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Global food waste emits substantial quantities of nitrogen to the environment (6.3 Mtons annually), chicken feather (CF) waste is a major contributor to this. Pyrolysis, in particular co-pyrolysis of nitrogen-rich and lignocellulosic waste streams is a promising strategy to improve the extent of pyrolytic nitrogen retention by incorporating nitrogen in its solid biochar structure. As such, this biochar can serve as a precursor for nitrogen-enriched activated carbons for application in supercapacitors. Therefore, this study investigates the co-pyrolysis of CF with macadamia nut shells (MNS) to create nitrogen-rich activated carbons. Co-pyrolysis increased nitrogen retention during pyrolysis from 9 % to 18 % compared to CF mono-pyrolysis, while the porosity was maintained. After removing undesirable inorganic impurities by dilute acid washing, this led to a specific capacitance of 21F/g using a scan rate of 20 mV/s. Finally, cycling stability tests demonstrated good stability with 73 % capacitance retention after 10 000 cycles.
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Carvão Vegetal , Macadamia , Eliminação de Resíduos , Animais , Galinhas , Nitrogênio/química , Plumas , Alimentos , Pirólise , EletrodosRESUMO
Mass drug administration of praziquantel becomes a less attractive strategy for elimination of schistosomiasis in low-prevalence areas due to cost implications and low treatment compliance. We aimed to determine the feasibility of a Test-Treat-Track-Test-Treat (5T) strategy in two low-prevalence villages; the 5T strategy has been successfully implemented in diseases such as malaria. A total of 200 school children aged 6-12 years were randomly selected from two schools and tested for Schistosoma mansoni infection using the point-of-care circulating cathodic antigen test. Schistosoma mansoni-positive children, referred to as first-generation cases (FGCs), were tracked and treated including up to five members of their families. Second-generation cases, identified by the FGCs as their close, non-relative contacts, were also tracked, tested, and treated, including up to five members of their families. The prevalence of schistosomiasis among screened FGCs was 16.5% (33/200) in both villages. Twenty-four FGCs were included in the study. Prevalence among 94 contacts of FGCs was 46.8% (44/94). The proportion was higher in Muda than Bulunga village (61.2% versus 31.1%, χ2 = 10.6611, P = 0.005). Prevalence among SGCs and their contacts was 37.5% (9/24) and 47.1% (49/104), respectively. Overall, the 5T strategy identified 102 additional cases out of 222 tracked from FGCs, 95% of whom were treated, at a total time of 52 hours. Our data demonstrate the potential of the 5T strategy in identifying and treating additional cases in the community and hence its practicality in schistosomiasis control in low-prevalence settings at relatively low time and resources investment.
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Anti-Helmínticos , Esquistossomose mansoni , Esquistossomose , Criança , Animais , Humanos , Prevalência , Tanzânia/epidemiologia , Esquistossomose/diagnóstico , Esquistossomose/tratamento farmacológico , Esquistossomose/epidemiologia , Praziquantel/uso terapêutico , Esquistossomose mansoni/diagnóstico , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/epidemiologia , Schistosoma mansoni , Fezes , Anti-Helmínticos/uso terapêuticoRESUMO
INTRODUCTION: Bladder cancer is a possible outcome of chronic urinary schistosomiasis in many endemic countries. In Tanzania, the Lake Victoria area is one of the areas with the highest prevalence of urinary schistosomiasis and higher incidences of squamous cell carcinoma (SCC) of the urinary bladder. A previous study in the area over one decade (2001-2010) showed SCC to be common in patients aged below 50 years. With various prevention and intervention programs there are likely to be notable changes in schistosomiasis-related urinary bladder cancer, which is currently unknown. Updated information on the status of SCC in this area will be useful for giving an insights into efficacy of control interventions implemented and help guide the initiation of new ones. Therefore, this study was done to determine the current trend of schistosomiasis-related bladder cancer in lake zone, Tanzania. METHODS: This was a descriptive retrospective study of histologically confirmed urinary bladder cancer cases diagnosed at the Pathology Department of Bugando Medical Centre over 10 years period. The patient files and histopathology reports were retrieved and information was extracted. Data were analyzed using Chi-square and student t-test. RESULTS: A total of 481 patients were diagnosed with urinary bladder cancer during the study period whereby, 52.6% were males and 47.4% were females. The mean age regardless of histological type of cancer was 55 ± 14.2 years. The SCC was the commonest histological type accounting for 57.0%, followed by transitional cell carcinoma 37.6%, and 5.4% were adenocarcinomas. The Schistosoma haematobium eggs were observed in 25.2% and were commonly associated with SCC (p = 0.001). Poorly differentiated cancers were observed mostly in females (58.6%) compared to males (41.4%) (p = 0.003). Muscular invasion of the urinary bladder by cancer was observed in 11.4% of the patients, and this was significantly higher in non-squamous than in squamous cancers (p = 0.034). CONCLUSION: Schistosomiasis-related cancers of the urinary bladder in the Lake zone of Tanzania is still a problem. Schistosoma haematobium eggs were associated with SCC type indicating the persistence of infection in the area. This calls for more efforts on preventive and intervention programs to reduce the burden of urinary bladder cancer in the lake zone.
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BACKGROUND: Urogenital schistosomiasis remains as a public health problem in Tanzania and for the past 15 years, mass drug administration (MDA) targeting primary school children has remained as the mainstay for its control. However, after multiple rounds of MDA in highly risk groups, there are no data on the current status of Schistosoma haematobium in known endemic areas. Furthermore, the performance of commonly used diagnostic test, the urine reagent strips is not known after the decline in prevalence and intensities of infection following repeated rounds of treatment. Thus, after 15 of national MDA, there is a need to review the strategy and infection diagnostic tools available to inform the next stage of schistosomiasis control in the country. METHODS/FINDINGS: A analytical cross-sectional study was conducted between October and November, 2019 among pre-school (3-5years old) and school aged children (6-17 years old) living in four (4) districts with low (<10%) and moderate (10%-<50%) endemicity for schistosomiasis as per WHO classification at the start of the national control programme in 2005/06, with mean prevalence of 20.7%. A total of 20,389 children from 88 randomly selected primary schools participated in the study. A questionnaire was used to record demographic information. A single urine sample was obtained from each participant and visually examined for macrohaematuria, tested with a dipstick for micro-haematuria, to determine blood in urine; a marker of schistosome related morbidity and a proxy of infection. Infection intensity was determined by parasitological examination of the urine sample for S. haematobium eggs. Overall, mean infection prevalence was 7.4% (95%CI: 7.0-7.7, 1514/20,389) and geometric mean infection intensity was 15.8eggs/10mls. Both infection prevalence (5.9% versus 9%, P<0.001) and intensity (t = -6.9256, P<0.001) were significantly higher in males compared to females respectively. Light and heavy infections were detected in 82.3% and 17.7% of the positive children respectively. The prevalence of macrohaematuria was 0.3% and that of microhaematuria was 9.3% (95%CI:8.9-9.7). The sensitivity and specificity of the urine reagent strip were 78% (95%CI: 76.1-79.9) and 99.8% (95%CI: 99.7-99.9). Having light (P<0.001) and heavy infection intensities (P<0.001) and living in the study districts increased the odd of having microhaematuria. Predictors of S. haematobium infection were being male (P<0.003), microhaematuria (P<0.001), and living in the three study districts (P<0.001) compared to living at Nzega district. CONCLUSION: The findings provide an updated geographical prevalence which gives an insight on the planning and implementation of MDA. Comparing with the earlier mapping survey at the start of the national wide mass drug administration, the prevalence of S. haematobium infection have significantly declined. This partly could be attributed to repeated rounds of mass drug administration. The urine reagent strips remain as a useful adjunct diagnostic test for rapid monitoring of urogenital schistosomiasis in areas with low and high prevalence. Based on prevalence levels and with some schools having no detectable infections, review of the current blanket mass drug administration is recommended.
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Esquistossomose Urinária , Criança , Animais , Feminino , Pré-Escolar , Humanos , Masculino , Adolescente , Esquistossomose Urinária/diagnóstico , Esquistossomose Urinária/epidemiologia , Esquistossomose Urinária/tratamento farmacológico , Fitas Reagentes , Hematúria/diagnóstico , Hematúria/epidemiologia , Administração Massiva de Medicamentos , Prevalência , Estudos Transversais , Tanzânia/epidemiologia , Schistosoma haematobium , Fatores de RiscoRESUMO
BACKGROUND: Appropriate behaviour change with regard to safe water contact practices will facilitate the elimination of schistosomiasis as a public health concern. Various approaches to effecting this change have been trialled in the field but with limited sustainable outcomes. Our case study assessed the effectiveness of a novel theatre-based behaviour change technique (BCT), in combination with cohort awareness raising and capacity training intervention workshops. METHODOLOGY: Our study was carried out in four rural communities in the Mwanza region of Tanzania and in the semi-urban town of Kemise, Ethiopia. We adapted the Risk, Attitude, Norms, Ability and Self-regulation (RANAS) framework and four phases using a mixed methods approach. Participatory project phase engagement and qualitative formative data were used to guide the design of an acceptable, holistic intervention. Initial baseline (BL) data were collected using quantitative questionnaire surveys with 804 participants in Tanzania and 617 in Ethiopia, followed by the theatre-based BCT and capacity training intervention workshops. A post-intervention (PI) survey was carried out after 6 months, with a participant return rate of 65% in Tanzania and 60% in Ethiopia. RESULTS: The intervention achieved a significant improvement in the knowledge of schistosomiasis transmission being associated with poorly managed sanitation and risky water contact. Participants in Tanzania increased their uptake of preventive chemotherapy (males: BL, 56%; PI, 73%, females: BL, 43%; PI, 50%). There was a significant increase in the selection of sanitation (Tanzania: BL, 13%; PI, 21%, Ethiopia: BL, 63%; PI, 90%), safe water and avoiding/minimising contact with infested waters as prevention methods in Tanzania and Ethiopia. Some of the participants in Tanzania followed on from the study by building their own latrines. CONCLUSIONS: This study showed that substantial positive behaviour changes in schistosomiasis control can be achieved using theatre-based BCT intervention and disease awareness training. With the appropriate sensitisation, education and stakeholder engagement approaches, community members were more open to minimising risk-associated contact with contaminated water sources and were mobilised to implement preventive measures.
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Esquistossomose , Feminino , Humanos , Masculino , Saneamento/métodos , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Inquéritos e Questionários , Tanzânia/epidemiologia , ÁguaRESUMO
Coronavirus disease 2019 (COVID-19) has quickly become the most important health burden globally as a result of the pandemic. Pregnant women are considered to be in a high-risk group because COVID-19 infection in this group may result in extensive damage. We aimed to describe COVID-19 infections in four pregnant women in Ilam, Iran. All had positive results first by real-time PCR, then by computed tomographic scan. All of these patients were hospitalized, and all of them were treated successfully. This study showed that although pregnant women are at a higher risk of COVID-19 infection, they can be treated successfully. It also demonstrated that receiving care and treatment at the hospital can be a good experience for pregnant women.
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BACKGROUND: Vector control through long-lasting insecticidal nets (LLINs) and focal indoor residual spraying (IRS) is a major component of the Tanzania national malaria control strategy. In mainland Tanzania, IRS has been conducted annually around Lake Victoria basin since 2007. Due to pyrethroid resistance in malaria vectors, use of pyrethroids for IRS was phased out and from 2014 to 2017 pirimiphos-methyl (Actellic® 300CS) was sprayed in regions of Kagera, Geita, Mwanza, and Mara. Entomological surveillance was conducted in 10 sprayed and 4 unsprayed sites to determine the impact of IRS on entomological indices related to malaria transmission risk. METHODS: WHO cone bioassays were conducted monthly on interior house walls to determine residual efficacy of pirimiphos-methyl CS. Indoor CDC light traps with or without bottle rotator were hung next to protected sleepers indoors and also set outdoors (unbaited) as a proxy measure for indoor and outdoor biting rate and time of biting. Prokopack aspirators were used indoors to capture resting malaria vectors. A sub-sample of Anopheles was tested by PCR to determine species identity and ELISA for sporozoite rate. RESULTS: Annual IRS with Actellic® 300CS from 2015 to 2017 was effective on sprayed walls for a mean of 7 months in cone bioassay. PCR of 2016 and 2017 samples showed vector populations were predominantly Anopheles arabiensis (58.1%, n = 4,403 IRS sites, 58%, n = 2,441 unsprayed sites). There was a greater proportion of Anopheles funestus sensu stricto in unsprayed sites (20.4%, n = 858) than in sprayed sites (7.9%, n = 595) and fewer Anopheles parensis (2%, n = 85 unsprayed, 7.8%, n = 591 sprayed). Biting peaks of Anopheles gambiae sensu lato (s.l.) followed periods of rainfall occurring between October and April, but were generally lower in sprayed sites than unsprayed. In most sprayed sites, An. gambiae s.l. indoor densities increased between January and February, i.e., 10-12 months after IRS. The predominant species An. arabiensis had a sporozoite rate in 2017 of 2.0% (95% CI 1.4-2.9) in unsprayed sites compared to 0.8% (95% CI 0.5-1.3) in sprayed sites (p = 0.003). Sporozoite rates were also lower for An. funestus collected in sprayed sites. CONCLUSION: This study contributes to the understanding of malaria vector species composition, behaviour and transmission risk following IRS around Lake Victoria and can be used to guide malaria vector control strategies in Tanzania.
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Anopheles/fisiologia , Biodiversidade , Inseticidas/administração & dosagem , Malária Falciparum/prevenção & controle , Controle de Mosquitos , Mosquitos Vetores/fisiologia , Compostos Organotiofosforados/administração & dosagem , Animais , Anopheles/efeitos dos fármacos , Malária Falciparum/transmissão , Mosquitos Vetores/efeitos dos fármacos , Plasmodium falciparum/isolamento & purificação , Densidade Demográfica , Estações do Ano , Esporozoítos/isolamento & purificação , TanzâniaRESUMO
Praziquantel (PZQ)-based mass drug administration (MDA) is the main approach for controlling schistosomiasis in endemic areas. Interventions such as provision and use of clean and safe water, minimizing contacts with infested water, disposal of human waste in latrines, and snail control provide additional key interventions to break the transmission cycle and could complement and perhaps sustain the benefits of MDA. However, all interventions deployed need to be accepted by the targeted communities. A qualitative study was conducted to examine factors that might differentiate villages which did not show a substantial decrease in Schistosoma mansoni prevalence despite repeated, high treatment coverage referred to as "persistent hotspot (PHS) villages" from villages which showed a substantial decrease in prevalence referred to as "responding (RES) villages." A convenient sample of adults was drawn from eight villages. Thirty-nine key informants were interviewed and 16 focus groups were held with a total of 123 participants. Data were analyzed manually using a thematic content approach. In both PHS and RES villages, schistosomiasis was not considered to be a priority health problem because of its chronic nature, lack of knowledge and awareness, and poverty among study communities. Persistent hotspot villages exhibited poor leadership style, lack of or insufficient social engagement, little or lack of genuine community participation, little motivation, and commitment to schistosomiasis control compared with RES villages where there were commitment and motivation to fight schistosomiasis. We support the view of scholars who advocate for the adoption of a biosocial approach for effective and sustainable PZQ-based MDA for schistosomiasis control.
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Administração Massiva de Medicamentos , Esquistossomose/prevenção & controle , Adulto , Anti-Helmínticos , Feminino , Grupos Focais , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Fatores Socioeconômicos , Tanzânia/epidemiologia , Adulto JovemRESUMO
The high prevalence of coronavirus disease 2019 (COVID-19) has received much attention all over the world. Nurses are in the first line of defence against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and are placed in a high-risk situation. This study aimed to report on infection with SARS-CoV-2 during patient care among nures in the Mostafa Khomini Hospital, Ilam, Iran. In this hospital 125 nurses were enrolled in the COVID-19 centre. Five out of 125 nurses (4%) who enrolled in the COVID-19 infection centre, developed COVID-19. They were first positive by real-time PCR but the CT scan was positive for only one of them. None of the infected nurses were hospitalized and all of them preferred to quarantine at home and receive the necessary care and treatment (oseltamivir, azithromycin and lopinavir/ritonavir). This study showed that, regardless of self caring, the nurses were exposed to the virus, because at the start of the SARS-CoV-2 outbreak in Iran, there was no special protection against this infection, so the nurses were placed at risk. This study also reported that receiving the necessary care and treatment at home was a good experience for nurses and can be used in some cases.
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The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was created to conduct research that could inform programmatic decision-making related to schistosomiasis. SCORE included several large cluster randomized field studies involving mass drug administration (MDA) with praziquantel. The largest of these were studies of gaining or sustaining control of schistosomiasis, which were conducted in five African countries. To enhance relevance for routine practice, the MDA in these studies was coordinated by or closely aligned with national neglected tropical disease (NTD) control programs. The study protocol set minimum targets of at least 90% for coverage among children enrolled in schools and 75% for all school-age children. Over the 4 years of intervention, an estimated 3.5 million treatments were administered to study communities. By year 4, the median village coverage was at or above targets in all studies except that in Mozambique. However, there was often a wide variation behind these summary statistics, and all studies had several villages with very low or high coverage. In studies where coverage was estimated by comparing the number of people treated with the number eligible for treatment, denominator estimation was often problematic. The SCORE experiences in conducting these studies provide lessons for future efforts that attempt to implement strong research designs in real-world contexts. They also have potential applicability to country MDA campaigns against schistosomiasis and other NTDs, most of which are conducted with less logistical and financial support than was available for the SCORE study efforts.
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Anti-Helmínticos/uso terapêutico , Administração Massiva de Medicamentos , Esquistossomose/tratamento farmacológico , África , Animais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Moçambique , Doenças Negligenciadas/tratamento farmacológico , Doenças Negligenciadas/prevenção & controle , Praziquantel/uso terapêutico , Prevalência , Saúde Pública , População Rural , Schistosoma , Esquistossomose/prevenção & controle , Instituições AcadêmicasRESUMO
The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) conducted large field studies on schistosomiasis control and elimination in Africa. All of these studies, carried out in low-, moderate-, and high-prevalence areas, resulted in a reduction in prevalence and intensity of Schistosoma infection after repeated mass drug administration (MDA). However, in all studies, there were locations that experienced minimal or no decline or even increased in prevalence and/or intensity. These areas are termed persistent hotspots (PHS). In SCORE studies in medium- to high-prevalence areas, at least 30% of study villages were PHS. There was no consistent relationship between PHS and the type or frequency of intervention, adequacy of reported MDA coverage, and prevalence or intensity of infection at baseline. In a series of small studies, factors that differed between PHS and villages that responded to repeated MDA as expected included sources of water for personal use, sanitation, and hygiene. SCORE studies comparing PHS with villages that responded to MDA suggest the potential for PHS to be identified after a few years of MDA. However, additional studies in different social-ecological settings are needed to develop generalizable approaches that program managers can use to identify and address PHS. This is essential if goals for schistosomiasis control and elimination are to be achieved.
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Administração Massiva de Medicamentos , Esquistossomose , África/epidemiologia , Animais , Anti-Helmínticos/uso terapêutico , Feminino , Humanos , Higiene , Masculino , Praziquantel/uso terapêutico , Prevalência , População Rural , Saneamento , Schistosoma haematobium/efeitos dos fármacos , Schistosoma mansoni/efeitos dos fármacos , Esquistossomose/tratamento farmacológico , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Esquistossomose/transmissão , Água/parasitologiaRESUMO
BACKGROUND: Schistosomiasis is a neglected tropical disease that continues to cause morbidity and mortality in Sub Saharan Africa. Due to its endemicity, co-infection with malaria is common. The diseases cause anaemia and impaired nutritional status among children. We investigated the prevalence of intestinal schistosomiasis and its association with malaria, anaemia and nutritional status among school children. METHODS: This was a cross sectional survey among 830 children in Nyamikoma village along Lake Victoria in Tanzania. A pre-tested questionnaire was used to collect socio-demographic data, history of drug use, and clinical data. Two faecal samples were collected on two consecutive days and analyzed using thick smears Kato Katz method. Diagnosis of malaria was done by malaria rapid diagnostic test, and haemoglobin concentration was determined using HemoCue. Nutritional status was assessed by anthropometric measurements. RESULTS: The overall prevalence of intestinal schistosomiasis was 90.6% (95% CI = 88.6% - 92.6%). Intensity of infection was light 24.1% (200/830), moderate 38.4% (319/830) and heavy 28.1% (233/830). Pre-adolescents (≤12 years) were more infected with intestinal schistosomiasis (93.2%) than adolescents (>12 years) (84.7%) (p < 0.001). Prevalence of malaria was 1.7% (14/824), and that of intestinal schistosomiasis-malaria co-infection was 1.6% (13/824). The overall prevalence of anaemia was 24.6% (95%CI = 18.7% - 30.5%). Severe anaemia was found in 2.3% (19/824) of study participants. The prevalence of stunting and wasting were 29.0% and 11.3%, respectively. On both univariate and multivariate regression analysis, only lower age was significantly associated intestinal schistosomiasis infection, but not anemia, malaria, stunting or wasting. However among those infected, a negative binomial regression analysis indicated independent significant association of male sex, loose stool consistency, and stunting with high eggs count/gram of stool. CONCLUSIONS: Despite several rounds of annual mass praziquantel administration, intestinal schistosomiasis is highly prevalent among school children particularly in younger children living in the study area. Biannual targeted mass praziquantel treatments or alternative regimens may be considered in future in the study area to redress the situation.
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Enteropatias Parasitárias/epidemiologia , Esquistossomose/epidemiologia , Criança , Coinfecção/complicações , Estudos Transversais , Feminino , Humanos , Enteropatias Parasitárias/complicações , Malária/complicações , Masculino , Desnutrição/complicações , Prevalência , População Rural/estatística & dados numéricos , Esquistossomose/complicações , Tanzânia/epidemiologiaRESUMO
BACKGROUND: In an effort to complement the current chemotherapy based schistosomiasis control interventions in Shinyanga district, community knowledge, perceptions and water contact practices were qualitatively assessed using focus group discussions and semi structured interviews involving 271 participants in one S. haematobium prevalent community of Ikingwamanoti village, Shinyanga district, Northwestern, Tanzania. METHODS: In October, 2016 we conducted 29 parent semi structured interviews and 16 focus group discussions with a total of 168 parent informants. Adult participants were conveniently selected from three sub-villages of Butini, Miyu, and Bomani of Ikingwamanoti village, Shinyanga district. In March, 2017, a total of 103 children informants participated in 10 focus group discussions and 20 semi structured interviews, administered to children from standard four, five, six and seven attending Ikingwamanoti Primary School. Note taking and digital recorders were used to collect narrative data for thematic analysis of emergent themes. RESULTS: Among participants, 75% parents and 50% children considered urinary schistosomiasis as a low priority health problem. Of the informants, 70% children and 48.3% parents had misconceptions about the cause, modes of transmission and control of schistosomiasis demonstrating gaps in their biomedical knowledge of the disease. Assessment of treatment seeking behavior for urinary schistosomiasis revealed a combination of traditional and modern health care sectors. However, modern medicines were considered effective in the treatment of urinary schistosomiasis. Lack of alternative sources of water for domestic and recreational activities and unhygienic water use habits exposed community members to high risk of acquiring urinary schistosomiasis. CONCLUSION: Use of Schistosoma haematobium contaminated water sources for daily domestic and recreational use facilitated contraction of urinary schistosomiasis among community members in Shinyanga district. People's perceptions of urinary schistosomiasis as a less priority health problem promoted persistence of the disease. Future efforts to control urinary schistosomiasis should take into account integrated approaches combining water, sanitation and hygiene, health education, alternative sources of clean and safe water to facilitate behavior change.
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Conhecimentos, Atitudes e Prática em Saúde , Higiene , Pais/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Schistosoma haematobium , Esquistossomose Urinária/psicologia , Adolescente , Adulto , Animais , Criança , Estudos Transversais , Transmissão de Doença Infecciosa , Feminino , Grupos Focais , Humanos , Masculino , Percepção , Prevalência , Pesquisa Qualitativa , Saneamento , Esquistossomose Urinária/epidemiologia , Esquistossomose Urinária/transmissão , Tanzânia/epidemiologia , ÁguaRESUMO
Solid-state nanopores are powerful tools for sensing of single biomolecules in solution. Fabrication of solid-state nanopores is still challenging, however; in particular, new methods are needed to facilitate the integration of pores with larger nanofluidic and electronic device architectures. We have developed the tip-controlled local breakdown (TCLB) approach, in which an atomic force microscope (AFM) tip is brought into contact with a silicon nitride membrane that is placed onto an electrolyte reservoir. The application of a voltage bias at the AFM tip induces a dielectric breakdown that leads to the formation of a nanopore at the tip position. In this work, we report on the details of the apparatus used to fabricate nanopores using the TCLB method, and we demonstrate the formation of nanopores with smaller, more controlled diameters using a current limiting circuit that zeroes the voltage upon pore formation. Additionally, we demonstrate the capability of TCLB to fabricate pores aligned to embedded topographical features on the membranes.
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Single-dose targeted praziquantel preventive chemotherapy is the WHO-recommended intervention for schistosomiasis control in endemic countries. The objective of this study was to assess the efficacy and safety of single-dose praziquantel among Schistosoma mansoni-infected children in north-western Tanzania. A prospective safety and efficacy surveillance study was conducted among 341 school-going children treated with a single-dose praziquantel 40 mg/kg body weight. Socio-demographic, pre-treatment, and post-treatment stool examination and safety data were collected. The primary and secondary outcomes were treatment efficacy (parasitological cure and egg reduction rates at three weeks post-treatment) and treatment-related adverse events, respectively. The overall cure rate and egg reduction rate were 81.2% (76.8-85.3%) and 95.0% (92.7-97.3%), respectively. There was no significant association between cure rate and pre-treatment infection intensity. The incidence of treatment-associated adverse events was 28.5% (23.7-33.3%), with abdominal pain being the most common. Post-treatment abdominal pain and vomiting were significantly associated with pre-treatment infection intensity (p < 0.001) and anemia (p = 0.03), respectively. Praziquantel single-dose is still safe and efficacious against Schistosoma mansoni infection. However, the lack of cure in about one-fifth and adverse events in a quarter, of the infected children indicate the need for close praziquantel safety monitoring and treatment optimization research to improve efficacy.
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Recent studies demonstrated a high antioxidant capacity for pomegranate components due to their rich bioactive compounds, such as conjugated fatty acids and phenolics. The objective of the present study was, therefore, to assess whether pomegranate seed or pomegranate seed pulp (peel + seed) supplementation could be effective to improve antioxidant status, and hence metabolic profile and performance in periparturient dairy cows. After a 1-wk pretreatment period, Holstein cows (primiparous n = 12, multiparous n = 18) were assigned to 3 dietary treatments from 25 d before expected calving through 25 d postcalving. The dietary treatments included (1) control (CON); (2) diet supplemented with pomegranate seeds (PS; 400 g/cow per day); and (3) diet supplemented with pomegranate seed pulp (PSP; 400 g of seeds/cow per day + 1200 g of peels/cow per day). Compared with CON, supplementation with either PS or PSP had no effects on dry matter intake, rumen fermentation, and plasma concentrations of cholesterol, total protein, globulin, and aspartate amino transferase, but enhanced plasma total antioxidant activity, and lowered triacylglycerol, free fatty acids (FFA), and ß-hydroxybutyrate at both pre- and postpartum periods. Plasma concentration of glucose, albumin, malondialdehyde (MDA) and blood superoxide dismutase (SOD) activity were not affected by dietary treatments at prepartum, whereas SOD activity increased and glucose, albumin, MDA, and FFA-to-albumin ratio decreased by feeding both by-products at postpartum period. In contrast to PS, supplementing PSP resulted in a greater decrease in plasma glucose and triacylglycerol concentration and higher increase in SOD activity. Energy- and fat-corrected milk yields were higher in cows fed PSP diet compared with those fed CON or PS diets, but content of milk fat, protein, and lactose were similar across the dietary treatments. These findings indicated that dietary pomegranate by-products supplementation, in particular PSP, could improve antioxidant status, which was associated with a decline in lipid oxidation (FFA and ß-hydroxybutyrate) and peroxidation (MDA) and an enhancement in glucose utilization as well as fat-corrected milk yield.
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Bovinos/fisiologia , Suplementos Nutricionais , Lythraceae , Metaboloma/efeitos dos fármacos , Extratos Vegetais/farmacologia , Ácido 3-Hidroxibutírico/sangue , Animais , Antioxidantes/análise , Glicemia/análise , Dieta/veterinária , Ácidos Graxos não Esterificados/sangue , Feminino , Frutas/química , Lactação/efeitos dos fármacos , Leite/metabolismo , Oxirredução , Período Periparto , Rúmen/metabolismo , Sementes/química , Superóxido Dismutase/metabolismo , Triglicerídeos/sangueRESUMO
BACKGROUND: The effect of Human Immunodeficiency Virus-1 (HIV-1) on CD4+ Th2 cells is hypothesized to affect parasitological diagnosis of Schistosoma mansoni using Kato Katz technique. Thus, the use of more sensitive technique such as Point-of-Care Circulating Cathodic Antigen (POC-CCA) test is recommended. However, the sensitivity of this diagnostic test in diagnosing S.mansoni infection and the usefulness of it in monitoring efficacy of praziquantel drug in presence of HIV-1 co-infection remains inconclusive. The Primary objective of the present study was to assess accuracy of the POC-CCA test in diagnosing S.mansoni infection before and after praziquantel treatment in adult population co-infected with HIV -1. METHODS: A prospective longitudinal study was conducted among individuals aged 15-55 years at Igalagala village, north-western Tanzania. At baseline and 4 weeks after treatment, a single stool and urine samples were collected from each participants. Kato Katz (KK) technique and Point-of-Care Circulating Cathodic Antigen tests were used for diagnosis of Schistosoma mansoni. RESULTS: At baseline, based on KK and POC-CCA, the prevalence of S.mansoni was 57.8% (95%CI: 52.9-62.4) and 87.5% (95%CI: 83.9-90.4). Based on KK technique and POC-CCA test, 3.6% and 5.7% of the study participants were co-infected with S.mansoni and HIV-1. At baseline, in the general population, the sensitivities of POC-CCA test using KK technique and combine gold standard were 96.3%(95%CI: 93.1-98.3) and 97.6%(95%CI:95.5-98.9) respectively. In the HIV-1 seropositive group, at baseline, the sensitivities of POC-CCA test using KK technique and combined gold standards, were 93.3%(95%CI:68.1-99.8) and 96%(95CI%:79.6-99.9). Four weeks after treatment, in general population, the sensitivities of POC-CCA test using KK technique and combined gold standards were 47.8%(95%CI:26.8-69.4) and 84.4%(95%CI:74.4-91.7). In the HIV-1 seropositive group, using KK technique, the sensitivity was 100% (95%CI:2.5-100). CONCLUSION: The sensitivity of POC-CCA in diagnosing S.mansoni infection was higher than KK technique in adult individuals likely to have low infection intensity and co-infected with HIV-1. However, its sensitivity decreases following praziquantel treatment but remained higher than Kato Katz technique. If the goal of the post-treatment is to identify uncured individuals, then POC-CCA test offers the best choice.
RESUMO
BACKGROUND: The major drawback of the community-based mass drug administration (MDA) approach against schistosomiasis is that treatment is offered blindly without testing for the targeted infection. This partly contributes to the low treatment coverage. One approach to overcome this limitation is to introduce a diagnostic component in the treatment approach. This will improve drug uptake and compliance to treatment. This study is conducted to assess the feasibility and acceptability of integrating point-of-care Circulating Cathodic Antigen (POC-CCA) test to community-based directed MDA in improving treatment coverage and compliance with treatment among adults. METHODS: This is a randomized control community trial in which 30 clusters were randomly assigned to either an intervention or control arm to evaluate two interventions on treatment coverage and compliance with treatment. In each cluster, 150 adult participants were enrolled. Community Health Workers (CHW) in both arms were trained on all aspects of praziquantel (PZQ) distribution and management of mild side effects. In the intervention arm, CHWs had additional training on how to use POC-CCA to diagnose intestinal schistosomiasis. In the intervention arm, participants were tested using POC-CCA test for presence of intestinal schistosomiasis and treated based on test results, while in the control arm, participants were treated with PZQ without testing. The primary outcome measure was the proportion of participants provided with PZQ between the two arms and geographical clusters. Secondary outcomes were prevalence of S. mansoni infection based on the POC-CCA test conducted by CHWs, ability of CHWs to use the POC-CCA test accurately and safely and community acceptability of the POC-CCA test results from CHWs. Both quantitative and qualitative techniques have been used to collect data at study endpoint. DISCUSSION: The study will generate evidence on the importance of integrating a diagnostic component into the community directed MDA conducted by CHWs. Findings will generate discussion on the current MDA policy and practice in Tanzania. TRIAL REGISTRATION: PACTR201804003343404 (25/4/2018).
Assuntos
Agentes Comunitários de Saúde , Técnicas e Procedimentos Diagnósticos , Administração Massiva de Medicamentos , Sistemas Automatizados de Assistência Junto ao Leito/organização & administração , Praziquantel/uso terapêutico , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/diagnóstico , Adulto , Animais , Antígenos de Helmintos/análise , Feminino , Humanos , Masculino , Schistosoma mansoni/imunologia , Esquistossomose mansoni/tratamento farmacológico , TanzâniaRESUMO
In this article, an analytical approach is presented for the analysis of electromagnetic (EM) scattering from radially inhomogeneous spherical structures (RISSs) based on the duality principle. According to the spherical symmetry, similar angular dependencies in all the regions are considered using spherical harmonics. To extract the radial dependency, the system of differential equations of wave propagation toward the inhomogeneity direction is equated with the dual planar ones. A general duality between electromagnetic fields and parameters and scattering parameters of the two structures is introduced. The validity of the proposed approach is verified through a comprehensive example. The presented approach substitutes a complicated problem in spherical coordinate to an easy, well posed, and previously solved problem in planar geometry. This approach is valid for all continuously varying inhomogeneity profiles. One of the major advantages of the proposed method is the capability of studying two general and applicable types of RISSs. As an interesting application, a class of lens antenna based on the physical concept of the gradient refractive index material is introduced. The approach is used to analyze the EM scattering from the structure and validate strong performance of the lens.
RESUMO
BACKGROUND: Schistosomiasis represents a major public health problem in Tanzania despite ongoing national control efforts. This study examined whether intestinal schistosomiasis is associated with malaria and assessed the contribution of intestinal schistosomiasis and malaria on anaemia and undernutrition in school children in Mara region, North-western Tanzania. METHODS: Stool samples were collected from each of 928 school children randomly selected from 5 schools and examined for intestinal schistosomiasis using the Kato Katz method. Finger prick blood samples were collected and examined for malaria parasites and haemoglobin concentrations using the Giemsa stain and Haemocue methods, respectively. Nutritional status was assessed by taking anthropometric measurements. RESULTS: The overall prevalence and infection intensity of S. mansoni was 85.6% (794/928) and 192 (100-278), respectively. The prevalence of malaria was 27.4% (254/928) with significant differences among villages (χ 2 = 96.11, p < 0.001). The prevalence of anaemia was 42.3% (392/928) with significant differences among villages (χ 2 = 39.61, p < 0.001). The prevalence of stunting, thinness and underweight was 21, 6.8 and 1.3%, respectively. Stunting varied significantly by sex (χ 2 = 267.8, p < 0.001), age group (χ 2 = 96.4, p < 0.001) and by village (χ 2 = 20.5, p < 0.001). Out of the 825 infected children, 217 (26.4%) had multiple parasite infections (two to three parasites). The prevalence of co-infections occurred more frequently in boys than in girls (χ 2 = 21.65, p = 0.010). Mean haemoglobin concentrations for co-infected children was significantly lower than that of children not co-infected (115.2 vs 119.6; t = 0.01, p = 0.002). Co-infected children were more likely to be stunted than children who were not co-infected (χ 2 = 11.6, p = 0.003). On multivariate analysis, age group, village of residence and severe anaemia were significant predictors of stunting after adjusting for sex and infection status. CONCLUSIONS: Intestinal schistosomiasis and malaria are prevalent in Mara region. Coinfections of these parasites as well as chronic undernutrition were also common. We recommend Mara region to be included in national schistosomiasis control programmes.