Epidemiological aspects of dengue in Aracaju, State of Sergipe, Brazil

INTRODUCTION: The dengue fever remains to be a disease of serious public health concern, and its incidence has increased in the past decades. This study aimed to characterize the epidemiological incidence of dengue in the period 2001-2010. METHODS: This is an epidemiological study of dengue in the municipality of Aracaju, state of Sergipe, in the period between 2001 and 2010, whose data were obtained from the Information System of Diseases Notifications. A descriptive analysis of the number of confirmed cases of dengue, according to year, semester, sanitary district, age, and sex, was performed. RESULTS: There were 16,462 confirmed cases, especially in 2008, which obtained the highest incidence of the disease, with 10,485 confirmed cases. The first semester obtained the highest registration of cases during the years of research; this was predominated by females between 15 and 49 years old. With regard to the territorial distribution, the second district of the municipality obtained the highest number of cases. CONCLUSIONS: In 2008, in the City of Aracaju, SE, a significant increase in the proportion of dengue cases compared with other years was verified. However, a fast decline in the other years was observed, possibly because of the intensification of preventive actions to combat the mosquito that transmits the dengue virus.

Seroepidemiological monitoring in sentinel animals and vectors as part of arbovirus surveillance in the state of Mato Grosso do Sul, Brazil

INTRODUCTION: From February-September 2010, seroepidemiological surveys were conducted on non-human primates and transmitter vector capture was used to investigate the possible circulation of arboviruses in the municipalities of Bonito, Campo Grande, and Jardim, State of Mato Grosso do Sul, Brazil. METHODS: A total of 65 primates from the wild and captivity were used, and potential vectors were captured using Castro and dip nets. Serum samples were tested at the Instituto Evandro Chagas, State of Pará, using the hemagglutination inhibition test to detect total antibodies against 19 different arboviruses. Virus isolation was attempted from serum samples and arthropod suspensions using newborn mice and the C6/36 cell line clone. In addition, identification of the vector species was conducted. RESULTS: From the 19 serum samples from Campo Grande, 1 sample had a 1:20 titer for Flavivirus. From the 35 samples collected in Bonito, 17 samples had antibodies to arboviruses, 4 (11.4%) were positive for Alphavirus, and 5 (14.2%) were positive for Flavivirus. Monotypic reactions were observed for the Mayaro (n = 10) and Oropouche (n = 5) viruses, and 6 (17.1%) samples had titers for >1 virus. We captured 120 Culicidae individuals that were potential arbovirus transmitters in Jardim; however, all the samples were negative for the viruses. CONCLUSIONS: Mato Grosso do Sul has a variety of vertebrate hosts and transmission vectors, thereby providing ideal conditions for the emergence or reemergence of arboviruses, including some pathogenic to human beings.

Larval control of Anopheles (Nyssorhinchus) darlingiusing granular formulation of Bacillus sphaericus in abandoned gold-miners excavation pools in the Brazilian Amazon Rainforest

INTRODUCTION: Use of a Bacillus sphaericus based mosquito larvicide was evaluated as an intervention for malaria vector control at a mining site in Amapá, Brazil. Impacts on larval and adult densities of the primary vector Anopheles darlingi were measured over the course of a 52 week study period.METHODS: In Calçoene, State of Amapá, gold mining activity occurs in 19 mining sites in gold-miners of Lourenço. Large pools are formed in mining sites and naturally colonized by Anopheles darlingi. During one year, the impact of applications of VectoLex(r) CG to these larval sources was evaluated. Applications of 20kg/ha were made as needed, based on 10 immature (3rd, 4th instars and pupae) surveillance of health and established thresholds. RESULTS: One hundred percent initial control was observed 48h after each treatment. The pools received from 2-10 (5.3±1.6) treatments during the year. The average re-treatment interval in productive pools was 9.4±4.3 weeks. During weeks 3-52 of the study, mean density of late stage larvae was 78% and pupae were 93% lower in the treated pools than in untreated pools (p< 0.0001, n=51) while reduction of adult mosquitoes was 53% in comparison to the untreated area during the last five months of the study, which were the rainy season (p<0.001).CONCLUSIONS:VectoLex(r) CG reduced immature Anopheles darlingi infestation levels during the entire study period, and reduced adult mosquito populations during the rainy season.

Survey of Bancroftian filariasis infection in humans and Culex mosquitoes in the western Brazilian Amazon region: implications for transmission and control

IntroductionThe aim of this work was to identify possible lymphatic filariasis foci in the western Brazilian Amazonian that could be established from the reports of Rachou in the 1950s. The study was conducted in three cities of the western Brazilian Amazon region - Porto Velho and Guajará-Mirim (State of Rondônia) and Humaitá (State of Amazonas).MethodsFor human infection evaluation thick blood smear stained with Giemsa was used to analyze samples collected from 10pm to 1am. Polymerase chain reaction (PCR) was used to examine mosquito vectors for the presence of Wuchereria bancrofti DNA. Humans were randomly sampled from night schools students and from inhabitants in neighborhoods lacking sanitation. Mosquitoes were collected from residences only.ResultsA total 2,709 night students enrolled in the Program for Education of Young Adults (EJA), and 935 people registered in the residences near the schools were examined, being 641 from Porto Velho, 214 from Guajará-Mirim and 80 from Humaitá. No individual examined was positive for the presence of microfilariae in the blood stream. A total of 7,860 female Culex quinquefasciatus specimens examined were negative by PCR.ConclusionsThis survey including human and mosquito examinations indicates that the western Amazon region of Brazil is not a focus of Bancroftian filariasis infection or transmission. Therefore, there is no need to be included in the Brazilian lymphatic filariasis control program.

Evaluation of larvicidal activity and brine shrimp toxicity of rhizome extracts of Zingiber zerumbet (L.) Smith

Introduction In this study, we used dichloromethane (DCM) and methanol (MeOH) extracts of the Zingiber zerumbet rhizome to evaluate brine shrimp lethality and larvicidal activity on Aedes aegypti and Anopheles nuneztovari mosquitoes. Methods Bioassays were performed by exposing third-instar larvae of each mosquito species to the DCM or MeOH extracts. Results Probit analysis with DCM and MeOH extracts demonstrated efficient larvicidal activity against A. aegypti and A. nuneztovari larvae. Conclusions The DCM and MeOH extracts showed higher activity against A. nuneztovari larvae than against A. aegypti larvae, suggesting that the extracts have species-specific activity.

First report of yellow fever virus in non-human primates in the State of Parana, Brazil

Sylvatic yellow fever is a zoonosis associated mainly with wild animals, especially those in the genus Alouatta, that act as the source of infection. Once infected, these animals pass the disease on to humans by way of an infected mosquito belonging to the genera Aedes, Haemagogus, or Sabethes. The present study is the first report of a case of yellow fever in non-human primates (NHP) in the State of Paraná, Brazil. After the case was diagnosed, several prophylactic measures were adopted to prevent outbreaks of the disease in humans.

Description of microsporidia in simulids: molecular and morphological characterization of microsporidia in the larvae of Simulium pertinax Kollar (Diptera: Simuliidae)

IntroductionMicrosporidia constitute the most common black fly pathogens, although the species' diversity, seasonal occurrence and transmission mechanisms remain poorly understood. Infections by this agent are often chronic and non-lethal, but they can cause reduced fecundity and decreased longevity. The objective of this study was to identify microsporidia infecting Simulium (Chirostilbia) pertinax (Kollar, 1832) larvae from Caraguatatuba, State of São Paulo, Brazil, by molecular and morphological characterization.MethodsLarvae were collected at a single point in a stream in a rural area of the city and were kept under artificial aeration until analysis. Polydispyrenia spp. infection was characterized by the presence of at least 32 mononuclear spores measuring 6.9 ± 1.0 × 5.0 ± 0.7µm in persistent sporophorous vesicles. Similarly, Amblyospora spp. were characterized by the presence of eight uninucleate spores measuring 4.5 × 3.5µm in sporophorous vesicles.ResultsThe molecular analysis confirmed the presence of microsporidian DNA in the 8 samples (prevalence of 0.51%). Six samples (Brazilian larvae) were related to Polydispyrenia simulii and Caudospora palustris reference sequences but in separate clusters. One sample was clustered with Amblyospora spp. Edhazardia aedis was the positive control taxon.ConclusionsSamples identified as Polydispyrenia spp. and Amblyospora spp. were grouped with P. simulii and Amblyospora spp., respectively, corroborating previous results. However, the 16S gene tree showed a considerable distance between the black fly-infecting Amblyospora spp. and the mosquito-infecting spp. This distance suggests that these two groups are not congeneric. Additional genomic region evaluation is necessary to obtain a coherent phylogeny for this group.

Larvicidal activity of the methanol extract and fractions of the green fruits of Solanum lycocarpum(Solanaceae) against the vector Culex quinquefasciatus (Diptera: Culicidae)

IntroductionThe larvicidal activity of Solanum lycocarpumagainst Culex quinquefasciatus is unknown.MethodsWe evaluated the larvicidal activity of extracts of the green fruits of Solanum lycocarpum against third and fourth instar larvae of C. quinquefasciatus.ResultsDichloromethane and ethyl acetate fractions showed the greatest larvicidal effect at 200mg/L (83.3% and 86.7%, respectively). The methanol and dichloromethane, ethyl acetate, and hydromethanolic fractions demonstrated larvicidal effects against C. quinquefasciatus, with LC50 values of 126.24, 75.13, 83.15, and 207.05mg/L, respectively.ConclusionsThus, when considering new drugs with larvicidal activity from natural products, S. lycocarpum fruits may be good candidate sources.

Twenty-eight years of Aedes albopictus in Brazil: a rationale to maintain active entomological and epidemiological surveillance

INTRODUCTION: Aedes albopictus was first detected in Brazil in 1986. This mosquito species presents a major threat to public health because Brazilian populations have shown substantial vector competence for arboviruses such as dengue and chikungunya. METHODS: We updated the records of Ae. albopictus in several States of Brazil, focusing on areas in which its presence had been reported after 2002. RESULTS: Twenty-eight years after its arrival in Brazil, Ae. albopictus has been detected in 24 of 27 States. CONCLUSIONS: The rapid spread of this species and its high vector competence demonstrate the danger of Ae. albopictus in Brazil.

Larvicidal activity of oils, fatty acids, and methyl esters from ripe and unripe fruit of Solanum lycocarpum (Solanaceae) against the vector Culex quinquefasciatus (Diptera: Culicidae)

ABSTRACTINTRODUCTION:The larvicidal activity of oils, fatty acids, and methyl esters of Solanum lycocarpum fruit against Culex quinquefasciatus is unknown.METHODS:The larvicidal activity of samples of ripe and unripe fruit from S. lycocarpum was evaluated against third and fourth instar larvae of C. quinquefasciatus .RESULTS:The oils, fatty acids, and methyl esters of S. lycocarpum showed the greatest larvicidal effect (57.1-95.0%) at a concentration of 100mg/L (LC 50values between 0.70 and 27.54mg/L).CONCLUSIONS:Solanum lycocarpum fruit may be a good source of new natural products with larvicidal activity.

Pesquisa de campo sobre malária humana, numa área endêmica na amazônia brasileira

Realizou-se um estudo epidemiológico sobre malária na população humana residente no município de Ariquemes, Estado de Rondônia. Um formulário composto de questões dirigidas no setndo de obter dos colonizadores o grau de conhecimento sobre os fatores condicionados à malária, principalmente sobre o aspecto migracional e conhecimentos sobre a transmissão e terapêutica da enfermidade. O questionário foi aplicado em 936 chefes de famílias perfazendo um total de 4.633 indivíduos, representando 8% da população fixa do município de Ariquemes. De cada indivíduo foi coletada uma amostra de sangue e examinada para plasmódios. O estudo foi dividido e aplicado nas duas áreas, rural e urbana, do município, para fins de comparação. Dos 2.310 indivíduos estudados na área urbana, 68 eram portadores de infecção malárica, 69% com P. falciparum e 31% com P. vivax. Nos 2.323 residentes na área rural, detectou-se 151 casos de infecção, sendo 53% para P. falciparum e 47% para P. vivax. O sexo masculino foi o mais acometido e a faixa etárua de maior prevalência no setor urbano foi de 15 à 29 anos e no rural foi de 6 à 14 anos. Todos esses pacientes foram tratados radicalmente utilizando-se o esquema terapêutico da SUCAM orientado pela Organização Mundial da Saúde. Observou-se a ocorrência de exportação de casos de malária da área rural para urbana nas migrações internas. Mais de 50% da população desconhece o papel do mosquito na transmissão da malária e a grande maioria dos colonizadores são analfabetos ou alfabetizados até o 1o grau. A quase totalidade da população é oriunda dos estados do sul, principalmente do Estado do Paraná. Os esquemas assistenciais de saúde a essa população é bastante precário, talvez devido ao grande afluxo migracional na região.

BIOLOGIA DE ANOFELINOS AMAZÔNICOS. XXL OCORRRÊNCIA DE ESPÉCIES DE ANOPHELES E OUTROS CULICÍDEOS NA ÁREA DE INFLUÊNCIA DA HIDRELÉTRICA DE BALBINA - CINCO ANOS APÓS O ENCHIMENTO DO RESERVATÓRIO

Um inquérito entomològico foi realizado na área de influência da Hidrelétrica de Balbina, situada a 146 km de Manaus, Amazonas, para avaliar os possíveis efeitos sobre as populações de Anophelese de outros culicídeos. Cinco anos após a formação do lago, An. darlingi, An. nuneztovarie An. triannulatusforam as espécies encontradas com maior freqüência nas coletas realizadas em 1. Rodovia BR-174, 2. Acceso á Usina Hidrelétrica de Balbina e 3. Área Uatumã-Morena. Para cada espécie os índices mosquito/homem/hora foram respectivamente: Area 1 - 0,57; 12,85; 0,43. Área 2 - 0; 3,75; 0,18 e Área 3 - 0; 26,38; 0,34. Representantes das duas primeiras espécies se mostraram positivas para Plasmodiumcom testes imunoenzimáticos. A prevalência de mosquitos positivos foi 1:35 para An. darlingie apenas 1:548 para An. nuneztovari.A densidade dos outros culicídeos foi baixa (Área 1 - 3,23 m/h/h; Área 2 - 4,5 m/h/h; Área 3 - 7,40 m/h/h) embora a diversidade foi comparável ( 32 espécies diferentes) com as encontradas em outras hidrelétricas construídas em rios de águas brancas ou claras da Amazônia. Nas águas pretas da Balbina, uma proliferação inicial de macrófitas foi seguida pela redução destas possivelmente pela falta de nutrientes na água. A diminuição no crescimento de macrófitas deve estar relacionada com a escassez de Mansoniasp. na área.

Feeding of the Brycon cephalus, Triportheus elongatus and Semaprochilodus insignis (osteichthyes, characiformes) larvae in Solimões/Amazonas River and floodplain areas.

Information on larval fish feeding is essential for understanding their trophic relations, including the management in conditions totally or partially controlled by humans. An experiment was designed to evaluate the larval diets of three commercially important species. Four varzea-lakes and the adjacent river were sampled with bongo and hand nets from January 1993 to November 1995. Larval diets were evaluated by length-classes and capture sites, and were tested by two factor ANOVA. The larvae were feeding in all habitats, except in the flooded forests. The three species had different diets, which varied with their length and lake. The rotifers were the main initial food item of the three species, replaced by fish larvae in Brycon cephalus, cladocerans in Triportheus elongatus and detritus in Semaprochilodus insignis. The increase of the ingestion limit, as the larvae grew, was higher than the increase in the consumed prey size for the three species.

Fisheries and fishing effort at the Indigenous Reserves Ashaninka/Kaxinawá, river Breu, Brazil/Peru

This article aimed to describe the subsistence fisheries of traditional populations of three ethnic groups, one Ashaninka and two Kaxinawá, lying on the banks of the River Breu. Initially, monitors were trained to fill logbooks with data from fisheries of the villages during an annual cycle (august/1995 august/1996). Based on these data, it was realized an inventory of the most common fish species caught as well as one about the fishing environment. The following results were obtained: i) Indians prefer to use pools, locally known as "poços", for fishing; ii) the most common caught species are the "mandis" (35%, Pimelodidae), armored catfishes (Loricariidae), specially Hypostomus sp. (25%), the "curimatá" (9%, Prochilodus sp.) and the "saburus" (8%, Curimatidae), among others; iii) the fishing gears that lead to a high rate of fishing are the native "tingui", nets and bow and arrows; iv) fisheries are more intensive during summer; v) the fishing effort and their associated factors statistically significant in predicting the catches in the Indian Reserve were f1 = number of fishermen, f2 = (number of fishermen*total time devoted to fishing), f3 = [(number of fishermen)*(total time devoted to fishing)-(the time displacement)] and the factor villages and fishing gears; vi) although almost all the fisheries are done by walking to the fishing places, catches increase when paddle boats are used; and vii) the most active fishermen belong to Kaxinawá tribe.

Abundance of two Dendrocincla woodcreepers (aves: Dendrocolaptidae) in relation to forest structure in Central Amazonia

Few studies have been conducted to verify how the structure of the forest affects the occurence and abundance of neotropical birds. Our research was undertaken between January 2002 and July 2004 at the Reserva Ducke, near Manaus (02º55',03º01'S; 59º53',59º59'W) in central Amazonia, to verify how the forest structure affects the occurrence and abundance of two bird species: the Plain-brown Woodcreeper Dendrocincla fuliginosa and the White-chinned Woodcreeper Dendrocincla merula. Bird species occurrence was recorded using lines of 20 mist-nets (one sample unit), along 51 1-km transects distributed along 9 pararel 8 km trails covering an area of 6400 ha. Along these transects, we placed 50 x 50m plots where we recorded forest structure components (tree abundance, canopy openness, leaf litter, standing dead trees, logs, proximity to streams, and altitude). We then related these variables to bird occurence and abundance using multiple logistic and multiple linear regression models, respectively. We found that D. fuliginosa frequently used plateau areas; being more abundant in areas with more trees. On the other hand, D. merula occurred more frequently and was more abundant in areas with low tree abundance. Our results suggest that although both species overlap in the reserve (both were recorded in at least 68% of the sampled sites), they differ in the way they use the forest microhabitats. Therefore, local variation in the forest structure may contribute to the coexistence of congeneric species and may help to maintain local alpha diversity.