scholarly journals Egg excretion in the initial phase of experimental murine schistosomiasis mansoni: stability and association with worm burden

1995 ◽  
Vol 37 (4) ◽  
pp. 325-329 ◽  
Author(s):  
Regina Lunardi Rocha ◽  
Manoel Otávio da Costa Rocha ◽  
Ênio Roberto Pietra Pedroso ◽  
Enrico Antônio Colosimo ◽  
Paulo Marcos Zech Coelho
Keyword(s):  
Schistosoma Mansoni ◽  
Initial Phase ◽  
Worm Burden ◽  
Chronic Phase ◽  
Infection Intensity ◽  
Schistosome Infection ◽  
Schistosomiasis Mansoni

Stability of faecal egg excretion and correlation with results related to worm burden at the initial phase of schistosomiasis mansoni were observed in two groups of mice infected with different Schistosoma mansoni cercarial burdens, by means of analysis of quantitative parasitological studies and schistosome counts after perfusion. Thus, it may be stated that few quantitative parasitological stool examinations could be sufficient to express the infection intensity at the initial phase, on the same grounds that it was already demonstrated at the chronic phase. Furthermore, it is confirmed that the use of the number of eggs passed in the faeces as a tool to estimate the worm burden at the initial phase of schistosome infection is adequate.

Variable generation of specific acquired resistance in CBA/Ca mice chronically infected with schistosomiasis mansoni

Parasitology ◽  
1989 ◽  
Vol 99 (3) ◽  
pp. 357-364
Author(s):  
V. S. Delgado ◽  
D. J. Mclaren
Keyword(s):  
Schistosoma Mansoni ◽  
Worm Burden ◽  
Acquired Resistance ◽  
Acquired Immunity ◽  
Infection Model ◽  
Schistosome Infection ◽  
Immune Mechanisms ◽  
Schistosomiasis Mansoni ◽  
Variable Generation ◽  
Worm Migration

SummaryNaive CBA/Ca mice and CBA/Ca mice infected 12 weeks previously with 20 normal cercariae of Schistosoma mansoni were challenged percutaneously with isotopically labelled parasites. Challenge worm migration was followed, in 5 separate experiments, by means of compressed organ autoradiography. In three experiments, 43.1 % of challenge parasites did not arrive in the lungs of infected mice on day 6 as compared to 7.7 % in naive controls, thereby indicating that pre-lung sites constitute the first barrier in resistance to reinfection. A further 15% of the challenge worm burden was lost in the lungs or en route to the liver in the immune animals, and portal perfusion revealed that 25.4% of the challenge was lost in the liver. Two other experiments revealed no comparable phases of pre-liver attrition however; instead resistance was only evident at final perfusion on days 28 or 35. These data reveal the variable generation of specific acquired immunity in mice harbouring a chronic schistosome infection and thus clarify current discrepancies in the literature. The results are discussed in relation to documented evidence for the nature of specific and non-specific immune mechanisms reported to operate at different sites in the infection model of schistosomiasis mansoni.

scholarly journals Pulmonary manifestations in the initial phase of schistosomiasis mansoni

1995 ◽  
Vol 37 (4) ◽  
pp. 311-318 ◽  
Author(s):  
Manoel Otávio C. Rocha ◽  
Regina Lunardi Rocha ◽  
Ênio Roberto P. Pedroso ◽  
Dirceu B. Greco ◽  
Cid Sérgio Ferreira ◽  
...  
Keyword(s):  
Initial Phase ◽  
Worm Burden ◽  
Moderate Intensity ◽  
Control Group ◽  
Common Symptom ◽  
Thoracic Pain ◽  
Schistosomiasis Mansoni ◽  
Pulmonary Manifestations ◽  
Radiological Changes ◽  
Blood Eosinophils

The clinical and radiological pulmonary manifestations in the initial phase of schistosomiasis mansoni were studied in thirty previously healthy individuals who were simultaneously infected. The findings were compared with those concerning a control group and related to possible pathogenetic factors. The respiratory manifestations were of light or of moderate intensity, the dry cough being the most common symptom. The significant radiological alterations were: thickening of bronchial walls and beaded micronodulation, predominantly localized in the lower pulmonary fields. It was observed significant association between wheezing and IgE levels, estimated by the area of immediate intradermal reaction, as well as between the number of blood eosinophils and the occurrence of radiological changes. Moreover, there was correlation between the worm burden and the presence of wheezing, thoracic pain and beaded micronodulation. Thus, the clinical and radiological pulmonary manifestations described are significant part of the initial phase of schistosomiasis mansoni and present the worm burden, eosinophilia and levels of IgE as probable pathogenetic factors.

scholarly journals Candidate gene family-based and case-control studies of susceptibility to high Schistosoma mansoni worm burden in African children: a protocol

2021 ◽  
Vol 4 ◽  
pp. 36
Author(s):  
Oscar A. Nyangiri ◽  
Sokouri A. Edwige ◽  
Mathurin Koffi ◽  
Estelle Mewamba ◽  
Gustave Simo ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Ivory Coast ◽  
Worm Burden ◽  
Infection Intensity ◽  
Case Control ◽  
Control Analysis ◽  
Nucleotide Polymorphisms ◽  
Case Control Studies ◽  
African Countries ◽  
Family Based

Background: Approximately 25% of the risk of Schistosoma mansoni is associated with host genetic variation. We will test 24 candidate genes, mainly in the Th2 and Th17 pathways, for association with S. mansoni infection intensity in four African countries, using family based and case-control approaches. Methods: Children aged 5-15 years will be recruited in S. mansoni endemic areas of Ivory Coast, Cameroon, Uganda and the Democratic Republic of Congo (DRC). We will use family based (study 1) and case-control (study 2) designs. Study 1 will take place in Ivory Coast, Cameroon, Uganda and the DRC. We aim to recruit 100 high worm burden families from each country except Uganda, where a previous study recruited at least 40 families. For phenotyping, cases will be defined as the 20% of children in each community with heaviest worm burdens as measured by the circulating cathodic antigen (CCA) assay. Study 2 will take place in Uganda. We will recruit 500 children in a highly endemic community. For phenotyping, cases will be defined as the 20% of children with heaviest worm burdens as measured by the CAA assay, while controls will be the 20% of infected children with the lightest worm burdens. Deoxyribonucleic acid (DNA) will be genotyped on the Illumina H3Africa SNP (single nucleotide polymorphisms) chip and genotypes will be converted to sets of haplotypes that span the gene region for analysis. We have selected 24 genes for genotyping that are mainly in the Th2 and Th17 pathways and that have variants that have been demonstrated to be or could be associated with Schistosoma infection intensity.   Analysis: In the family-based design, we will identify SNP haplotypes disproportionately transmitted to children with high worm burden. Case-control analysis will detect overrepresentation of haplotypes in extreme phenotypes with correction for relatedness by using whole genome principal components.

scholarly journals Characterization of the non-apparent clinical form in the initial phase of schistosomiasis mansoni

1993 ◽  
Vol 35 (3) ◽  
pp. 247-251 ◽  
Author(s):  
Manoel Otávio da Costa Rocha ◽  
Enio Roberto Pietra Pedroso ◽  
Jayme Neves ◽  
Roberto Sena Rocha ◽  
Dirceu Bartolomeu Greco ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Clinical Picture ◽  
Initial Phase ◽  
Cutaneous Reaction ◽  
Clinical Form ◽  
Blood Eosinophilia ◽  
Schistosomiasis Mansoni ◽  
History Of

In this paper the history of 115 recruits that had bathed simultaneously in streams contaminated with Schistosoma mansoni, during military maneuvers, is reported. Thirty four of the infected patients presented the initial phase of the infection diagnosed through epidemiologic, clinical and laboratorial parameters. Three out of the 34 patients did not reveal the clinical picture of the infection, thus being considered representatives of the non-apparent form of the disease. Differences between the intensity of blood eosinophilia, the area of immediate cutaneous reaction and the number of Schistosoma eggs eliminated in the stools proved not to be statistically significant (p>0.05) when the non-apparent and acute cases of schistosomiasis were compared. These cases actually may be considered evidences of the non-apparent form hitherto merely taken for granted in the literature.

scholarly journals Kinectics of the pulmonary phase of Schistosoma mansoni in mice treated with dexamethasone

1990 ◽  
Vol 32 (3) ◽  
pp. 168-171 ◽  
Author(s):  
Marco Victor Hermeto ◽  
Rosilene Siray Bicalho ◽  
Alan Lane de Melo ◽  
Leógenes Horácio Pereira
Keyword(s):  
Schistosoma Mansoni ◽  
Adult Worm ◽  
Worm Burden ◽  
Early Death ◽  
Portal System ◽  
The Third ◽  
Schistosomiasis Mansoni ◽  
Worm Recovery

In the experimental schistosomiasis mansoni glucocorticoids cause a reduction in the worm burden when administered in the week of infection or, the longest, at the next week. In order to determinate the probable(s) site(s) of reduction of the worm burden, mice were infected with cercariae of LE strain of S. mansoni and dexamethasone was administered daily (50 mg/kg, subcutaneously) starting 1 hour before infection until the eighth day. Mice were sacrificed daily starting on the third day after infection until the ninth day, and schistosomula from lungs were collected. Six weeks after infection, the remaining mice were sacrificed and perfused for adult worm recovery. Analysis of the results showed that the non-treated mice presented larger numbers of lung larvae than the treated ones, and this difference was also found later in the worm burden in the portal system. This difference may reflect the early death of larvae in treated animals, before or after reaching the lungs.

scholarly journals Schistosoma mansoni in mice: modulation of granulomatous response after reinfection and chemotherapeutic treatment

1994 ◽  
Vol 27 (3) ◽  
pp. 119-125 ◽  
Author(s):  
Paulo Marcos Z. Coelho ◽  
Pedro Raso ◽  
Rômulo Teixeira de Mello ◽  
Nivaldo H. Toppa
Keyword(s):  
Schistosoma Mansoni ◽  
Acute Phase ◽  
Specific Treatment ◽  
Chronic Phase ◽  
Histopathologic Examination ◽  
Schistosomiasis Mansoni ◽  
Human Schistosomiasis ◽  
Chemotherapeutic Treatment ◽  
Granulomatous Response

Mice previously infected with Schistosoma mansoni, and cured by specific treatment (400mg/kg oxamniquine, p. o.) in the chronic phase of the disease, were reinfected 20 days after treatment to assess their capacityfor modulation ofthe granulomatous response. Histopathologic examination of the animals ' liver, at 60 days after reinfection, evidenced the presence of typical granulomas of the chronic phase in most animals. This infer that the capacity for modulation of the granulomatous response had been maintained, thus preventing a new acute phase of the disease. Conversely, a group of previously infected mice, untreated and submitted to reinfection, showed reactivation of the granulomatous response in 50% of the animals. The possible implications of these findings in human schistosomiasis mansoni are discussed.

scholarly journals Candidate gene family-based and case-control studies of susceptibility to high Schistosoma mansoni worm burden in African children: a protocol

2021 ◽  
Vol 4 ◽  
pp. 36
Author(s):  
Oscar A. Nyangiri ◽  
Sokouri A. Edwige ◽  
Mathurin Koffi ◽  
Estelle Mewamba ◽  
Gustave Simo ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Ivory Coast ◽  
Worm Burden ◽  
Infection Intensity ◽  
Case Control ◽  
Control Analysis ◽  
Nucleotide Polymorphisms ◽  
Case Control Studies ◽  
African Countries ◽  
Family Based

Background: Approximately 25% of the risk of Schistosoma mansoni is associated with host genetic variation. We will test 24 candidate genes, mainly in the Th2 and Th17 pathways, for association with S. mansoni infection intensity in four African countries, using family based and case-control approaches. Methods: Children aged 5-15 years will be recruited in S. mansoni endemic areas of Ivory Coast, Cameroon, Uganda and the Democratic Republic of Congo (DRC). We will use family based (study 1) and case-control (study 2) designs. Study 1 will take place in Ivory Coast, Cameroon, Uganda and the DRC. We aim to recruit 100 high worm burden families from each country except Uganda, where a previous study recruited at least 40 families. For phenotyping, cases will be defined as the 20% of children in each community with heaviest worm burdens as measured by the circulating cathodic antigen (CCA) assay. Study 2 will take place in Uganda. We will recruit 500 children in a highly endemic community. For phenotyping, cases will be defined as the 20% of children with heaviest worm burdens as measured by the CAA assay, while controls will be the 20% of infected children with the lightest worm burdens. Deoxyribonucleic acid (DNA) will be genotyped on the Illumina H3Africa SNP (single nucleotide polymorphisms) chip and genotypes will be converted to sets of haplotypes that span the gene region for analysis. We have selected 24 genes for genotyping that are mainly in the Th2 and Th17 pathways and that have variants that have been demonstrated to be or could be associated with Schistosoma infection intensity.   Analysis: In the family-based design, we will identify SNP haplotypes disproportionately transmitted to children with high worm burden. Case-control analysis will detect overrepresentation of haplotypes in extreme phenotypes with correction for relatedness by using whole genome principal components.

scholarly journals Dehydroepiandrosterone Sulfate Treatment of Mice Modulates Infection with Schistosoma mansoni

1998 ◽  
Vol 5 (2) ◽  
pp. 251-253 ◽  
Author(s):  
Padraic G. Fallon ◽  
Emma J. Richardson ◽  
Frances M. Jones ◽  
David W. Dunne
Keyword(s):  
Schistosoma Mansoni ◽  
Partial Resistance ◽  
Worm Burden ◽  
Hormone Treatment ◽  
Dehydroepiandrosterone Sulfate ◽  
Schistosome Infection ◽  
Female Mice ◽  
Humoral Responses

ABSTRACT Female mice treated with dehydroepiandrosterone sulfate early during infection were partially protected (P < 0.05–0.005) from Schistosoma mansoni infection. Hormone treatment did not modify parasite-specific cellular or humoral responses. Serum dehydroepiandrosterone sulfate levels and testosterone infection were negatively correlated, r = −0.621 andr = −0.653, respectively, with schistosome worm burden. The partial resistance to schistosome infection in dehydroepiandrosterone sulfate-treated female mice may be due to the known antischistosomular activity of testosterone.

Efficacy of treatment of murine Schistosoma mansoni infections with praziquantel and oxamniquine correlates with infection intensity: role of host antibody

Parasitology ◽  
1995 ◽  
Vol 111 (1) ◽  
pp. 59-66 ◽  
Author(s):  
P. G. Fallon ◽  
J. V. Hamilton ◽  
M. J. Doenhoff
Keyword(s):  
Schistosoma Mansoni ◽  
Worm Burden ◽  
Infection Intensity ◽  
Intensity Of Infection ◽  
Drug Induced ◽  
Pre Treatment ◽  
Cure Rates ◽  
Treated Worm ◽  
Murine Antibody

SUMMARYThe reduction in worm burden obtained by treatment of Schistosoma mansoni with praziquantel and oxamniquine was greater in mice with heavy infections than in relatively lightly infected animals. The reduction in worm burden achieved by each drug correlated with the size of the pre-treatment worm burden (r2 = 0·82 and 0·81 for praziquantel and oxamniquine, respectively). Intensity of infection did not affect the degree of tegumental damage and drug-induced antigen exposure on worms recovered soon after treatment with praziquantel. However, praziquantel-treated worms from mice with heavy infections had significantly more murine antibody attached to the treated-worm surface than worms from praziquantel-treated lightly infected mice. Heavily infected mice had greater levels of circulating anti-worm antibodies than lighter infected mice. The correlation between infection intensity and cure rates achieved by praziquantel and oxamniquine may thus be a reflection of the higher litres of relevant antibody in heavily infected mice mediating death of drug-treated worms.

The influence of the H-2 complex on responses to infection by Schistosoma mansoni in mice

Parasitology ◽  
1983 ◽  
Vol 86 (1) ◽  
pp. 19-30 ◽  
Author(s):  
Janet T. Jones ◽  
D. M. Mccaffery ◽  
J. R. Kusel
Keyword(s):  
Major Histocompatibility Complex ◽  
Antibody Response ◽  
Schistosoma Mansoni ◽  
Genetic Background ◽  
Worm Burden ◽  
Major Effect ◽  
Schistosomiasis Mansoni ◽  
Histocompatibility Complex ◽  
Faecal Egg Count ◽  
Antibody Titres

SUMMARYIn order to determine whether a given H-2 haplotype has similar effects on responses to schistosomiasis mansoni on different genetic backgrounds, mice of 2 pairs of congenic strains (H-2b and H-2k on BALB/c and C57BL/10 backgrounds) were infected. Worm burdens, mortality, splenomegaly, tissue and faecal egg counts, and antibody titres to worm and egg antigens were measured. The genetic background had a major effect on the genesis of splenomegaly, on the deposition of eggs in the spleen, the maximum faecal egg count, the antibody titre to egg and worm antigens and the rate of generation of antibody response. The H-2 haplotype was shown to consistently influence the maximum faecal egg count and the antibody titres. Worm burden was not influenced by genetic differences between strains and mortality differences were not significant. The data presented here indicate that the effect of the major histocompatibility complex on responses to infection is greatly influenced by the genetic background on which it is expressed.

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