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BACKGROUND: Malaria is one of the most severe global public health problems worldwide, particularly in Africa, where Nigeria has the greatest number of malaria cases. This community-based study was designed to investigate the prevalence and risk factors of malaria and to evaluate the knowledge, attitudes, and practices (KAP) regarding malaria among rural Hausa communities in Kano State, Nigeria. METHODS: A cross-sectional community-based study was conducted on 551 participants from five local government areas in Kano State. Blood samples were collected and examined for the presence of Plasmodium species by rapid diagnostic test (RDT), Giemsa-stained thin and thick blood films, and PCR. Moreover, demographic, socioeconomic, and environmental information as well as KAP data were collected using a pre-tested questionnaire. RESULTS: A total of 334 (60.6 %) participants were found positive for Plasmodium falciparum. The prevalence differed significantly by age group (p < 0.01), but not by gender or location. A multivariate analysis showed that malaria was associated significantly with being aged 12 years or older, having a low household family income, not using insecticide treated nets (ITNs), and having no toilets in the house. Overall, 95.6 % of the respondents had prior knowledge about malaria, and 79.7, 87.6 and 95.7 % of them knew about the transmission, symptoms, and prevention of malaria, respectively. The majority (93.4 %) of the respondents considered malaria a serious disease. Although 79.5 % of the respondents had at least one ITN in their household, utilization rate of ITNs was 49.5 %. Significant associations between the respondents' knowledge concerning malaria and their age, gender, education, and household monthly income were reported. CONCLUSIONS: Malaria is still highly prevalent among rural Hausa communities in Nigeria. Despite high levels of knowledge and attitudes in the study area, significant gaps persist in appropriate preventive practices, particularly the use of ITNs. Innovative and Integrated control measures to reduce the burden of malaria should be identified and implemented in these communities. Community mobilization and health education regarding the importance of using ITNs to prevent malaria and save lives should be considered.
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Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Nigéria/epidemiologia , Prevalência , Fatores de Risco , População Rural , Inquéritos e Questionários , Adulto JovemRESUMO
The oil well cementing job is the operation in which a cement paste is pumped to fill the annulus behind the casing. Inclusion of nanomaterials in oil well cement results in improving the cement properties. This paper provides a comprehensive overview of incorporating nanosilica into oil well cement, addressing various aspects of the nanosilica manufacturing process, dispersion challenges, the impact on cement hydration and properties, as well as the operational challenges. The addition of nanosilica is found to enhance cement properties such as hydration rate, compressive strength at low temperatures, and resistance to deterioration at high temperatures. However, challenges arise, including increased viscosity and the need for higher water content. Dispersion of nanosilica into cement slurry remains a difficulty, compounded by the high manufacturing cost, limiting its practical application. The paper recommends further research to improve nanosilica dispersion, explore cost-effective raw materials, and overcome operational challenges for broader utilization in oil well cementing.
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Foam cement is a versatile cementing material that has found numerous applications in the oil and gas industry. As research continues to advance and improve the properties of foam cement, it is likely that we will see an increased use of this material in the years to come. This review aims to summarize the current state of the art and the latest developments in the utilization of foam cement in oil fields. The study focuses on the key benefits of foam cement, including its light weight, excellent flow properties, ability to maintain its structural integrity over time, and high compressive strength. It also examines its various applications in oil field operations, such as cementing against fragile formations, well abandonment, zonal isolation, cementing offshore wells, and well remedial cementing. Furthermore, the paper evaluates the various factors that influence the performance of foam cement, such as the mixing design, foam structure, and stability. In addition, the methods for evaluating the foamed cementing job and the integrity of the formed cement sheath are also presented. The review also highlights the current challenges and limitations of foam cement technology that should be considered when using foamed cement in oil field applications and discusses the future directions for its development and optimization. This review provides a comprehensive overview of the applications of foam cement in oil fields and will be of great interest to engineers, researchers, and practitioners in the oil and gas industry.
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High-density cement slurries used in oil well cementing often face challenges such as particle settling, poor rheological properties, permeability, and compressive strength degradation, which can compromise zonal isolation and well integrity. This study focuses on using kaolinite, a clay mineral, as an additive due to its potential to improve the performance of high-density cement by modifying key properties. Several concentrations of kaolinite were examined to evaluate their influence on several cement properties such as rheology, thickening time, permeability, porosity, and compressive strength. Additionally, it assesses the impact of kaolinite on cement sheath solids settling using both conventional methods and nuclear magnetic resonance (NMR). The results revealed that an optimal concentration of 1% kaolinite by weight of cement (BWOC) significantly reduced particle settling by 74.4%, enhanced compressive strength by 13%, and lowered permeability and porosity by 74% and 7%, respectively. Additionally, kaolinite improved rheological properties by an 8.4% reduction in plastic viscosity, a 19.4% increase in yield point, and a 30% increase in gel strength. Kaolinite also acted as a retarder, increasing thickening time. These improvements contribute to better cement sheath integrity and wellbore stability, highlighting kaolinite's potential as an effective additive for high-density cement.
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Casing cementing is one of the most crucial operations in the oil well drilling process since it determines the durability and stability of the well throughout its life. Different additives have been mixed into the oil well cement slurry to improve the properties of both the cement slurry and the solidified cement sheath. Graphite is a waste material with a huge potential to be utilized in cementing to improve the properties of the oil well cement and reduce the graphite waste content in the environment. This study intends to analyze the effect of graphite on alteration in properties of the cement compressive and tensile strength, Poisson's ratio, Young's modulus, porosity, and permeability for three days of curing. Based on the trend of the properties during the three days of curing, equations were established to describe the future change in cement properties with time. Two formulas of cement, the base (with no graphite) and graphite-based (with 0.2% by weight of cement graphite) were prepared in this study. The results showed that the graphite successfully increased the compressive strength, tensile strength, and Poisson's ratio of the cement sheath, throughout the curing process. Young's modulus was decreased after the incorporation of graphite which indicates an enhancement in cement resistance to shear forces. The porosity and permeability were also decreased indicating formation of a more densified cement sheath.
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In the oil and gas industry, cementing is a very important process to maintain the stability of the well. The cement can provide an effective plug against fluid movement and at the same time supports the casing and formations. Based on the operation conditions, different types of additives are used to make the cement slurry, and incorporation of a new additive considerably affects all properties of the cement slurry and the solidified sheath. In this work, lab experiments were performed to investigate alteration of the Saudi Class G cement properties after incorporation of olive waste into the slurry, and the possibility of replacing the commercial retarder with olive waste was also studied in this work. Five samples with different olive waste content were prepared, and their rheological characteristics, thickening time, mechanical properties, and permeability were evaluated after 24 h of curing at 95 °C. The results indicated that olive waste could replace the use of a commercial retarder. The incorporation of olive waste did not affect the cement plastic viscosity, while the yield point, 10 s, and 10 min gel strengths of the cement were considerably increased with the increase in the olive waste content. The cement compressive strength was also increased with the incorporation of olive waste of a maximum of 0.375%, and the permeability decreased with the addition of a maximum of 0.25% olive waste.
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Blastocystis infection has a worldwide distribution especially among the disadvantaged population and immunocompromised subjects. This study was carried out to determine the prevalence and the association of Blastocystis infection with the socio-economic characteristics among 300 primary schoolchildren, living in rural communities in Lipis and Raub districts of Pahang state, Malaysia. Stool samples were collected and examined for the presence of Blastocystis using direct smear microscopy after in vitro cultivation in Jones' medium. The overall prevalence of Blastocystis infection was found to be as high as 25.7%. The prevalence was significantly higher among children with gastrointestinal symptoms as compared to asymptomatic children (x2 =4.246; P=0.039). Univariate and multivariate analyses showed that absence of a piped water supply (OR=3.13; 95% CI=1.78, 5.46; P<0.001) and low levels of mothers' education (OR=3.41; 95% CI=1.62, 7.18; P<0.01) were the significant predictors of Blastocystis infection. In conclusion, Blastocystis is prevalent among rural children and the important factors that determine the infection were the sources of drinking water and mothers' educational level. Interventions with provision of clean water supply and health education especially to mothers are required.
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Infecções por Blastocystis/epidemiologia , Blastocystis , Água Potável/parasitologia , Adolescente , Análise de Variância , Infecções Assintomáticas , Infecções por Blastocystis/diagnóstico , Infecções por Blastocystis/fisiopatologia , Criança , Fezes/parasitologia , Feminino , Humanos , Malásia/epidemiologia , Masculino , Prevalência , População Rural , Instituições Acadêmicas , Fatores Socioeconômicos , Abastecimento de Água/economiaRESUMO
Soil-transmitted helminthiasis (STH), among the most common neglected tropical diseases, is a major public health problem in Malaysia with a possible impact on the nutritional status and school participation of rural children. This study was carried out among Aboriginal schoolchildren, living in an endemic area for STH in Malaysia, to determine the possible relationship between intestinal helminthiasis and school absenteeism. We also evaluated whether successful treatment of the infection will affect school attendance among the subjects. Stool analysis revealed that more than 90% of the subjects were infected with at least 1 helminth species, with Ascaris lumbricoides and Trichuris trichiura infections being most prevalent. Infection of moderate-to-heavy worm burdens, low level of fathers' education and anaemia were identified as the significant predictors of high absenteeism among the subjects (P<0·05). Following treatment of the infected children, it was found that school absenteeism was reduced significantly (P<0·01). In conclusion, STH continues to have significant impacts on public health, particularly in rural communities with a negatively significant effect on the school participation of Aboriginal children. A school-based de-worming programme should be introduced and incorporated in the current educational assistance targeted towards the Aboriginal communities, under the auspices of the government.
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Absenteísmo , Helmintíase/epidemiologia , Enteropatias/epidemiologia , População Rural , Instituições Acadêmicas , Solo/parasitologia , Estudantes , Adolescente , Animais , Ascaríase/epidemiologia , Ascaríase/parasitologia , Ascaríase/prevenção & controle , Ascaríase/transmissão , Criança , Fezes/parasitologia , Feminino , Helmintíase/parasitologia , Helmintíase/prevenção & controle , Helmintíase/transmissão , Helmintos , Infecções por Uncinaria/epidemiologia , Infecções por Uncinaria/parasitologia , Infecções por Uncinaria/prevenção & controle , Infecções por Uncinaria/transmissão , Humanos , Enteropatias/parasitologia , Enteropatias/prevenção & controle , Enteropatias Parasitárias , Malásia/epidemiologia , Masculino , Estado Nutricional , Recidiva , Tricuríase/epidemiologia , Tricuríase/parasitologia , Tricuríase/prevenção & controle , Tricuríase/transmissãoRESUMO
Throughout the life of a well, the cement sheath is exposed to several loadings, which can harm its key properties and impede its functions. These loadings become more significant at the early age of forming the cement sheath in which the properties of the cement are not completely developed. In this study, 10 cement samples with and without laponite particles were prepared and cured for five different periods (6, 12, 24, 48, and 72 h). The failure properties, petrophysical parameters, elastic properties, and density variation along the samples were examined. All of the samples were characterized by nuclear magnetic resonance and X-ray diffraction to understand the influence of the curing times on the cement properties. The results showed that the compressive and tensile strengths of both cement systems increased with the curing time and the incorporation of the laponite particle increased the strength of the cement. The permeability of both cement samples decreased with curing time, and the addition of laponite also decreased the permeability of the cement samples because of the presence of laponite-clay particles. The addition of laponite particles also increased the elasticity of the cement as indicated by the decrease in Young's modulus and the increase in Poisson's ratio. Logarithmic relationships were established to represent the changes in porosity, compressive strength, and tensile strength, while the changes in the other properties of permeability, Poisson's ratio, Young's modulus, and density variation were represented accurately with power-law equations.
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Oil-well cement physical characteristics considerably change after being carbonated by a CO2-rich solution. In this study, the influence of graphite particles in the characteristics of oil-well cement reacted with a CO2-rich solution at 130 °C and 10 MPa for 10 days was studied. After 10 days of carbonation, incorporating 0.2% by weight of cement (BWOC) of graphite into the cement slurry decreased the carbonation depth by 29.8% as confirmed by the direct measurement and the micro-computerized tomography scan technique. The addition of 0.2% BWOC of graphite also reduced the cement matrix permeability by 31.4% and increased its compressive strength by 16.4% and tensile strength by 23.8% compared to the sample without graphite. The decrease in the cement matrix portlandite concentration and permeability of the samples prepared with graphite contributed to promote the cement matrix carbonation resistance. The microscopic images also proved that the incorporation of graphite delayed the leaching of calcium carbonate, and this is also attributed to decreasing the cement strength deterioration.
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We reviewed the epidemiology of STH in Malaysia from the 1970s to 2009. High prevalence rates persist among the rural Aborigines, estate workers and in urban slums and squatter areas. Trichuris trichiura is the most prevalent helminth in Malaysia ranging from 2.1% to 98.2%. Ascaris lumbricoides follows closely with a prevalence rate of 4.6-86.7%, while hookworm is the least prevalent (0-37.0%). A countrywide control program with special emphasis on school-based intervention is highly recommended among aboriginal people.
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Helmintíase/epidemiologia , Helmintíase/transmissão , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/transmissão , Microbiologia do Solo , Solo/parasitologia , Distribuição por Idade , Animais , Ascaris lumbricoides/isolamento & purificação , Criança , Helmintíase/prevenção & controle , Humanos , Enteropatias Parasitárias/prevenção & controle , Malásia/epidemiologia , Fatores de Risco , Trichuris/isolamento & purificaçãoRESUMO
A reliable assessment of the aquifer contamination vulnerability is essential for the conservation and management of groundwater resources. In this study, a recent technique in artificial intelligence modeling and computational optimization algorithms have been adopted to enhance the groundwater contamination vulnerability assessment. The original DRASTIC model (ODM) suffers from the inherited subjectivity and a lack of robustness to assess the final aquifer vulnerability to nitrate contamination. To overcome the drawbacks of the ODM, and to maximize the accuracy of the final contamination vulnerability index, two levels of modeling strategy were proposed. The first modeling strategy used particle swarm optimization (PSO) and differential evolution (DE) algorithms to determine the effective weights of DRASTIC parameters and to produce new indices of ODVI-PSO and ODVI-DE based on the ODM formula. For strategy-2, a deep learning neural networks (DLNN) model used two indices resulting from strategy-1 as the input data. The adjusted vulnerability index in strategy-2 using the DLNN model showed more superior performance compared to the other index models when it was validated for nitrate values. Study results affirmed the capability of the DLNN model in strategy-2 to extract the further information from ODVI-PSO and ODVI-DE indices. This research concluded that strategy-2 provided higher accuracy for modeling the aquifer contamination vulnerability in the study area and established the efficient applicability for the aquifer contamination vulnerability modeling.
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Aprendizado Profundo , Água Subterrânea , Algoritmos , Inteligência Artificial , Monitoramento Ambiental , Modelos Teóricos , Redes Neurais de ComputaçãoRESUMO
Silica flour is one of the most commonly used material in cementing oil wells at high-temperature conditions of above 230 °F to prevent the deterioration in the strength of the cement. In this study, replacement of the silica flour with the granite waste material at which an inexpensive and readily available material in cementing oil-wells is evaluated. Four cement samples with various amounts of silica flour and granite powder were prepared in this work. The effect of including the granite waste instead of silica flour in the cement elastic, failure, and petrophysical properties after curing the samples at 292 °F and 3000 psi was examined. The results revealed that replacement of the silica flour with 40% by weight of cement (BWOC) optimized the cement performance and confirmed that this concentration of granite could be used as an alternative to the silica flour in oil-well cementing. This concertation of granite slightly improved the elastic properties of the cement. It also improved the cement compressive and tensile strengths by 5.7 and 39.3%, respectively, compared to when silica flour is used. Replacement of the silica flour with 40% BWOC of granite waste also reduced the cement permeability by 64.7% and porosity by 17.9%.
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After oil and gas well drilling, they should be cased and cemented to ensure the stability of the wellbore and to isolate the trouble zones. To achieve these jobs, several additives are incorporated into the cement slurry to improve the cement matrix durability, especially at temperatures above 230 F. The tire waste material is an industrial waste that comes from automobile tires. The purpose of this work is to investigate the prospect of utilizing tire waste in oil-well cement under high-temperature and high-pressure conditions of 292 F and 3000 psi. Three cement samples with different concentrations of the tire waste material were prepared. The effects of tire waste on the cement rheological properties, elastic and failure parameters, and permeability were examined. The results showed that adding 0.3% by weight of cement (BWOC) of the tire waste material considerably improved the cement to the cement slurry and cement matrix properties, and it decreased the cement plastic viscosity by 53.1% and increased its yield point by 142.4% compared to the base cement. The cement samples with 0.3% BWOC of tire waste have Young's modulus which is 10.8% less than that of the base cement and Poisson's ratio of 14.3% greater than that of the base cement. By incorporating 0.3% of the tire waste, both compressive and tensile strengths of the cement increased by 48.3 and 11.7%, respectively, compared with those of the base cement. The cement permeability was decreased by 66.0% after adding 0.3% of the tire waste. Besides the improvement in the properties of cement, the use of the tire waste material has other economical and environmental advantages because these are very cheap materials dominant in our life.
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High-temperature conditions drastically compromise the physical properties of cement, especially, its strengths. In this work, the influence of adding nanoclay (NC) particles to Saudi class G oil well cement (OWC) strength retrogression resistance under high-temperature condition (300 °C) is evaluated. Six cement slurries with different concentrations of silica flour (SF) and NC were prepared and tested under conditions of 38 °C and 300 °C for different time periods (7 and 28 days) of curing. The changes in the cement matrix compressive and tensile strengths, permeability, loss in the absorbed water, and the cement slurry rheology were evaluated as a function of NC content and temperature, the changes in the structure of the cement surfaces were investigated through the optical microscope. The results revealed that the use of NC (up to 3% by weight of cement (BWOC)) can prevent the OWC deterioration under extremely high-temperature conditions. Incorporating more than 3% of NC severely damaged the cement matrix microstructure due to the agglomeration of the nanoparticles. Incorporation of NC particles increased all the cement slurry rheological properties.
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Schistosomiasis remains one of the most prevalent neglected tropical diseases especially in Nigeria which has the greatest number of infected people worldwide. A cross-sectional study was conducted among 551 participants from Kano State, North Central Nigeria. Fecal samples were examined for the presence of Schistosoma mansoni eggs using the formalin-ether sedimentation method while the urine samples were examined using the filtration technique for the presence of S. haematobium eggs. Demographic, socioeconomic and environmental information was collected using a pre-validated questionnaire. The overall prevalence of schistosomiasis was 17.8%, with 8.9% and 8.3% infected with S. mansoni and S. haematobium, respectively and 0.5% presenting co-infection with both species. The multiple logistic regression analysis revealed that age < 18 years (OR = 2.13; 95% CI; 1.34- 3.41), presence of infected family members (OR = 3.98; 95% CI; 2.13-7.46), and history of infection (OR = 2.87; 95% CI; 1.87- 4.56) were the significant risk factors associated with schistosomiasis in these communities. In conclusion, this study revealed that schistosomiasis is still prevalent among Hausa communities in Nigeria. Mass drug administration, health education and community mobilization are imperative strategies to significantly reduce the prevalence and morbidity of schistosomiasis in these communities.
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Esquistossomose Urinária/epidemiologia , Esquistossomose mansoni/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Nigéria/epidemiologia , Prevalência , Fatores de Risco , Schistosoma haematobium/isolamento & purificação , Schistosoma mansoni/isolamento & purificação , Esquistossomose Urinária/diagnóstico , Esquistossomose mansoni/diagnóstico , Fatores Socioeconômicos , Adulto JovemRESUMO
BACKGROUND: Schistosomiasis is one of the most common neglected tropical diseases, especially in the developing countries in Africa, Asia and South America, with Nigeria having the greatest number of cases of schistosomiasis worldwide. This community-based study aims to evaluate the knowledge, attitude and practices (KAP) regarding schistosomiasis among rural Hausa communities in Kano State, Nigeria. METHODS: A cross-sectional study was carried out among 551 participants from Hausa communities in five local government areas in Kano State, North Central Nigeria. Demographic, socioeconomic and environmental information as well as KAP data were collected using a pre-tested questionnaire. Moreover, faecal and urine samples were collected and examined for the presence of Schistosoma mansoni and S. haematobium eggs respectively. RESULTS: The overall prevalence of schistosomiasis was 17.8%, with 8.9% and 8.3% infected with S. mansoni and S. haematobium respectively, and 0.5% had co-infection of both species. Moreover, 74.5% of the participants had prior knowledge about schistosomiasis with 67.0% of them how it is transmitted and 63.8% having no idea about the preventive measures. Three-quarters of the respondents considered schistosomiasis a serious disease while their practices to prevent infections were still inadequate, with only 34.7% of them seeking treatment from clinics/hospitals. Significant associations between the KAP and age, gender, education and employment status were reported. Multiple logistic regression analysis revealed that age, gender, history of infection and educational level of the respondents were the most important factors significantly associated with the KAP on schistosomiasis among this population. CONCLUSIONS: Schistosomiasis is still prevalent among Hausa communities in Nigeria and participants' knowledge about the disease was poor. Mass drug administration, community mobilization and health education regarding the cause, transmission and prevention of schistosomiasis and education about good personal and sanitary hygiene practices should be considered in order to significantly reduce the prevalence and morbidity of infection within these communities.
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Conhecimentos, Atitudes e Prática em Saúde , População Rural , Esquistossomose/epidemiologia , Adolescente , Adulto , Estudos Transversais , Feminino , Geografia , Humanos , Masculino , Nigéria/epidemiologia , Razão de Chances , Vigilância da População , Prevalência , Esquistossomose/parasitologia , Fatores Socioeconômicos , Adulto JovemRESUMO
BACKGROUND: Lymphatic filariasis (LF) is a major cause of permanent disability in many tropical and sub-tropical countries of the world. Malaysia is one of the countries in which LF is an endemic disease. Five rounds of the mass drug administration (MDA) program have been conducted in Malaysia as part of the Global Program to Eliminate Lymphatic Filariasis (GPELF) by year 2020. This study investigated the level of awareness of LF and the MDA program in a population living in an endemic area of the country. METHODS: A descriptive cross-sectional survey that involved 230 respondents (≥15 years old) living in the LF endemic communities of Terengganu state in Peninsular Malaysia was performed. Demographic, socioeconomic, and knowledge, attitudes and practices (KAP) data of the respondents were obtained using pre-tested questionnaires and were analyzed using SPSS software version 13.0. RESULTS: More than 80% of the respondents were aware of LF and the common symptoms of the disease. Moreover, about 70% of the respondents that were aware of LF indicated that it is a problematic disease. Approximately 77% of the respondents indicated that filariasis is transmitted by mosquitoes. Two-thirds of respondents preferred hospital treatment for illness; however, only 12% had participated and/or received treatment for LF during an MDA program. Only 35% of the respondents that participated in this research were aware of the MDA program that had taken place in the area. None of the respondents had knowledge of the drug used in the treatment of LF. The findings from this research indicated that there was no significant association between LF awareness and with gender, age group, educational status, occupation, or socio-economic status of the respondents (P >0.05). CONCLUSION: A good proportion of the respondents are aware of LF, its mode of transmission and symptoms, however they demonstrated a poor knowledge of MDA which took place in the study area. For greater understanding of LF in the Malaysian population, there is a need for an enhancement in the delivery of health education and information programs and mass mobilization campaigns in endemic communities.
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Filariose Linfática/epidemiologia , Adolescente , Adulto , Animais , Estudos Transversais , Culicidae/parasitologia , Coleta de Dados , Filariose Linfática/tratamento farmacológico , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Insetos Vetores , Malásia/epidemiologia , Masculino , Pessoa de Meia-Idade , Saúde da População Rural , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto JovemRESUMO
BACKGROUND: Despite the intensive global efforts to control intestinal parasitic infections, the prevalence of soil-transmitted helminth (STH) infections is still very high in many developing countries particularly among children in rural areas. METHODS: A randomized, double-blind, placebo-controlled trial was conducted on 250 Aboriginal schoolchildren in Malaysia to investigate the effects of a single high-dose of vitamin A supplementation (200,000 IU) on STH reinfection. The effect of the supplement was assessed at 3 and 6 months after receiving interventions; after a complete 3-day deworming course of 400 mg/daily of albendazole tablets. RESULTS: Almost all children (98.6%) were infected with at least one STH species. The overall prevalence of ascariasis, trichuriasis and hookworm infection was 67.8%, 95.5% and 13.4%, respectively. Reinfection rates of Ascaris, Trichuris and hookworm were high; at 6 months, assessment reached 80% of the prevalence reported before treatment. There were no significant differences in the reinfection rates and intensities of STH between vitamin A supplemented-children and those who received placebo at 3 and 6 months (p > 0.05). CONCLUSIONS: Vitamin A supplementation showed no protective effect against STH reinfection and this could be due to the high endemicity of STH in this community. Long-term interventions to reduce poverty will help significantly in reducing this continuing problem and there is no doubt that reducing intestinal parasitic infection would have a positive impact on the health, nutrition and education of these children. TRIAL REGISTRATION: This trial was registered at clinicaltrials.gov as NCT00936091.
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Helmintíase/tratamento farmacológico , Helmintíase/prevenção & controle , Solo/parasitologia , Vitamina A/farmacologia , Albendazol/administração & dosagem , Albendazol/uso terapêutico , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/uso terapêutico , Criança , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Feminino , Helmintíase/epidemiologia , Humanos , Malásia/epidemiologia , Masculino , Vitamina A/administração & dosagemRESUMO
BACKGROUND: Despite the continuous efforts to improve the quality of life of Orang Asli (Aborigines) communities, these communities are still plagued with a wide range of health problems including parasitic infections. The first part of this study aimed at determining the prevalence of soil-transmitted helminth (STH) infections and identifying their associated factors among rural Orang Asli children. METHODS: A cross-sectional study was carried out among 484 Orang Asli children aged ≤ 15 years (235 females and 249 males) belonging to 215 households from 13 villages in Lipis district, Pahang, Malaysia. Faecal samples were collected and examined by using formalin-ether sedimentation, Kato Katz and Harada Mori techniques. Demographic, socioeconomic, environmental and behavioural information were collected by using a pre-tested questionnaire. RESULTS: Overall, 78.1% of the children were found to be infected with one or more STH species. The prevalence of trichuriasis, ascariasis and hookworm infections were 71.7%, 37.4% and 17.6%, respectively. Almost all, three quarters and one fifth of trichuriasis, ascariasis and hookworm infections, respectively, were of moderate-to-heavy intensities. Multiple logistic regression analysis showed that age of ≥ 6 years (school-age), using unsafe water supply as a source for drinking water, absence of a toilet in the house, large family size (≥ 7 members), not washing hands before eating, and not washing hands after defecation were the key factors significantly associated with STH among these children. CONCLUSION: This study reveals an alarmingly high prevalence of STH among Orang Asli children and clearly brings out an urgent need to implement school-based de-worming programmes and other control measures like providing a proper sanitation, as well as a treated drinking water supply and proper health education regarding good personal hygiene practices. Such an integrated control program will help significantly in reducing the prevalence and intensity of STH in Orang Asli communities.