF were associated with severe disease.ConclusionsThe present study provides evidence that both microbial translocation and extensive immune activation occur during severe DENV infection and may play an important role in the pathogenesis.
Seventy-seven human cases of sylvatic yellow fever were reported in Brazil during the period January-June 2000. The first cases were reported 1 week after New Year's day and originated at Chapada dos Veadeiros, a tourist canyon site in Goiás state, near Brasília, the Brazilian capital. The laboratory procedures used for diagnoses included serology with an IgM capture assay and plaque reduction neutralization test, virus isolation in suckling mice and C6/36 cells, and immunohistochemistry. All cases were diagnosed by at least two different laboratory procedures, with the exception of the first three fatal cases, which were diagnosed on the basis of clinical and epidemiological information. The cases were reported in eight Brazilian states as follows: Goiás with 64.9% (50 cases); Amazonas (1); Bahia (10); Distrito Federal (1); Mato Grosso (4); Minas Gerais (2); Pará (1); São Paulo (2); and Tocantins (6). Patient ages were within the following ranges: 13-74 years old (mean 34.3), 64 (84.4%) were male, especially agricultural workers (n = 30), but tourists (n = 11), carpenters (n = 4), fishermen (n = 4), students (n = 3), truck drivers (n = 3), and other people (n = 22) were also sickened. The case fatality rate was 50.6% (39/77). In Bahia state, a serologic survey that was carried out has suggested a symptomatic/asymptomatic coefficient of 1:4. Field studies developed in Distrito Federal, Goiás, and São Paulo states showed that Haemagogus janthinomys was the mosquito species associated with the transmission. A single strain was also obtained from Aedes scapularis in Bahia. Epizootic occurrence (monkey mortality) was observed in 49 municipalities mainly in Goiás state, where 40 municipalities made reports, 21 of which also diagnosed human cases. Data obtained by the National Institute of Meteorology in Brazil showed an increase in temperature and rain in December 1999 and the first 3 months of 2000 in Goiás and surrounding states, which perhaps has contributed to the intense and widespread transmission of the yellow fever virus. The relatively small number of cases probably reflects the extensive use of yellow fever 17D-vaccine during the last 3 years, in which about 45 million doses were used. During the last months of 1999, 16 and 11 yellow fever cases were reported in Tocantins and Goiás states, respectively. It is noteworthy that the last reported autochthonous cases of sylvatic yellow fever in São Paulo and Bahia, both states outside the endemic/enzootic area, had occurred in 1953 and 1948, respectively.
This article discusses the emergence of the concept of emerging and reemerging infectious diseases. It argues that the concept surfaces due to the limits of the epidemiologic transition theory in explaining the current trends in morbidity and mortality. The bases of the epidemiologic transition theory are discussed, as well as the reasons for its limits. Then, the concept of emerging and reemerging infectious diseases, the factors related to them, and the major episodes of emergence and reemergence of diseases in Brazil are presented. Finally, the article discusses the challenges brought by the emergence and reemergence of infectious diseases, and the proposals to face them.
Trachoma was considered to have been 'eradicated' from the state of São Paulo, Brazil, until 1982 when a number of new cases of trachoma were reported in preschool children in Bebedouro, a small town in northwestern São Paulo. A household survey was undertaken to assess the prevalence and epidemiological characteristics of trachoma. A total of 2939 people of all ages was examined having been selected from a two-stage probalilistic household sampling frame based on census data. Overall, 7.2% of the population had evidence of one or more signs of trachoma and 2.1% had inflammatory trachoma. Inflammatory trachoma was more common in children aged one to ten years, especially in the peripheral urban and rural areas, and was more common in boys. The presence of chlamydia was confirmed by direct fluorescent antibody cytology. No cases of blindness due to trachoma were seen. A number of socioeconomic and hygiene variables were studied in order to determine the independent risk factors for trachoma in a household. Variables significantly associated with the occurrence of trachoma in the household were the number of children in the house aged one to ten years, the 'per capita' water consumption, the frequency of garbage collections, source of water, and the educational level of the head of household. Clustering of trachoma in different parts of this community was entirely explained by the concentration of households with these characteristics.
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