First report on surface aspects of Mansonella ozzardi (spirurida: onchocercidae) microfilariae by scanning electron microscopy: preliminary results

Blood samples from Mansonella ozzardi infected volunteers from Vila Antimary (Amazonas State) were processed and a protocol to isolate and prepare microfilariae was carried out in order to perform Scanning Electron Microscopy (SEM) analysis. Data obtained from ultrastructure showed some undescribed structural points of the parasite such as a dimple in the anterior end of the larva and small points ­orifice-like­ that may be related to amphidial structures or simply pores. Another interesting feature was the tip of the tail which is very similar to that found in the rodent parasite Dunnifilaria meningica

Blackfly control from a health education perspective: the individual, the organization, and sustainability of the process

Abstract INTRODUCTION: This study analyzed blackfly awareness and perceptions of health education practices for blackfly control among vulnerable populations in Brazil. METHODS: An exploratory descriptive quantitative research analysis was performed to investigate and analyze the awareness of and potential participation in blackfly control measures by vulnerable populations. RESULTS: Countryside resident participants (n = 24/38; 63.2% of the total sample) reported that blackflies were an obstacle to the performance of their work activities. CONCLUSIONS: Blackflies are a public health problem, and actions for blackfly control have been carried out without social participation or educational health practices that involve proper community knowledge.

Evidence of phenotypic plasticity of larvae of Simulium subpallidum Lutz in different streams from the Brazilian Cerrado

In this paper, the overall morphological differences between populations of Simulium subpallidum Lutz, 1909 are studied. Several studies found in the literature point to a relationship between the labral fans and body size and the habitat where blackfly larvae occur. However, other characteristics potentially related to the microhabitat, such as abdominal hook circlet morphology, which is used for larvae to fix themselves in the substratum, and thoracic prolegs morphology, which help larvae move in the substratum, were analyzed in three different populations of S. subpallidum, one of which occupied a faster flow. The results suggest phenotypic plasticity in S. subpallidum and a tendency toward larger structures in faster flows.

New records of Mansonella ozzardi: a parasite that is spreading from the state of Amazonas to previously uninfected areas of the state of Acre in the Purus River region

Mansonella ozzardi infections are common in the riverside communities along the Solimões, Negro and Purus Rivers in the state of Amazonas (AM). However, little is known about the presence of this parasite in communities located in regions bordering AM and the state of Acre. The prevalence rate of M. ozzardi infections was determined in blood samples from volunteers according to the Knott method. A total of 355 volunteers from six riverine communities were enrolled in the study and 65 (18.3%) were found to be infected with M. ozzardi. As expected, most of the infections (25%) occurred in individuals involved in agriculture, cattle rearing and fishing and an age/sex group analysis revealed that the prevalence increased beginning in the 40-50-years-of-age group and reached 33% in both sexes in individuals over 50 years of age. Based on the described symptomatology, articular pain and headache were found to be significantly higher among infected individuals (56 and 65% prevalence, respectively, p < 0.05). Sera from volunteers were subjected to ELISA using a cocktail of recombinant proteins from Onchocerca volvulus to evaluate the specificity of the test in an endemic M. ozzardi region. No cross-reactions between M. ozzardi-infected individuals and recombinant O. volvulus proteins were detected, thus providing information on the secure use of this particular cocktail in areas where these parasites are sympatric.

Simulium (Chirostilbia) brunnescens (Diptera: Simuliidae) - new species from the Brazilian cerrado, Manso Dam, state of Mato Grosso, Brazil

A new species of Simuliidae, Simulium (Chirostilbia) brunnescens, was discovered at Chapada dos Guimarães, state of Mato Grosso, Brazil, and nearby municipalities (Paranatinga, Rosário do Oeste and Nobres). This species is described here based on the adults, pupae and larvae. This species is closely related to Simulium (C.) subpallidum Lutz, but could be differentiated in all stages: females, leg colour pattern and frontal dilatation size; males, gonostyle shape; pupae, number of gill filaments; larvae, body size and colour, postgenal cleft, ratio between antenna and stalk of labral fan.

Diversity and microdistribution of black fly (Diptera: Simuliidae) assemblages in the tropical savanna streams of the Brazilian cerrado

We describe the abiotic factors affecting the distribution of black flies at a microhabitat scale, rather than at the regional scale usually present in the literature on the Neotropics. Black fly larvae were sampled from the Tocantins River and three tributaries, located in the Brazilian savanna (state of Tocantins, Brazil) during six bi-monthly sampling periods from October 2004-August 2005. At each sampling site, 15 random quadrats (30 x 30 cm) were sampled each period and for each quadrat were determined mean water velocity, predominant substrate type (rocks, riffle litter or riparian vegetation) and depth detrended correspondence analysis (DCA) was used to determine associations with current velocity, whereas correspondence analysis (CA) was used to estimate site specific current velocity associations. Canonical correspondence analysis (CCA) was used to identify general microhabitat associations. The CCA showed that most species had a trend towards riffle litter, except for Simulium nigrimanum associated with rocky substrate and Simulium cuasiexiguum associated with riparian vegetation. The DCA showed a well defined pattern of water velocity associations. The CA revealed that the species showed different speed associations from one site to another, suggesting different competitive pressures resulting in the occurrence of different realized niches.

The phylogeny of Simulium (Chirostilbia) (Diptera: Simuliidae) and perspectives on the systematics of the genus in the Neotropical Region

Recently, knowledge of Neotropical Simuliidae has been accumulating quickly. However, information about supra-specific relationships is scarce and diagnoses of Simulium subgenera are unsatisfactory. To investigate the relationships among Simulium (Chirostilbia) species and test the subgenus monophyly, we performed a cladistic analysis. The ingroup included all species of this subgenus and the outgroup included representatives of the 17 species groups of Neotropical Simulium and three Holarctic species. The study was based on a data matrix with 31 terminal taxa and 45 morphological characteristics of adult, pupa and larva. The phylogenetic analysis under equal weights resulted in eight most-parsimonious trees (length = 178, consistency index = 34, retention index = 67). The monophyly of the S. (Chirostilbia) was not supported in our analysis. The Simulium subpallidum species group was closer to Simulium (Psilopelmia) and Simulium (Ectemnaspis) than to the Simulium pertinax species group. Additionally, we describe the three-dimensional shape of the terminalia of male and female of Simulium (Chirostilbia) for the first time and provide comments about the taxonomic problems involving some species of the subgenus: Simulium acarayense, Simulium papaveroi, S. pertinax, Simulium serranum, Simulium striginotum and S. subpallidum.

New records of the black fly fauna (Diptera: Simuliidae) in two rivers of the western Amazonia, Brazil / Novos registros da simuliofauna (Diptera: Simuliidae) em dois rios da Amazônia Ocidental, Brasil

Our goal was to verify the presence and the composition of black floy species in the Antimari and Acre rivers, located in the end of Western Amazonia, where this entomological inquiry was accomplished. Along the Antimari and Acre rivers, 19 localities were studied and 133 larvae and 197 pupae were collected, totalizing 330 black floy immatures. The following species are recorded for the first time in this area: Simulium (Psaroniocompsa) amazonicum Goeldi, Simulium (Psaroniocompsa) oyapockense Floch & Abonnenc, Simulium (Psaroniocompsa) quadrifidum Lutz, Simulium (Psilopelmia) lutzianum Pinto, Simulium (Psilopelmia) perfloavum Roubaud and Simulium (Notolepria) exiguum Roubaud. Our data suggest that S. amazonicum, S. oyapockense and S. quadrifidum have a wide geographical distribution as well as population density.

O objetivo deste trabalho foi verificar a presença e composição de simulídeos nos rios Antimari e Acre, localizados no extremo oeste da Amazônia Ocidental. Foram levantados 19 pontos de coleta ao longo dos rios Antimari e Acre, onde foram coletadas 133 larvas e 197 pupas, totalizando 330 imaturos de simulídeos. As seguintes espécies foram encontradas pela primeira vez na região: Simulium (Psaroniocompsa) amazonicum Goeldi, Simulium (Psaroniocompsa) oyapockense Floch & Abonnenc, Simulium (Psaroniocompsa) quadrifidum Lutz, Simulium (Psilopelmia) lutzianum Pinto, Simulium (Psilopelmia) perfloavum Roubaud e Simulium (Notolepria) exiguum Roubaud. Os resultados sugerem que S. amazonicum, S. oyapockense e S. quadrifidum têm distribuição geográfica mais ampla e são mais frequentes nessa região.

Local distribution of blackfly (Diptera, Simuliidae) larvae in two adjacent streams: the role of water current velocity in the diversity of blackfly larvae / Distribuição local de larvas de simulídeos (Diptera, Simuliidae) em dois rios adjacentes: O papel da velocidade da correnteza na diversidade de larvas de simulídeos

This study aimed to evaluate the influence of water velocity speed on the local distribution and taxocenosis structure of blackfly larvae. The larvae were collected from two adjacent streams located in the municipality of Angra dos Reis (RJ): Caputera River and one of its tributaries. Riffle litter patches were sampled randomly using a 30 x 30 cm quadrat. Four blackfly species were found: Simulium incrustatum s. l. Lutz, 1910; Simulium (Inaequalium) sp. ; Simulium pertinax s. l. Kollar, 1832 and Simulium subpallidum s. l. Lutz, 1909. Among these species, Simulium pertinax s. l. was clearly associated with higher water current speeds, while Simulium subpallidum s. l. showed association with lower water velocities, and Simulium (Inaequalium) sp. had a relatively constant distribution along the water current gradient.

Este estudo teve como objetivo avaliar, nos criadouros de simulídeos, a influência da velocidade da água sobre a ocorrência de suas larvas e estrutura de suas taxocenoses. Para obtenção da amostragem foram utilizados "quadrats" de madeira distribuídos aleatoriamente no rio Caputera e um de seus tributários. Foram encontradas quatro espécies: Simulium incrustatum sl. Lutz, 1910; Simulium (Inaequalium) sp. ; Simulium pertinax sl. Kollar, 1832 e Simulium subpallidum sl. Lutz 1909. S. (Inaequalium) sp. teve uma distribuição quase constante ao longo do gradiente de correnteza. S. pertinax se mostrou fortemente associada às velocidades mais altas de correnteza, enquanto que S. subpallidum se mostrou associado às velocidades mais baixas.

Detection of Onchocerca volvulus (Nematoda: Onchocercidae) infection in vectors from Amazonian Brazil following mass Mectizan™ distribution

Detection of Onchocerca volvulus in Simulium populations is of primary importance in the assessment of the effectiveness of onchocerciasis control programs. In Brazil, the main focus of onchocerciasis is in the Amazon region, in a Yanomami reserve. The main onchocerciasis control strategy in Brazil is the semi-annually mass distribution of the microfilaricide ivermectin. In accordance with the control strategy for the disease, polymerase chain reaction (PCR) was applied in pools of simuliids from the area to detect the helminth infection in the vectors, as recommended by the Onchocerciasis Elimination Program for the Americas and the World Health Organization. Systematic sampling was performed monthly from September 1998 to October 1999, and a total of 4942 blackflies were collected from two sites (2576 from Balawaú and 2366 from Toototobi). The molecular methodology was found to be highly sensitive and specific for the detection of infected and/or infective blackflies in pools of 50 blackflies. The results from the material collected under field conditions showed that after the sixth cycle of distribution of ivermectin, the prevalence of infected blackflies with O. volvulus had decreased from 8.6 to 0.3 percent in Balawaú and from 4 to 0.1 percent in Toototobi.

Caracteres diagnósticos de Simulium (Chirostilbia) pertinax Kollar (Diptera: Simuliidae) / Diagnostic Caracteres of Simulium (Chirostilbia) pertinax Kollar (Diptera: Simuliidae)

Este estudo teve por objetivo verificar padrões morfológicos que proporcionassem o correto diagnóstico de Simulium (Chirostilbia) pertinax Kollar. A análise morfológica de fêmeas e pupas permitiu encontrar estruturas bem características e de fácil utilização para identificação da espécie. Alguns caracteres diagnósticos (coloração do escudo, área nudiocular e paraprocto) podem apresentar pequenas variações e outros são constantes (coloração das pernas, cibário, forquilha, filamentos branquiais e casulo).

This study had as objective to verify the morphologic patterns that provide a correct diagnosis of Simulium (Chirostilbia) pertinax Kollar. The analysis of female and pupa morphology allowed to find characteristic structures that could be easily used to identify the species.Some diagnostic characteres (shield coloration, nudiocular area and paraprocto) show small variations and other are constant (leg coloration, cibarium, fork, branchial filaments and cocoon).

Doença de além-mar: estudos comparativos da oncocercose na América Latina e Africa / Overseas disease: comparative studies of onchocerciasis in Latin America and Africa

Objetiva investigar os aspectos históricos da introduçäo e disseminaçäo da oncocercose na América Latina, e realizar estudos comparativos sobre a história da doença nos dois continentes. A importância que adquiriu acarretou a revalorizaçäo das coleçöes de simuliídeos, cujas espécies brasileiras começaram a ser estudadas por Adolpho Lutz no início do século XX.

Coleçäo de simuliídeos (Diptera - Simuliidae) de Adolpho Lutz, sua história e importância / Adolpho Lutz`s collection of black flies (Diptera - Simuliidae), its history and importance

Apresenta as espécies de simuliídeos que pertencem à coleçäo de Adolpho Lutz depositadas no Laboratório de Simuliídeos e Oncocercose do Departamento de Entomologia do Instituto Oswaldo Cruz (IOC). Pioneiro no estudo desses dípteros, Lutz descreveu cerca de 25 espécies de diferentes localidades do Brasil. Vetor da oncocercose, os simuliídeos tiveram sua importância médico-sanitária reconhecida em fins da década de 1920.