Distribution and Schistosoma mansoni infection of Biomphalaria glabrata in different habitats in a rural area in the Jequitinhonha Valley, Minas Gerais, Brazil: environmental and epidemiological aspects

This paper examines the distribution and infection of Biomphalaria glabrata with Schistosoma mansoni in all aquatic snail habitats in a rural area in the state of Minas Gerais, Brazil, in relation to physico/biotic and behavioral factors. Snail and environmental surveys were carried out semi-annually between July 2001 and November 2002 at 106 sites. Collected snails were examined in the laboratory for infection. B. glabrata densities were highest in overflow ponds, irrigation ponds, springs, canals and wells, and lowest in fishponds and water tanks. Snail densities were higher during the hot, rainy season except for streams and canals and were statistically associated with the presence of fish, pollution, and vegetation density. Tilapia fish and an unidentified Diptera larva were found to be predators of B. glabrata but ducks were not. Twenty-four of the 25 infected snails were collected in 2001(1.4% infection rate) and only one in 2002, after mass chemotherapy. The occurrence of B. glabrata in all 11 snail habitats both at and away from water contact sites studied indicates widespread risk of human infection in the study area. In spite of the strong association between B. glabrata and tilapia in fishponds we do not recommend its use in schistosomiasis control for ecological reasons and its relative inefficiency in streams and dams.

Morphobiological aspects of Rhodnius brethesi Matta, 1919 (Hemiptera:Reduviidae) from the Upper and Middle Negro River, Amazon region of Brazil: I - scanning electron microscopy

The occurrence of autochthonous cases of Chagas disease in the Amazon region of Brazil over recent decades has motivated an intensification of studies in this area. Different species of triatomines have been identified, and ten of these have be proven to be carriers of the parasite Trypanosoma cruzi or " cruzi-like " parasites. Studies conducted in the municipalities of Santa Isabel do Rio Negro and Barcelos, located on the Upper and Middle of the Negro River, microregion of Negro River, state of Amazonas have confirmed not only that Rhodnius brethesi is present in the palm tree Leopoldinia piassaba, but also that this insect was recognized by palm fiber collectors. A morphological study of eyes, inter-ocular and inter-ocellar regions, antennae, buccula, labrum, rostrum, stridulatory sulcus and feet, including the apex of the tibia, spongy fossette and ctenidium was conducted by scanning electron microscopy. The buccula and the stridulatory sulcus presented notable differences in specimens of different genera and also of different species. These data make it possible to suggest that the details presented in these structures can be included as diagnostic characteristics to be used in new dichotomous keys, thereby contributing towards studies of taxonomy and systematics and furnishing backing for comparative analysis of specimens collected from different localities.

The spatial distribution of Schistosoma mansoni infection before and after chemotherapy in the Jequitinhonha Valley in Brazil

Schistosomiasis prevalence and egg counts remained low one year after chemotherapy in most households in a hyperendemic rural area in northern Minas Gerais but several distinct spatial patterns could be observed in relation to IgE levels and to a lesser extent to exposure risk (TBM) and type of water supply. An inverse relationship between pre-treatment household prevalence and egg counts on the one hand and post-treatment IgE levels on the other were noted in two of the five communities. Low exposure risk was associated with the low pre-treatment infection rates in the central village but did not contribute to the decline of infection rates after chemotherapy in the study area, as indicated by the significant increase in water contact during the posttreatment period (p < 0.0001). Distance between households and the streams and socioeconomic factors were also unimportant in predicting the spatial distribution of infection. These results are consistent with the production and antiparasitic effect of high levels of IgE in Schistosoma mansoni infection.

Vector bionomics and malaria transmission in the Upper Orinoco River, Southern Venezuela

A longitudinal epidemiological and entomological study was carried out in Ocamo, Upper Orinoco River, between January 1994 and February 1995 to understand the dynamics of malaria transmission in this area. Malaria transmission occurs throughout the year with a peak in June at the beginning of the rainy season. The Annual Parasite Index was 1,279 per 1,000 populations at risk. Plasmodium falciparum infections accounted for 64% of all infections, P. vivax for 28%, and P. malariae for 4%. Mixed P. falciparum/P. vivax infections were diagnosed in 15 people representing 4% of total cases. Children under 10 years accounted for 58% of the cases; the risk for malaria in this age group was 77% higher than for those in the greater than 50 years age group. Anopheles darlingi was the predominant anopheline species landing on humans indoors with a biting peak between midnight and dawn. A significant positive correlation was found between malaria monthly incidence and mean number of An. darlingi caught. There was not a significant relationship between mean number of An. darlingi and rainfall or between incidence and rainfall. A total of 7295 anophelines were assayed by ELISA for detection of Plasmodium circumsporozoite (CS) protein. Only An. darlingi (55) was positive for CS proteins of P. falciparum (0.42%), P. malariae (0.25%), and P. vivax-247 (0.1%). The overall estimated entomological inoculation rate was 129 positive bites/person/year. The present study was the first longitudinal entomological and epidemiological study conducted in this area and set up the basic ground for subsequent intervention with insecticide-treated nets.

Spiritual Kinship, Political Mobilization and Social Cooperation: a Swiss Alpine valley in the Eighteenth and Nineteenth Centuries

In this chapter I will present some observations and results about Ritual Kinship and political mobilization of popular groups in an Alpine valley: the Val de Bagnes, in the Swiss canton of Valais, - a mountain valley, well known today thanks to the tourist station of Verbier - where we can rely on excellent sources about local families. This region presents a particular political situation, because the 11 major villages of the valley form only one commune, which includes the whole valley.¦There are two major reasons to choose the Val de Bagnes for our inquiry on kinship and social networks in a rural society:¦A. The existence of sharp political and social conflicts during the 18th and the 19th centuries;¦B. The existence of almost systematic genealogical data between 1700 and 1900. (Casanova, Gard, Perrenoud 2005-08)¦The 18th century was characterized by the struggle of an important part of the community of Bagnes against the feudal lord, the abbot of St-Maurice. The culminating point was a local upheaval in 1745 in Le Châble, during which the abbot was forced to sign several documents in accordance with the wishes of the rebels (Guzzi-Heeb 2007). In the 19th century feudal lordship was abolished, but now the struggle confronted a liberal-radical faction and the conservative majority in the commune.¦The starting point of my presentation focuses on this question: which role did spiritual kinship play in the political mobilization of popular groups and in the organization of competing factions? This question allows us to shed light on some utilizations and meanings of spiritual kinship in the local society. Was spiritual kinship a significant instrument for economic cooperation? Or was it a channel for privileged social contacts and transactions?

Current profile of Mansonella ozzardi (Nematoda: Onchocercidae) in communities along the Ituxi river, Lábrea municipality, Amazonas, Brazil

The objective of this paper was to describe the current status of Mansonella ozzardi prevalence among the inhabitants of 12 communities along the Ituxi river, in Lábrea municipality, state of Amazonas. The prevalence of M. ozzardi was determined using thick blood smears obtained by digital punctures. M. ozzardi was found in 30.23% of the samples collected (39/129), with similar prevalence between genders (males: 30.30%; females: 30.16%); the highest prevalence was found in homemakers (45.45%) followed by farmers (38.77%). Among age groups, males and females older than 48 exhibited the highest rates. These results show a significative increase in the prevalence when compared to a epidemiological study made 26 years ago in the same area as well as a different epidemiological profile (gender and occupation) in relation to other areas in Amazonas.

Pre-Columbian Chagas disease in Brazil: Trypanosoma cruzi I in the archaeological remains of a human in Peruaçu Valley, Minas Gerais, Brazil

We evaluated the presence and distribution of Trypanosoma cruzi DNA in a mummy presenting with megacolon that was dated as approximately 560 ± 40 years old. The mummy was from the Peruaçu Valley in the state of Minas Gerais, Brazil. All samples were positive for T. cruzi minicircle DNA, demonstrating the presence and broad dissemination of the parasite in this body. From one sample, a mini-exon gene fragment was recovered and characterized by sequencing and was found to belong to the T. cruzi I genotype. This finding suggests that T. cruzi I infected humans during the pre-Columbian times and that, in addition to T. cruzi infection, Chagas disease in Brazil most likely preceded European colonization.

Sandflies (Diptera: Psychodidae: Phlebotominae) collected on the banks of the Velhas River in the state of Minas Gerais, Brazil

Leishmaniases are endemic to several Brazilian states, including Minas Gerais. As many cases of these diseases are diagnosed in Minas Gerais every year, this paper aimed to determine the diversity of the species of sandflies vector of leishmaniases, in Lassance and Corinto on the banks of the Velhas River. Over two years, 21,014 specimens of sandflies, belonging to 19 species were captured with light traps. Of these specimens, Nyssomyia neivai (Pinto 1926) (84.18%), Nyssomyia intermedia (Lutz & Neiva 1912) (13.41%), Evandromyia lenti(Mangabeira 1938) (0.99%) and Evandromyia sallesi (Galvão & Coutinho 1939) (0.48%) were the most represented. The former two species could be involved in the epidemiological chain of leishmaniasis in this region. No significant difference was found between the species compositions on the two river banks.

Night and crepuscular mosquitoes and risk of vector-borne diseases in areas of piassaba extraction in the middle Negro River basin, state of Amazonas, Brazil

A study of crepuscular and night-biting mosquitoes was conducted at remote settlements along the Padauiri River, middle Negro River, state of Amazonas, Brazil. Collections were performed with human bait and a CDC-light trap on three consecutive days per month from June 2003-May 2004. In total, 1,203 h of collection were performed, of which 384 were outside and 819 were inside houses. At total of 11,612 specimens were captured, and Anophelinae (6.01%) were much less frequent than Culicinae (93.94%). Anopheles darlingi was the most frequent Anophelinae collected. Among the culicines, 2,666 Culex (Ae.) clastrieri Casal & Garcia, 2,394 Culex. (Mel.) vomerifer Komp, and 1,252 Culex (Mel.) eastor Dyar were the most frequent species collected. The diversity of insects found reveals the receptivity of the area towards a variety of diseases facilitated by the presence of vectors involved in the transmission of Plasmodium, arboviruses and other infectious agents.

Analysis of Pleistocene paleodrainage evolution in the Po Basin (Italy) by multivariate statistical techniques

In order to obtain a high-resolution Pleistocene stratigraphy, eleven continuouslycored boreholes, 100 to 220m deep were drilled in the northern part of the PoPlain by Regione Lombardia in the last five years. Quantitative provenanceanalysis (QPA, Weltje and von Eynatten, 2004) of Pleistocene sands was carriedout by using multivariate statistical analysis (principal component analysis, PCA,and similarity analysis) on an integrated data set, including high-resolution bulkpetrography and heavy-mineral analyses on Pleistocene sands and of 250 majorand minor modern rivers draining the southern flank of the Alps from West toEast (Garzanti et al, 2004; 2006). Prior to the onset of major Alpine glaciations,metamorphic and quartzofeldspathic detritus from the Western and Central Alpswas carried from the axial belt to the Po basin longitudinally parallel to theSouthAlpine belt by a trunk river (Vezzoli and Garzanti, 2008). This scenariorapidly changed during the marine isotope stage 22 (0.87 Ma), with the onset ofthe first major Pleistocene glaciation in the Alps (Muttoni et al, 2003). PCA andsimilarity analysis from core samples show that the longitudinal trunk river at thistime was shifted southward by the rapid southward and westward progradation oftransverse alluvial river systems fed from the Central and Southern Alps.Sediments were transported southward by braided river systems as well as glacialsediments transported by Alpine valley glaciers invaded the alluvial plain.Kew words: Detrital modes; Modern sands; Provenance; Principal ComponentsAnalysis; Similarity, Canberra Distance; palaeodrainage

Dispersal and survival of Nyssomyia intermedia and Nyssomyia neivai (Diptera: Psychodidae: Phlebotominae) in a cutaneous leishmaniasis endemic area of the speleological province of the Ribeira Valley, state of São Paulo, Brazil

The dispersal and survival of the phlebotomines Nyssomyia intermedia and Nyssomyia neivai (both implicated as vectors of the cutaneous leishmaniasis agent) in an endemic area was investigated using a capture-mark-release technique in five experiments from August-December 2003 in municipality of Iporanga, state of São Paulo, Brazil. A total of 1,749 males and 1,262 females of Ny. intermedia and 915 males and 411 females of Ny. neivai were marked and released during the five experiments. Recapture attempts were made using automatic light traps, aspiration in natural resting places and domestic animal shelters and Shannon traps. A total of 153 specimens (3.48%) were recaptured: 2.59% (78/3,011) for Ny. intermedia and 5.35% (71/1,326) for Ny. neivai. Both species were recaptured up to 144 h post-release, with the larger part of them recaptured within 48 h. The median dispersion distances for Ny. intermedia and Ny. neivai, respectively, were 109 m and 100 m. The greatest dispersal range of Ny. intermedia was 180 m, while for Ny. neivai one female was recaptured in a pasture at 250 m and another in a pigsty at 520 m, showing a tendency to disperse to more open areas. The daily survival rates calculated based on regressions of the numbers of marked insects recaptured on the six successive days after release were 0.746 for males and 0.575 for females of Ny. intermedia and 0.649 for both sexes of Ny. neivai. The size of the populations in the five months ranged from 8,332-725,085 for Ny. intermedia males, 2,193-104,490 for Ny. intermedia females, 1,687-350,122 for Ny. neivai males and 254-49,705 for Ny. neivai females.

New insights on river water chemistry by using non-centred simplicial principal component analysis: a case study

The use of perturbation and power transformation operations permits the investigation of linear processes in the simplex as in a vectorial space. When the investigated geochemical processes can be constrained by the use of well-known starting point, the eigenvectors of the covariance matrix of a non-centred principalcomponent analysis allow to model compositional changes compared with a reference point.The results obtained for the chemistry of water collected in River Arno (central-northern Italy) have open new perspectives for considering relative changes of the analysed variables and to hypothesise the relative effect of different acting physical-chemical processes, thus posing the basis for a quantitative modelling

Spinitectus osorioi (Nematoda: Cystidicolidae) in the Mexican endemic fish Atherinella alvarezi (Atherinopsidae) from the Atlantic River drainage system in Chiapas, Southern Mexico

Specimens of Spinitectus osorioi Choudhury and Pérez-Ponce de León, an intestinal nematode species previously considered to be specific to Chirostoma spp and endemic to some lakes in the Pacific drainage in Michoacán, were collected from the freshwater fish Atherinella alvarezi (Díaz-Pardo) (Atherinopsidae) of the Michol River near Palenque, Chiapas, Southern Mexico, which belongs to the Atlantic drainage system. Studies using light and scanning electron microscopy revealed some taxonomically important, previously unreported or erroneously reported features of S. osorioi, such as the location of the vulva, the actual number and distribution of postanal papillae and phasmids and the presence of a short median cuticular ridge anterior to the cloacal opening (in addition to two long subventral ridges). The recorded somewhat shorter spicules (420-465 and 105-111 μm) and mostly smaller eggs (33-36 × 18-20 μm) as compared to the original species description may be due to a different type of host, geographical region or generally smaller body measurements of these specimens. These biometrical differences are considered to be within the limits of the intraspecific variability of S. osorioi. A key to species of Spinitectus parasitizing freshwater fishes in Mexico is provided.

Breeding sites of Culicoides pachymerus Lutz in the Magdalena River basin, Colombia

The breeding sites of Culicoides pachymerus are described for the first time in western Boyacá Province, Colombia, where this species is a public health problem. In addition to being a nuisance due to its enormous density and its high biting rates, C. pachymerus cause dermatological problems in the human population. Analysis of microhabitats by the sugar flotation technique and the use of emergence traps allowed us to recover 155 larvae of Culicoides spp and 65 adults of C. pachymerus from peridomiciliary muddy substrates formed by springs of water and constant rainwater accumulation. These important findings could aid in the design of integrated control meas-ures against this pest.

Mansonella ozzardi in Amazonas, Brazil: prevalence and distribution in the municipality of Coari, in the middle Solimões River

This study investigated some epidemiological aspects of the Mansonella ozzardi in municipality of Coari, Amazonas. Clinical symptoms were correlated with the filarial infection and the parasitic infection rates (PIR) were estimated in simuliid vectors. The general M. ozzardi human prevalence rate was 13.3% (231/1733), of which 10.2% (109/1069) were from the urban area and 18.4% (122/664) from the rural area. The prevalence rates were higher in men (14.5% urban and 19.7% rural) than in women (6.7% urban and 17.2% rural) and occurred in most age groups. The indices of microfilaremics were higher in people > 51 years old (26.9% urban and 61.5% rural). High prevalence rates were observed in retired people (27.1% urban area), housewives and farmer (41.6% and 25%, respectively, in rural area). The main clinical symptoms were joint pains and sensation of leg coldness. Only Cerqueirellum argentiscutum (Simuliidae) transmits M. ozzardi in this municipality (PIR = 5.6% urban and 7.1% rural). M. ozzardi is a widely distributed parasitic disease in Coari. Thus, temporary residency in the region of people from other localities involved with the local gas exploitation might be a contributing factor in spreading the disease.