Citizens can help to map putative transmission sites for snail-borne diseases.

INTRODUCTION: Schistosomiasis and fasciolosis are snail-borne diseases of great medical and veterinary health importance. The World Health Organization recommends complementing drug treatment with snail control and community involvement for disease elimination, but there is a general lack of snail experts and hence snail distribution data. Therefore, we adopted a citizen science approach and involved citizens in the monitoring of medically and veterinary important snail taxa. MATERIALS AND METHODS: Snail data was collected weekly by 25 trained citizen scientists (CSs) at 76 sites around southern Lake Albert (Uganda) for 20 months. At each site, snails were searched for 30 minutes, sorted, target snail hosts identified to genus level, counted and data submitted through a smartphone application. The quality of this data was assessed by comparing it to monthly data collected by an 'expert' malacologist using the same sampling protocol. Generalised binomial logistic and linear mixed-effects models were used to analyse the variables for agreement between the CSs and expert. FINDINGS: The binary agreement in presence/absence of Biomphalaria, Bulinus and Radix snails reported by the expert and CSs ranged between 70% and 86% (900 reports) with an average of 17% false negatives (sites wrongly defined as snail-free). The agreement for Biomphalaria and Radix increased with snail abundance, and false negatives decreased when the number of snails collected by citizens was aggregated per month. Site type significantly predicted binary agreement, which was lowest at lake sites (55%) and highest at spring sites (99%) with variations across genera. Similar temporal trends in snail abundance were recorded despite the expert reporting higher abundance. However, the relative abundance was consistent across site types. The match between the sites with highest Biomphalaria spp. abundance identified by CSs and expert was consistently high (~84.1%) and increased over time. CONCLUSIONS AND RECOMMENDATIONS: Our results demonstrate the potential of citizen science to map putative schistosomiasis transmission sites. We therefore argue that this inclusive, powerful and cost-effective approach can be more sustainable than top-down monitoring and intervention campaigns.

Age-group associations of schistosomiasis prevalence from trial data, Côte d'Ivoire, Kenya and the United Republic of Tanzania.

Objective: To determine if the prevalence of schistosomiasis in children aged 9-12 years is associated with the prevalence in 5-8-year-olds and adults after preventive chemotherapy in schools or the community. Methods: We combined data from four community-randomized, preventive chemotherapy trials in treatment-naïve populations in Côte d'Ivoire, Kenya and the United Republic of Tanzania during 2010-2016 according to the number of praziquantel treatments and the delivery method. Schistosoma mansoni infection was sought on two slides prepared from each participant's first stool using the Kato-Katz technique. We assessed associations between S. mansoni prevalence in 9-12-year-olds and 5-8-year-olds and adults in the community before and after treatment using Bayesian regression models. Findings: Stool samples from 47 985 5-8-year-olds, 81 077 9-12-year-olds and 20 492 adults were analysed. We found associations between the prevalence in 9-12-year-olds and that in 5-8-year-olds and adults after preventive treatment, even when only school-age children were treated. When the prevalence in 9-12-year-olds was under 10%, the prevalence in 5-8-year-olds was consistently under 10%. When the prevalence in 9-12-year-olds was under 50%, the prevalence in adults after two or four rounds of preventive chemotherapy was 10%-15% lower than before chemotherapy. Post-chemotherapy age-group associations were consistent with pre-chemotherapy associations in this analysis and previous studies. Conclusion: The prevalence of S. mansoni infection in 9-12-year-olds was associated with the prevalence in other age groups and could be used to guide community treatment decisions.

[High-quality acceleration of the Chinese national schistosomiasis elimination programme to advance the building of Healthy China].

The goal of achieving elimination of schistosomiasis across all endemic counties in China by 2030 was proposed in the Outline of the Healthy China 2030 Plan. On June 16, 2023, the Action Plan to Accelerate the Elimination of Schistosomiasis in China (2023-2030) was jointly issued by National Disease Control and Prevention Administration and other 10 ministries, which deployed the targets and key tasks of the national schistosomiasis elimination programme in China. This article describes the progress of the national schistosomiasis control programme, analyzes the opportunities to eliminate schistosomiasis, and proposes targeted recommendations to tackle the challenges of schistosomiasis elimination, so as to accelerate the process towards schistosomiasis elimination and facilitate the building of a healthy China.

[Interpretation of the Action Plan to Accelerate the Elimination of Schistosomiasis in China (2023-2030)].

On June 16, 2023, National Disease Control and Prevention Administration of the People's Republic of China, in collaboration with other ministries, formulated and issued the Action Plan to Accelerate the Elimination of Schistosomiasis in China (2023-2030). The implementation of this plan provides an important basis for achieving the targets set in the "Healthy China 2030" action plan and the implementation of the rural revitalization strategy. This paper describes the background, principles, targets, control strategies, safeguard measures and effectiveness evaluation of the plan, in order to guide the scientific and standardized implementation of actions for schistosomiasis elimination at the grassroots level, and facilitate the progress towards elimination of schistosomiasis in China with a high quality.

[Capacity building in schistosomiasis control institutions in China: a cross-sectional study].

OBJECTIVE: To understand the current status of capacity building in schistosomiasis control institutes in schistosomiasis-endemic provinces (municipality, autonomous region) of China. METHODS: The responsibilities and construction requirements of various schistosomiasis control institutions were surveyed by expert discussions, and field interviews and visits during the period between May and June, 2023, and the questionnaire for capacity maintenance and consolidation in schistosomiasis control institutions was designed. An online questionnaire survey was conducted in county-, municipal-, and provincial-level institutions that undertook schistosomiasis control and surveillance activities through the Wenjuanxing program. The distribution of schistosomiasis control institutions, the status of institutions, departments and staff undertaking schistosomiasis control activities and the translation of scientific researches on schistosomiasis control in China were analyzed. The laboratories accredited by China National Accreditation Service for Conformity Assessment (CNAS) were considered to be capable for testing associated with schistosomiasis control, and the testing capability of schistosomiasis control institutions was analyzed. RESULTS: A total of 486 valid questionnaires were recovered from 486 schistosomiasis control institutions in 12 endemic provinces (municipality, autonomous region) of China, including 12 provincial-level institutions (2.5%), 77 municipal-level institutions (15.8%) and 397 county-level institutions (81.7%). Of all schistosomiasis control institutions, 376 (77.4%) were centers for disease control and prevention or public health centers, 102 (21.0%) were institutions for schistosomiasis, endemic disease and parasitic disease control, and 8 (1.6%) were hospitals, healthcare centers or others. There were 37 713 active employees in the 486 schistosomiasis control institutions, including 5 675 employees related to schistosomiasis control, and the proportions of employees associated with schistosomiasis control among all active employees were 5.9% (231/3 897), 5.5% (566/10 134), and 20.6% (4 878/23 682) in provincial-, municipal-, and county-level institutions, respectively. There were 3 826 full-time employees working in schistosomiasis control activities, with 30.5% (1 166/3 826), 34.6% (1 324) and 34.9% (1 336/3 826) at ages of 40 years and below, 41 to 50 years and over 50 years, and there were 1 571 (41.0%) full-time schistosomiasis control employees with duration of schistosomiasis control activities for over 25 years, and 1 358 (35.5%) employees with junior professional titles and 1 290 with intermediate professional titles (35.5%), while 712 (18.6%) full-time employees working in schistosomiasis control activities had no professional titles. The three core schistosomiasis control activities included snail control (26.3%, 374/1 420), epidemics surveillance and management (25.4%, 361/1 420) and health education (18.8%, 267/1 420) in schistosomiasis control institutions. The Kato-Katz method, miracidium hatching test with nylon gauzes, and indirect haemagglutination assay (IHA) were the most commonly used techniques for detection of schistosomiasis, and there were less than 50% laboratories that had capabilities or experimental conditions for performing enzyme-linked immunosorbent assay (ELISA), dipstick dye immunoassay (DDIA), dot immunogold filtration assay (DIG-FA), loop-mediated isothermal amplification (LAMP) and polymerase chain reaction (PCR) assays. During the period from 2018 to 2022, schistosomiasis control institutions had undertaken a total of 211 research projects for schistosomiasis control, with a total funding of 18.596 million RMB, published 619 articles, participated in formulation of 13 schistosomiasis control-related criteria, and applied for 113 schistosomiasis control-related patents, including 101 that were granted, and commercialized 4 scientific research outcomes. CONCLUSIONS: The proportion of independent specialized schistosomiasis control institutions is low in schistosomiasis control institutions in China, which suffers from problems of unsatisfactory laboratory testing capabilities, aging of staff and a high proportion of low-level professional titles. More investment into and intensified schistosomiasis control activities and improved capability building and talent cultivation in schistosomiasis control institutions are recommended to provide a powerful support for high-quality elimination of schistosomiasis in China.

Illness experiences and mental health challenges associated with female genital schistosomiasis in Cameroon: a gender analysis.

BACKGROUND: This paper highlights the role of cultural and structural gaps that shape illness experiences of women with manifestations of female genital schistosomiasis (FGS) and their impacts upon mental well-being. METHODS: Using ethnography, case study narrative accounts of women manifesting symptoms of FGS, as well as interviews with health workers within FGS-endemic rural fishing communities in Cameroon, we present experiences of women affected by FGS, alongside information on FGS health service provision. RESULTS: Our results show how gendered power dynamics in decision making, gendered experiences around menstrual health and structural gaps in service provision, combine and lead to poor mental well-being. Subfertility brings a heavy psychosocial toll from external blame and rejection, exacerbated by internalised stigma and the challenge of not being able to fulfil cultural and gendered social norms. CONCLUSIONS: Gender analysis is key to developing context-embedded understanding and addressing FGS-related challenges. With context-specific experiences demonstrating FGS comorbidity with mental ill health, there is a need to prioritise mental health integration at policy level through a person-centred approach. Furthermore, to address stigma and discrimination, campaigns to raise awareness in Cameroon, and beyond, are needed. CONTEXTE: Cet article met en évidence le rôle des lacunes culturelles et structurelles qui façonnent les expériences des femmes atteintes de schistosomiase génitale féminine (SGF) et leur impact sur le bien-être mental. LA MÉTHODE: À l'aide de l'ethnographie, de récits d'études de cas de femmes présentant des symptômes de schistosomiase génitale féminine, et d'entretiens avec des agents de santé au sein de communautés de pêcheurs ruraux endémiques de la schistosomiase génitale féminine au Cameroun, nous présentons les expériences des femmes touchées par le SGF, ainsi que des informations sur les services de santé liés au SGF. RÉSULTATS: Nos résultats montrent comment la dynamique du pouvoir dans la prise de décision, les expériences de la santé menstruelle et les lacunes structurelles dans la fourniture de services, interagissent et conduisent à un manque de bien-être psychologique. La sous-fécondité entraîne un lourd fardeau psychosocial du fait du blâme et de rejet externes auxquelles sont assujetties les personnes souffrant de la maladie, ce qui est exacerbé par la stigmatisation intériorisée et le défi que représente leur incapacité à respecter les normes sociales culturelles et sexospécifiques. CONCLUSION: L'analyse de genre est essentielle pour développer une compréhension intégrée au contexte et pour relever les défis liés aux SGF. les défis liés à l'ESF. Avec des expériences spécifiques au contexte démontrant la comorbidité de la FGS avec la mauvaise santé mentale, il est nécessaire de donner la priorité à l'intégration de la santé mentale au niveau politique par le biais d'une approche centrée sur la personne. l'intégration de la santé mentale au niveau politique par une approche centrée sur la personne. En outre, pour lutter contre la stigmatisation et la stigmatisation et la discrimination, des campagnes de sensibilisation sont nécessaires au Cameroun et au-delà. ANTECEDENTES: En este documento se pone de relieve el papel de las brechas culturales y estructurales que dan forma a las experiencias de enfermedad de las mujeres con manifestaciones de Esquistosomiasis Genital Femenina (EGF), y sus impactos en el bienestar mental. MÉTODO: Utilizando la etnografía, estudios de caso mediante relatos narrativos de mujeres que manifiestan síntomas de EGF y entrevistas con trabajadores sanitarios de comunidades pesqueras rurales endémicas en Camerún, presentamos las experiencias de las mujeres afectadas por la EGF, junto con información sobre la prestación de servicios sanitarios para la EGF. RESULTADOS: Nuestros resultados muestran cómo la dinámica de poder de género en la toma de decisiones, las experiencias de género en torno a la salud menstrual y las deficiencias estructurales en la prestación de servicios se combinan y conducen a un bienestar mental deficiente. La subfertilidad conlleva un alto coste psicosocial debido a la culpa y el rechazo externos, exacerbados por el estigma interiorizado y el reto de no poder cumplir las normas culturales y de género. CONCLUSIÓN: El análisis de género es clave para desarrollar una comprensión integrada en el contexto y abordarlos retos relacionados con la EGF. Dado que las experiencias específicas de cada contexto demuestran la comorbilidad de las EGF con la enfermedad mental, es necesario priorizar la integración de la salud mental en las políticas a través de un enfoque centrado en la persona. Además, para hacer frente al estigma y la discriminación, son necesarias campañas de sensibilización en Camerún y en otros lugares.

Expanding the swimmer's itch pool of the Benelux: a first record of the neurotropic Trichobilharzia regenti and potential link to human infection.

BACKGROUND: Swimmer's itch, an allergic contact dermatitis caused by avian and mammalian blood flukes, is a parasitic infection affecting people worldwide. In particular, avian blood flukes of the genus Trichobilharzia are infamous for their role in swimmer's itch cases. These parasites infect waterfowl as a final host, but incidental infections by cercariae in humans are frequently reported. Upon accidental infections of humans, parasite larvae will be recognized by the immune system and destroyed, leading to painful itchy skin lesions. However, one species, Trichobilharzia regenti, can escape this response in experimental animals and reach the spinal cord, causing neuroinflammation. In the last few decades, there has been an increase in case reports across Europe, making it an emerging zoonosis. METHODS: Following a reported case of swimmer's itch in Kampenhout in 2022 (Belgium), the transmission site consisting of a private pond and an adjacent creek was investigated through a malacological and parasitological survey. RESULTS: Six snail species were collected, including the widespread Ampullaceana balthica, a well-known intermediate host for Trichobilharzia parasites. Shedding experiments followed by DNA barcoding revealed a single snail specimen to be infected with T. regenti, a new species record for Belgium and by extension the Benelux. Moreover, it is the most compelling case to date of the link between this neurotropic parasite and cercarial dermatitis. Additionally, an Echinostomatidae sp. and Notocotylus sp. were isolated from two other specimens of A. balthica. However, the lack of reference DNA sequences for these groups in the online repositories prevented genus- and species-level identification, respectively. CONCLUSIONS: The presence of T. regenti in Belgium might have severe clinical implications and its finding highlights the need for increased vigilance and diagnostic awareness among medical professionals. The lack of species-level identification of the other two parasite species showcases the barcoding void for trematodes. Overall, these findings demonstrate the need for a Belgian framework to rapidly detect and monitor zoonotic outbreaks of trematode parasites within the One Health context.

Genetic characterization of schistosome species from cattle in Côte d'Ivoire.

BACKGROUND: Schistosomiasis is a water-based parasitic disease that affects humans, livestock and wild animals. While considerable resources are dedicated to the surveillance, disease mapping, control and elimination of human schistosomiasis, this is not the case for livestock schistosomiasis. Indeed, there are important data and knowledge gaps concerning the species present, population genetic diversity, infection prevalence, morbidity and economic impact. This study aimed to identify circulating schistosome species in cattle across Côte d'Ivoire and to investigate their population diversity and structuring. METHODS: Overall, 400 adult schistosomes were collected from slaughtered cattle at six sites across Côte d'Ivoire. Additionally, 114 miracidia were collected from live cattle at one site: Ferkessédougou, in the northern part of Côte d'Ivoire. DNA from all specimens was extracted and the cox1 and ITS1/2 regions amplified and analysed to confirm species. The genetic diversity and structuring of the schistosome populations were investigated using 12 microsatellite markers. RESULTS: All adult schistosomes and miracidia presented Schistosoma bovis mitochondrial cox1 profile. Nuclear ITS1/2 data were obtained from 101 adult schistosomes and four miracidia, all of which presented an S. bovis profile. Genetic diversity indices revealed a deficiency of heterozygotes and signals of inbreeding across all sites, while structure analyses displayed little geographic structuring and differentiation. Cattle in Côte d'Ivoire thus appear to be mono-species infected with S. bovis. Hybrids of Schistosoma haematobium × S. bovis have not been identified in this study. Cattle schistosomes appear to be panmictic across the country. CONCLUSIONS: Our results contribute to a deeper understanding of schistosome populations in Ivorian cattle and emphasize a One Health approach of joint human and animal surveillance and prevention and control programmes for schistosomiasis.

Parasites in ancient Egypt and Nubia: Malaria, schistosomiasis and the pharaohs.

The civilizations of ancient Egypt and Nubia played a key role in the cultural development of Africa, the Near East, and the Mediterranean world. This study explores how their location along the River Nile, agricultural practices, the climate, endemic insects and aquatic snails impacted the type of parasites that were most successful in their populations. A meta-analysis approach finds that up to 65% of mummies were positive for schistosomiasis, 40% for headlice, 22% for falciparum malaria, and 10% for visceral leishmaniasis. Such a disease burden must have had major consequences upon the physical stamina and productivity of a large proportion of the workforce. In contrast, the virtual absence of evidence for whipworm and roundworm (so common in adjacent civilizations in the Near East and Europe) may have been a result of the yearly Nile floods fertilising the agricultural land, so that farmers did not have to fertilise their crops with human faeces.

[Epidemiological and clinical features of newly reported advanced schistosomiasis cases in Sichuan Province from 2011 to 2022].

OBJECTIVE: To analyze the epidemiological characteristics of newly reported advanced schistosomiasis cases in Sichuan Province, so as to provide the evidence for analyzing the causes and formulating targeted control measures of newly reported advanced schistosomiasis cases. METHODS: Individual case investigation forms for advanced schistosomiasis cases were collected from the Sichuan Provincial Epidemic Annual Report System from 2011 to 2022, and patients' demographics, previous medical history and liver parenchymal grading were retrieved. All advanced schistosomiasis cases' medical records were reviewed, and the subtypes of schistosomiasis-endemic villages where the cases' household registration were, floating population, survival and death and time of death were collected. RESULTS: A total of 321 newly reported advanced schistosomiasis cases were found in Sichuan Province from 2011 to 2022, with a male to female ratio of 0.99 to 1. There were 274 cases at ages of over 50 years (85.4%), with the highest proportion seen at ages of 60 to 69 years (87 cases, 27.1%), and splenomegaly was the most common type (180 cases, 56.1%), with no dwarfism type detected. The highest number of cases was reported in 2011 (78 cases), followed by in 2022 (74 cases), and the highest number of cases were reported in Meishan City (199 cases, 62.0%), Dongpo District (131 cases, 40.8%), and hilly subtype areas (136 cases, 42.4%). As of the end of 2022, there were 111 deaths due to advanced schistosomiasis, with the highest number of deaths seen in 2018 (25 deaths), and the highest mortality was seen among patients with the ascites type (41.2%). There were 47 (37.3%), 40 (59.5%) and 4 (23.5%) cases with grade III liver parenchyma among patients with splenomegaly, ascites, and colonic proliferation types, respectively, and there was a significant difference in the grading of III liver parenchyma among three types of patients (H = 12.092, P < 0.05), with more severe liver parenchyma injuries seen among patients with the ascites type than among those with splenomegaly and colonic proliferation type (Z = 24.262 and 44.738, both Padjusted values < 0.05). CONCLUSIONS: There have been newly reported advanced schistosomiasis cases in Sichuan Province during recent years, and patients with the ascites type should be given a high priority among advanced schistosomiasis cases in Sichuan Province. Intensified clue surveys are needed for early identification and treatment of advanced schistosomiasis cases, so as to increase the survival rate and improve the quality of life.

[Tracking evaluation on the implementation of Survey of oncomelanid snails (WS/T 563-2017) in Sichuan and Anhui provinces].

To evaluate the implementation of Survey of oncomelanid snails (WS/T 563-2017) in schistosomiasis-endemic foci, two schistosomiasis-endemic counties were selected from two provinces of Sichuan and Anhui. Professional staff working in province-, city-, county- and township-level disease control and prevention institutions, parasitic disease control institutions or medical institutions were recruited, and the understanding, use and implementation of Survey of oncomelanid snails (WS/T 563-2017) were investigated using questionnaires and interviews. The awareness, use, proportion of propagation and implementation and correct rate of answering questions pertaining to Survey of oncomelanid snails (WS/T 563-2017) were analyzed. A total of 270 questionnaires were allocated, and 269 were recovered, including 254 valid questionnaires. The overall awareness of Survey of oncomelanid snails (WS/T 563-2017) was 84.64% (215/254), and propagation and implementation of Survey of oncomelanid snails (WS/T 563-2017) was not performed in 23.28% (17/73) of the survey institutions following implementation of Survey of oncomelanid snails (WS/T 563-2017), with meeting training and allocation of propagation materials as the main type of propagation and implementation. Among 254 respondents, 77.16% (196/254) were familiar with the standard, 66.14% (168/254) understood the conditions for use of the standard during snail surveys, and 96.85% (246/254) had the approach for identifying snails. In addition, there were 41.73% (106/254), 50.78% (129/254) and 7.48% (19/254) of respondents that considered the operability of Survey of oncomelanid snails (WS/T 563-2017) was very good, good and general, respectively. The findings demonstrate that the issue and implementation of Survey of oncomelanid snails (WS/T 563-2017) has filled the gap for the standardization of snail control techniques, and which plays an importang guiding role in the national schistosomiasis control program.

Swimmer's itch control: Timely waterfowl brood relocation significantly reduces an avian schistosome population and human cases on recreational lakes.

Swimmer's itch (SI) is a dermatitis in humans caused by cercariae of avian and mammalian schistosomes which emerge from infected snails on a daily basis. Mitigation methods for SI have long been sought with little success. Copper sulfate application to the water to kill the snail hosts is the historically employed method, but is localized, temporary, and harmful to many aquatic species. Here, we test an alternative method to control Trichobilharzia stagnicolae, a species well-known to cause SI in northern Michigan and elsewhere in North America. Summer relocation of broods of the only known vertebrate host, common merganser (Mergus merganser), greatly reduced snail infection prevalence the following year on two large, geographically separated lakes in northern Michigan. Subsequent years of host relocation achieved and maintained snail infection prevalence at ~0.05%, more than an order of magnitude lower than pre-intervention. A Before-After-Control-Intervention (BACI) study design using multiple-year snail infection data from two intervention lakes and three control lakes demonstrates that dramatic lake-wide reduction of an avian schistosome can be achieved and is not due to natural fluctuations in the parasite populations. The relevance of reducing snail infection prevalence is demonstrated by a large seven-year data set of SI incidence in swimmers at a high-use beach, which showed a substantial reduction in SI cases in two successive years after relocation began. In addition, data from another Michigan lake where vertebrate-host based intervention occurred in the 1980's are analyzed statistically and show a remarkably similar pattern of reduction in snail infection prevalence. Together, these results demonstrate a highly effective SI mitigation strategy that avoids the use of environmentally suspect chemicals and removes incentive for lethal host removal. Biologically, the results strongly suggest that T. stagnicolae is reliant on the yearly hatch of ducklings to maintain populations at high levels on a lake and that the role of migratory hosts in the spring and fall is much less significant.

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.

Prevalence of helmintic infections in Brazilian Maxakali indigenous: a repeated cross-sectional design.

BACKGROUND: The prevalence of intestinal parasites is known to be high among Amerindian populations; further, there are serious problems in the healthcare of these populations in Brazil. The Maxakali, located in the northeastern region of Minas Gerais, Brazil, is an indigenous group that still preserves many of its cultural aspects. This study aimed to compare the positivity rate of schistosomiasis and soil-transmitted helminths in this ethnic group in epidemiological surveys conducted in 1972 and 2014. METHODS: Stool parasitological examinations were performed by the Kato-Katz technique during both periods in this population. In 2014, the parasitological diagnosis was also realized with the TF-Test® technique. RESULTS: In 1972, 270 inhabitants were examined. The positivity rates were 67.4% for Schistosoma mansoni, 72.9% for hookworms, 43.7% for Ascaris lumbricoides, and 23.7% for Trichuris trichiura. In 2014, 545 individuals were examined, and the positivity rates obtained were 45.7% for S. mansoni, 22.8% for hookworms, 0.6% for A. lumbricoides, and 2.8% for T. trichiura. CONCLUSIONS: The comparison of the parasitological surveys conducted in 1972 and 2014, indicates that the indigenous Maxakali remained neglected by the health and indigenous protection authorities during these four decades. The infection rate observed in 2014 for schistosomiasis and hookworm remains high, considering the current epidemiological view of these diseases in the Brazilian population.

A machine learning approach for modeling the occurrence of the major intermediate hosts for schistosomiasis in East Africa.

Schistosomiasis, a prevalent water-borne disease second only to malaria, significantly impacts impoverished rural communities, primarily in Sub-Saharan Africa where over 90% of the severely affected population resides. The disease, majorly caused by Schistosoma mansoni and S. haematobium parasites, relies on freshwater snails, specifically Biomphalaria and Bulinus species, as crucial intermediate host (IH) snails. Targeted snail control is advisable, however, there is still limited knowledge about the community structure of the two genera especially in East Africa. Utilizing a machine learning approach, we employed random forest to identify key features influencing the distribution of both IH snails in this region. Our results reveal geography and climate as primary factors for Biomphalaria, while Bulinus occurrence is additionally influenced by soil clay content and nitrogen concentration. Favorable climate conditions indicate a high prevalence of IHs in East Africa, while the intricate connection with geography might signify either dispersal limitations or environmental filtering. Predicted probabilities demonstrate non-linear patterns, with Bulinus being more likely to occur than Biomphalaria in the region. This study provides foundational framework insights for targeted schistosomiasis prevention and control strategies in the region, assisting health workers and policymakers in their efforts.

Human cercarial dermatitis (HCD) in the UK: an overlooked and under-reported nuisance?

BACKGROUND: Human cercarial dermatitis (HCD) is a clinical disease typically caused by skin-penetrative larvae of avian schistosomes. Its geographical epidemiology is firmly tied with that of infected freshwater intermediate snail hosts. To better understand the current distribution of HCD and its level of nuisance in the UK, we undertook a systematic literature review. METHODS: Following PRIMSA guidelines, PubMed and Scopus databases were searched with keywords "human cercarial dermatitis" OR "swimmer's itch" AND "United Kingdom". Articles about imported cases of HCD, or HCD outside the UK, were not formally included. RESULTS: A total of 30 articles were initially identified. A further two were gained by inspection of all citations. After screening, eight publications were analysed where the location, number of cases and putative avian schistosome species incriminated were tabulated. HCD is mainly found in the south of England, though gaps in evidence and reporting remain across the UK. CONCLUSIONS: Despite its noted recent rise in open water swimmers, published literature on HCD across the UK is sparse; this condition is both overlooked and under-reported. We therefore recommend establishing a national database that raises awareness and encourages self-reporting of this nuisance disease.

Mass drug administration campaigns: comparing two approaches for schistosomiasis and soil-transmitted helminths prevention and control in selected Southern Malawi districts.

BACKGROUND: Mass drug administration is one of the key interventions recommended by WHO to control certain NTDs. With most support from donors, health workers distribute antihelminthic drugs annually in Malawi. Mean community coverage of MDA from 2018 to 2020 was high at 87% for praziquantel and 82% for albendazole. However, once donor support diminishes sustaining these levels will be challenging. This study intended to compare the use of the community-directed intervention approach with the standard practice of using health workers in delivery of MDA campaigns. METHODS: This was a controlled implementation study carried out in three districts, where four health centres and 16 villages in each district were selected and randomly assigned to intervention and control arms which implemented MDA campaigns using the CDI approach and the standard practice, respectively. Cross-sectional and mixed methods approach to data collection was used focusing on quantitative data for coverage and knowledge levels and qualitative data to assess perceptions of health providers and beneficiaries at baseline and follow-up assessments. Quantitative and qualitative data were analyzed using IBM SPSS software version 26 and NVivo 12 for Windows, respectively. RESULTS: At follow-up, knowledge levels increased, majority of the respondents were more knowledgeable about what schistosomiasis was (41%-44%), its causes (41%-44%) and what STH were (48%-64%), while knowledge on intermediate host for schistosomiasis (19%-22%), its types (9%-13%) and what causes STH (15%-16%) were less known both in intervention and control arm communities. High coverage rates for praziquantel were registered in intervention (83%-89%) and control (86%-89%) communities, intervention (59%-79) and control (53%-86%) schools. Costs for implementation of the study indicated that the intervention arm used more resources than the control arm. Health workers and community members perceived the use of the CDI approach as a good initiative and more favorable over the standard practice. CONCLUSIONS: The use of the CDI in delivery of MDA campaigns against schistosomiasis and STH appears feasible, retains high coverages and is acceptable in intervention communities. Despite the initial high costs incurred, embedding into community delivery platforms could be considered as a possible way forward addressing the sustainability concern when current donor support wanes. TRIAL REGISTRATION: Pan-African Clinical Trials Registry PACTR202102477794401, date: 25/02/2021.

Evaluating the long-term impact of COVID-19-associated public health interventions on zoonotic and vector-borne diseases in China: an interrupted time series analysis.

BACKGROUND: The long-term impact of COVID-19-associated public health interventions on zoonotic and vector-borne infectious diseases (ZVBs) remains uncertain. This study sought to examine the changes in ZVBs in China during the COVID-19 pandemic and predict their future trends. METHODS: Monthly incidents of seven ZVBs (Hemorrhagic fever with renal syndrome [HFRS], Rabies, Dengue fever [DF], Human brucellosis [HB], Leptospirosis, Malaria, and Schistosomiasis) were gathered from January 2004 to July 2023. An autoregressive fractionally integrated moving average (ARFIMA) by incorporating the COVID-19-associated public health intervention variables was developed to evaluate the long-term effectiveness of interventions and forecast ZVBs epidemics from August 2023 to December 2025. RESULTS: Over the study period, there were 1,599,647 ZVBs incidents. HFRS and rabies exhibited declining trends, HB showed an upward trajectory, while the others remained relatively stable. The ARFIMA, incorporating a pulse pattern, estimated the average monthly number of changes of - 83 (95% confidence interval [CI] - 353-189) cases, - 3 (95% CI - 33-29) cases, - 468 (95% CI - 1531-597) cases, 2191 (95% CI 1056-3326) cases, 7 (95% CI - 24-38) cases, - 84 (95% CI - 222-55) cases, and - 214 (95% CI - 1036-608) cases for HFRS, rabies, DF, HB, leptospirosis, malaria, and schistosomiasis, respectively, although these changes were not statistically significant besides HB. ARFIMA predicted a decrease in HB cases between August 2023 and December 2025, while indicating a relative plateau for the others. CONCLUSIONS: China's dynamic zero COVID-19 strategy may have exerted a lasting influence on HFRS, rabies, DF, malaria, and schistosomiasis, beyond immediate consequences, but not affect HB and leptospirosis. ARFIMA emerges as a potent tool for intervention analysis, providing valuable insights into the sustained effectiveness of interventions. Consequently, the application of ARFIMA contributes to informed decision-making, the design of effective interventions, and advancements across various fields.

Development of prediction models to identify hotspots of schistosomiasis in endemic regions to guide mass drug administration.

Schistosomiasis is a neglected tropical disease affecting over 150 million people. Hotspots of Schistosoma transmission-communities where infection prevalence does not decline adequately with mass drug administration-present a key challenge in eliminating schistosomiasis. Current approaches to identify hotspots require evaluation 2-5 y after a baseline survey and subsequent mass drug administration. Here, we develop statistical models to predict hotspots at baseline prior to treatment comparing three common hotspot definitions, using epidemiologic, survey-based, and remote sensing data. In a reanalysis of randomized trials in 589 communities in five endemic countries, a regression model predicts whether Schistosoma mansoni infection prevalence will exceed the WHO threshold of 10% in year 5 ("prevalence hotspot") with 86% sensitivity, 74% specificity, and 93% negative predictive value (NPV; assuming 30% hotspot prevalence), and a regression model for Schistosoma haematobium achieves 90% sensitivity, 90% specificity, and 96% NPV. A random forest model predicts whether S. mansoni moderate and heavy infection prevalence will exceed a public health goal of 1% in year 5 ("intensity hotspot") with 92% sensitivity, 79% specificity, and 96% NPV, and a boosted trees model for S. haematobium achieves 77% sensitivity, 95% specificity, and 91% NPV. Baseline prevalence is a top predictor in all models. Prediction is less accurate in countries not represented in training data and for a third hotspot definition based on relative prevalence reduction over time ("persistent hotspot"). These models may be a tool to prioritize high-risk communities for more frequent surveillance or intervention against schistosomiasis, but prediction of hotspots remains a challenge.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry traces the geographical source of Biomphalaria pfeifferi and Bulinus forskalii, involved in schistosomiasis transmission.

BACKGROUND: Freshwater snails of the genera Bulinus spp., Biomphalaria spp., and Oncomelania spp. are the main intermediate hosts of human and animal schistosomiasis. Identification of these snails has long been based on morphological and/or genomic criteria, which have their limitations. These limitations include a lack of precision for the morphological tool and cost and time for the DNA-based approach. Recently, Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight (MALDI-TOF) mass spectrometry, a new tool used which is routinely in clinical microbiology, has emerged in the field of malacology for the identification of freshwater snails. This study aimed to evaluate the ability of MALDI-TOF MS to identify Biomphalaria pfeifferi and Bulinus forskalii snail populations according to their geographical origin. METHODS: This study was conducted on 101 Bi. pfeifferi and 81 Bu. forskalii snails collected in three distinct geographical areas of Senegal (the North-East, South-East and central part of the country), and supplemented with wild and laboratory strains. Specimens which had previously been morphologically described were identified by MALDI-TOF MS [identification log score values (LSV) ≥ 1.7], after an initial blind test using the pre-existing database. After DNA-based identification, new reference spectra of Bi. pfeifferi (n = 10) and Bu. forskalii (n = 5) from the geographical areas were added to the MALDI-TOF spectral database. The final blind test against this updated database was performed to assess identification at the geographic source level. RESULTS: MALDI-TOF MS correctly identified 92.1% of 101 Bi. pfeifferi snails and 98.8% of 81 Bu. forskalii snails. At the final blind test, 88% of 166 specimens were correctly identified according to both their species and sampling site, with LSVs ranging from 1.74 to 2.70. The geographical source was adequately identified in 90.1% of 91 Bi. pfeifferi and 85.3% of 75 Bu. forskalii samples. CONCLUSIONS: Our findings demonstrate that MALDI-TOF MS can identify and differentiate snail populations according to geographical origin. It outperforms the current DNA-based approaches in discriminating laboratory from wild strains. This inexpensive high-throughput approach is likely to further revolutionise epidemiological studies in areas which are endemic for schistosomiasis.