Schistosomiasis with a Focus on Africa

Mechanisms of Arachidonic Acid In Vitro Schistosomicidal Potential

Arachidonic acid (ARA) was shown to possess safe and effective schistosomicidal impact on larval and adult Schistosoma mansoni and Schistosoma hematobium in vitro and in vivo in laboratory rodents and in children residing in low and high endemicity regions. We herein examine mechanisms underlying ARA schistosomicidal potential over two experiments, using in each pool a minimum of 50 adult male, female, or mixed-sex freshly recovered, ex vivo S. mansoni. Worms incubated in fetal calf serum-free medium were exposed to 0 or 10 mM ARA for 1 h at 37 °C and immediately processed for preparation of surface membrane and whole worm body homogenate extracts. Mixed-sex worms were additionally used for evaluating the impact of ARA exposure on the visualization of outer membrane cholesterol, sphingomyelin (SM), and ceramide in immunofluorescence assays. Following assessment of protein content, extracts of intact and ARA-treated worms were examined and compared for SM content, neutral sphingomyelinase activity, reactive oxygen species levels, and caspase 3/7 activity. Arachidonic acid principally led to perturbation of the organization, integrity, and SM content of the outer membrane of male and female worms and additionally impacted female parasites via stimulating neutral sphingomyelinase activity and oxidative stress. Arachidonic powerful action on female worms combined with its previously documented ovocidal activities supports its use as safe and effective therapy against schistosomiasis, provided implementation of the sorely needed and long waited-for chemical synthesis.

Insights into the epidemiology, pathogenesis, and differential diagnosis of schistosomiasis

Schistosomiasis is a neglected tropical disease that is prevalent in low- and middle-income countries. There are five human pathogenic species, of which Schistosoma haematobium, Schistosoma mansoni and Schistosoma japonicum are the most prevalent worldwide and cause the greatest burden of disease in terms of mortality and morbidity. In addition, hybrid schistosomes have been identified through molecular analysis. Human infection occurs when cercariae, the larval form of the parasite, penetrate the skin of people while bathing in contaminated waters such as lakes and rivers. Schistosomiasis can cause both urogenital and intestinal symptoms. Urogenital symptoms include haematuria, bladder fibrosis, kidney damage, and an increased risk of bladder cancer. Intestinal symptoms may include abdominal pain, sometimes accompanied by diarrhoea and blood in the stool. Schistosomiasis affects more than 250 million people and causes approximately 70 million Disability-Adjusted Life Years (DALYs), mainly in Africa, South America, and Asia. To control infection, it is essential to establish sensitive and specific diagnostic tests for epidemiological surveillance and morbidity reduction. This review provides an overview of schistosomiasis, with a focus on available diagnostic tools for Schistosoma spp. Current molecular detection methods and progress in the development of new diagnostics for schistosomiasis infection are also discussed.

Assessing urogenital schistosomiasis and female genital schistosomiasis (FGS) among adolescents in Anaocha, Anambra State, Nigeria: implications for ongoing control efforts

BACKGROUND

Urogenital schistosomiasis (UgS) remains a persistent health challenge among adolescents in Anambra State, Nigeria, despite ongoing control efforts. Mass praziquantel treatment programs, initiated in 2013, primarily target primary school-aged children (5-14 years old), leaving adolescents (10-19 years old) enrolled in secondary schools vulnerable to urogenital schistosomiaisis. Additionally, the extent of female genital schistosomiasis (FGS), a neglected gynaecological manifestation of UgS remains unclear.

METHODOLOGY

To address these gaps, a cross-sectional study was conducted in Anaocha Local Government Area from February to May 2023. Four hundred and seventy consenting adolescents aged 10-19 years were enrolled. Urinalysis including urine filtration was employed to confirm haematuria and detect urogenital schistosomiasis (UGS) among the participants. For females with heavy infections (≥ 50 eggs/10 ml urine), a gynaecologist performed colposcopy examinations, complemented by acetic acid and Lugol's iodine staining to assess for female genital schistosomiasis (FGS) lesions or other related reproductive health conditions. Socio-demographic data, including information on potential risk factors, were systematically collected using the Kobo ToolBox software, following gender-sensitive data collection guidelines. Data were analysed using SPSS version 25, incorporating descriptive statistics, multinomial logistic regression, odds ratios, and significance testing.

RESULTS

Among the 470 adolescents (52.8% females, 47.2% males) examined, an overall UgS prevalence of 14.5% was observed, with an average of 5.25 eggs per 10 ml of urine. Females had a slightly higher prevalence (16.1%), and 7.5% had heavy infections. Although gender differences in infection rates were not statistically significant, males had slightly higher odds of infection (OR: 1.332; 95% CI: 0.791-2.244; p-value: 0.280). Adolescents aged 10-14 had the highest prevalence, with significantly increased odds of infection (OR: 1.720; 95% CI: 1.012-2.923; p-value: 0.045). Colposcopy examinations of females with heavy infections revealed FGS lesions and co-infections with Trichomonas vaginalis. Haematuria, though prevalent (24.6%), was not the sole indicator, as those without it faced significantly higher odds of infection (OR: 2.924; 95% CI: 1.731-4.941; p-value: 0.000). Dysuria and genital itching/burning sensation were other UgS and FGS associated symptoms. Direct water contact was associated with higher infection odds (OR: 2.601; 95% CI: 1.007-6.716; p-value: 0.048). Various risk factors were associated with UgS.

CONCLUSION

The study highlights the need for a comprehensive Urogenital Schistosomiasis (UGS) control strategy that includes secondary school adolescents, emphasizes risk factor management, promotes safe water practices, and raises awareness about UGS and Female Genital Schistosomiasis (FGS) among adolescents, thus improving control efforts and mitigating this health challenge in the region.

A Rare Abdominal Pain Associated With Chronic Intestinal Schistosomiasis Diagnosed Endoscopically: A Case Study From Saudi Arabia

Chronic intestinal schistosomiasis (CIS) refers to the long-term effects of infection with Schistosoma parasites in the intestines. This condition typically develops after repeated or prolonged exposure to contaminated freshwater containing Schistosoma eggs. The current study reports a case of an adult male, who complained of abnormal abdominal and anal pain for a month and had a medical history of complex perianal fistulae. The endoscopic investigation revealed different degrees of hyperemia, concentrated in the sigmoid colon and rectum. Lesions were localized in the rectum and sigmoid colon. Yellow granular hyperplasia, whether concentrated or dispersed, single or multiple polyps, along with observations of mucosal congestion, edema, faint vascular striations, erosions, superficial ulcers, and scattered petechial hemorrhages were noted. Also, the segmented areas of the colon had different degrees of inflammation. The microscopic histopathological analysis showed a culprit of surgical scar tissue. The granulomas harbored Schistosome parasites at the submucosal depth. Also, an erosion in the colonic mucosal tissues accompanied by lymphoplasmacytic and micro-abscess infiltrates was seen. A Schistosoma bilharzial ova was observed in the granuloma at the submucosal level. Endoscopic and histopathological investigations are useful tools to differentiate between CIS and Crohn's disease. These tools can distinguish CIS from Crohn's disease. Early detection and treatment are essential to prevent the progression of the disease and minimize long-term complications.

A 14-year review (2007-2020) of helminthiasis epidemiology in a hospital in Southern Madrid, Spain

PURPOSE

Vast majority of helminth diseases remain neglected tropical diseases (NTDs), causing significant morbidity. The widespread and periodic distribution of antiparasitic drugs, remains the cornerstone for controlling these diseases. In Spain, most helminthiasis cases are imported, and suspicion and diagnosis have become increasingly important. Our primary objective is to present the epidemiological landscape of helminthiasis diagnoses within our facility, while also detailing the demographic characteristics of the affected population.

METHODS

A retrospective study was conducted at the Hospital Universitario Severo Ochoa (HUSO) from January 1, 2007, to December 31, 2020, encompassing all diagnosed cases of helminthiasis during this period. Comprehensive epidemiological, clinical, and microbiological data were gathered for all diagnosed patients. The study population comprised patients receiving treatment at the HUSO, as well as those receiving treatment at the Leganés and Fuenlabrada Primary Care Units. Subsequently, descriptive and comparative statistics were performed, comparing Spanish and foreign patients.

RESULTS

During this period, a total of 952 patients were diagnosed with some form of helminthiasis. Among them, 495 were Spanish, and 457 were foreign. The total number of helminths identified, including patients with multiple infections, was 1,010. Significant differences were observed between Africans and Americans in terms of age distribution, with a higher prevalence among Africans in the 0-15 age range and among Americans in the 31-60 age range. Variations were noted in the distribution of helminths, with S. stercoralis significantly affecting Americans. For Spanish patients, the presence of Trichuris trichiura and S. stercoralis was significantly associated with eosinophilia, whereas among foreign patients, it was associated with Trichuris trichiura, Ascaris lumbricoides among others. Regarding symptoms, skin manifestations were more frequent among Spanish, while digestive were more common among foreigners.

CONCLUSIONS

This study offers crucial epidemiological insights into helminth infections observed over time in a Madrid hospital. Although the prevalence of helminth infections has been decreasing, there is still a need for screening and diagnosing foreign patients.

Beyond schistosomiasis: unraveling co-infections and altered immunity

Schistosomiasis is a neglected tropical disease caused by the helminth Schistosoma spp. and has the second highest global impact of all parasites. Schistosoma are transmitted through contact with contaminated fresh water predominantly in Africa, Asia, the Middle East, and South America. Due to the widespread prevalence of Schistosoma, co-infection with other infectious agents is common but often poorly described. Herein, we review recent literature describing the impact of Schistosoma co-infection between species and Schistosoma co-infection with blood-borne protozoa, soil-transmitted helminths, various intestinal protozoa, Mycobacterium, Salmonella, various urinary tract infection-causing agents, and viral pathogens. In each case, disease severity and, of particular interest, the immune landscape, are altered as a consequence of co-infection. Understanding the impact of schistosomiasis co-infections will be important when considering treatment strategies and vaccine development moving forward.

Managing cirrhosis with limited resources: perspectives from sub-Saharan Africa

Cirrhosis represents the end stage of chronic liver disease. Sub-Saharan Africa, a resource-constrained region, has a high burden of chronic liver disease, with causes including chronic viral hepatitis, excessive alcohol use, and metabolic dysfunction-associated steatotic liver disease (MASLD), the risk of which is burgeoning. The development of liver cirrhosis predicts for morbidity and mortality, driven by both liver dysfunction and the consequences of portal hypertension. Compensated cirrhosis portends a better prognosis than decompensated cirrhosis, highlighting the need for the early diagnosis of cirrhosis and its causes. With resource challenges, the diagnosis and management of cirrhosis is demanding, but less costly and less invasive interventions with substantial benefits, ranging from simple blood tests to transient elastography, are feasible in such settings. Simple interventions are also available to manage the complex manifestations of decompensation, such as β blockers in variceal bleeding prophylaxis, salt restriction and appropriate diuretic use in ascites, and lactulose and generic rifaximin in hepatic encephalopathy. Ultimately, managing the underlying causative factors of liver disease is key in improving prognosis. Management demands expanded policy interventions to increase screening and treatment for hepatitis B and C and reduce alcohol use and the metabolic factors driving MASLD. Furthermore, the skills needed for more specialised interventions, such as transjugular intrahepatic portosystemic shunt procedures and even liver transplantation, warrant planning, increased capacity, and support for regional centres of excellence. Such centres are already being developed in sub-Saharan Africa, demonstrating what can be achieved with dedicated initiatives and individuals.

Efficacy and safety of praziquantel treatment against Schistosoma mansoni infection among pre-school age children in southern Ethiopia

BACKGROUND

Preventive chemotherapy with a single dose of praziquantel given to an all-at-risk population through mass drug administration is the cornerstone intervention to control and eliminate schistosomiasis as a public health problem. This intervention mainly targets school age children, and pre-school age children (pre-SAC) are excluded from receiving preventive chemotherapy, partly due to scarcity of data on praziquantel treatment outcomes.

METHODS

We conducted active efficacy and safety surveillance of praziquantel treatment among 240 Schistosoma mansoni-infected pre-SAC who received a single dose of praziquantel (40 mg/kg) in southern Ethiopia. The study outcomes were egg reduction rates (ERR) and cure rates (CRs) four weeks after treatment using the Kato-Katz technique and treatment-associated adverse events (AEs) that occurred within 8 days post-treatment.

RESULTS

The overall ERR was 93.3% (WHO reference threshold ≥ 90%), while the CR was 85.2% (95% CI = 80.0-89.5%). Baseline S. mansoni infection intensity was significantly associated with CRs, 100% among light infected than moderate (83.4%) or heavy (29.4%) infected children. An increase of 100 in baseline S. mansoni egg count per gram of stool resulted in a 26% (95% CI: 17%, 34%) reduction in the odds of cure. The incidence of experiencing at least one type of AE was 23.1% (95% CI: 18.0%, 29.0%). Stomachache, diarrhea, and nausea were the most common AEs. AEs were mild-to-moderate grade and transient. Pre-treatment moderate (ARR = 3.2, 95% CI: 1.69, 6.14) or heavy infection intensity (ARR = 6.5, 95% CI: 3.62, 11.52) was a significant predictor of AEs (p < 0.001). Sex, age, or soil-transmitted helminth coinfections were not significant predictors of CR or AEs.

CONCLUSIONS

Single-dose praziquantel is tolerable and effective against S. mansoni infection among pre-SAC, and associated AEs are mostly mild-to-moderate and transient. However, the reduced CR in heavily infected and AEs in one-fourth of S. mansoni-infected pre-SAC underscores the need for safety and efficacy monitoring, especially in moderate-to-high infection settings. Integrating pre-SACs in the national deworming programs is recommended to accelerate the elimination of schistosomiasis as a public health problem.

Evaluating the Prevalence and Risk Factors of Schistosomiasis Amongst School-Aged Children in Low- and Middle-Income Communities: Ehlanzeni District Municipality, South Africa, 2015-2021

This study aimed to assess the prevalence and identify risk factors of schistosomiasis among school-aged children in low- and middle-income communities. A retrospective cross-sectional study was conducted to review patient records of school-age children. Data on gender, age, sub-district, area residing in, patient status, history of bilharzia, presence of blood in the urine, and schistosomiasis diagnoses were collected. The data were analyzed using IBM Statistical Package for the Social Sciences (SPSS) version 27. Logistic regression was employed to determine the factors associated with schistosomiasis. The overall prevalence of schistosomiasis in the study population was 75%, with higher prevalence observed among male children (89%), children aged between 10 and 14 years (59%), urban areas (51%), and rural-dominated districts, particularly Bushbuckridge (42%) and City of Mbombela (51%). Age, especially 10-14 years old (p ˂ 0.01; 95%CI: 1.98-2.29), a history of bilharzia (p = 0.01; 95%CI: 1.15-1.96), and the presence of blood in urine (p ˂ 0.01; 95%CI: 2.02-2.40) were significantly associated with schistosomiasis while being a female child was found to be a protective factor (AOR: 0.35; CI 0.35-0.41). This study underscores the importance of implementing robust screening procedures and the necessity for health education to mitigate the high prevalence of schistosomiasis and prevent its further spread.

An accident waiting to happen? Exposing the potential of urogenital schistosomiasis transmission in the Lake Albert region, Uganda

BACKGROUND

Urogenital schistosomiasis caused by the parasitic blood fluke Schistosoma haematobium is the most common form of that constitutes a majority of over 240 million schistosomiasis cases. The enigmatic absence of urogenital schistosomiasis in Uganda has, until now, been attributed to the absence of substantial populations of suitable snail intermediate hosts.

METHODS

Malacological surveys were carried out in 73 sites southeast of Lake Albert, Uganda in October and November 2020. Collected snails were transported to the laboratory for identification. The snails were identified using partial mitochondrial cytochrome c oxidase subunit one and nuclear internal transcribed spacer barcoding. Schistosome infections in snails were also assessed using cercarial shedding and rapid diagnostic PCR techniques.

RESULTS

We found Bulinus globosus and Bulinus nasutus productus, the main intermediate species in the transmission of S. haematobium in mainland East Africa. In this survey, B. globosus was more common than B. nasutus productus, with the former reported at four sites (total count = 188) and the latter reported at one site (total count = 79). Molecular testing revealed a high prevalence of Schistosoma bovis in B. nasutus productus (16%), but no S. haematobium infections were found.

CONCLUSIONS

Given the abundance of snail hosts and the risky human water contact behaviours observed, we highlight the potential for urogenital schistosomiasis transmission in the region.

Prevalence and factors associated with ongoing transmission of Schistosoma haematobium after 12 rounds of Praziquantel Mass Drug Administration among school age children in Southern Tanzania

Background

World Health Organization (WHO) recommends periodic praziquantel Mass Drug Administration (MDA) to vulnerable populations, especially school-aged children, to reduce the risk of transmission. In the S. haematobium endemic Lindi region, on the southeastern coast of Tanzania, praziquantel has been distributed for more than a decade (12 rounds) in schools. However, there is a paucity of data on the current burden and factors perpetuating ongoing urogenital schistosomiasis among SAC. The study investigated the prevalence and factors associated with the ongoing transmission of S. haematobium among school-age children (SAC) after 12 rounds of praziquantel in Nachingwea, Southern Tanzania.

Material and methods

A quantitative cross-sectional study was conducted between May and June 2022 among 483 SAC in the Nachingwea district. Macrohematuria, microhaematuria, and S. haematobium eggs were assessed in the collected urine sample for each participant, using macroscopic observation, urine dipstick, and urine filtration techniques, respectively. Infection intensity was quantified for positive S. haematobium urine samples. Knowledge and attitudes towards schistosomiasis were assessed among participants through an interview-administered questionnaire, and water contact practices were registered through an observation checklist. Data were summarized using descriptive statistics, the Chi-square test, and logistic regression.

Results

The prevalence of S. haematobium infection was 10.6%, with 0.6% (3/51) prevalence of heavy infection. The factors associated with S. haematobium persistence transmission were a habit of visiting the water bodies (AOR = 1.62, 95% CI: 0.40-1.96), swimming in the visited water bodies (AOR = 4.58, 95% CI: 1.72-12.19), using water from the river source (AOR = 3.79, 95% CI: 1.51-9.51) and attending Mkumba Primary School (17.4%; AOR = 6.12, 95% CI: 1.64-22.85).

Conclusions

Findings suggest ongoing transmission of urogenital schistosomiasis in the Nachingwea District despite 12 rounds of praziquantel treatment, with a low prevalence of heavy infection (0.6%). Praziquantel distribution should be complemented with health education, especially on the cause and transmission of urogenital schistosomiasis to increase knowledge that will improve a good attitude towards schistosomiasis prevention. An adequate water supply is to be considered to reduce infections due to the visit to water sources for daily use.

Prevalence and Predictors Associated to Schistosoma mansoni Infection among Patients Attending the Saint Jean de Malte Hospital, Njombe, Littoral Region, Cameroon

Background

Schistosomiasis remains a major public health concern in sub-Saharan Africa. It has been associated to morbidity and mortality in developing countries including Cameroon, and Njombe-Penja health district is an endemic area. This study is aimed at determining the prevalence and risk factors of Schistosoma mansoni infection among patients attending the Saint Jean de Malte Hospital, Njombe.

Methods

A cross-sectional study design was employed, with the enrolment of 300 participants using convenience sampling technique. Data were collected using a structured questionnaire. Stool specimens were collected and examined using direct microscopy, Kato-Katz's method, and formol ether concentration technique. Data were analyzed using SPSS, and chi-square test was used to assess the association. Risk factors for S. mansoni infection were assessed using multivariable logistic regression, and a p < 0.05 was considered significant.

Results

The overall prevalence of Schistosoma mansoni infection was 13%. Schistosoma mansoni infection was mostly frequent among patients < 20 years and males. Stream usage (AOR = 2.15, 95% CI. 1.32-3.50), always visiting the stream (AOR = 11.35, 95% CI 2.33-55.33), always swimming and washing clothes in the stream (AOR = 7 : 10, 95% CI 2.31-21.80), age group < 20 years (AOR = 3.7, 95% CI 1.1-12.2), and age group 20-29 years (AOR = 2.58, 95% CI 1.14-18.42) were significantly associated with increased risk of S. mansoni infection.

Conclusion

These findings suggest that Schistosoma mansoni infection is of public health concern in Njombe and its environs. Age of <20 years and between 20 and 29 years, stream usage, always visiting the stream, and always swimming and washing clothes in the stream were the main risk factors of S. mansoni infection. Thus, mass drug administration and health education are required.

Geospatial disparities and predictors of anaemia among pregnant women in Sub-Saharan Africa

BACKGROUND

Anaemia has become a major public health concern among women in Sub-Saharan Africa (SSA). However, little is known about the spatial disparities in anaemia prevalence and their associated factors among pregnant women in the region. This study analysed the spatial disparities in anaemia and their associated factors among pregnant women in rural and urban settings in SSA.

METHODS

This is a secondary analysis of the most recent demographic and health surveys of 26 countries in SSA. Spatial autocorrelation and hotspot assessment were conducted, while a multivariate logistic regression model was used to identify demographic factors associated with anaemia.

RESULTS

Anaemia was reported among ~50% of pregnant women in urban and rural areas of SSA. The hotspot analysis identified the West African sub-region as having a higher concentration of anaemia cases in rural settings. In urban areas, the odds of anaemia were significantly higher among pregnant women in their second trimester (Adjusted OR = 2.39, CI = 1.99, 2.76). On the other hand, pregnant women in their third trimester (Adjusted OR = 1.98, CI = 1.77, 2.22) and those who had taken intestinal parasite drugs (Adjusted OR = 1.12 CI = 1.02, 1.23) had a higher likelihood of having anaemia in rural areas. Pregnant women aged 35-39 years (Adjusted OR = 0.52, CI = 0.33, 0.81) and those aged 40-44 years (Adjusted OR = 0.69, CI = 0.50, 0.95) had a lesser likelihood of having anaemia compared to women aged 15-19 years in urban and rural areas respectively. Compared to Congo DR, Benin (OR = 2.22, CI = 1.51, 3.28) and Mali (OR = 3.71, CI = 2.73, 5.05) had higher odds of anaemia in urban and rural areas respectively.

CONCLUSIONS

Spatial disparities in anaemia persist among pregnant women in rural and urban settings in SSA. Prevailing spatial variations in anaemia may be addressed by specialised interventions considering the contextual residential settings and socio-economic factors highlighted in this study.

Efficacy of Single-Dose Praziquantel for the Treatment of Schistosoma mansoni Infections among School Children in Rwanda

Preventive chemotherapy with single-dose praziquantel is the WHO-recommended intervention strategy to eliminate schistosomiasis as a public health problem in endemic countries. Surveillance of drugs used in mass drug administration (MDA) programs is recommended to evaluate its effectiveness in reducing transmissions. After a decade-long implementation of a school-based MDA program in Rwanda, we conducted efficacy surveillance of single-dose praziquantel MDA against S. mansoni infection. Two weeks before MDA, stool examinations were performed to screen MDA-eligible school children (n = 4998) for S. mansoni infection using the Kato-Katz technique, and 265 (6.5%) children tested positive for the infection. All children received praziquantel and albendazole as preventive chemotherapy through the MDA campaign. Infected children were enrolled and followed for efficacy monitoring, and stool examination was repeated after three weeks post-MDA (n = 188). Before treatment, 173 (92%) had a light infection, and 15 (8%) had a moderate infection intensity. The primary and secondary outcomes were parasitological cure and egg reduction rates at three weeks post-treatment. The overall cure and egg reduction rates for S. mansoni infection were 97.9% (95% CI = 94.6-99.4) and 97.02%, respectively. Among the 173 children with light infection intensity, 170 (98.3%, 95% CI = 95.0-99.6) were cured, and among the 15 children who had moderate infection intensity, 14 (93.3%) were cured. No significant association between cure rate and pre-treatment infection intensity was observed. We conclude that single-dose praziquantel is efficacious against light-to-moderate S. mansoni infection. Preventive chemotherapy with praziquantel effectively reduces schistosome reservoirs and transmission among school-age children.

Dried urine spot method for detection of Schistosoma mansoni circulating cathodic antigen in resource-limited settings: a proof of concept study

Background

Among the challenges in schistosomiasis surveillance and mapping surveys is the lack of a sensitive diagnostic method especially in low transmission setting. Currently, the WHO recommends the use point-of-care circulating cathodic antigen (Schisto POC-CCA) tests for surveillance and mapping of intestinal schistosomiasis. However, Schisto POC-CCA test has its drawbacks, one of which is the timely availability of test kits. One approach to overcoming this challenge is to develop a low-cost sampling method that allows for the collection and transport of urine specimens even in resource-limited settings.

Objective

To develop a simple and efficient method for the collection and detection of Schistosoma mansoni (S. mansoni) CCA using urine spotted onto filter paper.

Methodology

To develop a dried urine spot (DUS) method, various dried matrix extraction parameters were tested and optimized using predesigned steps. The parameters include the size of filter paper (determined by the number of punches), volume of solvents, and type of solvent. Moreover, we optimized the incubation conditions (time and temperature). Urine and stool specimens to conduct the experiments were collected from volunteer fishermen in Mwanza and this project staff. Data were entered into the Microsoft Excel spreadsheet and IBM Statistical Package for the Social Sciences, version 20 for analysis.

Results

The optimal results were obtained when the procedure was run under the following conditions: Five punches of filter paper containing DUS were dissolved in 150 µl of distilled water and incubated at room temperature for 24 hours in an Eppendorf tube. More than 93% of the assays performed under these conditions produced results that were either comparable to or significantly better than the standard method.

Conclusion

This study demonstrates the feasibility of collecting urine specimen (DUS) using filter paper and detecting Schistosoma CCA from DUS specimen using the Schisto POC-CCA cassette test.

Performance evaluation of the AiDx multi-diagnostic automated microscope for the detection of schistosomiasis in Abuja, Nigeria

In this research, we report on the performance of automated optical digital detection and quantification of Schistosoma haematobium provided by AiDx NTDx multi-diagnostic Assist microscope. Our study was community-based, and a convenient sampling method was used in 17 communities in Abuja Nigeria, based on the disease prevalence information extracted from the baseline database on schistosomiasis, NTD Division, of the Federal Ministry of Health. At baseline, samples from 869 participants were evaluated of which 358 (34.1%) tested S. haematobium positive by the reference diagnostic standard. Registered images from the fully automated (autofocusing, scanning, image registration and processing, AI image analysis and automatic parasite count) AiDx assist microscope were analyzed. The Semi automated (autofocusing, scanning, image registration & processing and manual parasite count) and the fully automated AiDx Assist showed comparable sensitivities and specificities of [90.3%, 98%] and [89%, 99%] respectively. Overall, estimated egg counts of the semi-automated & fully automated AiDx Assist correlated significantly with the egg counts of conventional microscopy (r = 0.93, p ≤ 0.001 and r = 0.89, p ≤ 0.001 respectively). The AiDx Assist device performance is consistent with requirement of the World Health Organization diagnostic target product profile for monitoring, evaluation, and surveillance of Schistosomiasis elimination Programs.

A mixed method analysis of the Botswana schistosomiasis control policy and plans using the policy triangle framework

BACKGROUND

The present goal of the World Health Organization (WHO) 2021-2030 roadmap for Neglected Tropical Diseases is to eliminate schistosomiasis as a public health problem, and reduce its prevalence of heavy infections to less than 1%. Given the evolution and impact of schistosomiasis in the Ngamiland district of Botswana, the aim of this study was to analyze the control policies for the district using the Policy Triangle Framework.

METHODS

The study used a mixed method approaches of an analysis of policy documents and interviews with 12 informants who were purposively selected. Although the informants were recruited from all levels of the NTD sector, the analysis of the program was predominantly from the Ngamiland district. Data were analyzed using Braun and Clarke's approach to content analysis.

RESULTS

The study highlights the presence of clear, objectives and targets for the Ngamiland control policy. Another theme was the success in morbidity control, which was realized primarily through cycles of MDA in schools. The contextual background for the policy was high morbidity and lack of programming data. The implementation process of the policy was centralized at the Ministry of Health (MOH) and WHO, and there was minimal involvement of the communities and other stakeholders. The policy implementation process was impeded by a lack of domestic resources and lack of comprehensive policy content on snail control and no expansion of the policy content beyond SAC. The actors were predominately MOH headquarters and WHO, with little representation of the district, local level settings, NGOs, and private sectors.

CONCLUSIONS

The lack of resources and content in the control of environmental determinants and exclusion of other at-risk groups in the policy, impeded sustained elimination of the disease. There is a need to guide the treatment of preschool-aged children and develop national guidelines on treating foci of intense transmission. Moreover, the dynamic of the environmental transmissions and reorientation of the schistosomiasis policy to respond to the burden of schistosomiasis morbidity, local context, and health system context are required.

Urinogenital schistosomiasis knowledge, attitude, practices, and its clinical correlates among communities along water bodies in the Kwahu Afram Plains North District, Ghana

BACKGROUND

Adequate knowledge and proper practices coupled with knowledge of the burden of disease are necessary for the eradication of Schistosoma infection. This study assessed knowledge, attitude, and practice (KAP) as well as health outcomes related to Schistosoma haematobium infection at Kwahu Afram Plains North District (KAPND).

METHODS

A cross-sectional survey using a structured questionnaire was carried out among 140 participants from four local communities in KAPND in August 2021. From these participants, 10ml of urine was collected for determination of the presence of S. haematobium and urine routine examination. In addition, 4ml of blood was collected and used for haematological examination. Descriptive statistics and logistic regression analysis using IBM SPSS were used to describe and represent the data collected.

RESULTS

The study reports a gap in knowledge about schistosomiasis in the study area with the majority indicating that they have not heard of schistosomiasis (60.7%), do not know the mode of transmission (49.3%), and do not know how the disease could be spread (51.5%). The overall prevalence of urinary schistosomiasis was 52.9%. This was associated with age, occupation, perceived mode of Schistosoma transmission, knowledge of Schistosoma prevention, awareness that schistosomiasis can be treated, frequency of visits to water bodies, and water usage patterns. In multivariate analysis, factors that remained significantly associated with S. haematobium infection were age 21-40 (OR  =  0.21, 95% CI: 0.06-0.76), 41-60 (OR  =  0.01, 95% CI: 0.01-0.52) and ≥ 60 (OR  =  0.02, 95% CI: 0.02-0.87), informal employment (OR  =  0.01, 95% CI: 0.01-0.69) and awareness of transmission by drinking water from river body (OR  =  0.03, 95% CI: 0.03-0.92). In Schistosoma infection, reduced haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, lymphocytes and eosinophils were observed. White blood cells, neutrophils, and monocytes were significantly elevated in infected states. Urine analysis revealed high pus cells and red blood cells counts among Schistosoma-positive participants.

CONCLUSION

Schistosoma infection is endemic among inhabitants in KAPND, and is associated with a gap in knowledge, awareness, and practice possibly due to inadequate education in the area. Poor clinical outcomes associated with Schistosoma infection have been demonstrated in the area. A well-structured public education, nutritional intervention, and mass drug administration will be necessary to eradicate this menace.

Review of Recent Prevalence of Urogenital Schistosomiasis in Sub-Saharan Africa and Diagnostic Challenges in the Field Setting

Human schistosomiasis is one of neglected tropical diseases that remain highly prevalent in sub-Saharan Africa (SSA). Human schistosomiasis is mainly caused by two species, Schistosoma haematobium and S. mansoni, leading to urogenital and intestinal schistosomiasis, respectively. The World Health Organization (WHO) recommends mass drug administration (MDA) with praziquantel as the primary method of global intervention. Currently, MDA with praziquantel covers over half of the target population in endemic SSA countries. However, an accurate diagnosis is crucial for monitoring and evaluating the effectiveness of MDA. The standard diagnosis of both urogenital and intestinal schistosomiasis relies on the microscopic identification of eggs. However, the diagnostic sensitivity of this approach is low, especially for light or ultra-light infections. This is because Schistosoma eggs are laid inside of the venous plexus of the urinary bladder or mesenteric vein, where the adult flukes live. Approximately half of the eggs circulate in the blood vessels or are packed in neighboring tissues, while the remaining half are expelled into the lumen of the urinary bladder or intestine intermittently when the blood vessels are ruptured. In the field setting, the accuracy of any diagnostic method is critical for proper management of the intervention. The present article reviews the recent prevalence of urogenital schistosomiasis in SSA and highlights the practical limitations of diagnostic methods such as urine microscopy, urine reagent strips, molecular diagnosis, and ultrasound scanning in the field setting. Despite continuous global efforts to eliminate schistosomiasis over the past 20 years, many areas still remain endemic in SSA. No single diagnostic approach achieves acceptable sensitivity and specificity in the field setting. Therefore, any field survey should employ a combination of these methods based on the purpose of the study to accurately monitor and evaluate urogenital schistosomiasis. Based on diagnostic values and a cost-benefit analysis, a urine reagent strip test can replace urine microscopy in the field setting. The WHO criteria by ultrasound diagnosis should be updated including the echogenic snow sign and contour distortion.

Addressing neglected tropical diseases in Africa: a health equity perspective

Africa accounts for over one-third of the global burden of neglected tropical diseases (NTDs). Although continental efforts have been made to combat these diseases, there still exists a significant gap in the fight, ranging from a lack of data to multisectoral participation and, most critically, health inequity. Here, we assess the effort made to combat challenges caused by health disparities to prevent and control neglected tropical diseases. This article engages a health equity view to addressing the need for inclusion in achieving universal health coverage towards eradicating NTDs and outlines strategies to achieve such. Health disparities exist, and there is substantial and irrefutable evidence for them. Inequitable distribution and limited access to basic and essential life resources such as water, housing, toilets, soap, and literacy continue to facilitate the existence of NTDs such as Schistosomiasis, soil-transmitted helminths, and trachoma, the occurrence of which can be avoided if affected populations have better access to those resources. To eradicate NTDs, health disparities must be addressed to provide excellent health care to all populations and adequate universal health coverage for long-term sustainability. NTD programmes need to be data-driven to ensure better decision-making and ensure the inclusion of diverse population groups including women, children, and youths. This will ensure that no one is left behind, drawing upon the sustainable development goals. Community participation and engagement should also be considered as an essential approach to ensure people are at the centre of health programmes and their implementation.

Two-stage automated diagnosis framework for urogenital schistosomiasis in microscopy images from low-resource settings

PURPOSE

Automated diagnosis of urogenital schistosomiasis using digital microscopy images of urine slides is an essential step toward the elimination of schistosomiasis as a disease of public health concern in Sub-Saharan African countries. We create a robust image dataset of urine samples obtained from field settings and develop a two-stage diagnosis framework for urogenital schistosomiasis.

APPROACH

Urine samples obtained from field settings were captured using the Schistoscope device, and S. haematobium eggs present in the images were manually annotated by experts to create the SH dataset. Next, we develop a two-stage diagnosis framework, which consists of semantic segmentation of S. haematobium eggs using the DeepLabv3-MobileNetV3 deep convolutional neural network and a refined segmentation step using ellipse fitting approach to approximate the eggs with an automatically determined number of ellipses. We defined two linear inequality constraints as a function of the overlap coefficient and area of a fitted ellipses. False positive diagnosis resulting from over-segmentation was further minimized using these constraints. We evaluated the performance of our framework on 7605 images from 65 independent urine samples collected from field settings in Nigeria, by deploying our algorithm on an Edge AI system consisting of Raspberry Pi + Coral USB accelerator.

RESULT

The SH dataset contains 12,051 images from 103 independent urine samples and the developed urogenital schistosomiasis diagnosis framework achieved clinical sensitivity, specificity, and precision of 93.8%, 93.9%, and 93.8%, respectively, using results from an experienced microscopist as reference.

CONCLUSION

Our detection framework is a promising tool for the diagnosis of urogenital schistosomiasis as our results meet the World Health Organization target product profile requirements for monitoring and evaluation of schistosomiasis control programs.

Prevalence and Determinants of Schistosoma mansoni Infection among Pre-School Age Children in Southern Ethiopia

School-based deworming program is implemented to control and eliminate Schistosoma mansoni infection in many endemic countries, including Ethiopia. However, pre-school-age children (pre-SAC) are not targeted to receive preventive chemotherapy against S. mansoni infection, partly due to a lack of information on the disease burden. We assessed the prevalence and correlates of S. mansoni infection among pre-SAC in Southern Ethiopia. A total of 1683 pre-SAC aged 4 to 7 years were screened for S. mansoni infection. A multilevel binary logistic regression was fitted to detect the significant determinants of S. mansoni infection. Adjusted odds ratios (AORs) with a 95% confidence interval (CI) were used to identify determinants of S. mansoni infection. The overall prevalence of S. mansoni infection was 14.3% (95% CI: 12.6, 16.0%). S. mansoni infection was significantly higher among 6-year-old (AOR = 2.58, 95% CI: 1.55, 4.27) and 7-year-old children (AOR = 4.63, 95% CI: 2.82, 7.62). Accompanying others to water sources sometimes (AOR = 2.60, 95% CI: 1.12, 6.01) and all the time (AOR = 5.91, 95% CI: 2.51, 13.90), and residing in less than one kilometer from the infested water source (AOR = 3.17, 95% CI: 1.47, 6.83) increased the odds of S. mansoni infection. In conclusion, the prevalence of S. mansoni infection among pre-SAC in the study area was moderate. The study highlights the urgent need to include pre-SAC aged 4 to 7 years in annual preventive chemotherapy campaigns to reduce the risk of possible sources of infection and enhance the achievement of the elimination target.

Niclosamide exposure disrupts antioxidant defense, histology, and the liver and gut transcriptome of Chinese soft-shelled turtle (Pelodiscus sinensis)

Niclosamide (NIC) is the only commercially available molluscicide for controlling schistosomiasis, and its negative effects on aquatic animals had been frequently reported in recent years. However, the toxicity mechanism of NIC on the Chinese soft-shelled turtle (Pelodiscus sinensis) have not yet been investigated. Therefore, juvenile turtles were exposed to 0 (control group), 10 (low NIC, L), and 50 (high NIC, H) μg/L NIC for 120 h and our results demonstrated that NIC exposure induced severe pathological changes in the liver of P. sinensis. And the typical symptom included edema, nuclear migration and deformation, and vacuolization. Compared with the liver, the NIC exposure did not cause significant damage in the gut tissue. In addition, the DHE staining demonstrated that the ROS production of liver and gut increased with the increase in concentration of NIC. The activities of antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) was inhibited with increased malondialdehyde (MDA) content, indicating that the antioxidant defense was significantly perturbed. Further, the transcriptome sequencing and was applied to evaluate the underlying toxicity mechanisms of NIC exposure in liver and gut of P. sinensis. Pathway enrichment showed that the disorder of lipid metabolism and innate immune regulation, including Toll-like receptors (TLRs), tumor necrosis factor (TNF), lectins, and complement and coagulation cascades, were toxicological properties of NIC on P. sinensis. Overall, the current study provides valuable information to understand the toxic effect of NIC on Chinese soft-shelled turtle.

A Critical Review on Human Malaria and Schistosomiasis Vaccines: Current State, Recent Advancements, and Developments

Malaria and schistosomiasis are two major parasitic diseases that remain leading causes of morbidity and mortality worldwide. Co-infections of these two parasites are common in the tropics, where both diseases are endemic. The clinical consequences of schistosomiasis and malaria are determined by a variety of host, parasitic, and environmental variables. Chronic schistosomiasis causes malnutrition and cognitive impairments in children, while malaria can cause fatal acute infections. There are effective drugs available to treat malaria and schistosomiasis. However, the occurrence of allelic polymorphisms and the rapid selection of parasites with genetic mutations can confer reduced susceptibility and lead to the emergence of drug resistance. Moreover, the successful elimination and complete management of these parasites are difficult due to the lack of effective vaccines against Plasmodium and Schistosoma infections. Therefore, it is important to highlight all current vaccine candidates undergoing clinical trials, such as pre-erythrocytic and erythrocytic stage malaria, as well as a next-generation RTS,S-like vaccine, the R21/Matrix-M vaccine, that conferred 77% protection against clinical malaria in a Phase 2b trial. Moreover, this review also discusses the progress and development of schistosomiasis vaccines. Furthermore, significant information is provided through this review on the effectiveness and progress of schistosomiasis vaccines currently under clinical trials, such as Sh28GST, Sm-14, and Sm-p80. Overall, this review provides insights into recent progress in malarial and schistosomiasis vaccines and their developmental approaches.

Schistosoma mansoni Infections and Morbidities Among School Children in Hotspot Areas of Jimma Town, Southwest Ethiopia: A Cross-Sectional Study

BACKGROUND

Schistosoma mansoni is endemic in all regions of Ethiopia. School-age children are highly vulnerable to schistosomiasis-related morbidities. This study aimed to determine the prevalence of S. mansoni and morbidities among schoolchildren in schistosomiasis hotspot areas of Jimma Town.

METHODS

Cross-sectional study was conducted among schoolchildren in Jimma Town. Stool sample was examined using Kato-Katz for the detection of S. mansoni.

RESULTS

A total of 332 schoolchildren were included in the study. The prevalence of S. mansoni and STHs was 20.2% and 19.9%, respectively. Males (adjusted odds ratio (AOR) = 4.9; 95% CI: 2.4-10.1; p = .001), swimming habits (AOR = 3.0; 95% CI: 1.1-8.3; p = .033) and schools attended (AOR = 4.3; 95% CI: 1.4-13.6; p = .012, AOR = 3.8; 95% CI: 1.3-10.9; p = .014) were associated factors for S. mansoni infections. Blood in stool (AOR = 2.0; CI: 1.0-4.1; p = .045) and feeling general malaise (AOR = 4.0; CI: 1.4-11.3; p = .007) were significantly associated with S. mansoni infection-related morbidities. Moreover, prevalence of stunting among schoolchildren 6 to 11 years of age was 29.7% (71/239).

CONCLUSION

The transmission of S. mansoni among schoolchildren is moderate. Sex, swimming habits and schools attended were associated with S. mansoni infections. Blood in stool and general malaise were clinical characteristics associated with S. mansoni infections. Integration of health promotion is needed to achieve control and elimination goals. Attention should also be given to stunted growth of the children.

Human Schistosomiasis Vaccines as Next Generation Control Tools

Human schistosomiasis remains one of the most important yet neglected tropical diseases, with the latest estimates from the Global Burden of Disease Study indicating that over 140 million people are infected with schistosomes [...]

Global trends in the epidemiology of bladder cancer: challenges for public health and clinical practice

Bladder cancer is among the ten most common cancers globally, causes considerable morbidity and mortality and is, therefore, a substantial burden for health-care systems. The incidence of bladder cancer is affected by demographic trends, most notably population growth and ageing, as well as exposure to risk factors, especially tobacco smoking. Consequently, the incidence has not been stable throughout the world over time, nor will it be in the near future. Further primary prevention efforts are of the utmost importance to reduce the medical and financial burden of bladder cancer on populations and health-care systems. Simultaneously, less-invasive and lower-cost approaches for the diagnosis of both primary and recurrent bladder cancers are required to address challenges posed by the increasing shortage of health-care professionals and limited financial resources worldwide. In this regard, urinary biomarkers have demonstrated promising diagnostic accuracy and efficiency. Awareness of the risk factors and symptoms of bladder cancer should also be increased in society, particularly among health-care professionals and high-risk groups. Studies investigating the associations between lifestyle factors and bladder cancer outcomes are scarce and should be a research priority. In this Review, we outline global trends in bladder cancer incidence and mortality, and discuss the main risk factors influencing bladder cancer occurrence and outcomes. We then discuss the implications, challenges and opportunities of these epidemiological trends for public health and clinical practice.

The Idiosyncratic Efficacy of Spironolactone-Loaded PLGA Nanoparticles Against Murine Intestinal Schistosomiasis

Background

Schistosomiasis is a chronic debilitating parasitic disease accompanied with severe mortality rates. Although praziquantel (PZQ) acts as the sole drug for the management of this disease, it has many limitations that restrict the use of this treatment approach. Repurposing of spironolactone (SPL) and nanomedicine represents a promising approach to improve anti-schistosomal therapy. We have developed SPL-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) to enhance the solubility, efficacy, and drug delivery and hence decrease the frequency of administration, which is of great clinical value.

Methods

The physico-chemical assessment was performed starting with particle size analysis and confirmed using TEM, FT-IR, DSC, and XRD. The antischistosomal effect of the SPL-loaded PLGA NPs against Schistosoma mansoni (S. mansoni)-induced infection in mice was also estimated.

Results

Our results manifested that the optimized prepared NPs had particle size of 238.00 ± 7.21 nm, and the zeta potential was -19.66 ± 0.98 nm, effective encapsulation 90.43±8.81%. Other physico-chemical features emphasized that nanoparticles were completely encapsulated inside the polymer matrix. The in vitro dissolution studies revealed that SPL-loaded PLGA NPs showed sustained biphasic release pattern and followed Korsmeyer-Peppas kinetics corresponding to Fickian diffusion (n<0.45). The used regimen was efficient against S. mansoni infection and induced significant reduction in spleen, liver indices, and total worm count (ρ<0.05). Besides, when targeting the adult stages, it induced decline in the hepatic egg load and the small intestinal egg load by 57.75% and 54.17%, respectively, when compared to the control group. SPL-loaded PLGA NPs caused extensive damage to adult worms on tegument and suckers, leading to the death of the parasites in less time, plus marked improvement in liver pathology.

Conclusion

Collectively, these findings provided proof-of-evidence that the developed SPL-loaded PLGA NPs could be potentially used as a promising candidate for new antischistosomal drug development.

Prevalence of Intestinal Parasitosis in Guinea: Systematic Review of the Literature and Meta-Analysis

BACKGROUND

Intestinal parasitosis constitute a major public health issue, particularly in sub-tropical and tropical areas. Even though they are classified as neglected tropical diseases, no national study has been carried out recently in Guinea to estimate the prevalence of intestinal parasitosis.

OBJECTIVE

A systematic review and meta-analysis aimed to determine the overall prevalence of intestinal parasitosis in Guinea.

METHOD

The PRISMA method was used to perform a systematic review and meta-analysis. The studies carried out in order to study intestinal parasitosis in Guinea and published between 2010 and 2020 were searched in online public databases. The prevalence of parasitosis was calculated by a random-effects meta-analysis. Subgroup comparisons were performed using Q-tests. Statistical analyses were performed with the R software. This review was registered with PROSPERO under the identification number CRD42022349743.

RESULTS

69 studies were selected out of 1230 studies identified in online public databases. The meta-analysis involved 44,186 people with an overall prevalence of intestinal parasitic infections of 52%.

CONCLUSIONS

This is the first study in Guinea to assess the prevalence of intestinal parasitic infections in different regions of the country. It was found that intestinal parasitosis are a real health problem in Guinea, hence, the need to put in place national strategies for regular control.

Metabolomics for biomarker discovery in schistosomiasis: A systematic scoping review

Background

Metabolomic based approaches are essential tools in the discovery of unique biomarkers for infectious diseases via high-throughput global assessment of metabolites and metabolite pathway dysregulation. This in-turn allows the development of diagnostic tools and provision of therapeutics. In this review, we aimed to give an overview of metabolite biomarkers and metabolic pathway alterations during Schistosoma haematobium and Schistosoma mansoni infections.

Methods

We conducted the review by systematically searching electronic databases and grey literature to identify relevant metabolomics studies on schistosomiasis. Arksey and O’Malley methodology for conducting systematic scoping reviews was applied. A narrative summary of results was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for scoping review guidelines.

Results

Twelve articles included in the review identified 127 metabolites, whose concentrations were considerably altered during S. mansoni and S. haematobium infections. The metabolites were assigned to metabolic pathways involved in energy (34.6%), gut microbial (11.0%), amino acid (25.2%), nucleic acids (6.3%), immune proteins (8.7%) hormones (2.4%) and structural proteins/lipids (11.8%). Energy related metabolic pathways were the most affected during schistosome infections with metabolites such as succinate, citrate, aconitate and fumarate of the tricarbocylic acid cycle being significantly altered in organ, serum and plasma samples. Amino acid metabolism was also impacted during schistosome infections as phenylacetylglycine, alanine, taurine, 2-oxoisocaproate and 2-oxoisovalerate emerged as potent biomarkers. Elevated structural proteins such as actin, collagen and keratin concentrations were identified as biomarkers of liver fibrosis, a common pathological feature in chronic schistosomiasis infections. Hippurate was a major metabolite biomarker in the gut microbial related pathway.

Conclusions

The analysis of the literature revealed that energy related metabolic pathways are considerably altered during S. mansoni and S. haematobium infections. Therefore, their metabolites may provide biomarkers for diagnosis and prognosis in addition to providing therapeutics for parasitic infections. This scoping review has identified a need to replicate more schistosomiasis metabolomic studies in humans to complement animal-model based studies.

A Nomogram for Predicting Prognosis of Advanced Schistosomiasis japonica in Dongzhi County-A Case Study

BACKGROUNDS

Advanced schistosomiasis is the late stage of schistosomiasis, seriously jeopardizing the quality of life or lifetime of infected people. This study aimed to develop a nomogram for predicting mortality of patients with advanced schistosomiasis japonica, taking Dongzhi County of China as a case study.

METHOD

Data of patients with advanced schistosomiasis japonica were collected from Dongzhi Schistosomiasis Hospital from January 2019 to July 2022. Data of patients were randomly divided into a training set and validation set with a ratio of 7:3. Candidate variables, including survival outcomes, demographics, clinical features, laboratory examinations, and ultrasound examinations, were analyzed and selected by LASSO logistic regression for the nomogram. The performance of the nomogram was assessed by concordance index (C-index), sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). The calibration of the nomogram was evaluated by the calibration plots, while clinical benefit was evaluated by decision curve and clinical impact curve analysis.

RESULTS

A total of 628 patients were included in the final analysis. Atrophy of the right liver, creatinine, ascites level III, N-terminal procollagen III peptide, and high-density lipoprotein were selected as parameters for the nomogram model. The C-index, sensitivity, specificity, PPV, and NPV of the nomogram were 0.97 (95% [CI]: [0.95-0.99]), 0.78 (95% [CI]: [0.64-0.87]), 0.97 (95% [CI]: [0.94-0.98]), 0.78 (95% [CI]: [0.64-0.87]), 0.97 (95% [CI]: [0.94-0.98]) in the training set; and 0.98 (95% [CI]: [0.94-0.99]), 0.86 (95% [CI]: [0.64-0.96]), 0.97 (95% [CI]: [0.93-0.99]), 0.79 (95% [CI]: [0.57-0.92]), 0.98 (95% [CI]: [0.94-0.99]) in the validation set, respectively. The calibration curves showed that the model fitted well between the prediction and actual observation in both the training set and validation set. The decision and the clinical impact curves showed that the nomogram had good clinical use for discriminating patients with high risk of death.

CONCLUSIONS

A nomogram was developed to predict prognosis of advanced schistosomiasis. It could guide clinical staff or policy makers to formulate intervention strategies or efficiently allocate resources against advanced schistosomiasis.

Urogenital schistosomiasis in three different water access in the Senegal river basin: prevalence and monitoring praziquantel efficacy and re-infection levels

BACKGROUND

Urogenital schistosomiasis is a neglected tropical disease most prevalent in sub-Saharan Africa. In the Senegal river basin, the construction of the Diama dam led to an increase and endemicity of schistosomiasis. Since 2009, praziquantel has frequently been used as preventive chemotherapy in the form of mass administration to Senegalese school-aged children without monitoring of the treatment efficacy and the prevalence after re-infection. This study aims to determine the current prevalence of urogenital schistosomiasis (caused by Schistosoma haematobium), the efficacy of praziquantel, and the re-infection rates in children from five villages with different water access.

METHODS

The baseline prevalence of S. haematobium was determined in August 2020 in 777 children between 5 and 11 years old and a single dose of praziquantel (40 mg/kg) was administered to those positive. The efficacy of praziquantel and the re-infection rates were monitored 4 weeks and 7 months after treatment, respectively, in 226 children with a high intensity of infection at baseline.

RESULTS

At the baseline, prevalence was low among children from the village of Mbane who live close to the Lac de Guiers (38%), moderate among those from the villages of Dioundou and Khodit, which neighbor the Doue river (46%), and very high at Khodit (90.6%) and Guia (91.2%) which mainly use an irrigation canal. After treatment, the observed cure rates confirmed the efficacy of praziquantel. The lowest cure rate (88.5%) was obtained in the village using the irrigation canal, while high cure rates were obtained in those using the lake (96.5%) and the river (98%). However, high egg reduction rates (between 96.7 and 99.7%) were obtained in all the villages. The re-infection was significantly higher in the village using the canal (42.5%) than in the villages accessing the Lac de Guiers (18.3%) and the Doue river (14.8%).

CONCLUSION

Praziquantel has an impact on reducing the prevalence and intensity of urogenital schistosomiasis. However, in the Senegal river basin, S. haematobium remains a real health problem for children living in the villages near the irrigation canals, despite regular treatment, while prevalence is declining from those frequenting the river and the Lac de Guiers. Trial registration ClinicalTrials.gov, NCT04635553. Registered 19 November 2020 retrospectively registered, https://www.

CLINICALTRIALS

gov/ct2/show/NCT04635553?cntry=SN&draw=2&rank=4.

Schistosomiasis model with treatment, habitat modification and biological control

Schistosomiasis is a parasitic disease caused by Schistosoma worm infection. Some species of snails can serve as the intermediate hosts for the parasite. Numerous interventions have been performed to repress the snail population. One of them is the use of molluscicide. Nevertheless, it is debated that molluscicide intervention has negative impacts on the ecosystem. To investigate the impact of more environmentally friendly interventions, we develop a schistosomiasis model with treatment, habitat modification and biological control. The biological control agent examined in our model is a snail predator. Moreover, to investigate the impact of snail habitat modification, we assume that the snail population grows logistically. We show that all solutions of our model are non-negative and bounded. We also study the existence and stability conditions of equilibrium points. The basic reproduction numbers are determined using the next-generation operator. Linearization combined with the Routh-Hurwitz criterion is used to prove the local stability condition of disease-free equilibrium points. Bifurcation theory is applied to investigate the local stability condition of the endemic equilibrium points. To examine the global behavior of our model, we use asymptotically autonomous system theory and construct a Lyapunov function. We perform several numerical simulations to validate and support our deductive results. Our results show that early treatment can reduce the basic reproduction number and schistosomiasis cases. In addition, modifying snail habitat and releasing the snail predator at the snail habitat can reduce schistosomiasis prevalence. We suggest using snail predators which can hunt and kill snails effectively as a biological control agent.

Prevalence and Molecular Identification of Schistosoma haematobium among Children in Lusaka and Siavonga Districts, Zambia

Schistosomiasis remains a public health concern in Zambia. Urinary schistosomiasis caused by Schistosoma haematobium is the most widely distributed infection. The aim of the current study was to determine the prevalence and risk factors of urinary schistosomiasis and identify the strain of S. haematobium among children in the Siavonga and Lusaka districts in Zambia. Urine samples were collected from 421 primary school children and S. haematobium eggs were examined under light microscopy. A semi-structured questionnaire was used to obtain information on the socio-demographic characteristics and the potential risk factors for urinary schistosomiasis. DNA of the parasite eggs was extracted from urine samples and the internal transcribed spacer gene was amplified, sequenced and phylogenetically analysed. The overall prevalence of S. haematobium was 9.7% (41/421) (95% CI: 7.16–13.08), male participants made up 6.2% (26/232) (95% CI: 4.15–9.03), having a higher burden of disease than female participants who made up 3.5% (15/421) (95% CI: 2.01–5.94). The age group of 11–15 years had the highest overall prevalence of 8.3% (35/421) (5.94–11.48). Participants that did not go fishing were 0.008 times less likely to be positive for schistosomiasis while participants whose urine was blood-tinged or cloudy on physical examination and those that lived close to water bodies were 9.98 and 11.66 times more likely to test positive for schistosomiasis, respectively. A phylogenetic tree analysis indicated that S. haematobium isolates were closely related to pure S. haematobium from Zimbabwe and hybrids of S. haematobium × S. bovis from Benin, Senegal and Malawi. The current study shows that urinary schistosomiasis is endemic in the study areas and is associated with water contact, and S. haematobium isolated is closely related to hybrids of S. bovis × S. haematobium strain, indicating the zoonotic potential of this parasite.

Schistosoma mansoni Epidemiology Among Snails, Rodents and Children: A One Health Approach

Background

Schistosoma is one of the prevalent parasitic infection in humans and animals. Schistosomiasis in children is particularly serious and results in liver and spleen enlargement, anemia, stunting, reduced ability to learn and death. The aim of this study was to measure the prevalence and distribution of schistosomiasis in children, rodents and snail populations in Aleffa and Takusa districts, north-west Ethiopia.

Methods

Disease status and exposure were simultaneously measured from December 2020 to December 2021. School children's stool specimens were collected for schistosomiasis examination by Kato Katz and formal-ether techniques. Live rodents and snails were trapped and collected in search of adult schistosoma, eggs, and cercariae, respectively. Multiple logistic regression analytic technique by using SPSS version 20 was conducted.

Results

Of 460 stool specimens examined, 116 (25.22) were found positive for S. mansoni infection. In the present finding, the possible determinants for the occurrence of intestinal schistosomiasis in school children were female sex (AOR = 1.09, 95% CI: 1.37–2.96); working with bare foot (AOR = 1.21, 95% CI: 1.08–1.52); skin cut/abrasion history (AOR = 3.6, 95% CI: 1.08–7.43) and swimming habit (AOR = 1.58, 95% CI: 1.33–1.99). The overall (n = 108) rodent prevalence of S. mansoniwas 23 (21.3%). Only 6 snails were shedding the infective stage of schistosoma cercariae.

Conclusion

The study revealed that there is a moderate prevalence of schistosomiasis in different hosts. Thus, multi-host intervention is crucial to achieving the goal of interrupting transmission of schistosomiasis in the study area. Further research to better understand and exploit the broader environmental, ecological context and encompassing dynamic interactions between all hosts over time will be crucial for building predictive models beyond the known fact of having or not having reservoirs/hybridization of schistosoma in our study area.

The Road to Elimination: Current State of Schistosomiasis Research and Progress Towards the End Game

The new WHO Roadmap for Neglected Tropical Diseases targets the global elimination of schistosomiasis as a public health problem. To date, control strategies have focused on effective diagnostics, mass drug administration, complementary and integrative public health interventions. Non-mammalian intermediate hosts and other vertebrates promote transmission of schistosomiasis and have been utilized as experimental model systems. Experimental animal models that recapitulate schistosomiasis immunology, disease progression, and pathology observed in humans are important in testing and validation of control interventions. We discuss the pivotal value of these models in contributing to elimination of schistosomiasis. Treatment of schistosomiasis relies heavily on mass drug administration of praziquantel whose efficacy is comprised due to re-infections and experimental systems have revealed the inability to kill juvenile schistosomes. In terms of diagnosis, nonhuman primate models have demonstrated the low sensitivity of the gold standard Kato Katz smear technique. Antibody assays are valuable tools for evaluating efficacy of candidate vaccines, and sera from graded infection experiments are useful for evaluating diagnostic sensitivity of different targets. Lastly, the presence of Schistosomes can compromise the efficacy of vaccines to other infectious diseases and its elimination will benefit control programs of the other diseases. As the focus moves towards schistosomiasis elimination, it will be critical to integrate treatment, diagnostics, novel research tools such as sequencing, improved understanding of disease pathogenesis and utilization of experimental models to assist with evaluating performance of new approaches.

Acquired Hepatocerebral Degeneration After a Splenorenal Shunt in the Sub-Saharan Africa Context: A Case Report and Brief Review of Literature

Acquired hepatocerebral degeneration (AHD) is a neurologic syndrome caused by liver dysfunction and long-standing portosystemic shunting. The pathogenesis of the condition is predominantly considered to be related to the deposition of manganese in parts of the brain due to shunting. We report a case of a 25-year-old male who underwent splenectomy and splenorenal shunt for recurrent upper GI bleeding (UGIB) due to esophageal varices caused by non-cirrhotic portal hypertension (NCPH). He presented with bradykinesia, hypophonia, gait instability, and rigidity of the lower extremities 18 months after the procedure was done.

Chromosome-level genome of Schistosoma haematobium underpins genome-wide explorations of molecular variation

Urogenital schistosomiasis is caused by the blood fluke Schistosoma haematobium and is one of the most neglected tropical diseases worldwide, afflicting > 100 million people. It is characterised by granulomata, fibrosis and calcification in urogenital tissues, and can lead to increased susceptibility to HIV/AIDS and squamous cell carcinoma of the bladder. To complement available treatment programs and break the transmission of disease, sound knowledge and understanding of the biology and ecology of S. haematobium is required. Hybridisation/introgression events and molecular variation among members of the S. haematobium-group might effect important biological and/or disease traits as well as the morbidity of disease and the effectiveness of control programs including mass drug administration. Here we report the first chromosome-contiguous genome for a well-defined laboratory line of this blood fluke. An exploration of this genome using transcriptomic data for all key developmental stages allowed us to refine gene models (including non-coding elements) and annotations, discover ‘new’ genes and transcription profiles for these stages, likely linked to development and/or pathogenesis. Molecular variation within S. haematobium among some geographical locations in Africa revealed unique genomic ‘signatures’ that matched species other than S. haematobium, indicating the occurrence of introgression events. The present reference genome (designated Shae.V3) and the findings from this study solidly underpin future functional genomic and molecular investigations of S. haematobium and accelerate systematic, large-scale population genomics investigations, with a focus on improved and sustained control of urogenital schistosomiasis.

More than 100 million people are infected with the carcinogenic blood fluke Schistosoma haematobium, the aetiological agent of urogenital schistosomiasis—a neglected tropical disease (NTD). In spite of its major significance, little is known about this fluke, its interactions with the human and snail intermediate hosts and the pathogenesis of the urogenital form of schistosomiasis at the molecular and biochemical levels. To enable research in these areas, we report the first chromosome-level genome and markedly enhanced gene models for S. haematobium. Comparative genomic analyses also reveal evidence of past introgression events between or among closely related schistosome species. This present reference genome for S. haematobium and the findings from this study should underpin future functional genomic and molecular investigations of S. haematobium and accelerate systematic, large-scale population genomics investigations, with a focus on improved control of urogenital schistosomiasis.

Low Sensitivity of Real Time PCRs Targeting Retrotransposon Sequences for the Detection of Schistosoma japonicum Complex DNA in Human Serum

While hybridization probe-based real-time PCR assays targeting highly repetitive multi-copy genome sequences for the diagnosis of S. mansoni complex or S. haematobium complex from human serum are well established, reports on the evaluation of respective assays for the identification of S. japonicum complex DNA in human serum are scarce. Here, we assessed the potential use of the retrotransposon sequences SjR2 and SjCHGCS19 from S. japonicum, S. mekongi and S. malayensis for the diagnosis of Asian Schistosoma infections. Based on available S. japonicum sequences and newly provided S. mekongi and S. malayensis sequences, hybridization probe-based real-time PCRs targeting SjR2 and SjCHGCS19 of the S. japonicum complex were designed both as consensus primer assays as well as multi-primer assays for the coverage of multiple variants of the target sequences. The assays were established using plasmids and S. mekongi DNA. While the consensus primer assays failed to detect S. mekongi DNA in human serum samples, the multi-primer assays showed positive or borderline positive results but only in 9.8% (6/61) of serum samples from patients with confirmed S. mekongi infections. Some cross-reactions with samples positive for S. mansoni or S. haematobium were observed but with the SjCHGCS19-PCR only. In spite of the low sensitivity, the presented experience may guide future evaluations of S. japonicum-complex-specific PCRs from human serum.

Parasitological and Biochemical Efficacy of the Active Ingredients of Allium sativum and Curcuma longa in Schistosoma mansoni Infected Mice

The active ingredients allicin and curcumin have a wide range of actions against fungi, bacteria, and helminths. Therefore, the study was aimed to evaluate the efficacy of allicin (AL) and curcumin (CU) as antischistosomal drugs and their biochemical effects in normal and Schistosoma mansoni-infected mice. Praziquantel (PZQ) was administrated for two successive days while AL or CU was given for two weeks from the week 7th postinfection (PI). The possible effect of different regimens on Schistosoma worms was evaluated by measuring the percentage of the recovered worms, tissue egg load, and oogram pattern. Serum alanine transaminase activity and levels of triglycerides, cholesterol, and uric acid were measured. Liver tissue malondialdehyde and reduced glutathione levels besides, the activities of glutathione-S-transferase, superoxide dismutase and catalase were assessed for the oxidative/antioxidant condition. DNA electrophoresis of liver tissue was used to indicate the degree of fragmentation. There was a significant reduction in the recovered worms and egg load, with a marked change of oogram pattern in all treated groups with PZQ, AL, and CU in comparison with infected-untreated mice. PZQ, AL, and CU prevented most of the hematological and biochemical disorders, as well as significantly improved the antioxidant capacity and enhanced DNA fragmentation in the liver tissue of schistosomiasis mice compared to the infected-untreated group. These promising results suggest that AL and CU are efficient as antischistosomal drugs, and it would be beneficial to test their combination to understand the mechanism of action and the proper period of treatment leading to the best result.