Schistosomiasis Endemic Areas Research Articles

Impact of earthquake disaster on schistosomiasis transmission and emergency prevention and control in Sichuan Province

Earthquake is a serious natural disaster. The earthquake that occurs in schistosomiasis-endemic areas not only causes direct human and economic losses, but also induces secondary disasters that greatly threaten public health safety in affected areas. This paper analyzed the impact of the 2008 Wenchuan Earthquake and 2013 Lushan Earthquake on schistosomiasis transmission in Sichuan Province, and proposed emergency measures and assessment activitiesresponding to schistosomiasis following earthquake disasters. The experiences from schistosomiasis control after two earthquake disasters in Sichuan Province may provide insights into the emergency control in other regions or after other natural disasters.

Spatial and Seasonal Distribution of Holochilus sciureus with Schistosoma mansoni Infection in an Endemic Area for Schistosomiasis in Brazil.

The occurrence of wild rodents in the Schistosoma mansoni life cycle may increase the transmission of schistosomiasis and understanding the spatial and seasonal distribution of the natural infection of these reservoirs is essential for the development of more effective control strategies. In this study, Holochilus sciureus rodents were captured from the flooded fields of São Bento city (an endemic area for schistosomiasis in Northeast Brazil), during the dry and rainy seasons. All these sites were georeferenced and the prevalence of S. mansoni was verified by the presence of adult worms in the mesenteric branches and livers of each animal. It was demonstrated that almost half of the animals collected were naturally infected with S. mansoni (45.45%) and this infection was not related to the distance from urban areas. Furthermore, the temperature, precipitation, sex, and weight did not interfere with the H. sciureus infection rates. Interestingly, we found, for the first time, the natural infection of H. sciureus in another endemic city of S. mansoni in Northeast Brazil. Therefore, the H. sciureus rodent shows a high natural infection rate for S. mansoni in the flooded fields of São Bento, regardless of the weather station, capture distance, and biological aspects. Additionally, we have demonstrated that H. sciureus naturally parasitized with S. mansoni may inhabit a much more extensive area that is currently described in the literature.

Spatiotemporal Heterogeneity in Human Schistosoma japonicum Infection at Village Level in Hubei Province, China.

The spatiotemporal dynamics of Schistosoma japonicum, combined with temporal heterogeneity among regions of different epidemic areal-types from a microscale viewpoint might capture the local change dynamics and thus aid in optimizing the combinations of precise schistosomiasis control measures. The prevalence data on schistosomiasis infection from 2007 to 2012 in the 30 most endemic counties of Hubei Province, Central China, were appended to the village-level administrative division polygon layer. Anselin local Moran’s I, a retrospective space–time scan statistic and a multilevel-growth model analysis framework, was used to investigate the spatiotemporal pattern of schistosomiasis resident infection rate (RIR) at the village level and how natural geographical environment influence the schistosomiasis RIR over time. Two spatiotemporal high-risk clusters and continuous high-rate clusters were identified mainly in the embankment region across flooding areas of lakes connected with the Yangze and Hanjiang Rivers. Moreover, 12 other clusters and outlier evolution modes were detected to be scattered across the continuous high-rate clusters. Villages located in embankment region had the highest initial values and most rapidly reduced RIRs over time, followed by villages located in marshland-and-lake regions and finally by villages located in hilly region. Moreover, initial RIR values and rates of change did significantly vary (p < 0.001 and p < 0.001, respectively) irrespective of their epidemic areal-type. These local spatiotemporal heterogeneities could contribute to the formulation of distinct control strategies based on local transmission dynamics and be applied in other endemic areas of schistosomiasis.

Molluscicidal activity of 25% wettable powder of pyriclobenzuron sulphate against Oncomelania hupensis robertsoni

To evaluate the molluscicidal activity of a novel molluscicide pyriclobenzuron against Oncomelania hupensis robertsoni in the mountain regions of Yunan Province, and test its toxicity to fish, so as to provide scientific evidence for the extensive application of this molluscicide in schistosomiasis-endemic foci of Yunan Province. In the laboratory and snail-breeding field of Dali Prefecture, Yunnan Province, the molluscicidal activity of 5% wettable powder of pyriclobenzuron sulphate (25% PBU) against O. hupensis robertsoni was assessed by using the immersion and spraying method, and the acute toxicity of 25% PBU to carp fries was tested, while 25% wettable powder of niclosamide ethanolamine salt (50% WPNES) served as a control. The 1-, 2- and 3-day 25% PBU LC50 and LC90 values were 0.47, 0.25 and 0.23 mg/L, and 1.54, 0.61 and 0.49 mg / L for O. h. robertsoni by using the immersion method in laboratory, and immersion with 25% PBU at 1.0 mg / L for 1 day achieved a comparable molluscicidal efficacy in relative to 50% WPNES at 1.0 mg/L. Spraying with 25% PBU at 4.0 g/m2 achieved 1-, 3- and 7-day snail mortalities of 64.23%, 96.67% and 100.00% in laboratory, respectively, which were not significantly different from those caused by treatment with 50% WPNES at 1.0 g/m2 (all P values > 0.05). One-day field immersion with 25% PBU at doses of 1, 2 and 4 g/m3 resulted in snail mortalities of 90.00%, 93.33% and 100.00%, respectively, which were not significantly different from those caused by treatment with 50% WPNES at 1.0 g/m3 (all P values > 0.05), and 3-day field spraying with 25% PBU at doses of 2.0 and 4.0 g/m2 caused snail mortalities of 86.36% and 87.72%, respectively, which were not significantly different from those caused by 50% WPNES treatment (both P values > 0.05). The 24-, 48- and 72-hour LC50 values of 25% PBU to carp fries were 29.38, 24.62 and 23.38 mg/L, respectively, and no fish death was observed within 72 hours of exposure to 25% PBU at a concentration of 17.5 mg/L and lower. 25% PBU is a novel, highly potent and environment-friendly molluscicide that is feasible in fish ponds, and the recommended dose is 1 g/m3 for field immersion and 2 g/m2 for field spraying in schistosomiasis-endemic areas of Yunnan Province.

Schistosomiasis in the Philippines: Innovative Control Approach is Needed if Elimination is the Goal.

In 1996, schistosomiasis due to Schistosoma japonicum was declared eradicated in Japan. In the People’s Republic of China, S. japonicum transmission has been interrupted in the major endemic areas in the coastal plains but the disease persists in the lake and marshland regions south of the Yangtze River. The disease remains a public health problem in endemic areas in the Philippines and in isolated areas in Indonesia. Comprehensive multidisciplinary campaigns had led to eradication of schistosomiasis in Japan and have been successful in the interruption of disease transmission in the major endemic regions of the People’s Republic of China. Unfortunately, the integrated measures cannot be duplicated in schistosomiasis endemic areas in the Philippines because of limited resources. The problem is also more complicated due to the topography in the Philippines and transmission is not seasonal as in China. An innovative approach is needed in the Philippines if schistosomiasis elimination is the goal.

Asian Schistosomiasis: Current Status and Prospects for Control Leading to Elimination.

Schistosomiasis is an infectious disease caused by helminth parasites of the genus Schistosoma. Worldwide, an estimated 250 million people are infected with these parasites with the majority of cases occurring in sub-Saharan Africa. Within Asia, three species of Schistosoma cause disease. Schistosoma japonicum is the most prevalent, followed by S. mekongi and S. malayensis. All three species are zoonotic, which causes concern for their control, as successful elimination not only requires management of the human definitive host, but also the animal reservoir hosts. With regard to Asian schistosomiasis, most of the published research has focused on S. japonicum with comparatively little attention paid to S. mekongi and even less focus on S. malayensis. In this review, we examine the three Asian schistosomes and their current status in their endemic countries: Cambodia, Lao People’s Democratic Republic, Myanmar, and Thailand (S. mekongi); Malaysia (S. malayensis); and Indonesia, People’s Republic of China, and the Philippines (S. japonicum). Prospects for control that could potentially lead to elimination are highlighted as these can inform researchers and disease control managers in other schistosomiasis-endemic areas, particularly in Africa and the Americas.

Appendicular Schistosomiasis in a Nigerian Woman

Aim: Schistosomiasis is a water-borne trematode infestation and is one of the most widespread parasitic diseases in the world. Schistosomiasis can affect any organ. This case report highlights the importance of awareness of unusual cause of common surgical presentations of schisto-somiasis in endemic areas and the need for appendectomy specimens to be sent for histological review so that patients can benefit from full investigations and specific antiparasitic treatment.&#x0D; Case Presentation: In this paper, the authors present a case of appendicular schistosomiasis that was incidentally discovered in a 33-year-old female patient from Lagos, Nigeria who underwent appendectomy for acute appendicitis. Appendectomy specimens removed from the patient appeared macroscopically normal but histopathological analysis revealed schistosomal eggs confirming the diagnosis of appendicular schistosomiasis.&#x0D; Discussion: Confirmation of appendicular schistosomiasis is a purely histological diagnosis, because there are no pathognomonic clinical or operative findings. Physicians practising in the endemic areas must be aware of the possibility of seeing atypical presentations of parasitic diseases.&#x0D; Conclusion: The authors therefore strongly recommend that all appendectomy specimens should be sent for histological review so that patients can benefit from full investigations and specific anti-parasitic treatment.

Modulation of Allergic Reactivity in Humans Is Dependent on Schistosoma mansoni Parasite Burden, Low Levels of IL-33 or TNF-α and High Levels of IL-10 in Serum.

Helminth infections and allergies are characterized by a predominant type-2 immune response. In schistosomiasis, the Th-2 response is usually accompanied by induction of immunoregulatory mechanisms that contribute to worm survival and less severe schistosomiasis. Although helminth-induced immunomodulatory mechanisms seem to affect atopy, epidemiological studies on the relationship between helminths and allergy have been inconsistent, and data suggest that the modulatory effects may be influenced by helminth species, chronicity of infection, and parasite burden. Here we performed a cross-sectional study to investigate the effects of Schistosoma mansoni parasite burden and immune response on allergic reactivity of individuals living in a schistosomiasis endemic area in Brazil. Fecal samples from the participants were collected for extensive parasitological examinations by spontaneous sedimentation, Kato-Katz, Helmintex and Saline Gradient tests and molecular detection of S. mansoni by qPCR. Additionally, the concentrations of cytokines and chemokines, total IgE and IgE-reactivity to common house dust allergens were quantified from serum samples. IgE reactivity to dust allergens was detected in 47 individuals (23.8%), and 140 individuals (54.4%) were diagnosed with S. mansoni infection. Most of the infected population (108 individuals) presented very low parasite burden (≤12 eggs/g of feces). The frequency and intensity (p ≤ 0.03) of allergic reactivity were lower in S. mansoni-infected compared with non-infected individuals. Multivariable logistic regression models adjusted by age revealed that allergic reactivity was positively associated with low IL-10 response (OR, 4.55, 95% CI, 0.56–7.36) and high concentration of the inflammatory mediators IL-33 (OR, 2.70, 95% CI, 1.02–7.15) or TNF-α (OR, 6.88, 95% CI, 0.32–143.39) in serum, and inversely associated with S. mansoni infection (OR, 0.38, 95% CI, 0.16–0.87). Most importantly, the logistic regression demonstrated that the modulatory effects of Schistosoma infection depend on parasite burden, with individuals infected with ≤12 eggs/g of feces showing allergic IgE-reactivity similar to non-infected individuals Altogether, our data show that immunomodulation of allergic reactivity depends on S. mansoni burden, low type-2 inflammatory response, and high level of IL-10.

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.

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.