GPS-based fine-scale mapping surveys for schistosomiasis assessment: a practical introduction and documentation of field implementation

Background Fine-scale mapping of schistosomiasis to guide micro-targeting of interventions will gain importance in elimination settings, where the heterogeneity of transmission is often pronounced. Novel mobile applications offer new opportunities for disease mapping. We provide a practical introduction and documentation of the strengths and shortcomings of GPS-based household identification and participant recruitment using tablet-based applications for fine-scale schistosomiasis mapping at sub-district level in a remote area in Pemba, Tanzania. Methods A community-based household survey for urogenital schistosomiasis assessment was conducted from November 2020 until February 2021 in 20 small administrative areas in Pemba. For the survey, 1400 housing structures were prospectively and randomly selected from shapefile data. To identify pre-selected structures and collect survey-related data, field enumerators searched for the houses’ geolocation using the mobile applications Open Data Kit (ODK) and MAPS.ME. The number of inhabited and uninhabited structures, the median distance between the pre-selected and recorded locations, and the dropout rates due to non-participation or non-submission of urine samples of sufficient volume for schistosomiasis testing was assessed. Results Among the 1400 randomly selected housing structures, 1396 (99.7%) were identified by the enumerators. The median distance between the pre-selected and recorded structures was 5.4 m. A total of 1098 (78.7%) were residential houses. Among them, 99 (9.0%) were dropped due to continuous absence of residents and 40 (3.6%) households refused to participate. In 797 (83.1%) among the 959 participating households, all eligible household members or all but one provided a urine sample of sufficient volume. Conclusions The fine-scale mapping approach using a combination of ODK and an offline navigation application installed on tablet computers allows a very precise identification of housing structures. Dropouts due to non-residential housing structures, absence, non-participation and lack of urine need to be considered in survey designs. Our findings can guide the planning and implementation of future household-based mapping or longitudinal surveys and thus support micro-targeting and follow-up of interventions for schistosomiasis control and elimination in remote areas. Trial registration ISRCTN, ISCRCTN91431493. Registered 11 February 2020, https://www.isrctn.com/ISRCTN91431493

Variation in Arsenic metabolism in schistosomiasis associated bladder pathology in a rural community, Eggua, Ogun State, Nigeria

Exposure to toxic inorganic Arsenic (iAs) in areas endemic for urogenital schistosomiasis may confer increased risk for bladder cancer. The severity of the adverse effects of iAs however depends on its metabolism, which is highly variable among individuals. Genetic polymorphism in Arsenic (+3) Methyl Transferase enzyme, accounts significantly for these variations. To investigate the relationship of AS3MT gene polymorphisms and Arsenic metabolism to schistosomiasis and/or associated bladder pathology, 119 individualsfrom Eggua in southwest Nigeria were recruited for this study. Screening for schistosomiasis and bladder pathology was done by microscopy and ultrasonography respectively. Wagtech Digital Arsenator was used to assess total urinary arsenic concentrations and thus determine the level of arsenic exposure. The single nucleotide polymorphism AS3MT/Met287Thr T>C (rs11191439) was genotyped using Alelle-Specific PCR. Of the participants who tested positive for schistosomiasis, 33.3% exhibited bladder pathology. Total urinary arsenic concentration in 80% of the participants was above the WHO limit of 0.05mg/L. The Met287Thr allelic distribution conformed to the Hardy-Weinberg equilibrium (X2= 0.161, P> 0.05). Observed allelic frequencies were 0.96 and 0.04 for wild-type T and mutant C alleles respectively. There was no significant relationship between AS3MT SNP, arsenic concentrations and schistosomiasis associated bladder pathology. In conclusion, the community is highly exposed to arsenic, although with a possible genetic advantage of increased AS3MT catalytic activity. However, we see the need for urgent intervention as inter-individual differences in arsenic metabolism may influence the bladder pathology status of individuals in the community. And although urogenital schistosomiasis is waning in Eggua, it is not known what synergy the infection and high arsenic exposure may wield on bladder pathology.

Host tissue proteomics reveal insights into the molecular basis of Schistosoma haematobium-induced bladder pathology

Background: Urogenital schistosomiasis remains a major public health concern worldwide. In response to egg deposition, the host bladder undergoes gross and molecular morphological changes relevant for disease manifestation. However, limited mechanistic studies to date imply that the molecular mechanisms underlying pathology have not been well-defined. We leveraged a mouse model of urogenital schistosomiasis to perform for the first time, proteome profiling of the early molecular events that occur in the bladder after exposure to S. haematobium eggs, and to elucidate the protein pathways involved in urogenital schistosomiasis-induced pathology. Methods: Purified S. haematobium eggs or control vehicle were microinjected into the bladder walls of mice. Mice were sacrificed seven days post-injection and bladder proteins isolated and processed for proteome profiling using mass spectrometry. Results: We demonstrate that biological processes including carcinogenesis, immune and inflammatory responses, increased protein translation or turnover, oxidative stress responses, reduced cell adhesion and epithelial barrier integrity, and increased glucose metabolism were significantly enriched in S. haematobium infection. Conclusion: S. haematobium egg deposition in the bladder results in significant changes in proteins and pathways that play a role in pathology. Our findings highlight the potential bladder protein indicators for host-parasite interplay and provide new insights into the complex dynamics of pathology and characteristic bladder tissue changes in urogenital schistosomiasis. The findings will be relevant for development of improved interventions for disease control.

Evaluation of falciparum parasitemia and urogenital schistosomiasis co-infection on haemoglobin and nutritional status of children and adolescents in riverine communities of southern Taraba State, Nigeria.

Malaria and urogenital schistosomiasis are parasitic infections usually acquired unknowingly and sometimes cause anaemia and affect the nutritional status of persons in endemic areas. This study assessed asymptomatic Plasmodium falciparum, Schistosoma haematobium and their co-infection status with respect to the association of haemoglobin level and nutritional status in children and adolescents resident at Takum Local Government, a rural suburb of Taraba State, Nigeria. Thick blood films and urine filtration technique were used respectively to determine P. falciparum and S. haematobium species. Haemoglobinometer measured haemoglobin concentration and Body Mass Index determined nutritional status for each participant. The study reported 32.9% (87/264), 28.7% (76/264) and 30.3% (80/264) respectively for asymptomatic malaria, urogenital schistosomiasis and co-infection. Participants in Chanchanji community significantly had the highest asymptomatic P. falciparum infection, 56.4% (22/39) (p=0.003). Sufa and Manya communities respectively had the highest S. haematobium infection, 39.4% (15/38) (χ2= 41.3, p=0.000) and coinfection, 32.1% (12/37) (χ2= 52.45, p=0.000). A negative association was observed between anaemia and co-infection (r = -0.77, p=0.000) as well as between nutritional status and co-infection (r = -0.63, p=0.000). Participants who did not use LLTNs and lived close to water bodies were predisposed to co-infection with adjusted OR=0.003 (%95CI: 0.00 – 0.03; p=0.000). Birama and Manya areas highly predicted participants to co-infection with respective adjusted OR = 13.20 (%95CI: 2.34-74.38; p=0.003) and adjusted OR=57.9, (%95CI: 4.92-681.24, p=0.001). The co-infection predisposed participants to moderate and severe anaemia with respective adjusted OR of 2.198 (%95CI:1.307-3.696, p=0.021) and 1.192 (%95CI:0.355-4.009, p=0.017). Undernutrition was significantly affected with co-infection adjusted OR=3.732 (95%CI:1.003-7.393, p=0.011). Co-infection was significantly associated with anaemia and nutritional status at p≤0.05. It is recommended that the State and NGOs should provide malaria Intermittent Prevention Treatment as well as deworm the children and adolescents in Takum LGA.

Molecular Docking and Dynamics Simulation Revealed Ivermectin as Potential Drug against Schistosoma-Associated Bladder Cancer Targeting Protein Signaling: Computational Drug Repositioning Approach

Urogenital schistosomiasis is caused by Schistosoma haematobium (S. haematobium) infection, which has been linked to the development of bladder cancer. In this study, three repurposing drugs, ivermectin, arteether and praziquantel, were screened to find the potent drug-repurposing candidate against the Schistosoma-associated bladder cancer (SABC) in humans by using computational methods. The biology of most glutathione S-transferases (GSTs) proteins and vascular endothelial growth factor (VEGF) is complex and multifaceted, according to recent evidence, and these proteins actively participate in many tumorigenic processes such as cell proliferation, cell survival and drug resistance. The VEGF and GSTs are now widely acknowledged as an important target for antitumor therapy. Thus, in this present study, ivermectin displayed promising inhibition of bladder cancer cells via targeting VEGF and GSTs signaling. Moreover, molecular docking and molecular dynamics (MD) simulation analysis revealed that ivermectin efficiently targeted the binding pockets of VEGF receptor proteins and possessed stable dynamics behavior at binding sites. Therefore, we proposed here that these compounds must be tested experimentally against VEGF and GST signaling in order to control SABC. Our study lies within the idea of discovering repurposing drugs as inhibitors against the different types of human cancers by targeting essential pathways in order to accelerate the drug development cycle.

“We know about schistosomiasis but we know nothing about FGS”: A qualitative assessment of knowledge gaps about female genital schistosomiasis among communities living in Schistosoma haematobium endemic districts of Zanzibar and Northwestern Tanzania

Background Schistosoma haematobium causes urogenital schistosomiasis and is widely distributed in Tanzania. In girls and women, the parasite can cause Female Genital Schistosomiasis (FGS), a gynecological manifestation of schistosomiasis that is highly neglected and overlooked by public health professionals and policy makers. This study explored community members’ knowledge, attitudes and perceptions (KAP) on and health seeking behavior for FGS. Methods/Principal findings Using qualitative research methods—including 40 Focus Group Discussions (FGDs) and 37 Key Informant Interviews (KIIs)—we collected data from 414 participants (Males n = 204 [49.3%] and Females n = 210 [50.7%]). The study engaged 153 participants from Zanzibar and 261 participants from Northwestern Tanzania and was conducted in twelve (12) purposively selected districts (7 districts in Zanzibar and 5 districts in northwestern Tanzania). Most participants were aware of urogenital schistosomiasis. Children were reported as the most affected group and blood in urine was noted as a common symptom especially in boys. Adults were also noted as a risk group due to their involvement in activities like paddy farming that expose them to infection. Most participants lacked knowledge of FGS and acknowledged having no knowledge that urogenital schistosomiasis can affect the female reproductive system. A number of misconceptions on the symptoms of FGS and how it is transmitted were noted. Adolescent girls and women presenting with FGS related symptoms were reported to be stigmatized, perceived as having a sexually transmitted infection (STI), and sometimes labeled as “prostitutes”. Health seeking behavior for FGS included a combination of traditional medicine, self-treatment and modern medicine. Conclusion/Significance Community members living in two very different areas of Tanzania exhibited major, similar gaps in knowledge about FGS. Our data illustrate a critical need for the national control program to integrate public health education about FGS during the implementation of school- and community-based mass drug administration (MDA) and with improvement of water, sanitation and hygiene (WASH) facilities.

Novel tools and strategies for breaking schistosomiasis transmission: study protocol for an intervention study

Background Global elimination of schistosomiasis as a public health problem is set as target in the new World Health Organization’s Neglected Tropical Diseases Roadmap for 2030. Due to a long history of interventions, the Zanzibar islands of Tanzania have reached this goal since 2017. However, challenges occur on the last mile towards interruption of transmission. Our study will investigate new tools and strategies for breaking schistosomiasis transmission. Methods The study is designed as an intervention study, documented through repeated cross-sectional surveys (2020–2024). The primary endpoint will be the sensitivity of a surveillance-response approach to detect and react to outbreaks of urogenital schistosomiasis over three years of implementation. The surveys and multi-disciplinary interventions will be implemented in 20 communities in the north of Pemba island. In low-prevalence areas, surveillance-response will consist of active, passive and reactive case detection, treatment of positive individuals, and focal snail control. In hotspot areas, mass drug administration, snail control and behaviour change interventions will be implemented. Parasitological cross-sectional surveys in 20 communities and their main primary schools will serve to adapt the intervention approach annually and to monitor the performance of the surveillance-response approach and impact of interventions. Schistosoma haematobium infections will be diagnosed using reagent strips and urine filtration microscopy, and by exploring novel point-of-care diagnostic tests. Discussion Our study will shed light on the field applicability and performance of novel adaptive intervention strategies, and standard and new diagnostic tools for schistosomiasis elimination. The evidence and experiences generated by micro-mapping of S. haematobium infections at community level, micro-targeting of new adaptive intervention approaches, and application of novel diagnostic tools can guide future strategic plans for schistosomiasis elimination in Zanzibar and inform other countries aiming for interruption of transmission. Trial registration ISRCTN, ISCRCTN91431493. Registered 11 February 2020, https://www.isrctn.com/ISRCTN91431493

Knowledge, attitudes and practices pertaining to urogenital schistosomiasis in Lambaréné and surrounding areas, Gabon

Background Control of schistosomiasis remains a priority in endemic areas. Local epidemiological data are necessary for a tailored control programme, including data on population behaviour in relation to the disease. The objective of this study was to assess schistosomiasis-related knowledge, attitudes and practices in the general population of Lambaréné, a small city in Gabon, in order to optimise the design and implementation of a local control programme that is tailored to need. Methods The study was cross-sectional in nature. Eligible adults and children living in the study area who volunteered (with informed consent) to participate in the study were interviewed using standardised questionnaires, one of which was a simplified version of the primary questionnaire for participants aged 6–13 years. Data on the participants’ knowledge, attitudes and practices that enhance the risk for contracting schistosomiasis were collected. Results A total of 602 participants were included. The mean (± standard deviation) age was 21.2 (± 15.0) years, the female:male gender ratio was 1.6 and 289 (48%) participants completed the simplified version the questionnaire. Of the 602 participants, 554 (92%) reported past or current contact with freshwater, 218 (36%) reported a history of a diagnosis of schistosomiasis and 193 (32%) reported past intake of praziquantel medication. The overall levels of knowledge and adequate attitudes toward schistosomiasis among young adults and adults were 68 and 73%, respectively. The proportion of participants pursuing risk-enhancing practices (REP) was 60% among the whole study population. Location was significantly associated with differences in knowledge and REP levels. A history of confirmed schistosomiasis and larger family size were significantly associated with an increase in good knowledge and REP levels. However, the indication of freshwater-associated activities was only associated with a significant increase in the REP level. Conclusions The results of this survey reveal a high level of population exposure to schistosomiasis, which is in line with known prevalence of schistosomiasis in Lambaréné and its surroundings. The local population has a reasonable level of knowledge of and adequate attitudes toward schistosomiasis but the level of REP is high, particularly in areas where piped water is absent. In terms of interventions, improving hygiene should have the highest priority, but in a context where provision of safe water is difficult to achieve, the effectiveness of praziquantel treatment and the education of at-risk populations on the need for protective behaviours should be a prominent feature of any local control programme. Graphical abstract

Urogenital schistosomiasis burden in school-aged children in Tiko, Cameroon: a cross-sectional study on prevalence, intensity, knowledge and risk factors

Background This study aimed at determining urogenital schistosomiasis (UGS) prevalence, intensity, knowledge and risk factors in school-aged children (SAC) in the new endemic focus of Tiko, Cameroon. Methods A cross-sectional study including 389 SAC of both sexes aged 5–15 years was carried out between April and June 2018. A structured questionnaire was used to collect demographic data, clinical and predisposing factors. Urine sample collected was used to detect Schistosoma haematobium eggs by filtration technique and microhaematuria by Heme dipstick COMBI 11. Logistic regression model was used to determine risk factors of UGS. Results The overall prevalence of UGS was 37.0% (CI 32.4–41.9) and 32.6% (CI 28.2–37.5) were positive by egg excretion while 24.4% (CI 20.4–28.9) by haematuria. S. haematobium egg excretion and haematuria were significantly higher in males (P = 0.016; P = 0.049) and children 12–15 years old (P = 0.009; P = 0.002), respectively. The mean number of eggs per 10 mL of urine was 77.6 (10.2) and ranged from 2 to 400. The proportion of light intensity of infection was higher (67.7%, CI 59.2–75.2) with no significant differences by sex, age and residence. However, the older children were more heavily infected when compared to the younger children, who had more of light infection. Overall, the mean knowledge score 1.42 (CI 1.32–1.51) on a scale of 6, was poor and the proportion of good knowledge of the disease (23.14%, CI 19.2–27.6) was low. Stream water contact (AOR = 4.94; P = 0.001) was the only significant risk factor identified. Conclusion Urogenital schistosomiasis is of public health concern among SAC in Tiko, Cameroon. Most participants have poor knowledge about the disease, hence education on vector-borne diseases and the avoidance of stream water contact should be implemented.

Impact of a Mobile Health System on the Suppression of Schistosoma Haematobium in Chad

This study determined the contribution of a mobile health (M-health) system to the treatment of Schistosoma haematobium in a region of Chad where S. haematobium is endemic. M-health involves the use of a mobile phone for health care. The study compared the prevalence of schistosomiasis in an area with an M-health system, newly installed in 2014, with an area without an adequate health infrastructure. Data were gathered after the M-health system had been running for 3 years. We took urine samples from children age 1 to 15 years, for a total of 200 children in a village in the M-health area and 200 in a village in a non-M-health area. Urine was checked for urinary schistosomiasis by using dipsticks for microhematuria and, in cases of positive dipstick results, microscopy was used to detect eggs. Comparison between the areas allowed us to assess the effectiveness of the installed M-health system after 3 years of operation. Based on dipstick outcomes, the non-M-health area had an infection rate of 51.5% compared with 29% in the M-health area. Microscopy results in non-M-health and M-health were 27.5% and 21%, respectively. The dipstick result difference between M-health and non-M-health areas was statistically significant. Dipsticks were more reliable than microscopy for the detection of schistosomiasis, especially in areas without qualified personnel. Based on these results, M-health proved its ability to reduce the infection rate of urogenital schistosomiasis, and the implementation of M-health shows great promise in areas where this disease is endemic and where no mass drug administration is provided.