Impact of COVID-19 on the registration of tegumentary leishmaniasis cases in Maranhão, Brazil / Impacto da COVID-19 no registro de casos de leishmaniose tegumentar no Maranhão, Brasil / Impacto de la COVID-19 en el registro de casos de leishmaniasis tegumentaria en Maranhão, Brasil

Background and Objectives: Elucidating the potential impact of COVID-19 on surveillance interventions and programs, such as the tegumentary leishmaniasis one, during the first year of the pandemic can help understand its consequences for notification systems, which can inform immediate public policy and health education actions, as well as highlight the need to implement new strategies to strengthen epidemiological surveillance services. The objective of the present study was to analyze the possible impact of the COVID-19 pandemic on the number of cases of tegumentary leishmaniasis in Maranhão, Brazil. Methods: Ecological study of confirmed cases of tegumentary leishmaniasis in the period from January 2015 to December 2020. Data were obtained from the Brazilian Information System for Notifiable Diseases. The P-score metrics were used to evaluate the possible underreporting of tegumentary leishmaniasis. Results: In the period from 2015 to 2020, 7,886 new cases of the disease were registered. For the year 2020, 1,346 cases were expected, but 1,158 were notified, which represented a decrease of 13.94%. The regional health centers of São Luís, São João dos Patos, and Presidente Dutra showed the greatest drops in possible expected new cases. Conclusion: The challenges in diagnosing tegumentary leishmaniasis cases seem to have intensified in the context of COVID-19 in Maranhão, which signals an important alert for health services and managers.(AU)

Justificativa e Objetivos: O potencial impacto da COVID-19 nas intervenções e nos programas de vigilância, como a leishmaniose tegumentar, durante o primeiro ano da pandemia, auxilia no entendimento das consequências da pandemia nos sistemas de notificação, com o intuito de subsidiar ações imediatas de políticas públicas e educação em saúde, além de evidenciar a necessidade de implementação de novas estratégias de fortalecimento dos serviços de vigilância epidemiológica. Este estudo teve como objetivo analisar o possível impacto da pandemia da COVID-19 no número de registros de casos de leishmaniose tegumentar no Maranhão, Brasil. Métodos: Trata-se de um estudo ecológico dos casos confirmados de leishmaniose tegumentar no período de janeiro de 2015 a dezembro de 2020. Os dados foram obtidos do Sistema de Informação de Agravos de Notificação. A métrica P-score foi utilizada para avaliar os possíveis subregistros de leishmaniose tegumentar. Resultados: No período de 2015 a 2020, foram registrados 7.886 casos novos da doença. Para o ano de 2020, eram esperados 1.346 casos, porém 1.158 foram notificados, o que representa uma diminuição de 13,94%. As regionais de saúde de São Luís, São João dos Patos e Presidente Dutra apresentam as maiores quedas de possíveis novos casos esperados. Conclusão: Os desafios no diagnóstico dos casos de leishmaniose tegumentar parecem ter se intensificado no contexto da COVID-19 no Maranhão, o que sinaliza um alerta importante para os serviços de saúde e gestores.(AU)

Justificación y Objetivos: El posible impacto de la COVID-19 en las intervenciones y programas de vigilancia, como el de la leishmaniasis tegumentaria, durante el primer año de la pandemia, ayuda a comprender las consecuencias de la pandemia en los sistemas de notificación, con el fin de subsidiar las acciones inmediatas de política pública y educación para la salud, además de resaltar la necesidad de implementar nuevas estrategias para fortalecer los servicios de vigilancia epidemiológica. Este estudio tuvo como objetivo analizar el posible impacto de la pandemia de COVID-19 en el número de registros de casos de leishmaniasis tegumentaria en Maranhão, Brasil. Métodos: Se trata de un estudio ecológico de los casos confirmados de leishmaniasis tegumentaria desde enero de 2015 hasta diciembre de 2020. Los datos se obtuvieron del Sistema de Información de Enfermedades de Declaración Obligatoria. Se utilizó la métrica P-score para evaluar los posibles subregistros de leishmaniasis tegumentaria. Resultados: Entre 2015 y 2020, se registraron 7.886 nuevos casos de la enfermedad. Para 2020 se esperaban 1.346 casos, pero se notificaron 1.158, lo que representa una disminución del 13,94%. Los centros regionales de salud de São Luís, São João dos Patos y Presidente Dutra presentaron las mayores caídas en los posibles nuevos casos esperados. Conclusión: Los desafíos en el diagnóstico de los casos de leishmaniasis tegumentaria parecen haberse intensificado en el contexto de la COVID-19 en Maranhão, lo que señala una alerta importante para los servicios y gestores de salud.(AU)

Shotgun Metagenomic Sequencing Reveals Virome Composition of Mosquitoes from a Transition Ecosystem of North-Northeast Brazil.

A wide diversity of pathogenic mosquito-borne viruses circulate in the Brazilian Amazon, and the intense deforestation can contribute to the spread of these viruses. In this context, this study aimed to investigate the viral diversity in mosquitoes of the genera Aedes, Culex, Haemagogus, and Sabethes from a transition area between the Amazon, Cerrado, and Caatinga biomes in Brazil. Metagenomic high-throughput sequencing was used to characterize the virome of 20 mosquito pools. A total of 15 virus-like genomes were identified, comprising species genomically close to insect-specific viruses of the families Iflaviridae, Metaviridae, Lispiviridae, Rhabdoviridae, Xinmoviridae, and Parvoviridae and species of plant viruses of the families Solemoviridae, Virgaviridae, and Partitiviridae. However, sequences of viruses associated with human and animal diseases were not detected. Most of the recovered genomes were divergent from those previously described. These findings reveal that there are a large number of unknown viruses to be explored in the middle-north of Brazil.

Spatiotemporal Distribution of Leishmaniasis in an Endemic Area of Northeast Brazil: Implications for Intervention Actions.

This study aimed to analyze the spatiotemporal distribution of leishmaniases, and contribute to the knowledge of their epidemiological dynamics from 2007 to 2017 in the municipality of Caxias, Maranhão, Northeast Brazil. Data on American tegumentary leishmaniasis (ATL) and human visceral leishmaniasis (HVL) were obtained in the Epidemiological Surveillance Sector of Caxias, while data on canine visceral leishmaniasis (CVL) were obtained in the Zoonoses Surveillance Unit. For data analysis and spatial representation of leishmaniasis cases, the geoprocessing of the data was performed, and the geometric features of the state of Maranhão, Caxias, and the disease registration sites were obtained from the shapefile database of the Brazilian Institute of Geography and Statistics. Geostatistics was used to create maps based on the Kernel density method, starting from the points, producing a raster file for each case with several data frames, allowing the instantaneous comparison of the phenomena. During the study period, ATL, HVL, and CVL were reported in Caxias, accounting for 114,304 and 8,498 cases, respectively. The geoprocessing analysis showed that leishmaniasis is widely distributed in the urban area of Caxias. However, there are risk areas for the transmission of these diseases to humans and dogs, associated with deforestation and urban expansion, and may vary over time. Preventive measures must focus on risk areas, including conservation efforts and urban planning, in order to reduce the transmission of leishmaniases.

Predominance of Leishmania (Leishmania) amazonensis DNA in Lutzomyia longipalpis sand flies (Diptera: Psychodidae) from an endemic area for leishmaniasis in Northeastern Brazil.

Leishmaniasis is a serious public health concern in the Northeastern region of Brazil, where the sand fly fauna is well studied, although few species have been identified as competent vectors. The detection of Leishmania spp. parasites in wild-caught sand flies could help sanitary authorities draw strategies to avoid the transmission of the parasites and, therefore, the incidence of leishmaniases. We detected Leishmania DNA in wild-caught sand flies and correlated that data with aspects of sand fly ecology in the Caxias municipality, Maranhao State, Brazil. The sand flies were sampled in the peridomicile (open areas in the vicinity of human residences) and intradomicile (inside the residences) from July/2019 to March/2020. Leishmania DNA was detected in females, targeting a fragment of the Internal Transcribed Spacer (ITS1) from ribosomal DNA. Among the fourteen species of sand flies identified, five (Lutzomyia longipalpis, Nyssomyia whitmani, Evandromyia evandroi, Micropygomyia trinidadensis, and Micropygomyia quinquefer) harbored DNA of Leishmania (Leishmania) amazonensis. The most abundant species in rural (Ny. whitmani: 35.2% and Ev. evandroi: 32.4%) and urban areas (Lu. longipalpis: 89.8%) are the permissive vectors of L. (L.) amazonensis, especially Ny. whitmani, a known vector of causative agents of cutaneous leishmaniasis. Although Lu. longipalpis is the vector of L. (L.) infantum, which was not detected in this study, its permissiveness for the transmission of L. (L.) amazonensis has been reported. We suspect that visceral leishmaniasis and cutaneous leishmaniasis are caused by L. (L.) amazonensis, and the transmission may be occurring through Lu. longipalpis, at least in the urban area.

Predominance of Leishmania (Leishmania) amazonensis DNA in Lutzomyia longipalpis sand flies (Diptera: Psychodidae) from an endemic area for leishmaniasis in Northeastern Brazil

ABSTRACT Leishmaniasis is a serious public health concern in the Northeastern region of Brazil, where the sand fly fauna is well studied, although few species have been identified as competent vectors. The detection of Leishmania spp. parasites in wild-caught sand flies could help sanitary authorities draw strategies to avoid the transmission of the parasites and, therefore, the incidence of leishmaniases. We detected Leishmania DNA in wild-caught sand flies and correlated that data with aspects of sand fly ecology in the Caxias municipality, Maranhao State, Brazil. The sand flies were sampled in the peridomicile (open areas in the vicinity of human residences) and intradomicile (inside the residences) from July/2019 to March/2020. Leishmania DNA was detected in females, targeting a fragment of the Internal Transcribed Spacer (ITS1) from ribosomal DNA. Among the fourteen species of sand flies identified, five (Lutzomyia longipalpis, Nyssomyia whitmani, Evandromyia evandroi, Micropygomyia trinidadensis, and Micropygomyia quinquefer) harbored DNA of Leishmania (Leishmania) amazonensis. The most abundant species in rural (Ny. whitmani: 35.2% and Ev. evandroi: 32.4%) and urban areas (Lu. longipalpis: 89.8%) are the permissive vectors of L. (L.) amazonensis, especially Ny. whitmani, a known vector of causative agents of cutaneous leishmaniasis. Although Lu. longipalpis is the vector of L. (L.) infantum, which was not detected in this study, its permissiveness for the transmission of L. (L.) amazonensis has been reported. We suspect that visceral leishmaniasis and cutaneous leishmaniasis are caused by L. (L.) amazonensis, and the transmission may be occurring through Lu. longipalpis, at least in the urban area.

Natural Infection of Aedes aegypti by Chikungunya and Dengue type 2 Virus in a Transition Area of North-Northeast Brazil.

Dengue fever, chikungunya, and Zika are diseases caused by viruses transmitted by Aedes aegypti and Aedes albopictus. In Brazil, the number of human infections is high, but few studies are performed in mosquito vectors. This study aimed to investigate the presence of Zika, Dengue and Chikungunya viruses in Ae. aegypti and Ae. albopictus from the municipalities of Alto Alegre, Caxias, Codó, and São Mateus do Maranhão, located in the state of Maranhão, Northeast Brazil. The mosquitoes were collected with a mechanical aspirator, identified, triturated, and then submitted to RNA extraction and RT-qPCR. The positive samples were confirmed by virus isolation and genome sequencing. Three hundred and forty-eight Ae. aegypti (176 males and 172 females) and 12 Ae. albopictus (eight males and four females) were collected and tested. Ae. aegypti was the only vector positive in two municipalities-Codó, with detection of Chikungunya virus (CHIKV) belonging to the East-Central-South African genotype, and in Caxias, with detection of Dengue virus (DENV)-2 belonging to the Asian/American genotype. The detection of CHIKV and DENV-2 is evidence that those viruses are maintained in arthropod vectors, and shows the epidemiological risk in the area for chikungunya cases and a possible increase of severe dengue cases, associated with the occurrence of dengue hemorrhagic fever.

Occurrence of Phlebotominae (Diptera: Psychodidae) in Urban Leishmaniasis Transmission Foci in North-Eastern Brazil.

In this study, we analyzed species composition, richness, and monthly and seasonal abundance of sand flies in an urban area, municipality Caxias, state Maranhão, endemic for American visceral and tegumentary leishmaniasis. Sand flies were caught using Center for Disease Control (CDC) light traps in peridomicile (animal shelter) and extradomicile (forest) environments twice a month for 1 yr. A total of 16,332 specimens belonging to 20 species were captured. The predominant species identified in this study were Lutzomyia longipalpis (Diptera: Psychodidae) (Lutz and Neiva 1912) (43.08%) and Lutzomyia whitmani (Diptera: Psychodidae) (Antunes and Coutinho 1939) (43.02%), which occurred throughout the year (every month). The highest abundance of phlebotomine was recorded during the dry season (53.75%) and in the urban peridomicile environment (59.1%), wherein 17 species were found. In the study area, L. longipalpis and L. whitmani are reported to be effective visceral or tegumentary leishmaniasis vectors, respectively, due to their abundance throughout the year.

Circulation of Chikungunya virus in Aedes aegypti in Maranhão, Northeast Brazil.

The simultaneous circulation of Dengue virus (DENV), Chikungunya virus (CHIKV) and Zika virus (ZIKV) arboviruses have placed Brazil among the main worldwide endemic areas. Brazilian Northeast region concentrates the highest incidence of infections caused by CHIKV and ZIKV. In Maranhão, the second biggest northeastern state, there are cases of human infections caused by these three arboviruses and presence of Aedes aegypti and Aedes albopictus vectors. In this context, this study aimed to investigate the circulation of CHIKV, DENV and ZIKV in Ae. aegypti and Ae. albopictus mosquitoes collected in urban areas of Barra do Corda, Caxias, Codó, São Luís and São Mateus do Maranhão municipalities in the state of Maranhão through Quantitative Reverse Transcription Polymerase Chain Reaction (RT-qPCR) technique. 428 Ae. aegypti and 1 Ae. albopictus were collected, which formed 44 pools. Three of these showed positive results for CHIKV: AR832767 (five Ae. aegypti female collected in Caxias), AR832784 and AR832785 (both composed of 20 Ae. aegypti female collected in São Mateus do Maranhão). This study consolidates information about CHIKV circulation in state of Maranhão, as well as the role of Ae. aegypti in the transmission of CHIKV in urban area.

Isolation and molecular characterization of Bacillus thuringiensis found in soils of the Cerrado region of Brazil, and their toxicity to Aedes aegypti larvae

ABSTRACT This study investigated the potential of Bacillus thuringiensis isolates obtained in the Cerrado region of the Brazilian state of Maranhão for the biological control of Aedes aegypti larvae. The isolates were obtained from soil samples and the identification of the B. thuringiensis colonies was based on morphological characteristics. Bioassays were run to assess the pathogenicity and toxicity of the different strains of the B. thuringiensis against third-instar larvae of A. aegypti. Protein profiles were obtained by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Polymerase chain reaction assays were used to detect the toxin genes found in the bacterial isolates. Overall, 12 (4.0%) of the 300 isolates obtained from 45 soil samples were found to present larvicidal activity, with the BtMA-104, BtMA-401 and BtMA-560 isolates causing 100% of mortality. The BtMA-401 isolate was the most virulent, with the lowest median lethal concentration (LC50) (0.004 × 107 spores/mL), followed by the Bacillus thuringiensis var. israelensis standard (0.32 × 107 spores/mL). The protein profiles of BtMA-25 and BtMA-401 isolates indicated the presence of molecular mass consistent with the presence of the proteins Cry4Aa, Cry11Aa and Cyt1, similar to the profile of Bacillus thuringiensis var. israelensis IPS-82. Surprisingly, however, none of the cry and cyt genes analyzed were amplified in the isolate BtMA-401. The results of the present study revealed the larvicidal potential of B. thuringiensis isolates found in the soils of the Cerrado region from Maranhão, although further research will be necessary to better elucidate and describe other genes associated with the production of insecticidal toxins in these isolates.

Leishmania infection and blood food sources of phlebotomines in an area of Brazil endemic for visceral and tegumentary leishmaniasis.

The aims of the study were to determine the blood feeding preferences of sandflies and to identify species of Leishmania that infected phlebotomines in Caxias, Maranhão, Brazil, an area that is highly endemic for leishmaniasis. Sandflies were captured in light traps located in the peridomiciliary environments of randomly selected houses in urban and rural settings between 1800 and 0600 hours on new moon days between March 2013 and February 2015. DNA extracts from 982 engorged female sandflies were submitted to fragment length polymorphism analysis to identify infecting species of Leishmania, and blood sources were identified for 778 of these specimens. Infection by Leishmania infantum was detected in Lutzomyia longipalpis, Lu. whitmani and Lu. termitophila; L. infantum/L. braziliensis in Lu. longipalpis, Lu. whitmani and Lu. trinidadensis; L. shawi in Lu. longipalpis; L. mexicana in Lu. longipalpis; L. braziliensis in Lu. longipalpis and Lu. whitmani; L. guyanensis in Lu. longipalpis and Lu. termitophila; L. amazonensis in Lu. longipalpis and L. lainsoni or L. naiffi in Lu. longipalpis, while Lu. longipalpis and Lu. trinidadensis were infected with unidentified Leishmania sp. Blood sources were identified in 573 individual phlebotomines and the preferred hosts were, in decreasing order, chicken, dog, rodent and human with lower preferences for pig, horse, opossum and cattle. Lu. longipalpis and Lu. whitmani performed mixed feeding on man, dog and rodent, while Lu. longipalpis was the most opportunistic species, feeding on the blood of all hosts surveyed, but preferably on dog/chicken, dog/rodent and rodent/chicken. Our findings reveal the concomitant circulation of Leishmania species that cause visceral leishmaniasis and tegumentary leishmaniasis in the study area, and explain the occurrence of autochthonous human cases of both clinical forms of leishmaniasis in Caxias, Maranhão. The results support our hypothesis that, in the municipality of Caxias, transmission of Leishmania occurs in close proximity to humans.

Anopheles diversity and malaria infection in the cocais zone, state of Maranhão, Brazil

A survey of the Anopheles species was conducted in the municipality of São Mateus, in the state of Maranhão. Species hematophagy habits, the influence of seasonality as well as the vector's infection by Plasmodium were studied. The female Anopheles mosquitoes were captured between February and December 2010 and in March 2012, from 18h00 to 21h00, in intra and peridomiciles. PCR was used for the infection studies. A total 615 specimens of Anopheles were captured, of which 223 (36.2%) in the locality of Piquizeiro and 392 (63.8%) on the Retiro Velho Farm belonging to the species An. nuneztovari, An. darlingi, An. triannulatus, An. albitarsise, and An. oswaldoi. In Piquizeiro most specimens were captured in the intradomiciliary area, while on the Retiro Velho Farm they were mostly found in the peridomiciliary area. The results show the influence of seasonality and time of capture in the hematophagy frequency of the captured Anopheles. The negative result for Plasmodium infection demonstrates a reduction in the number of malaria cases in the State during the study period

Isolation of Bacillus thuringiensis from the state of Amazonas, in Brazil, and screening against Aedes aegypti (Diptera, Culicidae)

We investigated the use of Bacillus thuringiensis isolated in the state of Amazonas, in Brazil, for the biological control of the dengue vector Aedes aegypti. From 25 soil samples collected in nine municipalities, 484 bacterial colonies were obtained, 57 (11.78%) of which were identified as B. thuringiensis. Six isolates, IBt-03, IBt-06, IBt-07, IBt-28, IBt-30, and BtAM-27 showed insecticidal activity, and only BtAM-27 presents the five genes investigated cry4Aa, cry4Ba, cry10Aa, cry11Aa, and cry11Ba. The IBt-07 and IBt- 28, with lower LC50 values, showed equal toxicity compared to the standards. The isolates of B. thuringiensis from Amazonas constitute potential new means of biological control for A. aegypti, because of their larvicidal activity and the possibility that they may also contain new combinations of toxins.

Flebotomíneos (díptera, psychodidae) em focos urbanos de leishmaniose visceral no estado do Maranhão, Brasil / Sandflies (Diptera, Psychodidae) in urban outbreaks of visceral leishmaniasis in the state of Maranhão, Brazil

Foram objetos deste estudo a riqueza, a abundância relativa e a frequência mensal das espécies de flebotomíneos (Diptera, Psychodidae) em uma área urbana do município de Codó, estado doMaranhão, que registra elevada prevalência de leishmaniose visceral. Os insetos foram capturados com armadilhas luminosas do tipo CDC, das 18 h às 6 h, duas vezes por mês, de junho de 2012 a maio de 2013. Foram coletados 5.722 espécimes de 11 espécies, sendo 10 pertencentes ao gênero Lutzomyia e 1 ao gênero Brumptomyia. A abundância foi maior no peridomicílio (4.009 exemplares:66 por cento machos e 34 por cento fêmeas) do que no intradomicílio (1.713 exemplares: 55,9 por cento machos e 44,1 por cento fêmeas). A espécie mais abundante foi L. longipalpis (97,7 por cento) e juntamente com L. evandroi, L.sordelli e L. termitophila foram as mais constantes ao longo do ano. A frequência dos flebotomíneos mostrou-se maior no período seco (57,9 por cento), elevando-se com o aumento da temperatura média(p=0,0156; r=0,1007) e reduzindo-se com o aumento da umidade relativa do ar (p=0,0001;r=-0,1740). Sugerem-se ações de controle vetorial durante a estação seca quando os flebotomíneossão mais abundantes.

The richness, relative abundance and the monthly frequency of species of sandflies (Diptera,Psychodidae) in an urban area of the municipality of Codo, Maranhão, a state that records a highprevalence of visceral leishmaniasis, was studied. The insects were captured with CDC light traps,from 18 h to 6 h, twice per month from June 2012 to May 2013 and 5,722 specimens of 11 species, 10belonging to the genus Lutzomyia and one to the genus Brumptomyia were collected. The abundancewas higher outdoors (4,009 samples: 66 percent males and 34 percent females) than in households (1,713 samples:55.9 percent males and 44.1 percent females). The most abundant species was L. longipalpis (97.7 percent), whichtogether with L. evandroi, L.sordellii and L. termitophila were more constant throughout the year. Thefrequency of sandflies was higher in the dry season (57.9 percent), rising with increasing mean temperature(p=0.0156, r=0.1007) and showed a decrease with increasing relative humidity (p=0.0001, r=-0.1740).Vector control during the dry season, when sandflies are most abundant, is suggested.

Conhecimentos de estudantes sobre Leishmaniose Visceral em escolas públicas de Caxias, Maranhão, Brasil / Knowledge of students about visceral leishmaniasis in public schools in Caxias, Maranhão, Brazil

Trata-se de um inquérito amostral (743 questionários), realizado nos meses de abril a novembro de 2009 em dez escolas públicas municipais, previamente sorteadas e localizadas em oito bairros da cidade de Caxias. Avaliou-se por meio da aplicação de questionários fechados, o conhecimento dos estudantes sobre a Leishmaniose Visceral (LV), seu vetor e prevenção. Os resultados mostraram mudanças com maior percentual de acertos quanto às respostas sobre a transmissão da doença e quanto aos sintomas da LV no homem e no cão após as campanhas. Contudo, as campanhas educativas são necessárias como medidas para fortalecer a participação da população no combate à LV, pois antes do trabalho educativo a maioria dos estudantes disse que se prevenia da doença evitando contato com cães doentes, entretanto, após as campanhas os mesmos disseram evitar acúmulo de lixo. A pesquisa pode servir como subsídio para orientar novas ações educativas das equipes locais de controle da LV.

This is a sample survey (743 questionnaires) conducted in the months from April to November 2009 in ten pre-selected public schools located in eight districts of the city of Caxias. The students' knowledge of viral leishmaniasis (VL) and its transmission and prevention was evaluated through closed questionnaires. The results showed changes with the highest percentage of correct answers for answers about the transmission of disease and the symptoms of VL in humans and dogs after the campaign. However, educational campaigns are necessary measures to strengthen public participation in combating VL since before the educational work the majority of students stated that the disease was prevented by avoiding contact with sick dogs, however, after the campaign they stated that they avoid accumulations of trash. The research may serve as input to orient further educational actions of local teams for the control of VL.

[Knowledge of students about visceral leishmaniasis in public schools in Caxias, Maranhão, Brazil]. / Conhecimentos de estudantes sobre Leishmaniose Visceral em escolas públicas de Caxias, Maranhão, Brasil.

This is a sample survey (743 questionnaires) conducted in the months from April to November 2009 in ten pre-selected public schools located in eight districts of the city of Caxias. The students' knowledge of viral leishmaniasis (VL) and its transmission and prevention was evaluated through closed questionnaires. The results showed changes with the highest percentage of correct answers for answers about the transmission of disease and the symptoms of VL in humans and dogs after the campaign. However, educational campaigns are necessary measures to strengthen public participation in combating VL since before the educational work the majority of students stated that the disease was prevented by avoiding contact with sick dogs, however, after the campaign they stated that they avoid accumulations of trash. The research may serve as input to orient further educational actions of local teams for the control of VL.

Variation in Aedes aegypti (Linnaeus) (Diptera, Culicidae) infestation in artificial containers in Caxias, state of Maranhão, Brazil.

INTRODUCTION: Dengue is a serious public health problem worldwide, with cases reported annually in tropical and subtropical regions. Aedes aegypti (Linnaeus, 1762), the main vector of dengue, is a domiciliary species with high dispersal and survival capacities and can use various artificial containers as breeding sites. We assessed potential container breeding sites of A. aegypti in the municipality of Caxias, Maranhão, Brazil. METHODS: In the initial phase, we analyzed 900 properties in 3 neighborhoods during the dry and rainy seasons (August-October 2005 and February-April 2006, respectively). During the second sampling period, September 2006-August 2007, we used 5 assessment cycles for 300 properties in a single neighborhood. RESULTS: During the dry and rainy seasons, water-storage containers comprised 55.7% (n = 1,970) and 48.5% (n = 1,836) of the total containers inspected, and showed the highest productivity of immature A. aegypti; we found 23.7 and 106.1 individuals/container, respectively, in peridomicile sites. In intradomicile sites, water-storage containers were also the most important breeding sites with 86.4% (n = 973) and 85.6% (n = 900) of all containers and a mean of 7.9 and 108.3 individuals/container in the dry and rainy seaso-October 2006 (1,342). The highest number of positives (70) was recorded in May, mostly (94%) in storage containers. CONCLUSIONS: Storage containers are the principal and most productive A. aegypti breeding sites and are a major contributing factor to the maintenance of this vector in Caxias.

Variation in Aedes aegypti (Linnaeus) (Diptera, Culicidae) infestation in artificial containers in Caxias, state of Maranhão, Brazil / Variação da infestação de Aedes aegypti (Linnaeus), (Diptera, Culicidae) em recipientes artificiais em Caxias, estado do Maranhão, Brasil

INTRODUCTION: Dengue is a serious public health problem worldwide, with cases reported annually in tropical and subtropical regions. Aedes aegypti (Linnaeus, 1762), the main vector of dengue, is a domiciliary species with high dispersal and survival capacities and can use various artificial containers as breeding sites. We assessed potential container breeding sites of A. aegypti in the municipality of Caxias, Maranhão, Brazil. METHODS: In the initial phase, we analyzed 900 properties in 3 neighborhoods during the dry and rainy seasons (August-October 2005 and February-April 2006, respectively). During the second sampling period, September 2006-August 2007, we used 5 assessment cycles for 300 properties in a single neighborhood. RESULTS: During the dry and rainy seasons, water-storage containers comprised 55.7% (n = 1,970) and 48.5% (n = 1,836) of the total containers inspected, and showed the highest productivity of immature A. aegypti; we found 23.7 and 106.1 individuals/container, respectively, in peridomicile sites. In intradomicile sites, water-storage containers were also the most important breeding sites with 86.4% (n = 973) and 85.6% (n = 900) of all containers and a mean of 7.9 and 108.3 individuals/container in the dry and rainy seaso-October 2006 (1,342). The highest number of positives (70) was recorded in May, mostly (94%) in storage containers. CONCLUSIONS: Storage containers are the principal and most productive A. aegypti breeding sites and are a major contributing factor to the maintenance of this vector in Caxias.

INTRODUÇÃO: A dengue constitui de um sério problema de saúde pública mundial, com casos sendo registrados anualmente nas regiões tropicais e subtropicais. O Aedes aegypti(Linnaeus, 1762) é o principal vetor da doença, um mosquito domiciliado de fácil dispersão e sobrevivência, com capacidade de utilizar variados recipientes artificiais como criadouro. Em vista disso, neste trabalho investigou-se os tipos de recipientes potenciais criadouros de A. aegypti na Cidade de Caxias, Maranhão, Brasil. MÉTODOS: Inicialmente, a pesquisa foi desenvolvida em três bairros e 900 imóveis analisados no período da seca e das chuvas (agosto a outubro de 2005 e fevereiro a abril de 2006, respectivamente). Um segundo período de amostragem ocorreu de setembro de 2006 a agosto de 2007 em que inspeções de cinco ciclos foram desenvolvidas em um dos bairros com 300 imóveis amostrados. RESULTADOS: Os recipientes de armazenamento de água representaram 55,7% (n=1.970) e 48,5% (n=1.836) do total dos inspecionados, e maior produtividade de imaturos de A. aegypti, com proporção de 23,7 e 106,1 por recipiente no peridomicílio, nas estações seca e chuvosa respectivamente. No intradomicílio, também foi mais representativo, 86,4% (n=973) e 84,6% (n=900), apresentando média de 7,9 e 108,3 indivíduos, nas duas estações. O maior número de recipientes com água foi registrado em setembro e outubro 2006 (1.342), obtendo-se maior número de positivos (70) no mês de maio, sendo (94%) pertencentes ao grupo armazenamento. CONCLUSÕES: Armazenamento são os principais criadouros de A. aegypti, contribuindo na manutenção do vetor na cidade de Caxias, Maranhão.

Evaluation of students' knowledge as a contribution to dengue control programs.

This study describes a survey (n=700) carried out in 14 elementary schools in the municipality of Caxias, State of Maranhão, Brazil. The survey was conducted between July and December 2007 in schools from seven neighborhoods on the outskirts of the western part of the municipality, where for the past three years high densities of immature Aedes aegypti mosquitoes have been recorded. The students' knowledge of dengue, its vector, and disease prevention was evaluated by targeted questionnaires. The students with the most comprehensive knowledge were found in schools in the Trizidela neighborhood, which has better social and urban conditions than the other neighborhoods. Moreover, educational campaigns are necessary to reinforce behavioral changes of the population, because the existence of breeding sites in the areas examined was mentioned, especially in the Tamarineiro neighborhood. The survey can be used to assist with new educational activities of local teams working with dengue control.

Evaluation of students' knowledge as a contribution to dengue control programs / Avaliação do conhecimento dos estudantes como contribuição ao programa de controle da dengue

Trata-se de um inquérito amostral (700 entrevistas) realizado em 14 Escolas Públicas da Rede Municipal de Ensino na cidade de Caxias, Estado do Maranhão. O inquérito foi realizado entre julho e dezembro de 2007, em escolas localizadas em sete bairros periféricos da zona oeste, os quais apresentaram registros de alta densidade de imaturos de Aedes aegypti nos últimos três anos. Avaliou-se por meio da aplicação de questionário fechado, o conhecimento dos escolares sobre o dengue, seu vetor e prevenção. Os resultados mostraram que as escolas do bairro Trizidela, com melhores condições sociais e urbanas em relação aos demais bairros periféricos, apresentaram estudantes com conhecimentos mais adequados. Contudo, as campanhas educativas são necessárias como medidas para fortalecer as mudanças de comportamento da população, pois foi mencionada a existência de criadouros nas áreas examinadas, com maior prevalência dos recipientes de armazenamento no bairro Tamarineiro. A pesquisa pode servir como subsídio para orientar novas ações educativas das equipes locais de controle do dengue.

This study describes a survey (n=700) carried out in 14 elementary schools in the municipality of Caxias, State of Maranhão, Brazil. The survey was conducted between July and December 2007 in schools from seven neighborhoods on the outskirts of the western part of the municipality, where for the past three years high densities of immature Aedes aegypti mosquitoes have been recorded. The students' knowledge of dengue, its vector, and disease prevention was evaluated by targeted questionnaires. The students with the most comprehensive knowledge were found in schools in the Trizidela neighborhood, which has better social and urban conditions than the other neighborhoods. Moreover, educational campaigns are necessary to reinforce behavioral changes of the population, because the existence of breeding sites in the areas examined was mentioned, especially in the Tamarineiro neighborhood. The survey can be used to assist with new educational activities of local teams working with dengue control.

Evaluation of the residual effect of temephos on Aedes aegypti (Diptera, Culicidae) larvae in artificial containers in Manaus, Amazonas State, Brazil.

Trial tests and container observations were conducted in households to verify the residual effect of temephos in Manaus, Amazonas State, Brazil. Three plastic buckets, three tin cans, and three tires filled with water from an artesian well and larvicide were used in the experiment, with twenty-five third-instar larvae, which remained exposed for 24h, followed by mortality readings. The same types of containers were selected from common households. Collection and counts followed by chemical treatment were carried out on the larvae that were found. Follow-up was performed weekly to verify recolonization by Aedes aegypti. The experiment showed 100% mortality in the plastic buckets until day 90, and 80% in the tin cans until day 30, decreasing from day 45 onwards. Mortality in the tires decreased to 35% in the first month. Household results showed 100% mortality for all containers after 24h and differentiated values in the subsequent readings. Larvae were observed on day 35 in a tin can and on day 21 in a gallon can. There was a large diversity of results in the tires, with recolonization observed from day 7 onwards.