Schistosomiasis Endemic Areas Research Articles

IgM and IgG Antibody Enzyme Linked Immunosorbent Assay Profile Detected Using Adult Schistosoma guineensis Extract In Sera from Cameroonian Infected by Schistosoma mansoni, Schistosoma haematobium and Schistosoma guineensis

Schistosomiasis is endemic in Cameroon with three Schistosoma species infecting human in many areas. Data from many countries endemic for S.mansoni, S.haematobium and S.japonicum reported an age-dependent antibody response profile using homologous adult schistosome antigen extract. Less is known about the antibody profile in schistosomiasis endemic areas in Cameroon. This study aimed to assess the IgM and IgG antibody profiles using adult S.guineensis extract in immune sera from Schistosoma egg positive Cameroonians from intestinal or urinary schistosomiasis endemic areas. Whole adult S.guineensis antigen was extracted from a Cameroonian S.guineensis strain maintained in laboratory. The antigen extract was a supernatant obtained after centrifugation of grinded freeze-thawed 45 days old worms in enzyme inhibitor solution. Sera were obtained from residents of schistosomiasis endemic areas with microscopically confirmed monospecific infection by S.guineensis, S.mansoni or S.haematobium and Schistosoma free control sera from non endemic area. IgM and IgG antibody titers detection was proceeded by indirect ELISA using HRP-conjugated secondary IgM or IgG antibody. Optical densities (OD) were recorded with a spectrophotometer plate reader at 495 nm and mean OD were statistically analyzed according to age using Student t-test and egg load using ANOVA test. A total of 189 sera were tested. Sera from S.haematobium, S.mansoni and S.guineensis infections represented 68, 73 and 46 respectively. Of S.mansoni infection sera, 31 were collected at Lagdo and 42 in S.mansoni monospecific focus. Age had no significant influence on mean IgM and IgG antibodies OD although mean IgM and IgG changed with age. Mean IgG antibody increased with age in the three schistosomiasis sera. According to age, mean IgM decreased in S.guineensis infections sera, decreased from young to participants aged 15 to 24 years then increased in older in schistosomiasis mansoni sera. In schistosomiasis haematobium sera, mean IgM increased from young to participants aged 15 to 24 years then decreased in older. Egg load influenced significantly mean IgM and IgG titers. Mean IgM OD decreased with egg load in each of the schistosomiasis whereas mean IgG decreased in intestinal schistosomiasis sera. Mean IgM and IgG antibody titers detected with adult S.guineensis extract using ELISA technique in either intestinal or urinary schistosomiasis endemic areas in Cameroon were not age dependent but egg load depended on egg load in urine and stool samples. Diagnostic performance of the adult S.guineensis extract in antibody detection has been tested.

Role of ecological approaches to eliminating schistosomiasis in Eryuan County evaluated by system modelling

BackgroundSchistosomiasis was severely prevalent in Yunnan Province, and it is difficult to achieve its elimination by convention approaches due to complexity of the nature. We explored the comprehensive model to eliminate schistosomiasis in Eryuan County, Yunnan Province, the People’s Republic of China, through integration with the ecological protection programme in Erhai Lake, in order to promote an efficient elimination strategy. We expected that this model is able to be tailored to other local settings, which help achieve the goal of precisely eliminating the disease in Yunnan Province.MethodsEryuan County of Yunnan Province was chosen as the study area, where the data on environmental protection activities in Erhai Lake and on the schistosomiasis control programme were collected through different departments of Erhai County government since 2015. System modelling was performed using system dynamics software to establish a simulation model in order to evaluate the effectiveness of intervention activities.ResultsEcological approaches to control schistosomiasis in Eryuan County consist of three major components: (i) implementing precise interventions to stop schistosomiasis transmission by means of controlling the source of infection, blocking the biological transmission chains and cutting off the route of disease transmission; (ii) employing ecological approaches to improve the co-effectiveness of environmental protection and schistosomiasis prevention in the study area; and (iii) strengthening the professional skills of personnel involving in the schistosomiasis control programme. Simulation results showed that this strategy could speed up the progress of schistosomiasis control programme moving from the control stage to the elimination stage.ConclusionsEcological approaches implemented in schistosomiasis endemic areas of the Eryuan region are able to improve the co-effectiveness of environmental protection and schistosomiasis control, providing a new avenue for eliminating schistosomiasis thanks to the application of precise interventions.

Endemic status of schistosomiasis in People's Republic of China in 2017

This report presents the endemic status of schistosomiasis in the People's Republic of China at national level in 2017, and analyzes the data collected from the national schistosomiasis prevention and control system and 457 national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) being endemic of schistosomiasis japonica in P. R. China, 5 provinces (municipality and autonomous region), i.e., Shanghai, Zhejiang, Fujian, Guangdong and Guangxi, continued to consolidate the status of elimination of schistosomiasis. Sichuan Province achieved the transmission interruption and 6 provinces of Yunnan, Jiangsu, Hubei, Anhui, Jiangxi and Hunan kept the transmission control by the end of 2017. There were 450 endemic counties (cities, districts) covering 259 million people, specifically including 28 544 endemic villages of 70 324.5 thousand people at risk. Among the 450 endemic counties (cities, districts), 47.78% (215/450), 34.00% (153/450) and 18.22% (82/450) reached the criteria of elimination, transmission interruption and transmission control, respectively. By the end of 2017, a total of 8 401 113 individuals received schistosomiasis examinations and 14 individuals were parasitologically diagnosed, decreased by 97.67% compared with 600 cases in 2016. It was estimated of 37 601 cases of schistosome infection, decreased by 30.95% compared with 54 454 cases in 2016. One acute schistosomiasis case was reported in 2017. There were 29 407 advanced schistosomiasis cases documented in 2017. Oncomelania hupensis snail surveys were performed in 19 784 endemic villages and O. hupensis snails were found in 7 310 villages, accounting for 36.95% of total villages, with 19 newly detected villages with snails.The snail survey covered an area of 622454.49 hm2 and snails were found in an area of 172501.56 hm2, including a newly detected area of 208.54 hm2. No schistosome-infected snails were found in 2017. A total of 737 016 bovines were raised in the schistosomiasis endemic areas. Of them, 454 830 bovines received the examinations for schistosome infection, and 1 bovine was stool examination positive. There were 119 326 schistosomiasis cases receiving chemotherapy in 2017, with 1 973 968 individuals undergoing expanded chemotherapy; one bovine with schistosomiasis receiving chemotherapy, with 418 925 bovines undergoing expanded chemotherapy. A total of 144 605.31 hm2 area with snail was controlled by using molluscicides, with actual molluscicide-treated area of 73 755.37 hm2; and 5 002.92 hm2 area with snail was treated by environmental modification. Based on the data from the 457 national schistosomiasis surveillance sites, the mean Schistosoma japonicum infection rate was 0.001 6% and 0 in humans and bovines, respectively. No schistosome-infected snails were found by microscopic examinations in all the surveillance sites, and 7 snail samples with schistosome nucleic acid positive were detected by loopmediated isothermal amplification (LAMP) among 6 surveillance sites. The results demonstrate a continuous decline trend on the endemic situation of schistosomiasis in P. R. China. However, the risk of epidemic rebound still exists in some regions and it is still a challenge to achieve the target set by the Thirteenth Five-Year National Plan for Schistosomiasis Control in 2020.

Antibody responses to Schistosoma mansoni schistosomula antigens.

SummaryWhile antigens from Schistosoma schistosomula have been suggested as potential vaccine candidates, the association between antibody responses with schistosomula antigens and infection intensity at reinfection is not well known. Schistosoma mansoni‐infected individuals were recruited from a schistosomiasis endemic area in Uganda (n = 372), treated with 40 mg/kg praziquantel (PZQ) and followed up at five weeks and at one year post‐treatment. Pre‐treatment and five weeks post‐treatment immunoglobulin (Ig) E, IgG1 and IgG4 levels against recombinant schistosomula antigens rSmKK7, rSmLy6A, rSmLy6B and rSmTSP7 were measured using ELISA. Factors associated with detectable pre‐treatment or post‐treatment antibody response against the schistosomula antigens and the association between five‐week antibody responses and one year post‐treatment reinfection intensity among antibody responders were examined. Being male was associated with higher pre‐treatment IgG1 to rSmKK7, rSmLy6a and AWA. Five weeks post‐treatment antibody responses against schistosomula antigens were not associated with one year post‐treatment reinfection intensity among antibody responders’ antibody levels against rSmKK7, rSmLy6B and rSmTSP7 dropped, but increased against rSmLy6A, AWA and SEA at five weeks post‐treatment among antibody responders. S. mansoni‐infected individuals exhibit detectable antibody responses to schistosomula antigens that are affected by treatment. These findings indicate that schistosomula antigens induce highly varied antibody responses and could have implications for vaccine development.

Schistosomiasis: Snail-vector control, molecular modelling and dynamic studies of bioactive N-acetylglycoside saponins from Tetrapleura tetraptera

Schistosomiasis, a chronic neglected tropical disease caused by the Schistosoma spp. parasite, is associated with disabling patient symptoms. The new focus of the WHO roadmap on 'transmission control, wherever possible’ offers drug development opportunities for intermediate-host control to prevent human-to-snail-to-human parasite transmission. Reports on the analysis of the impact of ‘chemical-based mollusciciding’ have concluded that constant application of molluscicides may contribute significantly towards the elimination of schistosomiasis in endemic areas. In South-Western Nigeria, Tetrapleura tetraptera is a tree whose fruit has been widely used in snail vector control. The presence of molluscicidal N-acetyl triterpene glycosides in the fruit has been reported. In this study, a bioactivity-directed fractionation of the fruit extract was performed to isolate the most potent molluscicidal saponin from the fruit. In an attempt to provide mechanistic insight into the observed activity, in silico screening was performed, profiling the molluscicidal N-acetyl triterpene glycosides reported from the fruit against two potential therapeutic targets in the mollusk used, NADH-ubiquinone oxidoreductase (NAD1) and retinoid X receptor. The docking predicted binary complexes of the saponins, which were subjected to explicit solvent conformational sampling from which patterns of structural stability were obtained. The binding energies alone did not account for the potency of the saponins indicating the influence of other factor like pharmacokinetic parameters. The study concluded that there is a preferential suitability of ND1’s MWFE site for the rational design and development of novel molluscicidal agents.

Trematodosis pada Sapi dan Kerbau di Wilayah Endemik Schistosomiasis di Provinsi Sulawesi Tengah, Indonesia

Cattle and buffaloes have economic value as a source of protein and draught power. The people of Sulawesi also use buffalo in various custom and religious activities. Infections by Trematodes may disrupt livestock productivity. In Indonesia, endemic Schistosomiasis can only be found in Central Sulawesi, Indonesia (Lindu, Napu, and Bada Valleys). There is no data on the status of Trematode infection in cattle and buffalo animals in the area. The study was conducted using a cross-sectional design to measure the prevalence of Trematodosis in cattle and buffalo around the endemic areas of Schistosomiasis in July-November 2016. A total of 261 stool samples consisting of 173 cattle and 88 buffaloes from 7 villages (Anca, Bewa, Mount Gintu, Sedoa, Wangga, Watumaeta, and Wuasa Villages) were collected and stored at 2-8 °C until further analysis. The Danish Bilharziasis Laboratory method was chosen to quantify the infection by trematodes. The prevalence of the overall trematodosis of this study was 85.06%. The prevalence of Trematodosis in buffalo was higher than in cattle and differed statistically (P<0.05). The highest prevalence was Paramphistomiasis (75.48%), followed by Fascioliasis (67.05%) and Schistosomiasis japonica (30.27%). The trematodosis prevalence of each village also varied and differed statistically (P<0.05). Intensites of infection of mild, moderate, and severe infections were reported in this study. Mixed infections by two even three species of trematodes were reported in this study. Two newly endemic Schistosomiasis villages are reported, namely Bewa Village and Gunung Gintu. The results of this study are used as a basis for controlling Trematodosis in large ruminants in endemic areas especially with zoonotic potential.

The paris system: A valuable new approach, but there is more to find in urine than high-grade urothelial carcinoma.

The paris system: A valuable new approach, but there is more to find in urine than high-grade urothelial carcinoma.

The current epidemiological status of urogenital schistosomiasis among primary school pupils in Katsina State, Nigeria: An imperative for a scale up of water and sanitation initiative and mass administration of medicines with Praziquantel.

IntroductionHuman schistosomiasis, a debilitating and chronic disease, is among a set of 17 neglected tropical infectious diseases of poverty that is currently posing a threat to the wellbeing of 2 billion people in the world. The SHAWN/WASH and MAM programmes in the study area require epidemiological data to enhance their effectiveness. We therefore embarked on this cross-sectional study with the aim of investigating the prevalence, intensity and risk factors of urogenital schistosomiasis.Methodology/ Principal findingsInterviewed 484 respondents produced terminal urine samples (between 10.00h – 14.00h) which were analyzed with Medi ─Test Combi 10 and centrifuged at 400 r.p.m for 4 minutes using C2 series Centurion Scientific Centrifuge. Eggs of S. haematobium were identified with their terminal spines using Motic Binocular Microscope. Data were analyzed with Epi Info 7. In this study, the overall prevalence and arithmetic mean intensity of the infection were 8.68% (6.39─ 11.64) and 80.09 (30.92─129.28) eggs per 10ml of urine respectively. Urogenital schistosomiasis was significantly associated with knowledge about the snail host (χ2 = 4.23; P = 0.0398); water contact activities (χ2 = 25.788; P = 0.0001), gender (χ2 = 16.722; P = 0.0001); age (χ2 = 9.589; P = 0.0019); economic status of school attended (χ2 = 4.869; P = 0.0273); residence distance from open water sources (χ2 = 10.546; P = 0.0012); mothers’ occupational (χ2 = 6.081; P = 0.0137) and educational status (χ2 = 4.139; P = 0.0419).Conclusion/ SignificanceThe overall prevalence obtained in this survey shows that the study area was at a low-risk degree of endemicity for urogenital schistosomiasis. Beneath this is a subtle, latent and deadly morbidity-inducing heavy mean intensity of infection, calling for urgent implementation of WHO recommendation that MAM with PZQ be carried out twice for School-Age Children (enrolled or not enrolled) during their primary schooling age (once each at the point of admission and graduation). The criteria for classifying endemic areas for schistosomiasis should also be reviewed to capture the magnitude of mean intensity of infection rather than prevalence only as this may underplay its epidemiological severity.

Field and laboratory comparative evaluation of a LAMP assay for the diagnosis of urogenital schistosomiasis in Cubal, Central Angola.

To evaluate the performance of Rapid-Heat LAMPellet assay in field conditions for diagnosis of urogenital schistosomiasis in an endemic area in Cubal, Angola, and to assess the reproducibility in a reference laboratory. A total of 172 urine samples from school-age children were tested for microhaematuria, microscopic detection of Schistosoma haematobium eggs and LAMP for DNA detection. Urine samples were stored in a basic equipped laboratory. Field-LAMP tests were performed with and without prior DNA extraction from urine samples, and the results were read by turbidity and by colour change. When field procedures were finished, samples were sent to a reference laboratory to be reanalysed by LAMP. A total of 83 of 172 (48.3%) were positive for microhaematuria, 87/172 (50.6%) were microscopy-positive for S.haematobium eggs detection, and 127/172 (73.8%) showed LAMP-positive results for detecting S.haematobium using purified DNA and 109/172 (63.4%) without prior DNA extraction. MacNemar's test showed a statistical significant relation between LAMP results and microscopy-detected S.haematobium infections and microhaematuria (P<0.001 in both cases), respectively. When samples of purified DNA were reanalysed in a reference laboratory in Spain using the same LAMP methodology, the overall reproducibility achieved 72.1%. The ease of use, simplicity and feasibility demonstrated by LAMP assay in field conditions together with the acceptable level of reproducibility achieved in a reference laboratory support the use of LAMP assay as an effective test for molecular diagnosis of urogenital schistosomiasis in endemic remote areas.

Study on distribution status of Oncomelania hupensis, the intermediate host of Schistosoma japonicum in Jiangxi Province Ⅱ Spatial-temporal distribution of snail-infested environments

To grasp the status of Oncomelania hupensis snail-infested environments in schistosomiasis endemic areas of Jiangxi Province, and establish the spatial database of snail-infested environments with the administrative village as the unit. The spatial and temporal distributions of the historical snail environments, existing snail environments, and suspicious snail-infested environments were analyzed by the historical data review and field investigations. The distribution of snail-infested environments in Jiangxi Province included two popular types of lakeshore and hills. The O. hupensis snail-infested environments were mainly concentrated in the Poyang Lake area, which accounting for 66.97% of the total snail-infested areas. The potential snail-infested environment area was 204 745.48 hm2, among which the potential snail-infested environment areas in the lakeshore and hills were 146 548.58 hm2 and 58 196.90 hm2, accounting for 71.58% and 28.42%, respectively. The real existing snail area was 83 234.50 hm2, among which the real existing snail areas in the lakeshore and hills were 80 890.81 hm2 and 2 343.69 hm2, accounting for 97.18% and 2.82%, respectively. The compressed snail area was 114 253.30 hm2 with a compression rate of 57.85%, of which the compression rates in the lakeshore and hills were 46.51% and 94.97%, respectively. In the four types of snail-infested environments, the areas of Type I, Type II, Type III and Type IV accounted for 55.77%, 25.75%, 13.91% and 4.57% of the total area, respectively. The spatial database of O. hupensis snail-infested environments is established comprehensively and systematically, that will be conducive to tracking and performing the dynamic updates of the data of snails, so as to provide an important technical support for investigation and monitoring in the future.

2160 Does maternal schistosomiasis affect the humoral and cellular vaccine responses of infants?

OBJECTIVES/SPECIFIC AIMS: The aims of this study are 2-fold: (1) to determine if maternal schistosomiasis affects maternal immunity to tetanus and/or transplacental transfer of antitetanus toxoid (TT) immunoglobulin G (IgG) from mother to infant and (2) determine the influence of maternal schistosomiasis on infant BCG vaccine immunogenicity. METHODS/STUDY POPULATION: The study will utilize blood samples from a historic cohort of 100 mother-infant pairs from Kisumu, Kenya, a schistosomiasis-endemic area. For the first aim, we will evaluate maternal schistosomal circulating anodic antigen, which has improved sensitivity and specificity to detect active schistosomiasis from serum, and antisoluble egg antigen IgG positivity compared with quantitative maternal anti-TT IgG at delivery and anti-TT IgG cord blood to maternal blood ratio (cord:maternal ratio). For the second aim, we will evaluate association between maternal schistosomiasis as detected by circulating anodic antigen and antisoluble egg antigen IgG at delivery and infant BCG-specific Th1-cytokine positive CD4+ cells at 10 weeks following BCG vaccination at birth. RESULTS/ANTICIPATED RESULTS: We hypothesize that active maternal schistosomiasis will be associated with decreased maternal anti-TT IgG and reduced efficiency of transplacental transfer, as measured by infant cord blood to maternal blood ratio of anti-TT IgG. We also expect that maternal schistosomiasis will be associated with decreased infant immunogenicity to BCG vaccine. DISCUSSION/SIGNIFICANCE OF IMPACT: This is a formative study on infant vaccine immunity using laboratory methodology not previously applied. Understanding infant immunity in the setting of maternal schistosomiasis will inform vaccination strategies and tailor vaccine development in schistosome-endemic areas such as Kenya, where neither TB nor neonatal tetanus have been eradicated. Additionally, our results will inform public health policies to consider integration of antischistosomal agents in antenatal care.

Seasonal variations in Schistosoma haematobium egg excretion in school-age girls in rural KwaZulu-Natal Province, South Africa

Background. A predominant feature of Schistosoma haematobium infection is urinary egg excretion, and microscopic egg detection remains the accepted standard field diagnostic tool. Praziquantel is the drug of choice for schistosomiasis, and the World Health Organization recommends that it should be administered to all children >4 years of age living in schistosomiasis-endemic areas. The frequency of mass drug administration depends on the prevalence rate in the community. Urinary schistosome egg output has a day-to-day and hour-to-hour intrasubject variation. Therefore, it is important to assess possible seasonal variations in egg excretion to improve the planning of drug treatment. Objectives. To assess the influence of seasonality on urinary schistosome egg excretion in South Africa (SA). Methods. We performed a prospective cohort study, exploring seasonal variations of S. haematobium egg excretion in 184 girls aged 10 - 12 years from randomly selected schools in a rural area of KwaZulu-Natal Province, SA. The area has a subtropical climate characterised by a cool dry season and a hot humid season. For children, water contact is higher in the latter season. At baseline, 108 girls were examined in the hot season, and 76 in the cold season. In the next year’s cold season the untreated patients were re-investigated before treatment. Results. There was a decrease in infection in the group initially tested in the hot season compared with the group tested in the cold season at both time points when adjusted for age and water contact (adjusted odds ratio 3.61 (95% confidence interval 1.14 - 11.44); p =0.03). Conclusions. This unique study shows that schistosomiasis prevalence determined by microscopy exhibits seasonal variation, with a higher prevalence in the hot rainy season. Precise community prevalence estimations are key in decisions to treat communities. There was significantly lower egg output in the cold season, and sampling in that season may therefore underestimate the prevalence of urinary schistosomiasis. The study indicates that sampling in SA should be done in the hot season.

Seasonal variations in Schistosoma haematobium egg excretion in school-age girls in rural KwaZulu-Natal Province, South Africa.

A predominant feature of Schistosoma haematobium infection is urinary egg excretion, and microscopic egg detection remains the accepted standard field diagnostic tool. Praziquantel is the drug of choice for schistosomiasis, and the World Health Organization recommends that it should be administered to all children &gt;4 years of age living in schistosomiasis-endemic areas. The frequency of mass drug administration depends on the prevalence rate in the community. Urinary schistosome egg output has a day-to-day and hour-to-hour intrasubject variation. Therefore, it is important to assess possible seasonal variations in egg excretion to improve the planning of drug treatment. To assess the influence of seasonality on urinary schistosome egg excretion in South Africa (SA). We performed a prospective cohort study, exploring seasonal variations of S. haematobium egg excretion in 184 girls aged 10 - 12 years from randomly selected schools in a rural area of KwaZulu-Natal Province, SA. The area has a subtropical climate characterised by a cool dry season and a hot humid season. For children, water contact is higher in the latter season. At baseline, 108 girls were examined in the hot season, and 76 in the cold season. In the next year's cold season the untreated patients were re-investigated before treatment. There was a decrease in infection in the group initially tested in the hot season compared with the group tested in the cold season at both time points when adjusted for age and water contact (adjusted odds ratio 3.61 (95% confidence interval 1.14 - 11.44); p=0.03). This unique study shows that schistosomiasis prevalence determined by microscopy exhibits seasonal variation, with a higher prevalence in the hot rainy season. Precise community prevalence estimations are key in decisions to treat communities. There was significantly lower egg output in the cold season, and sampling in that season may therefore underestimate the prevalence of urinary schistosomiasis. The study indicates that sampling in SA should be done in the hot season.

Evaluation of diagnostic methods for the detection of intestinal schistosomiasis in endemic areas with low parasite loads: Saline gradient, Helmintex, Kato-Katz and rapid urine test.

BackgroundIn some tropical countries, such as Brazil, schistosomiasis control programs have led to a significant reduction in the prevalence and parasite burden of endemic populations. In this setting, the Kato-Katz technique, as the standard diagnostic method for the diagnosis of Schistosoma mansoni infections, which involves the analysis of two slides from one fecal sample, loses its sensitivity. As a result, a significant number of infected individuals are not detected. The objective of this study was to perform extensive parasitological testing of up to three fecal samples and include a rapid urine test (POC-CCA) in a moderate prevalence area in Northern Minas Gerais, Brazil, and evaluate the performance of each test separately and in combination.Methods and findingsA total of 254 individuals were examined with variants of the standard Kato-Katz technique (up to18 Kato-Katz slides prepared from three fecal samples), a modified Helmintex (30 g of feces), the saline gradient (500 mg of feces), and the POC-CCA methods. We established a reference standard taking into consideration all the positive results in any of the parasitological exams. Evaluation of the parasite burden by two Kato-Katz slides confirmed that most of the individuals harbored a light infection. When additional slides and different parasitological methods were included, the estimated prevalence rose 2.3 times, from 20.4% to 45.9%. The best sensitivity was obtained with the Helmintex method (84%). All parasitological methods readily detected a high or moderate intensity of infection; however, all lost their high sensitivity in the case of low or very low intensity infections. The overall sensitivity of POC-CCA (64.9%) was similar to the six Kato-Katz slides from three fecal samples. However, POC-CCA showed low concordance (κ = 0.34) when compared with the reference standard.ConclusionsThe recommended Kato-Katz method largely underestimated the prevalence of S. mansoni infection. Because the best performance was achieved with a modified Helmintex method, this technique might serve as a more precise reference standard. An extended number of Kato-Katz slides in combination with other parasitological methods or with POC-CCA was able to detect more than 80% of egg-positive individuals; however, the rapid urine test (POC-CCA) produced a considerable percentage of false positive results.

Rodents as Natural Hosts of Zoonotic Schistosoma Species and Hybrids: An Epidemiological and Evolutionary Perspective From West Africa.

The complex multi-host disease dynamics of schistosomiasis and Schistosoma spp., including the emergence of zoonotic parasite hybrids, remain largely unexplored in West Africa. We elucidated the role of wild small mammals as reservoir for zoonotic Schistosoma species and hybrids in endemic areas of Senegal. We identified Schistosoma mansoni, Schistosoma bovis, and a Schistosoma haematobium/S. bovis hybrid, with local prevalence in wild rodents ranging from 1.9% to 28.6%. Our findings indicate that rodents may be an important local reservoir for zoonotic schistosomiasis in endemic areas of West Africa, amplifying transmission to humans and acting as natural definitive hosts of schistosome hybrids.

Review of the control of schistosomiasis in South Africa

Schistosomiasis is the second most important tropical disease in the world in terms of public health impact. In South Africa, more than 4 million people are estimated to be infected with schistosomiasis. School-age children usually have the highest prevalence and intensity of infection. Schistosoma haematobium may result in female genital schistosomiasis which presents as inflammation and ulceration of the genital mucosa and pathological blood vessels. These effects may increase the susceptibility of women with female genital schistosomiasis to HIV. Praziquantel is the drug used to treat schistosomiasis and it is best to treat people during the early stages of infection, before female genital schistosomiasis presents as lesions and sandy patches, as there currently is no treatment for these symptoms. Schistosomiasis is not regarded as a serious public health issue in South Africa despite evidence revealing the seriousness of the disease. In areas endemic for schistosomiasis, the World Health Organization recommends regular mass treatment of all school-age children. In 2001, South Africa became a signatory to the World Health Assembly resolution 54.19 which urged all member states to achieve the minimum goal of 75% treatment coverage in school-age children at risk by 2010. This goal was not achieved in South Africa, despite efforts made by the Department of Health, such as the first statutory school-based geohelminth control programme in the province of KwaZulu-Natal. However, this programme has not been continued. Therefore, there is still much work to be done in order to control and decrease the prevalence of schistosomiasis in endemic areas.

Spatial risk analysis on occurrences and dispersal of Biomphalaria straminea in and endemic area for schistosomiasis.

: Schistosomiasis is a rural endemic disease that has been expanding to urban and coastal areas in the state of Pernambuco, Brazil. The aim of this study was to characterize the distribution of breeding sites of the causative vector, Biomphalaria straminea in an endemic municipality for schistosomiasis and to present the predictive models for occurrences and dispersal of this vector snail to new areas. : A malacological survey was conducted during January to December 2015 in the municipality of São Lourenço da Mata, Pernambuco, Brazil to identify the breeding sites of Biomphalaria. Faecal contamination was determined by means of the Colitag™ diagnostic kit. Rainfall data were collected, and correlated with snail distribution data. Kernel density estimation, kriging and maximum entropy (MaxEnt) modeling were used for spatial data analysis, by means of the spatial analysis software packages. : Out of the 130 demarcated collection points, 64 were classified as breeding sites for B. straminea. A total of 5,250 snails were collected from these sites. Among these 64 sites, four were considered as foci of schistosomiasis transmission and 54 as potential transmission foci. An inverse relationship between rainfall and snail density was observed. Kernel spatial analysis identified three areas at higher risk of snail occurrence, which were also the areas of highest faecal contamination and included two transmission foci. Kriging and MaxEnt modeling simulated the scenarios obtained through the kernel analyses. : Use of geostatistical tools (Kriging and MaxEnt) is efficient for identifying areas at risk and for estimating the dispersal of Biomphalaria species across the study area. Occurrence of B. straminea in the study area is influenced by the rainy season, as it becomes more abundant during the period immediately after the rainy season, increasing the risk of dispersal and the appearance of new transmission foci.

Characteristics of the Heart of School-Age Children in a Schistosomiasis Endemic Area in Senegal

Introduction: In Senegal, surveys have revealed areas of high endemicity of Schistosomiasis including the town of Richard Toll. We undertook this study to determine the echocardiocardiographic characteristics of school-agechildren in endemic bilharziasis. Methodology: We performed a descriptive cross-sectional study in Richard Toll and Dakar in school-age children. Results: A total of 250 children were included. There was male predominance, age between 4 and 16 (10 years old ± 2.77). Hematuria was reported in 69.6% of cases in endemic areas. Positive testing for Schistoma haematobium was found exclusively in Richard-Toll at 33.5%. The diastolic, systolic, basal and median left ventricle dimensions were larger in Richard Toll’s population compared to Dakar. It was the same for the right chambers dimensions. The average pulmonary systolic arterial pressure was greater in Richard-Toll: 26.38 ± 3.16 mmHg versus 21.82 ± 1.73 mmHg in Dakar (p Conclusion: The heart of the school-aged child in endemic area is characterized by larger cavitary dimensions.

Influence of desiccation on the survival of Bulinus globosus under laboratory conditions

Environmental changes are generally known to influence the distribution and abundance of schistosome intermediate host snails (IHs). However, the influence of hydrologic changes per ser on the length of survival of schistosome IHs is not fully understood. To explore how desiccation may influence the survival of Bulinus globosus, the main IHs of Schistosoma haematobium in southern Africa, we conducted a study under laboratory conditions where snails were subjected to periods of desiccation and their survival evaluated. Desiccation period from 28 to 49 days post-draining of water was associated with an increase in mortality of 33.2 and 42.4% in large (mean shell height 7.81 ± 0.44 mm) and small (mean shell height 5.94 ± 0.68 mm) B. globosus snails, respectively. Although the duration of desiccation had no effect on the depth of burrowing, large size snails burrowed deeper into the soil than small size snails. The LT50 and LT90 of snails designated as large (7.81 ± 0.44 mm) were 73.35 ± 10.32 and 110.61 ± 21.03 days, respectively. On the other hand, LT50 and LT90 for snails designated as small (5.94 ± 0.68 mm) were 59.64 ± 8.56 and 84.19 ± 12.09 days, respectively. The survival of B. globosus during desiccation depended on the size/age of the snail where large size snails aestivate and survive for a longer period by burrowing deeper into the soil. We therefore conclude that adult B. globosus may play a significant role in habitat recolonization after a period of drought which is a common phenomenon in schistosomiasis endemic areas when population crashes.

S. Haematobium Infection and Chemotherapy-Induced Changes in Interleukin-6 and Acute Phase Proteins Associated with Inflammation in School Children in a Schistosomiasis-Endemic Area

Objective: There is an increased risk of cases of direct and indirect morbidities as a result of stimulation of tissue-destructive inflammation caused by Schistosoma haematobium infection, hence the need to determine the levels of inflammatory markers in Schistosoma haematobium infected children and also determine the effect of repeated annual mass treatment on levels of interleukin-6 and acute phase proteins.Methodology: Urine specimens from 212 school children were collected and examined to determine prevalence of Schistosoma haematobium at baseline and 2 years following annual rounds of praziquantel treatment. Levels of 4 acute phase proteins were measured from serum samples from the participants using the magnetic bead-based immuno-assays at baseline and 2 years following praziquantel treatment. Sandwich enzyme-linked immunosorbent assay was used to determine levels of interleukin-6.Results: The overall pre-treatment prevalence of Schistosoma haematobium infection was 23.1% at baseline and 0.47% after 2 years of annual treatments. Schistosoma haematobium infected children had marginally higher levels of procalcitonin and tissue plasminogen activator before treatment though the difference of all three was not significant p>0.05 using Mann-Whitney non-parametric U test. Levels of ferritin and fibrinogen were lower in Schistosoma haematobium infected children before treatment, however the difference was also not significant p>0.05 using Mann-Whitney test. There was no association between infection status or interleukin-6 and the levels acute phase proteins p>0.05 for all acute phase proteins using the Mann-Whitney U test.Discussion and conclusion: Findings from this study suggest no bearing of Schistosoma haematobium infection status on level of acute phase proteins before and after annual treatment with praziquantel. The extent of inflammation cannot be determined using ferritin, tissue plasminogen activator and fibrinogen. Levels of interleukin-6 did not have any bearing on levels of acute phase proteins. There is a need to explore other acute phase proteins as inflammatory markers in Schistosoma haematobium infection.