Diversity of social wasps (Hymenoptera, Vespidae) in Cerrado biome of the southern of the state of Minas Gerais, Brazil

An inventory of social wasps in Cerrado biome of the southern of the state of Minas Gerais was performed. A comparison between field and Riparian Forest areas was made in relation to species richness; correlations between diversity, sample methods and environmental factors were conducted. A total of 32 species was registered and Polybia fastidiosuscula de Saussure, 1854 was the most abundant species. The higher richness was in the Cerrado Field, as well as the highest diversity index. The temperature and rainfall had significant correlation with species richness and a significant variation in richness between dry and wet seasons was observed. Polybia fastidiosuscula was more abundant in the Riparian Forest during the dry season and in the Cerrado Field during wet season. The study area showed a great diversity of social wasps, with record both widely distributed species such as rare species, which indicates the quality and potential area for future studies.

Observations on the dipteran fauna in a focus of dermal leishmaniasis in the State of Minas Gerais: II. The distribution of families in relation to their medical, veterinary and economic importance

Miniature light traps used to collect Phlebotominae in a focus of dermal leishmaniasis in the eastern part of the State of Minas Gerais, Brazil. Over a period of seven months, the other Diptera captured in 179 light trap samples were identified to family level. The traps were placed in eight localities which constituted three different biotopes: three woodland aresas, cultivated land, and a peridomestic site. A comparison is made between the totals of Dipeterans collected in each biotope, the total numbers of families collected in each biotope and the estimated indices of diversity. Dendograms representing the degrees of association between families of Diptera in different biotopes are presented. Some families of Diptera are uniformly distributed throughout the study area; a few families seem to have become adapted to areas where human activity has induced the greatest ecological changes. The impact between Dipterans and human well-being is discussed. The availabel evidence indicates that transmission of dermal leishmaniasis does not occur in areas where sand flies can be captured in greatest densities.

Observations on the sandfly (Diptera: Psychodidae) fauna of Além Paraíba state of Minas Gerais, Brazil, and the isolation of a parasite of the Leishmania braziliensis complex from Psychodopygus hirsuta hirsuta

Dissection of 765 sandflies captured in Além Paraíba (the type locality of Leishmania braziliensis) resulted in the isolation, from Psychodopygus hirsuta hirsuta, of a parasite of the Le. braziliensis complex.

Biomphalaria occidentalis paraense, 1981 in the state of Minas Gerais, Brazil

A population of Biomphalaria occidentalis was found for the first time in the State of Minas Gerais. It was probavly introduced into the Várzea das Flores dam, in the municipality of Contagem, the area o0f study, during fish stocking in 1985. There is possibility of "competitive exclusion"between that species and B. glabrata, previously the only Biomphalaria found in the region. The present geographical distribution of B. occidentalis in Brazil is listed.

Schistosomiasis mansoni in the region of the Triângulo Mineiro, State of Minas Gerais, Brazil

In order to reevaluate the possible presence of schistosomiasis mansoni in the Triângulo Mineiro, one of the areas of the State of Minas Gerais where this parasite is not commonly found, malacological survey and fecal examinations were undertaken in the region between October 1990 and June 1992. A sample of 7,032 1st grade school children from 29 counties had their feces examined using the Kato-Katz method. Amongst the children examined, two from Planura and one from each countie of Capinópolis, Conceição das Alagoas, Uberaba, Uberlândia, Prata and Gurinhatã were positive for Schistosoma mansoni. None of the children were identified as being autoctonous cases. In the malacological survey, 5,406 planorbid snails were examined. The specimens were identified morphologically and examined for S. mansoni by squashing between glass plates. The species were identified as Biomphalaria tenagophila in three counties, as B. straminea in ten and B. intermedia in 16. No snails were found in eight other counties studies. The snails were found to be negative for S. mansoni. The presence of intermediate hosts for S. mansoni, associated with parasitized individuals emphasizes the necessity of epidemiological surveillance for schistosomiasis in the region of Triângulo in the State of Minas Gerais.

Cryptosporidium sp. in children suffering from acute diarrhea at Uberlândia City, State of Minas Gerais, Brazil

This study's objective was to search for Cryptosporidium sp. in diarrheic feces from children aged zero to 12 years and cared for at medical units within Universidade Federal de Uberlândia or at a private practice in Uberlândia, State of Minas Gerais, Brazil, from September 1992 to August 1993. Three fecal samples preserved in 10% formalin, were collected from 94 children. Oocyst concentration was performed through Ritchie's (modified) method and staining of fecal smears for each sample (total of 1128 slides) was done by the "Safranin/Methylene Blue" and the "Kinyoun (modified)" techniques. The Hoffmann, Pons & Janer method was also employed to look for other enteroparasites. From 94 children, 4.26% excreted fecal Cryptosporidium oocysts. The infection seemed to vary according to age: 5.08% of patients aged zero to two years old; 33.33% of those aging eight to ten years (P>0.05). Cryptosporidium appeared in November, December and March, during the rainy season. 20.21% of the children harbored at least one enteroparasite different from Cryptosporidium, mainly Giardia intestinalis (12.77%). From Cryptosporidium infected patients, two had only this kind, another harbored Giardia intestinalis; the last one hosted Strongyloides stercoralis.

Control of schistosomiasis mansoni in ravena (Sabará, State of Minas Gerais, Brazil) through Water supply and quadrennial treatments

In this study, the results obtained in a control programme of schistosomiasis in Ravena (Sabará, Minas Gerais) between 1980 and 1992 are evaluated. Control measures used in this programme were: specific treatment of the people infected with Schistosoma mansoni at four year-intervals (1980/84/88) and the supply of tap water to 90% of the residences in 1980. A significant reduction of the prevalence (36.7% to 11.5%, p < 0.05) and of the intensity of the infection (228.9 eggs per gram of feces (epg), s = 3.7 to 60.3 epg, s = 3.5, p < 0.05) was observed. No cases of the severe form of the disease were diagnosed in the area. Factors independently associated with the infection were in 1980 daily sand extraction and the lack of tap water in residences and in 1992 daily sand extraction and fishing and weekly swimming. Concluding, the supply of tap water together with quadrennial treatments significantly diminished both the prevalence and intensity of the S. mansoni infection, with the additional gain of persistent low indices even after four-year intervals between the treatments.

Rickettsiae-infected Ticks in an Endemic Area of Spotted Fever in the State of Minas Gerais, Brazil

A study on tick-borne rickettsiosis was developed in the county of Santa Cruz do Escalvado, State of Minas Gerais, Brazil, where a clinical case of the disease, confirmed by necropsy, had been reported. Of the 1,254 ticks collected, 1,061 belonged to the Amblyomma genus, 57 to the Rhipicephalus sanguineus species, 81 to Boophilus microplus, and 46 to Anocentor nitens. The hemolymph test associated with Giménez staining showed that 18 of the 221 A. cajennense specimens, 1 of the 16 R. sanguineus, 1 of the 22 B. microplus, 3 of the A. nitens, and 1 of the A. ovale contained rickettsia-like microorganisms. Only 3 A. cajennense ticks were positive under direct immunofluorescence. A. cajennense was the only species found on humans

Epidemiological Characteristics of Schistosoma mansoni Infection in Rural and Urban Endemic Areas of Minas Gerais, Brazil

To compare the epidemiological profile and socioeconomic factors associated to the infection by Schistosoma mansoni in a rural and an urban endemic area a cross-sectional study was performed in Água Branca de Minas (rural area) and Bela Fama (urban area), both situated in the State of Minas Gerais, Brazil. Two hundred and eighty eight individuals were surveyed in the rural area and 787 in the urban area. Water contact and socioeconomic questionnaires were used to identify risk factors for the infection. The prevalences of 38.8% and 9.7% and the geometric mean of eggs per gram of faeces of 117.8 and 62.3 were found in the rural and urban areas, respectively. By multivariate statistical analysis age groups over nine years old and previous specific treatment were associated with the infection in rural area. In urban area age over nine years old, low quality housing, weekly fishing and swimming were associated after adjustment by logistic regression

Evaluation of the Molluscicidal Properties of Euphorbia splendens var. hislopii (N.E.B.) Latex: Experimental Test in an Endemic Area in the State of Minas Gerais, Brazil

Following the positive results obtained regarding the molluscicidal properties of the latex of Euphorbia splendens that were corroborated in laboratory and field tests under restricted conditions, a field study was conducted in experimental streams located in an endemic area. After recording the average annual fluctuations of vectors in three streams, a solution of E. splendens latex at 12 ppm was applied in stream A, a solution of niclosamide at 3 ppm that was applied in stream B and a third stream (C) remained untreated for negative control. Applications of E. splendens and niclosamide resulted in a mortality of 100% among the snails collected in the streams A and B. No dead snails were found in the negative control stream. A monthly follow-up survey conducted during three consecutive months confirmed the return of vectors to both experimental streams treated with latex and niclosamide. This fact has called for a need to repeat application in order to reach the snails that remained buried in the mud substrate or escaped to the water edge, as well as, newly hatched snails that did not respond to the concentration of these molluscicides. Adults snails collected a month following treatment led us to believe that they had migrate from untreated areas of the streams to those previously treated

Strongyloides stercoralis and other Enteroparasites in Children at Uberlândia City, State of Minas Gerais, Brazil

To evaluate the rate of infection by Strongyloides stercoralis and other enteroparasites a survey was conducted in the city of Uberlândia, State of Minas Gerais, Brazil. A total of 900 stool samples from 300 children aging from four months to seven years, randomly selected in ten nursery schools from September 1994 to December 1995, were examined, both by the Baermann-Moraes and Lutz methods. Thirty nine children (13%) were found to be infected by S. stercoralis, 64.1% were boys and 35.9% were girls. Taking all the enteroparasites as a whole the results of the survey pointed out that 265 (88.4%) of the 300 children were infected by the following: Giardia lamblia, 78.3%; Ascaris lumbricoides, 15.3%; S. stercoralis, 13%; Hymenolepis nana, 6.7%; hookworms, 6%; Enterobius vermicularis, 4%; Hymenole-pis diminuta, 4% and Trichuris trichiura, 0.7%. From 265 infected children 64.5% were mono-infected, 27.2% were infected by two parasites and 8.3% had a poly-specific parasite burden. It was concluded that strongyloidiasis is hyperendemic in this area