Variation in water contact behaviour and risk of Schistosoma mansoni (re)infection among Ugandan school-aged children in an area with persistent high endemicity.

BACKGROUND: Annual mass drug administration with praziquantel has reduced schistosomiasis transmission in some highly endemic areas, but areas with persistent high endemicity have been identified across sub-Saharan Africa, including Uganda. In these areas many children are rapidly reinfected post treatment, while some children remain uninfected or have low-intensity infections. The aim of this mixed-methods study was to better understand variation in water contact locations, behaviours and infection risk in school-aged children within an area with persistent high endemicity to inform additional control efforts. METHODS: Data were collected in Bugoto, Mayuge District, Uganda. Two risk groups were identified from a longitudinal cohort, and eight children with no/low-intensity infections and eight children with reinfections were recruited. Individual structured day-long observations with a focus on water contact were conducted over two periods in 2018. In all identified water contact sites, four snail surveys were conducted quarterly over 1 year. All observed Biomphalaria snails were collected, counted and monitored in the laboratory for Schistosoma mansoni cercarial shedding for 3 weeks. RESULTS: Children came into contact with water for a range of purposes, either directly at the water sources or by coming into contact with water collected previously. Although some water contact practices were similar between the risk groups, only children with reinfection were observed fetching water for commercial purposes and swimming in water sources; this latter group of children also came into contact with water at a larger variety and number of sites compared to children with no/low-intensity infection. Households with children with no/low-intensity infections collected rainwater more often. Water contact was observed at 10 sites throughout the study, and a total of 9457 Biomphalaria snails were collected from these sites over four sampling periods. Four lake sites had a significantly higher Biomphalaria choanomphala abundance, and reinfected children came into contact with water at these sites more often than children with no/low-intensity infections. While only six snails shed cercariae, four were from sites only contacted by reinfected children. CONCLUSIONS: Children with reinfection have more high-risk water contact behaviours and accessed water sites with higher B. choanomphala abundance, demonstrating that specific water contact behaviours interact with environmental features to explain variation in risk within areas with persistent high endemicity. Targeted behaviour change, vector control and safe water supplies could reduce reinfection in school-aged children in these settings.

Factors Associated with Schistosoma mansoni Infestation in Northeast Brazil: A Need to Revisit Individual and Community Risk Factors.

In Brazil, schistosomiasis continues to be an important health issue. The aim of this study was to identify factors associated with Schistosoma mansoni infestation. A cross-sectional study was performed to assess factors associated with S. mansoni endemicity in a municipality in Northeast Brazil with a history of reporting schistosomiasis. Participants were divided into four groups: 1) new S. mansoni cases (n = 44), 2) past history of S. mansoni treatment (n = 78), 3) immediate neighbors (n = 158), and 4) nearby controls (n = 35). Multiple comparisons analysis was performed. Subjects had a mean of 6.6 ± 3.9 years of education, and no difference was observed regarding family income (one-way analysis of variance, P = 0.215). A total of 95.9% of the individuals had rudimentary cesspit as sanitary wastewater. The mean body mass index was 28.3 ± 5.1, with 41.0% and 24.1% overweight and obesity, respectively. Of note, 28.9% of adults had hypertension. Hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin were higher in the recent S. mansoni treated group (Wilks' lambda, P < 0.001). Male gender was more prevalent in new S. mansoni cases (likelihood ratio, P < 0.001), close proximity to water collections was a risk for S. mansoni infestation (likelihood ratio, P < 0.001), and a better hematological status was observed in individuals recently treated with praziquantel. This study indicates the need to maintain surveillance for S. mansoni in low-transmission areas and the need to establish community-based interventions to control transmission.

Analysis and spatial distribution of schistosomiasis mansoni in a historically endemic area of northeastern Brazil.

OBJECTIVE: To perform a descriptive analysis of the activities of the Schistosomiasis Control Program, as well as the spatial distribution of the condition in the state of Alagoas, Brazil, for the period from 2007 to 2016. METHODS: Descriptive ecological study. Data from positive human cases and operational data were collected in the Information System of the Schistosomiasis Control Program, and data for spatial analysis were collected on the website of the Brazilian Institute of Geography and Statistics. An analysis of spatial autocorrelation (Moran statistics) was performed, where a spatial pattern was established, which showed the Q1 and Q2 patterns to be the most important, and Q3 and Q4 representing transition areas. RESULTS: In the years under study, at least 85% (n = 60/70) of the municipalities carried out the activities recommended by the PCE (Schistosomiasis Control Program). Alagoas presented an average positivity rate of 7.1%, which is very high compared to the prevalence of 3.3% at the last national schistosomiasis survey conducted between 2010 and 2015. Moran's statistics showed 22/70 municipalities forming a Q1 cluster, of high/high pattern, and 32/70 municipalities forming a Q2 cluster, of low/low pattern, with the others in a transition area. Moran Map data, however, showed only 7/70 municipalities in the endemic area with a spatial autocorrelation, with these municipalities having the Mundau River as a common element. CONCLUSION: Schistosomiasis mansoni is of great importance for public health in Alagoas and that the use of spatial analysis can identify priority areas for preventive and control measures against schistosomiasis mansoni.

OBJECTIF: Effectuer une analyse descriptive des activités du programme de lutte contre la schistosomiase, ainsi que la distribution spatiale de la condition dans l'Etat d'Alagoas, au Brésil, pour la période de 2007 à 2016. MÉTHODES: Etude écologique descriptive. Les données sur les cas humains positifs et les données opérationnelles ont été collectées dans le système d'information du programme de lutte contre la schistosomiase et les données pour l'analyse spatiale ont été collectées du site Web de l'Institut brésilien de géographie et des statistiques. Une analyse de l'autocorrélation spatiale (statistiques de Moran) a été réalisée, où un modèle spatial a été établi, qui a montré que les modèles Q1 et Q2 étaient les plus importants, Q3 et Q4 représentant les zones de transition. RÉSULTATS: Au cours de toutes les années étudiées, au moins 85% (n = 60/70) des municipalités ont réalisé les activités recommandées par le PCE (Program de Contrôle de la Schistosomiase). En ce qui concerne le taux de positivité, Alagoas présentait un taux de positivité moyen de 7,1% pour la période étudiée, considéré comme très élevé par rapport aux données de la dernière enquête nationale sur la schistosomiase réalisée entre 2010 et 2015, qui montrait l'état avec une prévalence de 3,3%. Les statistiques de Moran ont montré 22/70 municipalités formant un regroupement Q1, de modèle élevé/élevé, et 32/70 municipalités formant un regroupement Q2, de modèle faible/faible, avec les autres dans une zone de transition. Les données de la carte Moran, cependant, ne montraient que 7/70 municipalités de la zone endémique avec une autocorrélation spatiale, ces municipalités ayant la rivière Mundau comme élément commun. CONCLUSION: Les données présentées ici montrent que la schistosomiase mansonnienne est d'une grande ampleur pour la santé publique à Alagoas et que l'utilisation de l'analyse spatiale peut identifier les domaines prioritaires pour l'adoption de mesures de prévention et de contrôle de la schistosomiase mansonnienne.

Interaction and involvement of cellular adhesion molecules in the pathogenesis of Schistosomiasis mansoni.

Parasites from genus Schistosoma currently infect more than 200 million people worldwide. Infection with Schistosoma mansoni causes intestinal schistosomiasis with geographical distribution across Africa, Middle East, Caribbean, Brazil, Venezuela and Suriname. People with Schistosomiasis mansoni suffer from a chronic disease as result of an exacerbated immune response to the eggs deposited in hepatic tissue. The presence of eggs in the tissue triggers the recruitment and activation of immune cells to wall off and isolate them from the rest of the organism. In this context, immune cells turn activated and increase the expression of cellular adhesion molecules (CAM), such as l-selectin and LFA-1, and DC-SIGN which through interaction with CAM expressed on activated endothelial vessels, help moving leukocytes quickly to the sites of infection (inflammation around the eggs), as a strategy to defend the organism from foreign invaders. Since the vertebrate host is not able to eliminate the foreign invader a granuloma formation take place in the tissue where the eggs are trapped, originating granulomas. Patients and mice with chronic schistosomiasis have increased levels of CAM in their circulation and egg-trapped tissue, which may contribute to the inflammatory process, granuloma formation and pathology aggravation. Here we systematically reviewed the findings raised over the last two decades that addressed the involvement of cellular adhesion molecules in the intestinal and hepatic inflammatory response and liver granuloma formation during Schistosomiasis mansoni. This review intends to contribute to the understanding of Schistosomiasis mansoni pathogenesis by discussing alterations and interactions in cellular adhesion molecules during the disease.

Co-infection of Schistosoma mansoni/hepatitis C virus and their associated factors among adult individuals living in fishing villages, north-western Tanzania.

BACKGROUND: Schistosoma mansoni and Hepatitis C virus (HCV) are co-existence in sub-Saharan Africa and co-infection is common among humans population. The immunological responses characterized with Th2-immune responses for S. mansoni and Th1-immune responses for HCV are responsible for development hepatic morbidities in infected individuals. However, the co-occurrences of S. mansoni and HCV infection, their related ultrasound detectable morbidities and associated risk factors at community levels have not been examined in fishing communities, north-western Tanzania. In this context, the present study covers that gap. METHODS: A cross-sectional study was conducted among 1924 asymptomatic individuals aged 15-55 years in four fishing villages (Igombe, Igalagala, Sangabuye and Kayenze) of Northwestern Tanzania. A single stool sample was collected from each study participants and examined for S. mansoni eggs using Kato Katz technique. Hepatitis C surface antigen (HCVsAg) was determined from a finger prick blood sample using a rapid test. RESULTS: Overall, 51.8% (997/1924; 95%CI: 49.6-54.1) of the study participants were infected with S. mansoni and had a mean intensity of 223.7epg (95%; 202.4-247.1). Of the study participants, 90 (4.7%) were infected with hepatitis C virus (HCV). Overall, 2. 4% (47/1924) of the study participants were co-infected with S. mansoni and hepatitis C virus. Among the co-infected individuals, 42.6%, 70.2% and 19.1% had splenomegaly, hepatomegaly and periportal fibrosis (PPF). Factors associated with S. mansoni/HCV co-infection were being aged 26-35 years (aRR = 2.67, 95%CI: 1.03-6.93, P < 0.04), 46-55 years (aRR = 2.89, 95%CI: 1.10-7.57, P < 0.03) and having marked hepatomegaly (aRR = 2.32, 95%CI: 1.09-4.9, P < 0.03). CONCLUSION: In this setting, S. mansoni and Hepatitis C are co-endemic and a proportion of individuals were co-infected. Hepatosplenic morbidities characterized with hepatomegaly, splenomegaly, hepatosplenomegaly and PPF were observed in co-infected individuals. These results highlight the need for integrated interventions measures against parasitic and viral diseases.

Assessment of the impact of changes in temperature in Biomphalaria glabrata (Say, 1818) melanic and albino variants infected with Schistosoma mansoni (Sambon, 1907) / Avaliação de impacto de alterações na temperatura em Biomphalaria glabrata variantes melânica e albina infectadas com Schistosoma mansoni

Abstract Fluctuations in population density of planorbid hosts of S. mansoni are influenced by climatic factors. The knowledge about interference from changes in water temperature in these populations is an important aspect of the epidemiology of schistosomiasis. In this experiment, it is explored the influence of different temperatures on the development of Schistosoma mansoni in Biomphalaria glabrata melanic and albino variants. The results indicated an intrinsic relationship between temperature and development of the parasite in the intramollusc phase, independent of the pigmentation of the mantle of the molluscs. The higher the temperature, the shorter the period necessary for the development of the parasite was while the higher the mortality of infected mollusks. It is concluded that, in the presence of climate change, the increasement of temperature in cold and flooded regions may encourage the establishment of new foci of transmission of schistosomiasis by changing the geographic extent and extending the epidemiological transmission potential. In warm climates, higher temperatures, however, could compromise the transmission of the disease because of biological stress suffered by parasite and host. Under these conditions, it can result in the death of the parasite or a change in their ability to infect new host species of molluscs in new areas. Mantle pigmentation patterns in molluscs have not shown significant interference in the development of the parasite.

Resumo Flutuações na densidade populacional de planorbídeos hospedeiros do S. mansoni são influenciadas por fatores climáticos. O conhecimento sobre a interferência de alterações na temperatura da água nestas populações é um aspecto importante da epidemiologia da esquistossomose. Neste experimento avaliou-se a influência de diferentes temperaturas no desenvolvimento de Schistosoma mansoni em Biomphalaria glabrata variantes melânica e albina. Os resultados indicaram uma relação intrínseca entre temperatura e desenvolvimento do parasito na fase intramolusco, independente da pigmentação do manto dos moluscos. Quanto mais elevada a temperatura, menor o período necessário para desenvolvimento do parasito e maior mortalidade dos moluscos infectados. Conclui-se que, na presença de alterações climáticas, o aumento da temperatura em regiões frias e alagadas poderá favorecer o estabelecimento de novos focos de transmissão da esquistossomose alterando a extensão geográfica e ampliando o potencial epidemiológico da transmissão. Em regiões de clima quente, o aumento da temperatura, por sua vez, poderá comprometer a transmissão da doença em virtude do estresse biológico sofrido por parasito e hospedeiro. Nestas condições, poderá ocorrer a morte do parasito ou uma alteração na sua habilidade de infectar novas espécies de moluscos hospedeiros em novas áreas. Padrões de pigmentação do manto nos moluscos não demonstraram interferência significativa no desenvolvimento do parasita.

Susceptibility of Biomphalaria glabrata submitted to concomitant infection with Angiostrongylus costaricensis and Schistosoma mansoni / Suscetibilidade de Biomphalaria glabrata submetida à infecção concomitante com Angiostrongylus costaricensis e Schistosoma mansoni

Abstract The easy adaptation of Angiostrongylus costaricensis, nematode responsible for abdominal angiostrongyliasis to several species of terrestrial and freshwater molluscs and the differences observed in the interactions of trematodes with their intermediate hosts have induced us to study the concomitant infection of Biomphalaria glabrata with Schistosoma mansoni and A. costaricensis. Prior exposure of B. glabrata to A. costaricensis (with an interval of 48 hours), favored the development of S. mansoni, observing higher infection rate, increased release of cercariae and increased survival of molluscs, when compared to molluscs exposed only to S. mansoni. Prior exposure of B. glabrata to A. costaricensis and then to S. mansoni also enabled the development of A. costaricensis since in the ninth week of infection, higher amount of A. costaricensis L3 larvae was recovered (12 larvae / mollusc) while for molluscs exposed only to A. costaricensis, the number of larvae recovered was lower (8 larvae / mollusc). However, pre-exposure of B. glabrata to S. mansoni (with an interval of 24 hours), and subsequently exposure to A. costaricensis proved to be very harmful to B. glabrata, causing extensive mortality of molluscs, reduced pre-patent period to release cercariae and greater recovery of L3 A. costaricensis larvae.

Resumo A facilidade de adaptação do Angiostrongylus costaricensis, nematódeo responsável pela angiostrongiliase abdominal, a diversas espécies de moluscos terrestres e dulciaquícolas e as divergências observadas nas interações dos trematódeos com seus hospedeiros intermediários nos induziu a estudar a infecção concomitante de Biomphalaria glabrata com Schistosoma mansoni e A. costaricensis. A exposição prévia de B. glabrata ao A. costaricensis (com intervalo de 48 horas), favoreceu o desenvolvimento do S. mansoni observando-se elevação da taxa de infecção, maior liberação de cercárias e maior sobrevivência dos moluscos, quando comparado com os moluscos expostos somente ao S. mansoni. A exposição de B. glabrata previamente ao A. costaricensis e posteriormente ao S. mansoni também facilitou o desenvolvimento do A. costaricensis uma vez que na nona semana de infecção foi recuperada maior quantidade de larvas L3 de A. costaricensis, enquanto nos moluscos expostos somente ao A. costaricensis, o número de larvas recuperadas foi menor . Entretanto a pré-exposição de B. glabrata ao S. mansoni (com intervalo de 24 horas), e posteriormente a exposição ao A. costaricensis mostrou-se muito prejudicial à B. glabrata provocando grande mortalidade dos moluscos, redução do período pré-patente para liberação de cercárias e maior recuperação de larvas L3 de A. costaricensis.

Susceptibility of Biomphalaria glabrata submitted to concomitant infection with Angiostrongylus costaricensis and Schistosoma mansoni.

The easy adaptation of Angiostrongylus costaricensis, nematode responsible for abdominal angiostrongyliasis to several species of terrestrial and freshwater molluscs and the differences observed in the interactions of trematodes with their intermediate hosts have induced us to study the concomitant infection of Biomphalaria glabrata with Schistosoma mansoni and A. costaricensis. Prior exposure of B. glabrata to A. costaricensis (with an interval of 48 hours), favored the development of S. mansoni, observing higher infection rate, increased release of cercariae and increased survival of molluscs, when compared to molluscs exposed only to S. mansoni. Prior exposure of B. glabrata to A. costaricensis and then to S. mansoni also enabled the development of A. costaricensis since in the ninth week of infection, higher amount of A. costaricensis L3 larvae was recovered (12 larvae / mollusc) while for molluscs exposed only to A. costaricensis, the number of larvae recovered was lower (8 larvae / mollusc). However, pre-exposure of B. glabrata to S. mansoni (with an interval of 24 hours), and subsequently exposure to A. costaricensis proved to be very harmful to B. glabrata, causing extensive mortality of molluscs, reduced pre-patent period to release cercariae and greater recovery of L3 A. costaricensis larvae.

Assessment of the impact of changes in temperature in Biomphalaria glabrata (Say, 1818) melanic and albino variants infected with Schistosoma mansoni (Sambon, 1907).

Fluctuations in population density of planorbid hosts of S. mansoni are influenced by climatic factors. The knowledge about interference from changes in water temperature in these populations is an important aspect of the epidemiology of schistosomiasis. In this experiment, it is explored the influence of different temperatures on the development of Schistosoma mansoni in Biomphalaria glabrata melanic and albino variants. The results indicated an intrinsic relationship between temperature and development of the parasite in the intramollusc phase, independent of the pigmentation of the mantle of the molluscs. The higher the temperature, the shorter the period necessary for the development of the parasite was while the higher the mortality of infected mollusks. It is concluded that, in the presence of climate change, the increasement of temperature in cold and flooded regions may encourage the establishment of new foci of transmission of schistosomiasis by changing the geographic extent and extending the epidemiological transmission potential. In warm climates, higher temperatures, however, could compromise the transmission of the disease because of biological stress suffered by parasite and host. Under these conditions, it can result in the death of the parasite or a change in their ability to infect new host species of molluscs in new areas. Mantle pigmentation patterns in molluscs have not shown significant interference in the development of the parasite.

Cutaneous ectopic schistosomiasis: diagnostic challenge.

Cutaneous schistosomiasis is a rare clinical manifestation of schistosomiasis, an infectious and parasitic disease, caused in Brazil by the trematode Schistosoma mansoni. The lesions are due to the deposition of eggs or, rarely, adult worms, usually involving the genital and groin areas. Extra-genital lesions occur mainly on the torso as papules of zosteriform appearance. The case of a patient with ectopic cutaneous schistosomiasis is reported in this article, due to the rarity of its occurrence and its difficult clinical diagnosis.

Cutaneous ectopic schistosomiasis: diagnostic challenge

Abstract Cutaneous schistosomiasis is a rare clinical manifestation of schistosomiasis, an infectious and parasitic disease, caused in Brazil by the trematode Schistosoma mansoni. The lesions are due to the deposition of eggs or, rarely, adult worms, usually involving the genital and groin areas. Extra-genital lesions occur mainly on the torso as papules of zosteriform appearance. The case of a patient with ectopic cutaneous schistosomiasis is reported in this article, due to the rarity of its occurrence and its difficult clinical diagnosis.

Bayesian risk mapping and model-based estimation of Schistosoma haematobium-Schistosoma mansoni co-distribution in Côte d'Ivoire.

BACKGROUND: Schistosoma haematobium and Schistosoma mansoni are blood flukes that cause urogenital and intestinal schistosomiasis, respectively. In Côte d'Ivoire, both species are endemic and control efforts are being scaled up. Accurate knowledge of the geographical distribution, including delineation of high-risk areas, is a central feature for spatial targeting of interventions. Thus far, model-based predictive risk mapping of schistosomiasis has relied on historical data of separate parasite species. METHODOLOGY: We analyzed data pertaining to Schistosoma infection among school-aged children obtained from a national, cross-sectional survey conducted between November 2011 and February 2012. More than 5,000 children in 92 schools across Côte d'Ivoire participated. Bayesian geostatistical multinomial models were developed to assess infection risk, including S. haematobium-S. mansoni co-infection. The predicted risk of schistosomiasis was utilized to estimate the number of children that need preventive chemotherapy with praziquantel according to World Health Organization guidelines. PRINCIPAL FINDINGS: We estimated that 8.9% of school-aged children in Côte d'Ivoire are affected by schistosomiasis; 5.3% with S. haematobium and 3.8% with S. mansoni. Approximately 2 million annualized praziquantel treatments would be required for preventive chemotherapy at health districts level. The distinct spatial patterns of S. haematobium and S. mansoni imply that co-infection is of little importance across the country. CONCLUSIONS/SIGNIFICANCE: We provide a comprehensive analysis of the spatial distribution of schistosomiasis risk among school-aged children in Côte d'Ivoire and a strong empirical basis for a rational targeting of control interventions.

High prevalence of Schistosoma mansoni in six health areas of - Kasansa health zone, Democratic Republic of the Congo: short report.

School-aged children suffer the most from schistosomiasis infection in sub Saharan Africa due to poverty and limited sanitary conditions. Mapping of disease burden is recommended and there is a need of updating prevalence data which is as old as 20 years in the Democratic Republic of Congo. An epidemiological and parasitological study was carried out in 2011 in the health zone of Kasansa. Six health areas (HA) were included in the study. In each health area, one primary school was selected. School-aged children were screened for S. mansoni infection using parallel Kato-Katz and direct microscopy techniques. A total of 335 school-aged children were screened. The average prevalence was 82.7% and ranged between 59.5-94.9%. Four of the six HAs had a prevalence level over 91%. Of all infected children, about half 112 (43.2%) had light parasite density. These results demonstrate that Schistosoma mansoni infection is a bigger problem than anticipated and there is an urgent need to implement effective control measures.

TGF beta and IL13 in Schistosomiasis mansoni associated pulmonary arterial hypertension; a descriptive study with comparative groups.

BACKGROUND: It is suggested that interleukin (IL)-13 and transforming growth factor (TGF)-beta play a role in the pulmonary vascular changes found in animal models of schistosomiasis. The aim of this study was to assess and compare the serum levels of total TGF-beta and IL-13 of patients with schistosomiasis with pulmonary arterial hypertension (PAH) and patients with schistosomiasis without PAH. METHODS: 34 patients from the schistosomiasis outpatient clinic of the Hospital das Clinicas, Recife, Pernambuco, Brazil, without PAH assessed by echocardiography and 34 patients from the Reference Centre of Pulmonary Hypertension of Pronto Socorro Cardiológico de Pernambuco, Recife, Brazil with PAH, confirmed by right heart catheterization, were enrolled on the study. Both groups presented with schistosomal periportal fibrosis after abdominal ultrasound. Serum levels of TGF-beta1 and IL-13 were determined by ELISA. Student t test to independent samples, Mann-Whitney test to nonparametric variables, Pearson correlation test for correlation analyses and Fisher Chi-squared test to compare categorical analyses were used. RESULTS: The median value of TGF-beta1 was significantly higher in patients with PAH (22496.9 pg/ml, interquartile range [IR] 15936.7 - 32087.8) than in patients without PAH (13629.9 pg/ml, IR: 10192.2- 22193.8) (p = 0.006). There was no difference in the median value of IL-13 in the group with Sch-PAH compared to patients without Sch-PAH (p > 0.05). CONCLUSION: Our results suggest that TGF-beta possibly plays a role in the pathogenesis of schistosomiasis-associated PAH.

Epidemiology of schistosomiasis in two high-risk communities of south Cote d'Ivoire with particular emphasis on pre-school-aged children.

Schistosomiasis control efforts mainly target school-aged children. We studied the epidemiology of schistosomiasis in two high-risk communities in south Côte d'Ivoire, placing particular emphasis on pre-school-aged children. We used a suite of diagnostic techniques, including Kato-Katz, urine filtration, reagent strips, and urine circulating cathodic antigen cassettes. Risk factors for schistosomiasis were determined by focus group discussions and a structured questionnaire. The prevalence of Schistosoma mansoni in the two study villages among the pre-school-aged children (age < 6 years) was 20.9% and 25.0%, whereas several-fold higher prevalences were found in school-aged children (58.7-68.4%) and adolescents/adults (59.5-61.7%). The prevalence of S. haematobium in the three age groups was 5.9-17.3%, 10.9-18.4%, and 3.8-21.3%, respectively. Most participants had light-intensity infections. Mothers' occupations and older siblings play important roles in the epidemiology of schistosomiasis in pre-schoolers. In the current epidemiologic settings, more attention is warranted on pre-school-aged children and adolescents/adults for successful schistosomiasis control.

Schistosoma mansoni infection among prenatal attendees at a secondary-care hospital in central Sudan.

OBJECTIVE: To investigate the epidemiology of Schistosoma mansoni infection among pregnant women in a secondary-care hospital in Geizera state, Sudan. METHOD: Between August and September 2010, a cross-sectional study was conducted and questionnaires were administered to obtain basic sociodemographic and obstetric characteristics of pregnant women attending prenatal care at Araba Waeshreen Hospital. Stool samples were investigated for helminth infection via formol-ether concentration and Kato-Katz techniques. RESULTS: Of 292 pregnant women, 38 (13.0%) had S. mansoni infections. Hymenolepis nana and hookworm infections were present in 5 (1.7%) and 1 (0.3%) women, respectively. The intensity of the S. mansoni infection was light, moderate, and high in 13 (34.2%), 21 (55.3%), and 4 (10.5%) women, respectively. In multivariate analyses, parity, gestational age, and occupation were not associated with S. mansoni infection, unlike maternal age less than 20 years (odds ratio [OR] 9.8; 95% confidence interval [CI], 1.5-16.3; P=0.01) and no education (OR 6.2; 95% CI, 2.8-12.9; P<0.001). CONCLUSION: There was a high level of S. mansoni infection among pregnant women in the present setting, especially among younger women and those with no education. Control and preventive measures should be used in the area.

Esquistossomose mansônica: aspectos gerais, imunologia, patogênese e história natural: [revisão] / Schistosomiasis mansoni: general aspects, immunology, pathogenesis and natural history: [review]

JUSTIFICATIVA E OBJETIVOS: A esquistossomose mansônica ainda hoje é um grave problema de saúde pública no país. Sua patogênese é dependente da interação do parasita e do hospedeiro podendo acometer diferentes órgãos e sistemas. O objetivo deste estudo foi trazer ao leitor uma visão geral da etiologia e da patogênese da esquistossomose, seus aspectos patológicos, determinantes de maior importância para seu desenvolvimento e manifestações clínicas. Foram utilizadas as palavras esquistossomose mansônica, etiologia, imunologia, patogênese e história natural como descritores na pesquisa de dados nas bases Scielo (Scientific Eletronic Library Online) e Pubmed (U. S. National Library of Medicine), assim como livros-texto relacionados ao tema. CONTEÚDO: O S. mansoni, apresenta alguns mecanismos de "escape" contra o sistema imunológico do hospedeiro dentre os quais alterações morfológicas e bioquímicas. Um dos eventos patogênicos mais importantes na esquistossomose é a formação do granuloma hepático e a fibrose hepática peri-portal. A formação dos granulomas em diferentes órgãos explica as manifestações da doença, como a hipertensão porta, a forma pseudotumoral, aneurológica e vásculo-pulmonar. CONCLUSÃO: A esquistossomose aguda é representada por manifestações pruriginosas na pele, de duração geralmente transitória e cedendo quase sempre espontaneamente. Em relação à sua fase crônica, pode se apresentar de maneira polimórfica, sendo a forma hepatointestinal a mais frequentemente observada,representando a fase intermediária na evolução da doença para aforma hepatoesplênica.

BAC KGROUND AND OBJECTIVES: The schistosomiasis mansoni is still regarded today as a grave public health problem for this country. Its pathogenesis is dependable on the host parasite interaction making it possible to affect different organs and systems. The aim of this article is to bring to the reader a general view of the etiology and pathogenesis of schistosomiasis,its pathological aspects, determinant and of major importance for its development and clinical manifestations. There have beenused the words schistosomiasis mansoni, etiology, immunology, pathogenesis and natural history as descriptions for the data researchon these databases: Scielo (Scientific Electronic Library Online) and Pubmed (U. S. National Library of Medicine), as much as textbooks related to the theme. CONTENTS : The Schistosoma mansoni presents some evasion mechanisms against the host's immunological system including morphological and biochemical modifications. One of the most important pathogenical events on the schistosomiasis is the formation of hepatic granuloma and periportal hepatic fibrosis.The formations of granulomas on different organs explain the manifestations of the disease, such as the portal hypertension,the pseudotumoral form, and the neurological and vascular lung forms. CONCLUSION: The acute schistosomiasis is represented by prickly skin manifestations, of generally transitory duration. They almost always give away spontaneously. In relation with its chronic phase this can present itself on a polymorphic manner.The hepatointestinal is the most frequently observed, representing the intermediate phase on the disease evolution towards the hepatosplenic form.

Evaluation of the role of angiogenic factors in the pathogenesis of schistosomiasis.

Schistosomiasis is one disease produced by helminths, which affect many people in tropical areas. Granuloma formation is the main mechanism involved in the pathogenesis of this disease. Experimental studies have demonstrated angiogenesis (blood vessels formation from pre-existing vessels) in the initial phase of granuloma formation. In the present work, VEGF (vascular endothelial growth factor) levels were analyzed in sera from people diagnosed with different helminthic infections. Patients with schistosomiasis and filariasis had significantly high VEGF levels in compared with healthy people and patients diagnosed with hookworms. In addition, the effects of angiogenesis inhibition using anti-angiogenic factors (endostatin) were evaluated in a schistosomiasis murine model. A lesion decrease was observed in mice infected with Schistosoma mansoni and treated with endostatin. Finally, mechanisms of angiogenesis induction were studied and observed that cercariae antigens stimulated the angiogenic factors by host alveolar macrophages.

[Relation between Shistosoma mansoni and hepatosplenomegalies]. / Relation entre Schistosoma mansoni et hépatosplénomégalies à Madagascar.

INTRODUCTION: Although they remain a neglected transmissible disease, affecting mainly people in poor countries, the combined forms of schistosomiasis are second only to malaria as a major parasitic disease. Although both urinary and intestinal schistosomiasis are endemic in Madagascar, this study focuses only on the intestinal forms. The symptoms may remain unnoticed or be ignored, for the seriousness of intestinal schistosomiasis is due mainly to its hepatosplenic complications. OBJECTIVES: To estimate the etiological fraction of Schistosoma mansoni involved in hepatomegaly (HM), splenomegaly (SM) and hepatosplenomegaly (HSM), with or without signs of portal hypertension (PHT). METHODS: This file-based retrospective study includes patients admitted to the University Hospital of Antananarivo, Madagascar, between January 2005 and July 2008, who presented with HM, SM, HSM and/or PHT. The case was attributed to schistosomiasis if blood serology, tested with ELISA, was positive for this parasite. The statistical analysis used three approaches: a cross-sectional approach, a longitudinal approach (retrospective cohort), and a "case-control" approach. RESULTS: Of 7308 admissions during this period, 269 (4%) were diagnosed with a hepatosplenic complication and were retained. The average age (+/- standard deviation) was 47.8 (+/- 16.4) years. HM accounted for 55.4% of cases, SM 18.9%, HTP 18.6% and HSM 18.6%. Serology was positive for schistosomiasis in 21.6% of cases. The sex ratio (men:women) for these cases was 1.9, and 67.3% of the patients were aged 30 years or older. The main schistosomiasis complications were SM (n=22) and HTP (n=22). The age group most affected depended on the specific complication: for HM, 28.6% of patients were aged between 40 and 49 years; for HSM, 57.1% were aged between 30 and 40 years. The prevalence of SM was lower in subjects between 50 and 59 years of age (4.5%) than the other complications. Patients with positive serology results were significantly younger than those with negative results, or whose serology was not checked (37.8 years vs. 50.5 years, p < 0.001). Stratification according to complication showed that the etiological fraction of schistosomiasis was 76% for patients with SM, 79% for HTP, 58% for HSM and 4.9% for HM. The retrospective cohort and the case-control analyses both showed that a history of dysentery and frequent contact with water were the main factors associated with complicated schistosomiasis. It is important to note that urban and rural residents had the same risk of developing schistosomiasis with complications (OR: 0.9 [0.4; 1.9]). CONCLUSION: This study showed that schistosomiasis infection is strongly associated with hepatosplenic pathologies. One of the shortcomings of the study is the absence of any analysis of the course and outcome in the study patients. Nevertheless, the course of oesophageal varices, SM or HSM in patients with HTP indicates that schistosomiasis was often fatal.