Detecção de flavivirus e alphavirus em mosquitos (diptera: culicidae) capturados em região próxima à Três Lagoas ­ Ms / Detection of flavivirus and alphavirus in mosquitoes (diptera: culicidae) captured in a region close to Tres Lagoas ­ Ms / Detección de flavivirus y alphavirus en mosquitos (diptera: culicidae) capturados en una región cercana a Tres Lagoas ­ Ms

Introdução: Arbovírus são causadores de doenças humanas, sendo que mudança ecológicas e aumento do contato humano-vetor aumenta a possibilidade de surtos. Objetivo: Detectar, identificar e caracterizar arbovírus presentes em mosquitos vetores capturados em regiões de mata próximas a Três Lagoas, MS. Metodologia: Mosquitos foram capturados utilizando armadilhas de luz em regiões de mata circunvizinha a Três Lagoas. Os mosquitos capturados foram classificados por gênero (chave morfológica) e agrupados em pools com até 20 espécimes, e utilizados através da reação de RT-PCR com posterior sequenciamento e análise filogenética. Resultados: Foram capturados 851 dos gêneros: Culex spp. (11 pools); Aedes spp. (13 pools); Haemagogus spp. (7 pools) e outros gêneros não identificados. Sequencias de vírus Dengue (DENV) foram amplificadas de 2/13 (15,38%) pools de Aedes spp. e uma sequência de vírus Mayaro (MAYV) 1/7 (7,7%) foi amplificada de pools de Haemagogus spp. As análises filogenéticas mostraram que as sequências de DENV agrupava-se no clado de DENV1 e DENV2. A sequência de MAYV agrupou-se junto a sequências de amostras de infecções humana por MAYV do grupo L. Conclusão: Estes resultados reforçam a circulação de DENV, que é causador de surtos anuais de doenças febris agudas no município, e detecção, por primeira vez na região, a circulação de MAYV, reforçando a necessidade de monitoramento viral constante nessa região.

Introduction: Arboviruses cause human diseases, and ecological changes and increased human-vector contact increase the possibility of outbreaks. Objective: To detect, identify and characterize arboviruses present in mosquito vectors captured in forest regions close to Tres Lagoas, MS. Methodology: Mosquitoes were captured using light traps in forest regions surrounding Tres Lagoas. The captured mosquitoes were classified by gender (morphological key) and grouped into pools with up to 20 specimens and used through the RT-PCR reaction with subsequent sequencing and phylogenetic analysis. Results: 851 of the genera were captured: Culex spp. (11 pools); Aedes spp. (13 pools); Haemagogus spp. (7 pools) and other unidentified genera. Dengue virus (DENV) sequences were amplified from 2/13 (15.38%) pools of Aedes spp. and a Mayaro virus (MAYV) sequence 1/7 (7.7%) were amplified from pools of Haemagogus spp. Phylogenetic analyzes showed that one of the DENV sequences clustered in the DENV1 and DENV2 clade. The MAYV sequence was grouped together with sequences from samples of human MAYV infections of the L group. Conclusion: These results reinforce the circulation of DENV, which causes annual outbreaks of acute febrile illnesses in the municipality, and detection, for the first time in the region, the circulation of MAYV, reinforcing the need for constant viral monitoring in this region.

Introducción: Los arbovirus causan enfermedades humanas, y los cambios ecológicos y el mayor contacto humano-vector aumentan la posibilidad de brotes. Objetivo: Detectar, identificar y caracterizar arbovirus presentes en mosquitos vectores capturados en regiones de selva próximas a Tres Lagoas, MS. Metodología: Los mosquitos fueron capturados utilizando trampas de luz en las regiones forestales que rodean Tres Lagoas. Los mosquitos capturados fueron clasificados por género (clave morfológica) y agrupados en pools de hasta 20 ejemplares, y utilizados mediante la reacción RT-PCR con posterior secuenciación y análisis filogenético. Resultados: Se capturaron 851 de los géneros: Culex spp. (11 pools); Aedes spp. (13 pools); Haemagogus spp. (7 pools) y otros géneros no identificados. Las secuencias del virus del dengue (DENV) se amplificaron a partir de 2/13 (15,38 %) grupos de Aedes spp. y una secuencia de virus Mayaro (MAYV) 1/7 (7,7%) de pools de Haemagogus spp. Los análisis filogenéticos mostraron que una de las secuencias de DENV se agrupaba en el clado DENV1 y DENV2. La secuencia de MAYV se agrupó con secuencias de muestras de infecciones humanas de MAYV del grupo L. Conclusión: Estos resultados refuerzan la circulación de DENV, causante de brotes anuales de enfermedades febriles agudas en el municipio, y la detección, por primera vez en la región, la circulación de MAYV, reforzando la necesidad de un monitoreo viral constante en esta región.

Análise do conteúdo de uma tecnologia para raciocínio diagnóstico de enfermagem / Análisis de contenido de una tecnología para el razonamiento diagnóstico en enfermería / Content analysis of a technology to the nursing diagnostic reasoning

RESUMO Objetivo: submeter à análise do conteúdo uma estratégia metacognitiva de avaliação indireta no pré-encontro com o cliente. Método: estudo metodológico. Utilizou-se o índice de concordância e confiabilidade entre juízes para os critérios de pertinência, adequação, clareza, concisão e precisão de uma tecnologia para raciocínio diagnóstico de enfermagem por iniciantes por meio de formulário eletrônico. Fizeram parte da amostra 13 juízes. Os dados foram analisados por estatística descritiva. Resultados: houve alta concordância e confiabilidade interavaliadores para 85 itens relacionados à etapa de coleta de dados e descrição da estratégia. Apenas cinco itens não alcançaram os critérios de validação e devem ser reformulados. Conclusão: a avaliação indireta no préencontro é pertinente ao processo de raciocínio diagnóstico, sendo possível desenvolver habilidades e competências diagnósticas no iniciante por meio de estratégias, propostas em uma tecnologia inovadora sob a forma de diagrama. .

RESUMEN Objetivo: analizar el contenido de una estrategia metacognitiva de la evaluación indirecta en la reunión previa con el cliente. Método: investigación metodológica; se utilizó el índice de concordancia y confiabilidad interevaluadores a los criterios de pertinencia, claridad adecuación, concisión y precisión de una tecnología para el razonamiento diagnóstico de enfermería para los principiantes a través de medios electrónicos. La muestra estuvo conformada por 13 jueces. Los datos fueron analizados utilizando estadística descriptiva. Resultados: alta confiabilidad interevaluadores de 85 artículos relacionados con la etapa de recolección de datos y la descripción de la estrategia. Sólo 05 artículos no alcanzaron los criterios de validación y deben ser modificados. Conclusión: se concluye que la evaluación indirecta en la reunión previa es relevante para el proceso de razonamiento de diagnóstico, es posible desarrollar habilidades y destrezas de diagnóstico a los principiantes a través de estrategias, propuestas sobre la tecnología innovadora en la forma de un diagrama. .

ABSTRACT Objective: to undergo a content analysis of a metacognitive strategy of indirect assessment in the pre-encounter with the client. Method: methodological study. Agreement and inter-rater reliability index for the criteria: relevance, adequacy, clarity, conciseness and accuracy of a technology to the nursing diagnosis reasoning for novices through an electronic form. The sample consisted of 13 raters. Data were analyzed using descriptive statistics. Results: high agreement and inter-rater reliability for 85 items related to data collection stage and the strategy description. Only fi ve items did not reach the validation criteria and must be rewritten. Conclusion: indirect assessment of the pre-encounter is relevant to the diagnostic reasoning process, being possible to develop competencies and diagnostic skills in the novice through strategies, proposals on innovative technology in the form of a diagram. .

Occurrence of West Nile Fever in equine, birds, human and mosquitoes in Beheira Province

A total of 257 serum samples including, equine [56], birds [95] and human [106] were collected from rural area in Behera Province during the period extended from the beginning of June to the end of October 2013 to be examined for presence of antibodies against West Nile virus by ELISA. In addition, a total of 943 mosquitoes [25 mosquitoes groups] were collected by CDC light trap from the same place and during the same period where homogenized tissue samples of mosquitoes were obtained to be examined for presence of viral RNA of WNV by real time RT-PCR. The serological examination of serum samples clarified that the prevalence of IgG antibodies against WNV was 100, 4.2 and 58.5% in equine, birds and human serum samples, respectively. Moreover, some epidemiological aspects of human samples were studied including gender, age and health status. Statistical analysis indicated significant differences in detection of IgG antibodies against WNFV in different genders where the higher detection rate was observed in females [42.30%], than in males [35%], in different age groups where the higher detection rate was observed in age group 40 - < 60 years [83.33%] followed by age group 20 - <40 years [42.85%], then the age group 60 - < 80 [37.50%] and the least detection rate of IgG was observed in age group 1 - < 20 years [16.66%] and in health status where the highest detection rate was recorded in meningitis patients [80.9%] followed by FUO patients [64.4%] and lastly apparent healthy individuals [40%]. On the other side, real time RT-PCR examination of samples of mosquitoes clarified no detection of the viral RNA of WNV in all examined samples. The obtained results confirmed the endimicity of WNV in equine in Egypt and the role played by birds in transmission of WNV to human. Although, examined mosquitoes were found to negative for presence of the viral RNA, their role in transmission of WNV could not denied

Why do we need alternative tools to control mosquito-borne diseases in Latin America?

In this opinion paper, we discuss the potential and challenges of using the symbiont Wolbachia to block mosquito transmitted diseases such as dengue, malaria and chikungunya in Latin America.

Filamentous fungi associated with mosquito larvae (Diptera: Culicidae) in municipalities of the Brazilian Amazon / Fungos filamentosos associados a larvas de mosquitos (Diptera: Culicidae) em municípios da Amazônia Brasileira

Several species of the family Culicidae are important vectors of diseases in humans and other animals. Immature stages are filter-feeders of organic particulate matter and microorganisms. Studies on microbial diversity can contribute to the discovery of new substances that can be used in the pharmaceutical industry for food or for biological control. The aim of this study was to isolate and identify the fungi associated with Culicidae larvae found in different habitats (natural and artificial), such as fruit shells, rock holes, lakes, aquatic plants, palm bracts and ceramic pots, in several municipalities of Brazilian Amazonia, especially in the states of Amazonas and Rondônia. A total of 38 fungal lineages were isolated from larvae of Aedes aegypti (L.), Aedes fluviatilis (Lutz), Trichoprosopon digitatum (Rondani), Anopheles argyritarsis argyritarsis Robineau-Desvoidy, Anopheles darlingi Root, Aedeomyia squamipennis (Lynch Arribálzaga), Mansonia titillans (Walker) and Uranotaenia sp. The following fungi occurred associated with the larvae of Culicidae: Acremonium kiliense, Aspergillus sydowii, Fusarium sacchari var. sacchari, Fusarium merismoides var. merismoides, Gliocladium viride, Paecilomyces sp., Penicillium citrinum, Penicillium sclerotiorum, Penicillium melinii and Penicillium oxalicum. Macro- and microscopic characteristics of the lineages are presented, as well as information on their geographical distribution.

Algumas espécies da família Culicidae são importantes vetores de doenças em humanos e em outros animais. Estágios imaturos são filtradores não seletivos de partículas orgânicas e microrganismos. Estudos da diversidade microbiológica podem contribuir para a descoberta de novas substâncias que podem ser usadas em indústrias farmacêuticas, para alimentação ou para controle biológico. O objetivo deste estudo foi isolar e identificar os fungos associados a larvas de Culicidae encontradas em diferentes tipos de criadouros (natural e artificial), como casca de frutos, buracos em pedras, lagoas, plantas aquáticas, bráctea de palmeira e potes de cerâmica, em vários municípios da Amazônia Brasileira, principalmente no Amazonas e em Rondônia. O total de 38 isolados foram obtidos a partir de larvas de Aedes aegypti (L.), Aedes fluviatilis (Lutz), Trichoprosopon digitatun (Rondani), Anopheles argyritarsis argyritarsis Robineau-Desvoidy, Anopheles darlingi Root, Aedeomyia squamipennis (Lynch Arribálzaga), Mansonia titillans (Walker) e Uranotaenia sp. Os fungos que ocorreram nas larvas de Culicidae foram: Acremonium kiliense, Aspergillus sydowii, Fusarium sacchari var. sacchari, Fusarium merismoides var. merismoides, Gliocladium viride, Paecilomyces sp., Penicillium citrinum, Penicillium sclerotiorum, Penicillium melinii, Penicillium oxalicum. Características macro-microscópicas dos isolados foram apresentadas, assim como informações sobre a distribuição geográfica.

Occurrence and diversity of mosquitocidal strains of Bacillus thuringiensis.

Ever since the discovery of the first Bacillus thuringiensis strain capable of killing mosquito larvae, namely, B. thuringiensis var israelensis, there are several reports from different parts of the world about the occurrence of mosquitocidal strains belonging to different subspecies/serotypes numbering thirty-six. The main sources of these wild type strains are soils/sediments, plants, animal feces, sick/moribund insects and waters. The toxicity of the strains within a subspecies/serotype varied widely. Some of the strains exhibited toxicity to mosquitoes as well as lepidopterans and dipterans (including mosquitoes) as well as plant parasitic nematodes.

Toxicity of a mosquitocidal metabolite of Pseudomonas fluorescens on larvae & pupae of the house fly, Musca domestica.

BACKGROUND & OBJECTIVES: Biological control through the use of parasitoids and pathogens is one of the alternatives to the use of chemical pesticides for control of insects of public health importance. At the Vector Control Research Centre, a liquid formulation developed using the metabolite of a Pseudomonas fluorescens strain was found to be lethal to larvae as well as pupae of vector mosquitoes. The lethal fraction of the metabolite is a protein with a molecular mass of 44 kDa and toxicity studies showed that it is safe to mammals. In the present study, this formulation was evaluated against immatures of the common house fly, Musca domestica, to find out whether it could be developed into a potential biocontrol tool. METHODS: Early second instar larvae of house fly were introduced into rearing medium incorporated with the formulation at concentrations of 1, 5, 10, 15, 20 and 25 per cent, which were equivalent to respectively 1.13, 5.63, 11.25, 16.88, 22.50 and 28.13 microg of the toxic protein/ g of rearing medium. Mortality was monitored until the emergence of adult house fly. Net mortality of larvae and pupae were calculated and the LC50 and LC90 values were determined through probit regression analysis. RESULTS: Larval mortality was obtained from day 3 to 6 post-treatment. Net mortality of larvae was higher at the concentration of 20 than at 25 per cent. However, it was higher at 25 per cent on day 5 and continued to day 6 when there was no larval mortality at other concentrations. The net mortality of pupae was higher than that of larvae at all the concentrations except at 20 per cent. The LC50 and LC90 values calculated from the net mortality of larvae and pupae together, from day 1 to 12 post-treatment, were respectively, 8.25 and 51.79 microg protein/g of the fly rearing medium. INTERPRETATION & CONCLUSION: The formulation prepared from the exotoxin of P. fluorescens was toxic to the house fly. Pupae were more susceptible than larvae and the activity of the toxin might have been through cuticular absorption. The results are indicative of the possibility of development of the mosquitocidal metabolite for house fly control through appropriate field evaluations.

Effect of entomopathogenic fungus, Beauveria bassiana on larvae of three species of mosquitoes.

Beauveria bassiana, an entomopathogenic fungus, was evaluated for its potential against second and third instar larvae of Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti. Conidiospores of this fungus were effective in causing infection leading to mortality of different larval instars. Larvae of Cx. quinquefasciatus were more susceptible to infection than An. stephensi and the second instar larvae of these two species were more susceptible than third instar larvae. Larvae of Ae. aegypti were resistant to infection by B. bassiana.

Current insecticide resistance patterns in mosquito vectors in Thailand.

Chemical pesticides are still commonly used in Thailand for control of agricultural pests and disease vectors. Organophosphates, carbamates and synthetic pyrethroids are commonly used for agricultural purposes, whereas synthetic pyrethroids have become more popular and predominate for public health use. The genetic selection of insecticide resistance (whether physiological, biochemical or behavioral) in pests and disease vectors has been extensively reported worldwide (Brown and Pal, 1971). The long-term intensive use of chemical pesticides to control insect pests and disease vectors is often cited as the reason behind the development of insecticide resistance in insect populations. Unfortunately, reliable information on vector resistance patterns to pesticides in Thailand is sparse because of a remarkable shortage of carefully controlled, systematic studies. This review gathers useful information on what is presently known about disease vector resistance to chemical pesticides in Thailand and provides some possible management strategies when serious insecticide resistance occurs.

Preferência para diferentes tipos de isca por mosquitos(diptera: culicidae)capturados em Goiânia-Goiás / Preference of mosquitoes captured in Goiânia-Goiás, Brazil, for different type of baits

Empregando-se como isca homem, ave (Gallus domesticus), cäo (Canis familiaris) e suíno (Scrofa domesticus), obteve-se um total de 9.060 mosquitos em capturas semanais, realizadas na Chácara Naves, em Goiânia, de janeiro a dezembro de 1992. Capturaram-se também culícideos em abrigos animais (pocilga e galinheiro). Dos 9.060 espécimes, 6.045 foram obtidos através de isca humana, 822 em ave, 41 em cäo, 27 em suíno, 2.114 em galinheiro e 11 em pocilga. Das 52 espécies registradas, foram capturadas 42 em isca humana, 22 em ave, 8 em cäo e 7 em suíno. Com relaçäo aos abrigos animais, 10 espécies foram obtidas em galinheiro e 4 em pocilga. Dentre as espécies capturadas 23 concorreram com mais de 0,5 (por cento) do total obtido. Destacaram-se como antropofílicas Aedes (Ochlerotatus) scapularis, Aedes (Ochlerotatus) serratus, Culex (Culex) dolosus, Haemagogus (Haemagogus) capricornii, Haemagogus (Conopostegus) leucocelaenus, Psorophora (Janthinosoma) ferox e Sabethes (Sabethoides) chlorapterus. Dentre os ornitofílicos salientam-se Aedonyia (Aedonyia) squamipennis, Culex scapuaris, A. serratus, Coquillettidia (Rhynchotaenia) juxtamansonia e C. dolosus. Os suínos atraíram principalmente A. scapularis e coquillettidia (Rhynchotaenia) venezuelensis. Em abrigo de ave foram reegistradas principalmente A. squamipennis, C. dolosus e C. pilosus. Apenas três espécies foram capturadas em pocilga

Factores sociales relacionados con la presencia de criaderos del mosquito Aedes aegypti en el corregimiento de Bella Vista, Panamá, 1996 / Socials factors concerning with the presence of breeding place of Aedes aegypti in the corregimiento de Bella Vista, Panama, 1996

En Panamá existe el riesgo de epidemia por Dengue Hemorrágico, debido al incremento de casos del Dengue Clásico, durante los últimos dos años. Algunos estudios previos de carácter cualitativos han sugerido la existencia de factores sociodemográficos asociados a la proliferación de criaderos del mosquito Aedes aegypti, vector del dengue. La presente investigación, de tipo cuantitativo de casos y controles, es la primera que se realiza en nuestro país, en el corregimiento de Bella Vista del Ýrea Metropolitana, explorando el conocimiento, la actitud y la conducta relacionados con variables tales como sexo, edad, escolaridad, ocupación, ingreso económico familiar y hacinamiento. En la población se evalúa: El conocimiento sobre el mosquito Aedes aegypti, el dengue en sus formas clásica y hemorrágica, la actitud ante la sospecha de enfermos por dengue en la familia, las medidas de control y la responsabilidad de prevenir epidemias del dengue, la conducta en relación a las acciones de participación comunitaria en el control del vector, ante la presencia de casos de dengue en la comunidad y de criaderos del mosquito en la propia vivienda. Aplicando análisis estadístico el conocimiento sobre el mosquito Aedes aegypti no presentó diferencias entre los grupos de estudio, pero el conocimiento del dengue clásico y el dengue hemorrágico fue tres veces mejor en el grupo de control con respecto al grupo caso (OR=3, p=0.0009). La actitud se evalúa como buena en ambos grupos del estudio; no se apreciaron diferencias significativas en el análisis. La conducta en el grupo caso y en el grupo control fue buena en el 48 por ciento y 70 por ciento respectivamente. El análisis estadístico de la conducta relacionada con la presencia de criaderos del mosquito mostró diferencias estadísticamente significativas, indicando que las variables educación universitaria, ingreso económico alto y sexo femenino, en edades entre los 20 y 59 años, ejercieron una influencia positiva en el grupo control (OR=3, p=0.0003)

Relación entre mosquitos vectores y aves acuáticas en la transmisión potencial de dos arbovirus / The relationship between mosquito vectors and aquatic birds in the potential transmission of 2 arboviruses

The authors studied for two years the role of the chicks of aquatic birds in the arboviral cycles in coastal lagoons in central Panama in order to determine the relation between Culex (Melanoconion) ocossa and Mansonia (Mansonia) dyari mosquitoes in the transmission and dissemination of the viruses of Saint Louis Encephalitis (SLE) and Venezuelan Equine Encephalitis (VEE). Mosquitoes were captured every fifteen days on two consecutive nights to isolate the virus, using light traps (CDC) and baited traps. The attempts to isolate the virus were made using Vero cell cultures and the determination of antibodies was performed. The results of the serologic tests seem to indicate that four bird species: the ex (?) heron (Bubulcus ibis), the American heron (Casmerodius albus), the spoon-billed duck (Cochlearius cochlearius) and the needle crow (Anhinga anhinga) could function as intermediate hosts in the transmission cycle of SLE. Two species, the ibis (Endocimus albus) and the spoon-billed duck (Cochlearius cochlearius) could also be intermediate hosts of VEE in the coastal lagoons of Panama. The presence of antibodies in chicks could indicate an infection acquired recently, after their birth, in this area. The VEE virus was recovered from blood filled mosquitoes which had fed on a spoon-billed duck probably infected and exposed in a Trinidad #10 trap. No SLE virus was isolated. Other unknown viruses were isolated from mosquitoes selected for these studies, such as C. ocossa and M. dyari. The results obtained with these studies indicate the need for more studies utilizing new field techniques in order to establish a link between SLE and VEE, the vector mosquitoes and the aquatic birds in the coastal lagoons of the area under investigation

Sensitivity of mosquito-pathogenic bacterial strains to various antibodies.

Four strains of Bacillus sphaericus, 1593, 2362, 9001 and 9002, B. thuringiensis H-14 and B. thuringiensis neoleonensis were tested for sensitivity against 18 antibiotics. The results revealed that all the four strains of B. sphaericus are resistant to colistin, nalidixic acid, polymyxin B and streptomycin. However, B. thuringiensis H-14 was resistant to 9 antibiotics, viz. ampicillin, cephalexin, carbenicillin, co-trimoxazole, colistin, cloxacillin, penicillin, nitrofurantoin and polymyxin B whereas B. thuringiensis neoleonensis was found to be resistant to 8 antibiotics. These results may help in isolation of potential and resistant mosquito pathogenic bacteria.

Brazilian dengue virus type 1 replication in mosquito cell cultures

The development of dengue viruses type 1 obtained from accute human sera and inoculated into mosquito cell cultures, was observed by standard transmission electron microscopy and cytochemical staining. It follows the trans-type mechanism already estabilished of other dengue types. Directed passage of single virus particles across the cell membrane seems to be a pathway of entry and exit in dengue-1 infected cells. The nature of numerous electron translucent vesicles and tubules, produced simmultaneously during virus replication inside the rough endoplasmic reticulum, was analyzed by cytochemical tests. The largest amount of virus particles was produced inside cell syncytia

Method for storing Lagenidium (Oomycetes: Lagenidiales).

Techniques for storing the mosquito pathogenic fungus, Lagenidium, were evaluated. A technique, which involves storage of fungal mycelia in sterile distilled water of pH 6-7 with 0.0025 M glucose at 30-35 degrees C, was found to be useful. When stored in this manner the fungus retained it's larvicidal activity for 190 days.

Effect of corn-steep liquor on growth and mosquito larvicidal activity of Bacillus thuringiensis var israelensis de Barjac 1978 and B. sphaericus Neide 1904.

Influence of corn steep liquor on the cell yield and toxicity of three strains of B. thuringiensis var israelensis and two strains of B. sphaericus was studied and compared with peptone-yeast extract using a laboratory fermentor. Large increase in the cell yield of all the three strains of B. thuringiensis var israelensis was observed when cornsteep liquor was used as the sole nitrogen source. Significant increase in toxicity was also observed in B. thuringiensis var israelensis strains B17 and B113. Among the two B. sphaericus strains tested, the strain 1593 showed no significant change in cell yield and toxicity, whereas the strain VCRC B42 showed increased cell yield and toxicity in this medium. The results indicate that cornsteep liquor can effectively replace both peptone and yeast extract in the media presently used for large scale multiplication of the two larvicidal bacilli.

Relationship between the prevalence of antibodies to hepatitis B core antigen and arbovirus in fishermen from the Ribeira Valley, Brazil

Sera from 299 fishermen 16 to 80 years old, residents in Cananeia and Iguape counties, southern cost of Säo Paulo State, Brazil, were studied in order to identify a possible association between the prevalance of specific antibodies to the hepatitis B virus (HBV) and exposure to haematophagus mosquitoes evaluated by the prevalence of arbovirus antibodies. This professional group presented the highest prevalence of arbovirus antibodies (54.1%) in past investigations carried out in this heavily forested region. Detection of antibody to hepatitis B core antigen (anti-HBc) in the sera was done by enzyme immunoassay (Roche). Prevalence of anti-HBc antibodies in this group was 31,4% (94/299) which is very high compared with 7,2% to 15.0% for different groups of healthy adults in State of Säo Paulo. No significant difference is observed between the prevalences of HBV antibodies in Iguape and Cananeia. Prevalence of anti-HBc and anti-arbovirus antibodies increases with age. There is a concordance in the distribution according to age groups of the frequency of anti-HBc and anti-arbovirus positivesera. Ag HBs was detected in 4% of the studied sera. These results support the hypothesis that the transmission of the hepatitis B virus and the arboviruses may be due to the same factor, one of the possibilities would be by anthropophilic mosquitoes

Characterization & larvicidal activity of indigenous isolates of Bacillus sphaericus from natural breeding habitats.

Soil, water and moribund/or dead mosquito larval samples collected from various mosquito breeding habitats of Pondicherry and Tamil Nadu were screened for the presence of mosquito pathogenic B. sphaericus isolates. From 1892 samples 21 isolates were obtained. All these isolates fell under 3 serogroups viz., H5a5b, H6 and H45, the latter two serotypes not reported hitherto as toxic to mosquito larvae and three phage-groups namely, phage group 2, phage group 3 and an unknown one. Twelve of the isolates were highly toxic and superior to the standard strains 1593, 2297 and 2362 supplied by Pasteur Institute, Paris when tested against Culex quinquefasciatus larvae. Out of these 12 strains 11 belonged to the serotype H5a5b and the phage-group 3 and 1 belonged to the serotype H45 and an unknown phage group.

Utility of cheap carbon & nitrogen sources for the production of a mosquito-pathogenic fungus, Lagenidium.

Attempts were made to produce Lagenidium in culture media containing corn starch, barley flour, wheat flour, jaggery, rice bran, rice flour or tapioca starch as the major carbon source and groundnut cake as nitrogen source in comparison with peptone-yeast extract-glucose-sunflower oil (PYGSF) agar medium. The number of zoospores produced by the mycelia grown in PYGSF agar medium was 20 x 10(4)/10 cm2 while that grown in the other media was 20-25 x 10(4)/10 cm2. With respect to the larvicidal activity, the mycelia grown for 7 days in the medium containing jaggery, tapioca starch, rice flour or rice bran caused 88-96 per cent mortality while that from other media, including PYGSF agar medium, caused 70-75 per cent mortality. Twelve batches of the fungus were produced using rice-groundnut cake-sunflower oil (RGNCSF) agar medium with consistent zoospore yield and larvicidal activity.