Correlação entre carga parasitária de S. mansoni e gravidade das formas clínicas em uma comunidade rural de Minas Gerais

Coura, J. Rodrigues; Conceição, Maria José

doi:10.1590/s0037-86821981000100009

Cited by 10 publications

(5 citation statements)

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“…The factors that cause the development of periportal fibrosis associated with hepatosplenic disease are poorly understood. Although high worm load is considered the major factor involved in pathogenesis (Cheever, 1968a;Coura and Conceição, 1981), additional factors, such as host genetics and immunologic response profiles, may play a role, since not all heavily-infected people will develop hepatosplenic disease. Some previous studies have demonstrated an association between Th2 cytokine production and intensity of infection (Zwingerber et al, 1991;Williams et al, 1994;Araújo et al, 1994;Viana et al, 1994).…”

Section: Introductionmentioning

confidence: 99%

Comparison of immune responses of Schistosoma mansoni-infected mice with distinct chronic forms of the disease

et al. 2004

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Background: Schistosoma mansoni-infected mice tend to present with either one of two different hepatic pathological patterns during chronic infection: periportal fibrosis (PF) with portal concentration of periovular granulomas and fibrosis or isolated granulomas (IG), with scattered periovular granulomas within the liver. These are models for the two clinical presentations of schistosomiasis, the severe hepatosplenic and the mild intestinal forms. In the present work, we examined the relationship between the development of these histopathological aspects and immunological markers in S. mansoni-infected mice. Although BALB/c mice with PF and IG had similar egg numbers in the liver, PF mice had higher liver collagen contents than mice with IG. Cultured spleen cells from mice with PF and IG had similar proliferation 20 and 40 weeks after S. mansoni infection upon stimulation with parasite egg antigen (SEA) or mitogen (Con A). Production of IL-4 upon SEA stimulation was higher in cell cultures from mice with PF, whereas IL-5 and IFN-␥ levels were not statistically different between PF and IG groups. Mice with IG had similar serum concentrations of total IgE and anti-SEA IgG1, IgG2a, IgG2b and IgG3 compared to sera from PF mice. Levels of IgG1 and IgG2a antibodies were the highest and the lowest detected, respectively. In conclusion, isogenic BALB/c mice infected with S. mansoni that develop periportal fibrosis or isolated granulomas have similar immunological patterns despite the two pathologic forms of schistosomal liver fibrosis.

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Section: Introductionmentioning

confidence: 99%

Comparison of immune responses of Schistosoma mansoni-infected mice with distinct chronic forms of the disease

et al. 2004

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“…These findings also point toward the fundamental importance of wormload in the pathogenesis of advanced schistosomiasis (Cheever, 1968). However, in prospective field studies in endemic areas individuals with the highest numbers of eggs eliminated in the feces were not necessarily at greater risk of developing periportal fibrosis (Coura and Conceição, 1981).…”

Section: Discussionmentioning

confidence: 88%

Characterization of the vascular changes in schistosomal portal (pipestem) fibrosis of mice

et al. 2006

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Mice chronically infected with Schistosoma mansoni develop one of two anatomical forms of hepatic lesions: severe, periportal (pipestem) fibrosis or milder, isolated granulomas. The pathogenesis of periportal fibrosis is poorly understood. In this work we compared mice with either periportal fibrosis or isolated granulomas to identify specific markers of severe pathology. BALB/c or Swiss Webster mice were infected with 30 cercarie, once or six times, and liver biopsies were performed to classify the animals into two pathological groups 16 weeks later. Sixty percent of the animals sacrificed at 20 or 24 weeks had periportal fibrosis, 15-20% had isolated granulomas and the remainder had indeterminate pathology. There was no correlation between frequency of infections or egg burden (eggs/gliver) at 20 and 24 weeks post-infection and the development of periportal fibrosis. Livers with periportal fibrosis at 20 or 24 weeks of infection were characterized by larger areas of fibrotic tissue and greater vascularization compared to livers of mice with isolated granulomas. Plastic casts of the portal vein system showed marked changes in vascular structure in mice with periportal fibrosis, including collateral vessels sprouting from the main portal branches, amputation of the more delicate peripheral ramifications, and distortions of the medium and small branches. Vascular changes were not observed in mice with isolated granulomas. These results suggest that the interaction between schistosome eggs and portal vascular changes is of paramount importance in the development of pipestem fibrosis.

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“…The mean intensity of infection of 58.5 eggs/g feces was low to the usually found in other Brazilian endemic areas. COU-RA & CONCEIÇÃO 6 recorded the mean values of 207 and 138 eggs/g feces respectively in of 1973 and 1974 in a rural community, in the State of Minas Gerais, where the B. glabrata is the major vector. In Pedro de Toledo, the highest intensity rate was observed more in the rural than in the urban area.…”

Section: Discussionmentioning

confidence: 99%

Schistosomiasis mansoni in the municipality of Pedro de Toledo (São Paulo, Brazil) where the Biomphalaria tenagophila is the snail host: I - Prevalence in human population (

Dias

Kawazoe

Glasser

et al. 1989

Rev. Inst. Med. trop. S. Paulo

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SUMMARYDue to the scarce information about the epidemiological features of schistoso¬ miasis in which the vector is Biomphalaria tenagophila, an investigation was carried in Pedro de Toledo in 1980 where such peculiarity is observed. Stool examinations (Kato Katz method) were performed in 4,741 individuals (22.8% positive to Schistosoma mansoni eggs) of this 583 had previously received chemoterapy and 4,158 remainders, untreated. The schistosomiasis prevalence in those two groups where respectively 31.7% and 21.6% . Epidemiological investigation showed that 83.6% were autochthonous cases from the studied area: the autochthonous prevalence rate, and the intensity of infection in the untreated autochthonous cases were higher in males than in females; the intensity in the latter untreated group was low, 58.5 eggs/g feces {geometric mean). Moreover, according to the age groups the intensity of infections correlated well (r s = 0.745) with the prevalence rates. Schistosomiasis was veri¬ fied to occur mostly during the leisure time and by the use of water streams for housework in rural zone. Only 0.4% out of 1,137 snails was positive for S. mansoni cercariae, apparently unchanged from the 1978 study when the human prevalence was 12.0%. The studied area presented differences and similarities in relation to the other Brazilian areas were the main intermediate host is B. glabrata.

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Correlação entre carga parasitária de S. mansoni e gravidade das formas clínicas em uma comunidade rural de Minas Gerais

Abstract: Observou-se uma correlação direta entre as formas hepato-esplênicas, preponderantes na faixa etária entre 11 e 15 anos com a maior intensidade de infecção, determinada pelo número mediano de ovos de S. mansoni por grama de fezes.

Cited by 10 publications

References 5 publications

Comparison of immune responses of Schistosoma mansoni-infected mice with distinct chronic forms of the disease

Comparison of immune responses of Schistosoma mansoni-infected mice with distinct chronic forms of the disease

Characterization of the vascular changes in schistosomal portal (pipestem) fibrosis of mice

Schistosomiasis mansoni in the municipality of Pedro de Toledo (São Paulo, Brazil) where the Biomphalaria tenagophila is the snail host: I - Prevalence in human population (

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