Analysis and estimative of schistosomiasis prevalence for the state of Minas Gerais, Brazil, using multiple regression with social and environmental spatial data

The aim of this work is to establish a relationship between schistosomiasis prevalence and social-environmental variables, in the state of Minas Gerais, Brazil, through multiple linear regression. The final regression model was established, after a variables selection phase, with a set of spatial variables which contains the summer minimum temperature, human development index, and vegetation type variables. Based on this model, a schistosomiasis risk map was built for Minas Gerais.     

Myofibroblasts in schistosomal portal fibrosis of man

Myofibroblasts, cells with intermediate features between smooth muscle cells and fibroblasts, have been described as an important cellular component of schistosomal portal fibrosis. The origin, distribution and fate of myofibroblasts were investigated by means of light, fluorescent, immunoenzymatic and ultrastructural techniques in wedge liver biopsies from 68 patients with the hepatosplenic form of schistosomiasis. Results demonstrated that the presence of myofibroblasts varied considerably from case to case and was always related to smooth muscle cell dispersion, which occurred around medium-sized damaged portal vein branches. By sequential observation of several cases, it was evident that myofibroblasts derived by differentiation of vascular smooth muscle and gradually tended to disappear, some of them further differentiating into fibroblasts. Thus, in schistosomal pipestem fibrosis myofibroblasts appear as transient cells, focally accumulated around damaged portal vein branches, and do not seem to have by themselves any important participation in the pathogenesis of hepatosplenic schistosomiasis.     

Evaluation of a 25-year-program for the control of schistosomiasis mansoni in an endemic area in Brazil

Background

Various studies showed that chemotherapy can control schistosomiasis morbidity, but association of measures (water supply, sewage disposal and increase of socioeconomic conditions) is necessary for transmission control.

Methodology/Principal Findings

A survey dealing with socioeconomic conditions, snail survey, contact with natural waters, and clinical and stool examinations was undertaken at an endemic area in the State of Minas Gerais, Brazil. The methodology used was the same for both evaluations (1981 and 2005). Four hundred and seventy-five out of 1,474 individuals studied in 1981 could be contacted. From these, 358 were submitted to stool examination, and 231 of them were clinically examined. Patients eliminating S. mansoni eggs in their stools were treated. The results showed that the prevalence rate in Comercinho, a municipality of the State of Minas Gerais, Brazil, was substantially reduced to 70.4% and 1.7% in 1981 and 2005, respectively, as well as the frequency of the hepatosplenic form (7% to 1.3%) after five treatments effectuated between 1981 and 1992. No other new case of this form was detected from 1981 onwards. Another important aspect to be considered was the improvement of people''s living standard that occurred in the region after more than two decades'' efforts (better housing, professional skill and adequate basic sanitation).

Conclusion/Significance

The control of morbidity and very significant decrease of schistosomiasis transmission in an area until then considered as hyperendemic was possible by means of association of successive specific treatments of the local population, together with the construction of privies, water supply in the houses and improvement of socioeconomic conditions.     

Schistosomal glomerular disease (a review)

In this review paper schistosomal glomerulopathy is defined as an immune-complex disease. The disease appears in 12-15 per cent of the individuals with hepatosplenic schistosomiasis. Portal hypertension with collateral circulation helps the by pass of the hepatic clearance process and the parasite antigens can bind to antibodies in the circulation and be trapped in the renal glomerulus. Chronic membranous-proliferative glomerulonephritis is the most common lesion present and the nephrotic syndrome is the usual form of clinical presentation. The disease can be experimentally produced, and schistosomal antigens and antibodies, as well as complement, can be demonstrated in the glomerular lesions. Specific treatment of schistosomiasis does not seem to alter the clinical course of schistosomal nephropathy.     

Schistosomal glomerulopathy and changes in the distribution of histological patterns of glomerular diseases in Bahia, Brazil

Distinct patterns of glomerular lesions, including membranoproliferative glomerulonephritis and focal segmental glomerulosclerosis, are associated with infection by Schistosoma mansoni or Schistosoma japonicum. Evidence suggests that immune complex deposition is the main mechanism underlying the different forms of schistosomal glomerulonephritis and that immune complex deposition may be intensified by portal hypertension. The relationship between focal segmental glomerulosclerosis and schistosomiasis remains poorly understood. A clinicopathologic classification of schistosomal glomerulopathies was proposed in 1992 by the African Association of Nephrology. In Brazil, mass treatment with oral medications has led to a decrease in the occurrence of schistosomal glomerulopathy. In a survey of renal biopsies performed in Salvador, Brazil, from 2003-2009, only 24 (4%) patients were identified as positive for S. mansoni infection. Among these patients, only one had the hepatosplenic form of the disease. Focal segmental glomerulosclerosis was found in seven patients and membranoproliferative glomerulonephritis was found in four patients. Although retrospective studies on the prevalence of renal diseases based on kidney biopsies may be influenced by many patient selection biases, a change in the distribution of glomerulopathies associated with nephrotic syndrome was observed along with a decline in the occurrence of severe forms of schistosomiasis.     

First report on the presence of Biomphalaria straminea in the municipality of Jaboticatubas,State of Minas Gerais,Brazil

This is the first report on occurrence of Biomphalaria straminea in the district of S?o José de Almeida (municipality of Jaboticatubas) State of Minas Gerais, Brazil. The presence of B. glabrata and B. tenagophila had already been reported in this area. Such municipality is part of the metropolitan region of Belo Horizonte and comprises 60% of the Tourist Complex of Serra do Cipó. Since the 1950s throughout the 1990s, a schistosomiasis prevalence ranging from 15 to 40% has been observed. Although no B. straminea specimen has been found naturally infected in the region, descendants of these snails collected in the area, showed to be experimentally susceptible to Schistosoma mansoni infection reaching rates from 14.6 to 28.6%. Even not being found naturally infected, in the State of Minas Gerais, the possibility that the species B. straminea may keep endemicity foci of schistosomiasis should be regarded, as in the Northeastern region of Brazil where the high density of this planorbid and the social-economic and sanitary conditions enable to the transmission.     

An analysis of the impact of the Schistosomiasis Control Programme in Brazil

The impact of the Schistosomiasis Control Programme (PCE) in Brazil was analyzed, covering the period 1976 to 2003, using the following indicators: percentage of Schistosoma mansoni carriers detected among the population examined in the coproscopic surveys (PPS): mortality rate for schistosomiasis, per 100,000 inhabitants (TME): hospitalization rate for schistosomiasis, per 100,000 inhabitants (TIE): average age of deaths caused by schistosomiasis (IMOE). There was a 38.5% reduction in the PPS after the introduction of the PCE, attributed to the treatment of carriers. Even in hyper-endemic municipalities, such as Conde and Cuitegí, in the state of Paraíba, the PPS fell more than 50% after the first year of treatment. The parasitic burden of the carriers also decreased in the two municipalities. The TME was reduced by 63.4% and the TIE by 77.3%. The mortality rate was highest among the 50-and-above age group. The country's IMOE rose 32.3%. The IMOE was seen to be much lower in the state of Minas Gerais, where the PCE was only initiated in 1983, with very limited coverage.     

Clinical aspects of hepatosplenic schistosomiasis: a contrast with cirrhosis.

The clinical picture of liver disease in endemic areas of Schistosomiasis mansoni differs in many ways from that observed in alcoholic and other types of cirrhosis. In hepatosplenic schistosomiasis there is predominance of the clinical manifestations of portal hypertension, e.g., bleeding esophageal varices, while ascites, jaundice, and hepatic precoma or coma are much less common. Ammonia tolerance is usually normal and helps explain the low mortality rate during bleeding. Of special interest is the observation of a high incidence of persistent hepatitis B surface antigenemia among patients with hepatosplenic schistosomiasis, suggesting increased susceptibility of such patients to the development of virus-induced chronic active hepatitis.     

Biological screening of Annonaceous Brazilian Medicinal Plants using Artemia salina (brine shrimp test).

Eighteen different extracts from five Annona species collected in Minas Gerais state, Brazil, were submitted to the brine shrimp lethality test in order to detect potential sources of novel cytotoxic, antitumor, pesticidal and anti-Trypanosoma cruzi compounds. All of the Annonaceous species tested showed good larvicidal activity as compared to a reference compounds and literature data.     

Histocompatibilty-linked susceptibility for hepatospleenomegaly in human schistosomiasis mansoni.

In schistosomiasis mansoni, the pathogenesis of hepatosplenic disease has been shown to be due primarily to immune mechanisms. The present study was designed to examine the relationship between the development of schistosomal hepatosplenomegaly in Egyptian school children and the HLA antigens. Two groups of schistosome-infected children with similar fecal egg counts were examined: one group (23 children) had no clinically demonstrable hepatosplenomegaly whereas all the children (28) in the second group suffered from liver enlargement. Furthermore, 13 of the 28 individuals in the latter group had splenomegaly as well. Our results show that hepatosplenomegaly was related to the presence of two HLA antigens: HLA AI and B5. The average relative risk of developing hepatomegaly is 29 for HLA AI and 18.9 for 55.6. Furthermore, the severity of hepatomegaly was correlated with the presence of these two HLA antigens. These findings represent a step toward elucidating the factors controlling the pathogenic mechanisms in human schistosomiasis mansoni.     

Occurrence of Ceratitis capitata Wied. (Diptera: Tephritidae) on papaya fruits in Minas Gerais State, Brazil

The objective of this work was to register the infestation of C. capitata on papaya fruits in Minas Gerais State. Papaya fruits were collected, in a commercial orchard, in Jaíba, north of the State of Minas Gerais. C. capitata was the only specie collected (794 individuals). Doryctobracon areolatus (Szépligeti) was collected parasitizing C. capitata larvae/pupae. The level of infestation was of 7,7 pupae/kg of fruit or 1,4 pupae/fruit, in average. C. capitata is registered for the first time on papaya fruits in the State of Minas Gerais.     

Genotype by environment interaction in Nelore cattle from five Brazilian states

Records from 75,941 Nelore cattle were used to determine the importance of genotype by environment interaction (GEI) in five Brazilian states. (Co)variance components were estimated by single-trait analysis (with yearling weight, W450, considered to be the same trait in all states) and multiple-trait analysis (with the record from each state considered to be a different trait). The direct heritability estimates for yearling weight were 0.51, 0.39, 0.44, 0.37 and 0.41 in the states of Goiás, Mato Grosso, São Paulo, Mato Grosso do Sul and Minas Gerais, respectively. The across-state genetic correlation estimates between Goiás and Mato Grosso, Goiás and Minas Gerais, São Paulo and Minas Gerais, and Mato Grosso do Sul and Minas Gerais ranged from 0.67 to 0.75. These estimates indicate that GEIs are biologically important. No interactions were observed between Goiás and São Paulo, Goiás and Mato Grosso do Sul, Mato Grosso and São Paulo, Mato Grosso and Mato Grosso do Sul, Mato Grosso and Minas Gerais, or São Paulo and Mato Grosso do Sul (0.82 to 0.97). Comparison of single and multiple-trait analyses showed that selection based on the former was less efficient in the presence of GEI, with substantial losses (up to 10%) during selection.     

First report of Panstrongylus megistus sylvatic focus in municipality of Bambuí, state of Minas Gerais, Brazil

In 1943, the Center for the Study and Prophylaxis of Chagas Disease, Oswaldo Cruz Foundation, state of Minas Gerais (MG), was created in the municipality of Bambuí to carry out studies related to Chagas disease in the mid-western region of MG. Since that time, several investigations have been conducted to determine the natural habitat of triatomines, but Panstrongylus megistus colonies have never been found in this region. This paper records the first finding of a P. megistus sylvatic colony in 69 years of research. The characteristics of this ecotope and its implications for the epidemiology of Chagas disease are discussed.     

First record of Eulaema helvola Moure (Hymenoptera: Apidae: Euglossina) for the State of Minas Gerais: biogeographic and taxonomic implications

The occurrence of Eulaema helvola Moure in the state of Minas Gerais, southeastern Brazil, is reported for the first time, extending its known geographic distribution in ca. 600 km eastwards and suggesting that this species may be parapatric or sympatric with E. seabrai Moure. Taxonomic and biogeographic implications of this finding are discussed.     

Haemostatic abnormalities in hepatosplenic schistosomiasis mansoni

Hepatosplenic schistosomiasis is a complex immuno-regulatory disease and is major health problem in endemic countries. Acute bleeding is one of its most serious complications and often life-threatening. Clinical studies have demonstrated that the patients with hepatosplenic schistosomiasis are prone to develop complex haemostatic abnormalities that may be linked to the potential risk of bleeding from ruptured esophageal varices in these patients. The deficit in haemostatic parameters is more pronounced with the advancement of the disease and is maximal in the patients with experience of haematomesis. Evidences of enhanced generation of thrombin and plasmin indicate the presence of low-grade DIC in advanced hepatosplenic schistosomiasis, which is considered as a principal cause of haemostatic abnormalities in this endemic disease. Demonstration of procoagulant expression in peripheral blood monocytes of the patients and in the livers, spleens and intestines of S. mansoni-infected mice suggest their possible implication in the causation of DIC in S. mansoni infections. Moreover, because in vitro analysis indicates a participation of immune mechanisms in the localized procoagulant expression, it seems likely that the immune responses to schstosomes play a major role in the pathogenic mechanisms of haemostatic abnormalities in hepatosplenic schistosomiasis.     

First record of the olive bud mite Oxycenus maxwelli (Keifer) (Acari: Eriophyidae) from Brazil

The mite Oxycenus maxwelli (Keifer) (Eriophyidae) is reported for the first time in Brazil infesting olive trees, Olea europaea. Specimens were found on seedlings at Maria da Fé, state of Minas Gerais, in 2007. Although minor symptoms were not noticed, significant damage to plants were observed. There is no reliable evidence of when the mite could have been introduced. It is believed that the mite occurs since the first introductions of olive trees, around 1820, through vegetative propagating material, but the mite remained unnoticed due to the lack of studies with olive trees in Brazil.     

Additions to the mycobiota of the weed Lantana camara (Verbenaceae) in southeastern Brazil

A sequel to the work of systematic surveying the mycobiota of Lantana camara aimed at finding potential biocontrol agents, was carried out during 1995–1996 covering part of its centre of origin in Brazil (state of Minas Gerais). Fifty-eight sampling sites, representing the four main climatic types in the state of Minas Gerais, were surveyed. Additional ad hoc collections were made in the states of Bahia, Espírito Santo, Paraná Rio de Janeiro and São Paulo. Fifteen fungal species were recorded in association with L. camara including the previously undescribed species Phomopsis lantanae-glutinosae sp. nov. Five fungi are also newly recorded on this host in Brazil: Cercospora lantanicola Corynespora cassiicola Meliola ambigua Mycovellosiella lantaniphila and Phomopsis lantanae. The following fungi, previously recorded on L. camara in Brazil, are recorded here for the first time in Minas Gerais: Dendryphielia aspera Micropustulomyces mucilaginosus Mycovellosiella lantanae Pseudocercospora guianensis and Puccinia lantanae.     

The impact of two education methods on knowledge of schistosomiasis transmission and prevention among schoolchildren in a rural community in northern Minas Gerais, Brazil

The objective of this study was to analyse the effect of using two health education approaches on knowledge of transmission and prevention of schistosomiasis of school children living in a rural endemic area in the state of Minas Gerais, Brazil. The 87 children participating in the study were divided into three groups based on gender, age and presence or absence of Schistosoma mansoni infection. In the first group the social representation model and illness experience was used. In the second group, we used the cognitive model based on the transmission of information. The third group, the control group, did not receive any information related to schistosomiasis. Ten meetings were held with all three groups that received a pre-test prior to the beginning of the educational intervention and a post-test after the completion of the program. The results showed that knowledge levels in Group 1 increased significantly during the program in regard to transmission (p = 0.038) and prevention (p = 0.001) of schistosomiasis. Groups 2 and 3 did not show significant increase in knowledge between the two tests. These results indicate that health education models need to consider social representation and illness experience besides scientific knowledge in order to increase knowledge of schistosomiasis transmission and prevention.     

Three new species of <Emphasis Type="Italic">Eupatorieae</Emphasis> (Compositae) from Brazil

Three new species of Eupatorieae (Asteraceae) were collected in the “campos rupestres” of the Cadeia do Espinha?o, Minas Gerais state, Brazil, in the Itacolomi State Park, located between the cities of Ouro Preto and Mariana, Minas Gerais, Brazil, during a floristic survey focusing on Compositae in this area. Eupatorium semiamplexifolium, Mikania badiniana, and Stevia alexii are described and illustrated.