In Situ Preparation of Dehydrodieugenol-Loaded Silver Nanoparticles and their Antischistosomal Activity.

Schistosomiasis is a major neglected disease that imposes a substantial worldwide health burden, affecting approximately 250 million people globally. As praziquantel is the only available drug to treat schistosomiasis, there is a critical need to identify new anthelmintic compounds, particularly from natural sources. To enhance the activity of different natural products, one potential avenue involves its combination with silver nanoparticles (AgNP). Based on this approach, a one-step green method for the in situ preparation of dehydrodieugenol (DHDG) by oxidation coupling reaction using silver and natural eugenol is presented. AgNP formation was confirmed by UV-Vis spectroscopy due to the appearance of the surface plasmon resonance (SPR) band at 430 nm which is characteristic of silver nanoparticles. The nanoparticles were spherical with sizes in the range of 40 to 50 nm. Bioassays demonstrated that the silver nanoparticles loaded with DHDG exhibited significant anthelmintic activity against Schistosoma mansoni adult worms without toxicity to mammalian cells and an in vivo animal model (Caenorhabditis elegans), contributing to the development of new prototypes based on natural products for the treatment of schistosomiasis.

The Effect of Different Formulations of Praziquantel in Reducing Worms in the Prepatent Period of Schistosomiasis in Murine Models.

Schistosomiasis is a widely distributed parasitic disease and one of the most important neglected tropical diseases globally, for which Praziquantel® (PZQ) is the only available treatment. In this context, tests with new PZQ formulations become relevant for disease control. This study evaluated the effects of PZQ treatment in the prepatent phase of schistosomiasis using two formulations: nanoencapsulated (PZQ-NANO) and active pharmaceutical ingredient (PZQ-API). Five experimental groups were established, for which the following serological parameters were evaluated: ALT, AST, ALP, and TP. Animals treated with PZQ-API at 15 and 30 days post-infection showed decreased eggs per gram of feces (EPG) compared to untreated infected animals. The same animals showed reductions of 63.6 and 65.1%, respectively, at 60 days post-infection. Animals treated with PZQ-NANO experienced no significant changes in EPG at any time of observation. Animals treated with either PZQ-API or PZQ-NANO had higher ALT and AST levels in the patent period (60 and 90 days post-infection). Treatment with PZQ, either API or NANO, at 15 days post-infection reduced AST, ALT, and TP levels. It is concluded that prepatent treatment with PZQ-API can reduce the parasite load of infected animals and that treatment at 15 days post-infection can prevent increased serum levels of ALT, AST, and TP.

Schistosoma mansoni miracidia: revisiting motility and survival parameters for improved computational modelling.

Schistosoma mansoni is the main causative agent of intestinal schistosomiasis which affects millions of people worldwide. At the larval stage, miracidia are released into bodies of water where they utilize their motility to successfully infect their intermediate host, snails. Here, we revisit the motility and survival of S. mansoni miracidia throughout its life span. Briefly, miracidia motility was monitored at 30-min and 60-min intervals under the presence/absence of natural/artificial light. Based on a subjective evaluation of activity, body shape and transparency, 6 categories of miracidia activity were established from its fully active stage to its immobile larva stage. The estimated life span of miracidia was 5.8 and 3.5 h in the experiments with 60-min and 30-min observation intervals, respectively. Death was defined by an absence of cilia and body movement. When mobility was used as a proxy for infectivity, infective miracidia were detected at 2.5 and 4.5 h, respectively. The present miracidia motility and survival re-evaluation supports parameters optimization for computational modelling of schistosomiasis transmission dynamics. Target control interventions, especially at late stages next to transmission interruption, may greatly benefit from improved modelling studies.

Transposable Elements in the Genome of Human Parasite Schistosoma mansoni: A Review.

Transposable elements (TEs) are DNA sequences able to transpose within the host genome and, consequently, influence the dynamics of evolution in the species. Among the possible effects, TEs insertions may alter the expression and coding patterns of genes, leading to genomic innovations. Gene-duplication events, resulting from DNA segmental duplication induced by TEs transposition, constitute another important mechanism that contributes to the plasticity of genomes. This review aims to cover the current knowledge regarding TEs in the genome of the parasite Schistosoma mansoni, an agent of schistosomiasis-a neglected tropical disease affecting at least 250 million people worldwide. In this context, the literature concerning TEs description and TEs impact on the genomic architecture for S. mansoni was revisited, displaying evidence of TEs influence on schistosome speciation-mediated by bursts of transposition-and in gene-duplication events related to schistosome-host coevolution processes, as well several instances of TEs contribution into the coding sequences of genes. These findings indicate the relevant role of TEs in the evolution of the S. mansoni genome.

Schistosoma mansoni Infection Is Impacted by Malnutrition.

Schistosomiasis remains one of the most important neglected tropical diseases in the world. It mainly affects developing countries, where it often coexists with malnutrition. Despite this, few studies have investigated the relationship between schistosomiasis and malnutrition. Herein, we evaluate the impact of malnutrition on experimental S. mansoni infection. Mice were divided into 5 groups: Control (Ctrl) diet (14% protein and 10% lipids), low-protein 3% (LP 3%), low-protein 8% (LP 8%), low-fat 2.5% (LF 2.5%), and low-fat 5% (LF 5%). Mice were fed with their respective diets and were infected when a difference of approximately 20% in the body weight between mice from any experimental group and mice from the control group was achieved. Nutritional, parasitological, and immunological parameters were assessed either just before infection and/or approximately 50 days later before mice were perfused. Our results showed that the 3% low-protein diet was the only one capable of establishing malnutrition in mice. Mice fed with this diet showed: (i) significant reduction in body weight and serum albumin levels before infection, (ii) decreased levels of all biochemical parameters evaluated before perfusion, (iii) decreased numbers of schistosome eggs trapped in intestines and impaired parasite fecundity, (iv) a delay in the granuloma development with a smaller granuloma area, and (v) reduced levels of IL-4 and IFN-γ in the liver. Our findings demonstrate that low protein supply leads to malnutrition in mice and impacts the cytokine milieu in the liver and granuloma formation. Additionally, the establishment of our murine malnutrition model will enable future studies aiming to better understand the complex relationships between nutrition, immune responses, and infection outcome.

A Modified ELISA Method to Evaluate the Interaction of Schistosoma mansoni Proteins with Plasminogen.

An important aspect of host-pathogen interactions is the interference of secreted proteins with the fibrinolytic system. Herein, we describe a modified ELISA method used to evaluate the interaction of a recombinant Schistosoma mansoni protein with plasminogen (PLG). Using this protocol, we demonstrated that a secreted protein, recombinant venom allergen-like protein 18 (rSmVAL18) acts as a plasminogen receptor increasing its activation into plasmin in the presence of the urokinase-type plasminogen activator (uPA). PLG binding was determined by immobilizing human PLG in the plate and incubating with the recombinant protein; competitive binding with a lysine analog demonstrated the interaction of the protein lysine residues with PLG Kringle domains. To assess the activation of S. mansoni recombinant protein-bound PLG, the amidolytic activity of generated plasmin was measured using the D-Val-Leu-Lys 4-nitroanilide dihydrochloride substrate.

In vitro activity, ultrastructural studies and in silico pharmacokinetic properties of indol-3-yl-thiosemicarbazones derivatives and analogues against juvenile and adult worms of S. mansoni.

The present work aimed to carry out in vitro biological assays of indol-3-yl derivatives thiosemicarbazones (2a-e) and 4-thiazolidinones (3a-d) against juvenile and adult worms of S. mansoni, as well as the in silico determination of pharmacokinetic parameters for the prediction of the oral bioavailability of these derivatives. All compounds were initially screened at a concentration of 200 µM against S. mansoni adult worms and the results evidenced the good activity of compounds 2b, 2d and 3b, which caused 100% mortality after 24, 48 and 72 h, respectively. Subsequent studies with these same compounds revealed that compound 2b was able to reduce the viability of the parasites by 85% and 83% at concentrations of 200 and 100 µM, respectively. In relation to the juvenile worms, all compounds (2b, 2d and 3b) were able to cause mortality, but compound 2b demonstrated better activity causing 100% mortality in 48 h. Additionally, it was possible to observe reduction in the viability of juvenile worms of 85%, 81% and 64% at concentrations of 200, 100 and 50 µM, respectively. Several ultrastructural damages were observed when adult and juvenile S. mansoni worms were exposed to compound 2b (200 µM) that was characterized by extensive destruction by the integument, which may justify the mortality rate of cultured parasites. In the DNA interaction assay, fragmentation of the genetic material of adult worms when treated with compound 2b (200 µM) was evidenced, indicating the apoptosis process as mechanism of parasite death. Regarding pharmacokinetic properties, all derivatives are according to the required parameters, predicting good oral bioavailability for the studied compounds. The results presented in this study reveal the good activity of compound 2b in both adult and juvenile worms of S. mansoni, pointing this compound as promising in the development of further studies on schistosomicidal activity.

Schistosoma mansoni Coinfection Attenuates Murine Toxoplasma gondii-Induced Crohn's-Like Ileitis by Preserving the Epithelial Barrier and Downregulating the Inflammatory Response.

Background and aims: Mice orally infected with T. gondii develop Crohn's disease (CD)-like enteritis associated with severe mucosal damage and a systemic inflammatory response, resulting in high morbidity and mortality. Previously, helminthic infections have shown therapeutic potential in experimental colitis. However, the role of S. mansoni in T. gondii-induced CD-like enteritis has not been elucidated. Our study investigated the mechanisms underlying T. gondii-induced ileitis and the potential therapeutic effect of S. mansoni coinfection. Methods: C57BL/6 mice were infected by subcutaneous injection of cercariae of the BH strain of S. mansoni, and 7-9 weeks later, they were orally infected with cysts of the ME49 strain of T. gondii. After euthanasia, the ileum was removed for histopathological analysis; staining for goblet cells; immunohistochemistry characterizing mononuclear cells, lysozyme expression, apoptotic cells, and intracellular pathway activation; and measuring gene expression levels by real-time PCR. Cytokine concentrations were measured in the serial serum samples and culture supernatants of the ileal explants, in addition to myeloperoxidase (MPO) activity. Results:T. gondii-monoinfected mice presented dense inflammatory cell infiltrates and ulcerations in the terminal ileum, with abundant cell extrusion, apoptotic bodies, and necrosis; these effects were absent in S. mansoni-infected or coinfected animals. Coinfection preserved goblet cells and Paneth cells, remarkably depleted in T. gondii-infected mice. Densities of CD4- and CD11b-positive cells were increased in T. gondii- compared to S. mansoni-infected mice and controls. MPO was significantly increased among T. gondii-mice, while attenuated in coinfected animals. In T. gondii-infected mice, the culture supernatants of the explants showed increased concentrations of TNF-alpha, IFN-gamma, and IL-17, and the ileal tissue revealed increased expression of the mRNA transcripts for IL-1 beta, NOS2, HMOX1, MMP3, and MMP9 and activation of NF-kappa B and p38 MAPK signaling, all of which were counterregulated by S. mansoni coinfection. Conclusion:S. mansoni coinfection attenuates T. gondii-induced ileitis by preserving mucosal integrity and downregulating the local inflammatory response based on the activation of NF-kappa B and MAPK. The protective function of prior S. mansoni infection suggests the involvement of innate immune mechanisms and supports a conceptually new approach to the treatment of chronic inflammatory diseases, including CD.

Molecular characterization of transport lectin vesicular integral membrane protein 36 kDa (VIP36) in the life cycle of Schistosoma mansoni.

VIP36 is a protein described as an L-type lectin in animals, responsible for the intracellular transport of glycoproteins within the secretory pathway, and also localized on the plasma membrane. Schistosoma mansoni has a complex system of vesicles and protein transport machinery to the cell surface. The excreted/secreted products of the larvae and eggs are known to be exposed to the host immune system. Hence, characterizing the role and action of SmVIP36 in the S. mansoni life cycle is important for a better understanding of the parasite-host relationship. To this purpose, we firstly performed in silico analysis. Analysis of SmVIP36 in silico revealed that it contains a lectin leg-like domain with a jellyroll fold as seen by its putative 3D tertiary structure. Additionally, it was also observed that its CRD contains calcium ion-binding amino acids, suggesting that the binding of SmVIP36 to glycoproteins is calcium-dependent. Finally, we observed that the SmVIP36 predicted amino acid sequence relative to its orthologs was conserved. However, phylogenetic analysis revealed that SmVIP36 follows species evolution, forming a further cluster with its definitive host Homo sapiens. Moreover, q-PCR analysis in the S. mansoni life cycle points to a significant increase in gene expression in the eggs, schistosomulae, and female adult stages. Similarly, protein expression increased in eggs, cercariae, schistosomulae, and adult worm stages. These results suggest that SmVIP36 might participate in the complex secretory activity within the egg envelope and tegument proteins, both important for the stages of the parasite that interact with the host.

Schistosomal-derived lysophosphatidylcholine triggers M2 polarization of macrophages through PPARγ dependent mechanisms.

Mansonic schistosomiasis is a disease caused by the trematode Schistosoma mansoni, endemic to tropical countries. S. mansoni infection induces the formation of granulomas and potent polarization of Th2-type immune response. There is great interest in understanding the mechanisms used by this parasite that causes a modulation of the immune system. Recent studies from our group demonstrated that lipids of S. mansoni, including lysophosphatidylcholine (LPC) have immunomodulatory activity. In the present study, our aim was to investigate the role of lipids derived from S. mansoni in the activation and polarization of macrophages and to characterize the mechanisms involved in this process. Peritoneal macrophages obtained from wild type C57BL/6mice or bone marrow derived macrophages were stimulated in vitro with lipids extracted from adult worms of S. mansoni. We demonstrated that total schistosomal-derived lipids as well as purified LPC induced alternatively activated macrophages/M2 profile observed by increased expression of arginase-1, mannose receptor, Chi3l3, TGFß and production of IL-10 and PGE2 24h after stimulation. The involvement of the nuclear receptor PPARγ in macrophage response against LPC was investigated. Through Western blot and immunofluorescence confocal microscopy we demonstrated that schistosomal-derived LPC induces increased expression of PPARγ in macrophages. The LPC-induced increased expression of arginase-1 were significantly inhibited by the PPAR-γ antagonist GW9662. Together, these results demonstrate an immunomodulatory role of schistosomal-derived LPC in activating macrophages to a profile of the type M2 through PPARγ-dependent mechanisms, indicating a novel pathway for macrophage polarization triggered by parasite-derived LPC with potential implications to disease pathogenesis.

El factor de crecimiento del endotelio vascular hepático en la infección murina por Schistosoma mansoni / The endothelial growth factor vascular infection in murine liver by Schistosoma mansoni

Los antígenos secretados por los huevos de S. mansoni inducen la proliferación de células endoteliales in vivo, así como la producción del Factor de Crecimiento del Endotelio Vascular (VEGF), sugiriendo que la patogénesis en la esquistosomiasis se relaciona con eventos angiogénicos. Se evaluó la expresión del VEGF, como una medida de angiogénesis estimulada por los huevos y los gusanos de S. mansoni, en la infección Bisexual (BIS) y los gusanos adulto (infección UNI) en el hígado de ratones Balb/c, antes y después del tratamiento con PZQ. Los resultados indican que tanto la infección UNI como BIS son capaces de estimular la producción de VEGF en tejido hepático, lo que explica la vascularizacón anómala durante este cuadro infeccioso. Este proceso se acompaña con la presencia de un elevado número de infiltrados leucocitarios en los sitios donde se observa lesión tisular; la producción de VEFG remite tras 48 de tratamiento con PZQ. Estos resultados indican que la producción anómala de VEGF junto con la intensa respuesta pro-inflamatoria asociada no solo a la actividad de VEGF sino también a los infiltrados leucocitarios observados en el tejido hepático, causada tanto por los huevos secretados como por las formas adultas de S. mansoni son los mecanismos que subyacen a las lesiones granulomatosas observadas durante el curso de la esquistosomiasis, pudiendo al menos revertirse el incremento en la vascularización mediante el uso de PZQ.

The antigens secreted by eggs of S. mansoni induce the proliferation of endothelial cells in vivo, as well as the production of Factor Vascular Endothelial Growth factor (VEGF), suggesting that the pathogenesis of schistosomiasis relations with angiogenic events. We evaluated the expression of VEGF, as a measure of angiogenesis stimulated by the eggs and worms S. mansoni in infection bisexual (BIS) and adult worms ( UNI infection ) in the liver of BALB / c mice before and after treatment with PZQ. These results indicate that abnormal production of VEGF with intense pro-inflammatory response not only associated with the activity of VEGF but also leukocyte infiltrates observed in the liver tissue caused by both secreted and eggs by adult forms S. mansoni are the mechanisms underlying granulomatous lesions observed during the course of schistosomiasis, and can be reversed at least the increased vascularization by using PZQ .

Two sequential PCR amplifications for detection of Schistosoma mansoni in stool samples with low parasite load / Duas amplificações sequenciais por PCR para detecção de Schistosoma mansoni em amostras de fezes com baixa carga parasitária

Schistosomiasis constitutes a major public health problem, with an estimated 200 million individuals infected worldwide and 700 million people living in risk areas. In Brazil there are areas of high, medium and low endemicity. Studies have shown that in endemic areas with a low prevalence of Schistosoma infection the sensitivity of parasitological methods is clearly reduced. Consequently diagnosis is often impeded due to the presence of false-negative results. The aim of this study is to present the PCR reamplification (Re-PCR) protocol for the detection of Schistosoma mansoni in samples with low parasite load (with less than 100 eggs per gram (epg) of feces). Three methods were used for the lysis of the envelopes of the S. mansoni eggs and two techniques of DNA extraction were carried out. Extracted DNA was quantified, and the results suggested that the extraction technique, which mixed glass beads with a guanidine isothiocyanate/phenol/chloroform (GT) solution, produced good results. PCR reamplification was conducted and detection sensitivity was found to be five eggs per 500 mg of artificially marked feces. The results achieved using these methods suggest that they are potentially viable for the detection of Schistosoma infection with low parasite load.

A esquistossomose constitui grande problema de saúde pública, sendo que estimativas apontam para 200 milhões de pessoas infectadas no mundo e 700 milhões de pessoas em áreas de risco. No Brasil, existem áreas de alta, média e baixa endemicidade. Estudos demonstram que nas áreas endêmicas de baixa prevalência da infecção, a reduzida sensibilidade dos métodos parasitológicos torna-se evidente. Isto dificulta o diagnóstico, pela presença de resultados falso-negativos. O objetivo deste estudo foi a padronização de um protocolo de reamplificação da PCR (Re-PCR) para a detecção de Schistosoma mansoni em amostras com menos de 100 ovos por grama (opg) de fezes. Foram utilizados três métodos para ruptura dos envoltórios dos ovos de S. mansoni e duas técnicas de extração de DNA foram aplicadas. O DNA extraído foi quantificado e os resultados sugerem que a técnica de extração de melhor produtividade foi a que associa esferas de vidro a uma solução de isotiocianato de guanidina/fenol/clorofórmio (GT). Aplicou-se a Re-PCR, que demonstrou sensibilidade para a detecção de cinco ovos/500 mg de fezes artificialmente marcadas. Assim, essas novas ferramentas são potencialmente aplicáveis nas infecções por S. mansoni com baixa carga parasitária.

Schistosoma mansoni antigens alter the cytokine response in vitro during cutaneous leishmaniasis

Schistosoma mansoni infection or associated products are able to down-modulate the type 1 CD4+ T cell inflammatory response characteristic of autoimmune diseases. In this study, we evaluated how S. mansoni antigens altered the immune response that was induced by the soluble Leishmania antigen (SLA) from cutaneous leishmaniasis (CL) patients. Cytokines were measured from the supernatants of peripheral blood mononuclear cell cultures stimulated with SLA. This was performed using the sandwich enzyme linked immunosorbent assay technique in the presence or absence of S. mansoni recombinant antigens Sm29, SmTSP-2 and PIII. The addition of S. mansoni antigens to the cultures resulted in the reduction of interferon gamma (IFN-γ) levels in 37-50 percent of patients. Although to a lesser extent, the antigens were also able to decrease the production of tumour necrosis factor-alpha (TNF-α). We compared patients that either had or did not have reduction in IFN-γ and TNF-α production in cultures stimulated with SLA in the presence of S. mansoni antigens. We found that there was no significant difference in the levels of interleukin (IL)-10 and IL-5 in response to S. mansoni antigens between the groups. The antigens used in this study down-modulated the in vitro proinflammatory response induced by SLA in a group of CL patients through a currently undefined mechanism.

Genital schistosomiasis mansoni concomitant to genital tumor in areas of low endemicity: challenging diagnosis

Genital infection by Schistosoma mansoni is usually misdiagnosed in individuals who reside in, or travel to endemic areas. We describe two cases of genital tumor associated with S. mansoni infection manifested by methrorragy. Surgical specimens revealed leiomyomas in both cases associated with S. mansoni. In one of them, granulomas were found in the ovary and in the other they were found in the uterine tube. Although none presented intestinal/hepatic disease, fecal egg excretion was detected in one. Both had elevated pretreatment antibody reactivity to S. mansoni antigen, but follow-up showed different outcomes. Schistosomiasis should be considered as a diagnosis in individuals with methrorragy residing in or having traveled to endemic areas. Since diagnosis follows genital amputation, and cure control is troublesome, improvement of diagnostic tools and follow-up markers are important priorities to decrease schistosomiasis morbidity.

Schistosoma mansoni: a rare cause of tubal infection

S. haematobium is an important cause of urinary schistosomiasis, and symptomatic female genital infection is a common gynecological finding in areas where S. haematobium is prevalent. On the other hand, genital manifestations of intestinal schistosomas as S. mansoni are not frequent or are misdiagnosed. A case of a 40-year-old woman with abnormal uterine bleeding and asymptomatic tubal infection by S. mansoni identified in histological examination is presented.

Reappraisal of experimental infections with cercariae and schistosomula of a brazilian strain of Schistosoma mansoni in mice

The present investigation involves a reevaluation of previous results obtained after experimental infection of Swiss Webster mice with cercariae and schistosomula of the Schistosoma mansoni LE strain maintained under laboratory conditions. Three experimental groups of mice were considered: the animals of the first group were percutaneously (ring method) infected with cercariae, those of the second were subcutaneously inoculated with cercariae and the mice of the third were inoculated by the same route with schistosomula transformed in vitro. The data obtained so far indicated that the most effective method of infection is the subcutaneous injection with schistosomula, with a mean adult worm burden recovery of 54.1% when compared to the abdominal percutaneous and subcutaneous routes of infection with cercariae, in which the values were 36.7% and 32.4%, respectively. This suggests that, in experimental infections of SW mice with a LE S. mansoni strain, the skin is to be considered an effective attrition site in the percutaneous route, whereas in the case of inoculation with cercariae, a small amount of larvae fails to be transformed into viable schistosomula, possibly due to skin phase avoidance. A brief discussion about attrition sites and elimination of larval S. mansoni worms in mice is presented.

Os objetivos da presente investigação foram os de reavaliar resultados anteriores obtidos através de infecções experimentais de camundongos SW com cercarias e esquistossômulos da cepa LE de Schistosoma mansoni mantida em laboratório. Três grupos de camundongos foram considerados: animais do primeiro grupo foram infectados com cercarias pela via percutânea (método do anel), os do segundo inoculados pela via subcutânea com cercarias e os do terceiro inoculados pela mesma via com esquistossômulos obtidos "in vitro". Os dados obtidos mostraram que a via de infecção mais eficiente é a injeção subcutânea de esquistossômulos transformados "in vitro", com média de recuperação de vermes adultos de 54.1%, quando comparada às vias percutânea abdominal e subcutânea, com médias de 36,7% e 32,4%, respectivamente, sugerindo que em infecções experimentais de camundongos SW com S. mansoni da cepa LE, a pele pode ser considerada um eficaz sítio de atrito na via percutânea, enquanto no caso da inoculação de cercarias, um pequeno número de larvas não se transforma em esquistossômulos viáveis, talvez pelo fato de a barreira da pele haver sido evitada. Breves considerações a respeito dos sítios de atrito e eliminação de formas larvares do S. mansoni em camundongos, são apresentadas.

Efetividade do Programa de Comunicação e Educação em Saúde no controle da infecção por S. mansoni em algumas areas do Estado da Bahia / The effectiveness of the Program of Communication and Education in Health on the control of S. mansoni infection in some areas of the state of Bahia

O Programa de Controle da Esquistossomose (PCE) vem sendo desenvolvido em áreas da Bahia pela Fundação Nacional de Saúde (FNS). Em 1989, ações de Informação, Educação, Comunicação e Mobilização Comunitária (IEC/MC) foram iniciadas. Neste estudo avalia-se o impacto epidemiológico do IEC/MC, adotando-se um desenho quasi-experimental, comparando-se prevalências de infecção por S. mansoni em áreas IEC/MC com estimativas de áreas referentes. Os dados são secundários, coletados rotineiramente pela FNS. Verificou-se uma redução da prevalência da esquistossomose em todas as áreas, que alcança maior intensidade nas áreas com IEC/MC. Aparentemente, ações de controle rotineiras realizadas isoladamente são mais efetivas entre escolares e pessoas do sexo masculino, enquanto que nas áreas com IEC/MC, observou-se maior impacto entre as mulheres, refletindo, provavelmente, as distintas estratégias adotadas. Aponta-se para a necessidade de estudos de avaliação qualitativos, além de estimativas do custo-benefício e custo-efetividade de modo a aprimorar o processo de tomada de decisões.

The Program for S. mansoni Control (PCE) has been developed in some areas of the State of Bahia by the Fundação Nacional de Saúde (FNS). In 1989, activities on Information, Education, Communication and Community Mobilization (IEC/MC) were initiated. This study evaluates the epidemiological impact of the IEC/MC, using a quasi-experimental study design strategy, comparing the prevalences of infection for S. mansoni in areas of IEC/MC and estimates of other areas. The data used were routinely collected by the local staff of the FNS. A decrease on the prevalence of S. mansoni infection was found in all study areas, specially in those of IEC/MC activities. Findings indicate that PCE activities are more effective among school-age individuals and male adults, although IEC/MC allows for higher epidemiological impact among women, reflecting the differences among the strategies. These findings point out the need for qualitative evaluation research, as well as cost benefit and cost effectiveness analyses, that are more appropriate for decision making processes.