Mayaro virus and dengue virus 1 and 4 natural infection in culicids from Cuiabá, state of Mato Grosso, Brazil

This study aimed to verify the diversity of Culicidae species and their frequency of infection with flaviviruses and alphaviruses in Cuiabá, state of Mato Grosso, Brazil. Mosquitoes were captured with Nasci aspirators and hand net in 200 census tracts, identified alive at species level and pooled in one-20 (11,090 mosquitoes, 14 species). Female pools (n = 610) were subjected to multiplex seminested-reverse transcription-polymerase chain reaction (RT-PCR) for 11 flavivirus and five alphavirus. Positive pools were tested by single RT-PCR followed by nucleotide sequencing, by RT-PCR for E1 gene [Mayaro virus (MAYV)] and by inoculation in Vero cells (MAYV) or C6/36 cells (flaviviruses). One/171 Aedes aegypti was positive for dengue virus (DENV)-1, 12/403 Culex quinquefasciatus, and four/171Ae. aegypti for MAYV, which was isolated from two pools containing two nonengorged females of Ae. aegypti and two ofCx. quinquefasciatus. DENV-4 was detected in 58/171 pools of Ae. aegytpi, 105/403 Cx. quinquefasciatus, two/five Psorophora sp., two/11 Psorophora varipes/Psorophora albigenu, one/one Sabethes chloropterus, two/five Culex bidens/Culex interfor, and one/one Aedes sp. DENV-4 was isolated from two pools containing three and 16 nonengorged Cx. quinquefasciatus females. Phylogenetic analysis revealed MAYV belongs to genotype L, clustering with human samples of the virus previously identified in the city. Cuiabá has biodiversity and ecosystem favourable for vector proliferation, representing a risk for arbovirus outbreaks.

Complete genome of a dengue virus serotype 4 strain from Amazonas, Brazil

Dengue virus (DENV) infections represent a significant concern for public health worldwide, being considered as the most prevalent arthropod-borne virus regarding the number of reported cases. In this study, we report the complete genome sequencing of a DENV serotype 4 isolate, genotype II, obtained in the city of Manaus, directly from the serum sample, applying Ion Torrent sequencing technology. The use of a massive sequencing technology allowed the detection of two variable sites, one in the coding region for the viral envelope protein and the other in the nonstructural 1 coding region within viral populations.

Primary dengue virus infections induce differential cytokine production in Mexican patients

Severe dengue pathogenesis is not fully understood, but high levels of proinflammatory cytokines have been associated with dengue disease severity. In this study, the cytokine levels in 171 sera from Mexican patients with primary dengue fever (DF) and dengue haemorrhagic fever (DHF) from dengue virus (DENV) 1 (n = 116) or 2 (n = 55) were compared. DF and DHF were defined according to the patient’s clinical condition, the primary infections as indicated by IgG enzymatic immunoassay negative results, and the infecting serotype as assessed by real-time reverse transcription-polymerase chain reaction. Samples were analysed for circulating levels of interleukin (IL)-12p70, interferon (IFN)-γ, tumour necrosis factor (TNF)-α, IL-6, and IL-8 using a commercial cytometric bead array. Significantly higher IFN-γ levels were found in patients with DHF than those with DF. However, significantly higher IL-12p70, TNF-α, and IL-6 levels were associated with DHF only in patients who were infected with DENV2 but not with DENV1. Moreover, patients with DF who were infected with DENV1 showed higher levels of IL-12p70, TNF-α, and IL-6 than patients with DHF early after-fever onset. The IL-8 levels were similar in all cases regardless of the clinical condition or infection serotype. These results suggest that the association between high proinflammatory cytokine levels and dengue disease severity does not always stand, and it once again highlights the complex nature of DHF pathogenesis.

Detection of all four dengue serotypes in Aedes aegypti female mosquitoes collected in a rural area in Colombia

The Aedes aegypti vector for dengue virus (DENV) has been reported in urban and periurban areas. The information about DENV circulation in mosquitoes in Colombian rural areas is limited, so we aimed to evaluate the presence of DENV in Ae. aegypti females caught in rural locations of two Colombian municipalities, Anapoima and La Mesa. Mosquitoes from 497 rural households in 44 different rural settlements were collected. Pools of about 20 Ae. aegypti females were processed for DENV serotype detection. DENV in mosquitoes was detected in 74% of the analysed settlements with a pool positivity rate of 62%. The estimated individual mosquito infection rate was 4.12% and the minimum infection rate was 33.3/1,000 mosquitoes. All four serotypes were detected; the most frequent being DENV-2 (50%) and DENV-1 (35%). Two-three serotypes were detected simultaneously in separate pools. This is the first report on the co-occurrence of natural DENV infection of mosquitoes in Colombian rural areas. The findings are important for understanding dengue transmission and planning control strategies. A potential latent virus reservoir in rural areas could spill over to urban areas during population movements. Detecting DENV in wild-caught adult mosquitoes should be included in the development of dengue epidemic forecasting models.

Primary dengue haemorrhagic fever in patients from northeast of Brazil is associated with high levels of interferon-β during acute phase

Dengue is an acute febrile disease caused by the mosquito-borne dengue virus (DENV) that according to clinical manifestations can be classified as asymptomatic, mild or severe dengue. Severe dengue cases have been associated with an unbalanced immune response characterised by an over secretion of inflammatory cytokines. In the present study we measured type I interferon (IFN-I) transcript and circulating levels in primary and secondary DENV infected patients. We observed that dengue fever (DF) and dengue haemorrhagic fever (DHF) patients express IFN-I differently. While DF and DHF patients express interferon-α similarly (52,71 ± 7,40 and 49,05 ± 7,70, respectively), IFN- β were associated with primary DHF patients. On the other hand, secondary DHF patients were not able to secrete large amounts of IFN- β which in turn may have influenced the high-level of viraemia. Our results suggest that, in patients from our cohort, infection by DENV serotype 3 elicits an innate response characterised by higher levels of IFN- β in the DHF patients with primary infection, which could contribute to control infection evidenced by the low-level of viraemia in these patients. The present findings may contribute to shed light in the role of innate immune response in dengue pathogenesis.

Caracterização das quedas de pacientes segundo notificação em boletins de eventos adversos

Este estudo foi desenvolvido com o objetivo de caracterizar as quedas de pacientes internados ocorridas em hospital terciário. Foram analisados 826 Boletins de Notificação de Eventos Adversos, de um período de 30 meses, que registraram 0,30 quedas por 1000 pacientes/dia. Quedas do leito foram mais frequentes (55%), com maior prevalência na enfermaria de neurologia. Maior frequência de quedas foi verificada no período noturno (63,7%), nos primeiros cinco dias da admissão (61,7%), nos pacientes de sexo masculino (57,5%) e na faixa etária maior de 60 anos (50%). Nos casos de quedas do leito, os diagnósticos relacionaram-se a doenças infecciosas e parasitárias (18,2%), doenças do sistema nervoso (18,2%) e doenças do aparelho circulatório (13,7%). Nas quedas da própria altura, os diagnósticos relacionaram-se a neoplasias (19,4%) e doenças do aparelho geniturinário (16,1%). A caracterização desses eventos adversos auxilia no reconhecimento dos grupos de maior risco e na elaboração de propostas preventivas.

Eventos adversos: análise de um instrumento de notificação utilizado no gerenciamento de enfermagem

A direção de enfermagem de um hospital universitário terciário da região Centro-Sul do Estado de São Paulo, visando a segurança do paciente e o estabelecimento de meio de comunicação entre equipe e direção, implementou em janeiro de 2004 o Boletim de Notificação de Eventos Adversos. O objetivo deste estudo foi analisar a utilização deste instrumento de comunicação e identificar: frequência, tipo, natureza e período dos incidentes/eventos adversos. Realizou-se análise descritiva dos dados de 826 boletins elaborados no período de janeiro/2004 a junho/2006. Verificou-se adesão à utilização do instrumento. Predominaram notificações de ocorrências assistenciais, embora notificações administrativas tenham apresentado número crescente de registros. Eventos adversos mais frequentes relacionaram-se à medicação, quedas, cateteres, sondas/drenos e integridade da pele. A praticidade do instrumento viabilizou sua utilização também por auxiliares e técnicos de enfermagem. A análise sistematizada e acompanhamento dos eventos adversos associados aos recursos de comunicação mostraram-se fundamentais para a segurança do paciente.

Perceptions of representatives of a committee against dengue in the health education actions, Goiás, Brazil.

This study aimed to analyze how the educational actions of prevention and control of dengue are performed in Goiás, from the perspective of representatives of the State Mobilization Committee against Dengue. It is a cross-sectional descriptive-analytical study, carried out in Goiânia with 43 representatives of public-private institutions, members of the State Mobilization Committee against Dengue of Goiás, in 2013. The data collection was done through questioning about the perception of health education for dengue prevention. Data were analyzed using content analysis and the WebQDA software. Three dimensions emerged from the analysis: educational aspects, management aspects, and community involvement. Respondents recognized the importance of health education for the prevention of dengue, and of the planning to strengthen the activities of the Committee.

Contrasting patterns of insecticide resistance and knockdown resistance (kdr) in Aedes aegypti populations from Jacarezinho (Brazil) after a Dengue Outbreak

ABSTRACT After a dengue outbreak, the knowledge on the extent, distribution and mechanisms of insecticide resistance is essential for successful insecticide-based dengue control interventions. Therefore, we evaluated the potential changes to insecticide resistance in natural Aedes aegypti populations to Organophosphates (OP) and Pyrethroids (PY) after chemical vector control interventions. After a Dengue outbreak in 2010, A. aegypti mosquitoes from the urban area of Jacarezinho (Paraná, Brazil) were collected in 2011 and 2012. Insecticide resistance to OP Temephos was assessed in 2011 and 2012 by dose–response bioassays adopting WHO-based protocols. Additionally, in both sampling, PY resistance was also investigated by the Val1016Ile mutation genotyping. In 2011, a random collection of mosquitoes was carried out; while in 2012, the urban area was divided into four regions where mosquitoes were sampled randomly. Bioassays conducted with larvae in 2011 (82 ± 10%; RR95 = 3.6) and 2012 (95 ± 3%; RR95 = 2.5) indicated an incipient altered susceptibility to Temephos. On the other hand, the Val1016IIe mutation analysis in 2011, presented frequencies of the 1016Ilekdr allele equal to 80%. Nevertheless, in 2012, when the urban area of Jacarezinho was analyzed as a single unit, the frequency of the mutant allele was 70%. Additionally, the distribution analysis of the Val1016Ile mutation in 2012 showed the mutant allele frequencies ≥60% in all regions. These outcomes indicated the necessity of developing alternative strategies such as insecticide rotations for delaying the evolution of resistance.

Achados ultra-sonográficos abdominais em pacientes com dengue

OBJETIVO: Apresentar os achados ultra-sonográficos abdominais em pacientes com dengue e compará-los aos descritos na literatura. MATERIAIS E MÉTODOS: Foram realizados exames ultra-sonográficos abdominais de 38 pacientes, 25 do sexo feminino e 13 do sexo masculino, com idade média de 35 anos, com diagnóstico de dengue sorologicamente confirmado. Os achados foram comparados com os descritos na literatura. RESULTADOS: Os achados ultra-sonográficos mais relevantes foram espessamento difuso da parede da vesícula biliar em 18 casos (47,4%), líquido livre na cavidade abdominal e/ou pélvica em 12 (31,6%), esplenomegalia em 11 (28,9%), hepatomegalia em 10 (26,3%) e líquido pericolecístico em 10 (26,3%). Vinte e seis por cento dos pacientes apresentaram exames ultra-sonográficos normais. CONCLUSÃO: Os achados ultra-sonográficos abdominais são uma ferramenta adicional útil na confirmação de casos suspeitos de dengue hemorrágica e na detecção precoce da gravidade e da progressão da doença, sendo de extrema importância para o radiologista o conhecimento destes possíveis achados.

Valor da ultrassonografia em crianças com suspeita de febre hemorrágica do dengue: revisão da literatura

O dengue é doença endêmica em regiões tropicais e subtropicais. Quando sintomática, classifica-se em febre do dengue e febre hemorrágica do dengue, com tendência a síndrome do choque do dengue. A febre hemorrágica do dengue é marcada por manifestações hemorrágicas, trombocitopenia e aumento da permeabilidade capilar. A síndrome do choque do dengue apresenta os achados de febre hemorrágica do dengue com hipotensão. Muitos achados ultrassonográficos têm sido descritos, incluindo derrame pleural, ascite, espessamento da parede da vesícula biliar e derrame pericárdico. O objetivo desta revisão da literatura é descrever os achados ultrassonográficos e demonstrar o papel da ultrassonografia em crianças com suspeita de febre hemorrágica do dengue

Produtos naturais para o controle da transmissão da dengue: atividade larvicida de Myroxylon balsamum (óleo vermelho) e de terpenóides e fenilpropanóides

The bioassay-guided fractionation of the hexane extract obtained from the medicinal plant Myroxylon balsamum (red oil) was conducted in preparative thin layer chromatography on silica gel. The obtained fractions and some terpenoids and phenylpropanoids were assayed as larvicidal on third instar Aedes aegypti larvae, NPPN colony. The results indicate that the sesquiterpene nerolidol was the active constituent in the extract and that the sesquiterpenes were more active than the monoterpenes and phenylpropanoids utilized in this study. Lipophilicity seems to be an important property for the activity since the compounds with hydroxyl, carbonyl and methoxyl groups were less active. The results confirm also that essential oils can be a good tool for the control of dengue.

Rotenoids from Tephrosia toxicaria with larvicidal activity against Aedes aegypti, the main vector of dengue fever

In the search for new larvicides from plants, we have investigated the potential activity of the rotenoids deguelin (1), 12a-hydroxy-α-toxicarol (2) and tephrosin (3), isolated from the bioactive ethanol extract of roots of Tephrosia toxicaria Pers., against Aedes aegypti, the main vector of dengue. The absolute configuration of these compounds was determined by circular dichroism (CD) spectra. The LC50 values of the compounds evaluated justify the potential of T. toxicaria as a new natural larvicide.

Genetic characterization of dengue virus type 3 isolates in the State of Rio de Janeiro, 2001

The genetic characterization of dengue virus type 3 (DEN-3) strains isolated from autochthonous cases in the State of Rio de Janeiro, Brazil, in 2001 is presented. Restriction site-specific (RSS)-PCR performed on 22 strains classified the Brazilian DEN-3 viruses as subtype C, a subtype that contains viruses from Sri Lanka, India, Africa and recent isolates from Central America. Nucleic acid sequencing (positions 278 to 2550) of one DEN-3 strain confirmed the origin of these strains, since genotype III - classified by sequencing - and RSS-PCR subtype C are correlated. This genetic subtype has been associated with hemorrhagic dengue epidemics and the information provided here could be useful to implement appropriate prevention and control measures.

Molecular epidemiology of type 1 and 2 dengue viruses in Brazil from 1988 to 2001

Dengue is a mosquito-borne viral infection that in recent decades has become a major international public health concern. Epidemic dengue fever reemerged in Brazil in 1981. Since 1990 more than one dengue virus serotype has been circulating in this tropical country and increasing rates of dengue hemorrhagic fever and dengue shock syndrome have been detected every year. Some evidence supports the association between the introduction of a new serotype and/or genotype in a region and the appearance of dengue hemorrhagic fever. In order to study the evolutionary relationships and possible detection of the introduction of new dengue virus genotypes in Brazil in the last years, we analyzed partial nucleotide sequences of 52 Brazilian samples of both dengue type 1 and dengue type 2 isolated from 1988 to 2001 from highly endemic regions. A 240-nucleotide-long sequence from the envelope/nonstructural protein 1 gene junction was used for phylogenetic analysis. After comparing the nucleotide sequences originally obtained in this study to those previously studied by others, and analyzing the phylogenetic trees, we conclude that, after the initial introduction of the currently circulating dengue-1 and dengue-2 genotypes in Brazil, there has been no evidence of introduction of new genotypes since 1988. The increasing number of dengue hemorrhagic fever cases seen in Brazil in the last years is probably associated with secondary infections or with the introduction of new serotypes but not with the introduction of new genotypes.