RESUMEN
Notwithstanding the global efforts made to control intestinal parasitic infections, soil-transmitted helminth (STH) infections are still one of the most prevalent infections globally, especially in developing countries. A double-blinded, randomized controlled trial was conducted on 343 primary schoolchildren (8-12 years old) with vitamin A deficiency (VAD) in rural areas of Malaysia to investigate the effects of red palm olein (RPO)-enriched biscuits on STH reinfection rates and infection intensities. The effects of the RPO-enriched biscuits (experimental group, n = 153) and palm olein (PO)-enriched biscuits (control group, n = 190), were assessed at 3- and 6-month after the administration of complete triple-dose albendazole (one dose of 400 mg for three consecutive days). The overall STH infection rate at baseline was recorded at 65.6%. At 6-month, a significantly lower reinfection rate of A. lumbricoides was observed in the experimental group (35.3%) compared to the control group (60.0%) (P< 0.05), and a significant reduction in fecal egg count (epg) of A. lumbricoides was observed in the experimental group from baseline (P< 0.001), but no significant reduction was observed in the control group. No significant differences in the reduction of infection intensities of T. trichiura and hookworm were observed between experimental and control groups at 3- and 6-month (P>0.05). These findings suggest the potential beneficial effects of RPO-enriched biscuit supplementation on the reinfection of A. lumbricoides, which could be attributed to its high carotenoids content by enhancing host immune response and mucosal epithelium integrity. However, further studies are warranted to confirm whether RPO supplementation could result in similar parasite-specific beneficial effects in other community settings, as well as to explore the underlying mechanisms.
Asunto(s)
Antihelmínticos , Ascariasis , Helmintiasis , Infecciones por Uncinaria , Tricuriasis , Deficiencia de Vitamina A , Animales , Ascaris lumbricoides , Reinfección/tratamiento farmacológico , Deficiencia de Vitamina A/tratamiento farmacológico , Tricuriasis/tratamiento farmacológico , Antihelmínticos/uso terapéutico , Helmintiasis/tratamiento farmacológico , Suelo/parasitología , Heces/parasitología , Suplementos DietéticosRESUMEN
In Malaysia, soil-transmitted helminth (STH) infections still persist among indigenous communities. In the past, local studies have focused mostly on epidemiologic aspects of STH infections with a scarcity of information on the efficacy of deworming treatment. The present study consisted of 2 phases: a cross-sectional phase on current epidemiological status and risk factors of STH infections and a longitudinal study over 6 weeks on triple dose albendazole efficacy against STH infections. A total of 253 participants were recruited at baseline and a pre-tested questionnaire was administered to obtain information on socio-demographics, environmental and behavioural risk factors. Stool samples were evaluated using a modified Kato-Katz technique. Cure rate (CR) and egg reduction rate (ERR) were assessed at 3 weeks following a 3-day course of 400mg albendazole treatment and infection status were observed again at 6 weeks. Baseline positivity of trichuriasis, ascariasis and hookworm infections were 56.1%, 11.9% and 20.2%, respectively. Multivariate analysis showed age below 18 years old (P = 0.004), without latrine in house (P = 0.042) and indiscriminate defecation (P = 0.032) were associated with STH infections. In the longitudinal study (N = 89), CR for trichuriasis was 64.6%, while CR of 100% was observed for both ascariasis and hookworm. ERR was above 90% for all three STH species. A rapid increased of Trichuris trichiura egg output was observed at 6 weeks. In conclusion, STH infections are highly prevalent among indigenous communities. Children and teenagers, poor sanitation and hygiene behaviour were determinants for STH infections. Triple dose albendazole is found to be efficacious against Ascaris lumbricoides and hookworm infections but has moderate curative effect with high ERR against T. trichiura. Although triple dose albendazole regimen has logistic challenges and may not be a routine option, consideration of this treatment regime may still be necessary in selective communities to reduce high intensity of T. trichiura infection.
Asunto(s)
Antihelmínticos , Ascariasis , Helmintiasis , Infecciones por Uncinaria , Tricuriasis , Adolescente , Albendazol/farmacología , Albendazol/uso terapéutico , Animales , Antihelmínticos/farmacología , Antihelmínticos/uso terapéutico , Ascariasis/tratamiento farmacológico , Ascaris lumbricoides , Niño , Estudios Transversales , Heces , Helmintiasis/tratamiento farmacológico , Helmintiasis/epidemiología , Infecciones por Uncinaria/tratamiento farmacológico , Humanos , Estudios Longitudinales , Suelo , Tricuriasis/tratamiento farmacológico , TrichurisRESUMEN
BACKGROUND: Periodic administration of anthelmintic drugs is a cost-effective intervention for morbidity control of soil-transmitted helminth (STH) infections. However, with programs expanding, drug pressure potentially selecting for drug-resistant parasites increases. While monitoring anthelmintic drug efficacy is crucial to inform country control program strategies, different factors must be taken into consideration that influence drug efficacy and make it difficult to standardize treatment outcome measures. We aimed to identify suitable approaches to assess and compare the efficacy of different anthelmintic treatments. METHODOLOGY: We built an individual participant-level database from 11 randomized controlled trials and two observational studies in which subjects received single-agent or combination therapy, or placebo. Eggs per gram of stool were calculated from egg counts at baseline and post-treatment. Egg reduction rates (ERR; based on mean group egg counts) and individual-patient ERR (iERR) were utilized to express drug efficacy and analyzed after log-transformation with a linear mixed effect model. The analyses were separated by follow-up duration (14-21 and 22-45 days) after drug administration. PRINCIPAL FINDINGS: The 13 studies enrolled 5,759 STH stool-positive individuals; 5,688 received active medication or placebo contributing a total of 11,103 STH infections (65% had two or three concurrent infections), of whom 3,904 (8,503 infections) and 1,784 (2,550 infections) had efficacy assessed at 14-21 days and 22-45 days post-treatment, respectively. Neither the number of helminth co-infections nor duration of follow-up affected ERR for any helminth species. The number of participants treated with single-dose albendazole was 689 (18%), with single-dose mebendazole 658 (17%), and with albendazole-based co-administrations 775 (23%). The overall mean ERR assessed by day 14-21 for albendazole and mebendazole was 94.5% and 87.4%, respectively on Ascaris lumbricoides, 86.8% and 40.8% on hookworm, and 44.9% and 23.8% on Trichuris trichiura. The World Health Organization (WHO) recommended criteria for efficacy were met in 50%, 62%, and 33% studies of albendazole for A. lumbricoides, T. trichiura, and hookworm, respectively and 25% of mebendazole studies. iERR analyses showed similar results, with cure achieved in 92% of A. lumbricoides-infected subjects treated with albendazole and 93% with mebendazole; corresponding figures for hookworm were 70% and 17%, and for T. trichiura 22% and 20%. CONCLUSIONS/SIGNIFICANCE: Combining the traditional efficacy assessment using group averages with individual responses provides a more complete picture of how anthelmintic treatments perform. Most treatments analyzed fail to meet the WHO minimal criteria for efficacy based on group means. Drug combinations (i.e., albendazole-ivermectin and albendazole-oxantel pamoate) are promising treatments for STH infections.
Asunto(s)
Antihelmínticos , Helmintiasis , Helmintos , Infecciones por Uncinaria , Tricuriasis , Albendazol/uso terapéutico , Ancylostomatoidea , Animales , Antihelmínticos/uso terapéutico , Helmintiasis/tratamiento farmacológico , Infecciones por Uncinaria/tratamiento farmacológico , Humanos , Mebendazol/uso terapéutico , Suelo/parasitología , Tricuriasis/tratamiento farmacológico , TrichurisRESUMEN
The price of certain antiparasitic drugs (e.g., albendazole and mebendazole) has dramatically increased since 2010. The effect of these rising prices on treatment costs and use of standard of care (SOC) drugs is unknown. To measure the impact of drug prices on overall outpatient cost and quality of care, we identified outpatient visits associated with ascariasis, hookworm, and trichuriasis infections from the 2010 to 2017 MarketScan Commercial Claims and Encounters and Multi-state Medicaid databases using Truven Health MarketScan Treatment Pathways. Evaluation was limited to members with continuous enrollment in non-capitated plans 30 days prior, and 90 days following, the first diagnosis. The utilization of SOC prescriptions was considered a marker for quality of care. The impact of drug price on the outpatient expenses was measured by comparing the changes in drug and nondrug outpatient payments per patient through Welch's two sample t-tests. The total outpatient payments per patient (drug and nondrug), for the three parasitic infections, increased between 2010 and 2017. The increase was driven primarily by prescription drug payments, which increased 20.6-137.0 times, as compared with nondrug outpatient payments, which increased 0.3-2.2 times. As prices of mebendazole and albendazole increased, a shift to alternative SOC and non-SOC drug utilization was observed. Using parasitic infection treatment as a model, increases in prescription drug prices can act as the primary driver of increasing outpatient care costs. Simultaneously, there was a shift to alternative SOC, but also to non-SOC drug treatment, suggesting a decrease in quality of care.
Asunto(s)
Albendazol/economía , Antihelmínticos/economía , Ascariasis/economía , Infecciones por Uncinaria/economía , Ivermectina/economía , Mebendazol/economía , Tricuriasis/economía , Albendazol/uso terapéutico , Animales , Antihelmínticos/uso terapéutico , Ascariasis/diagnóstico , Ascariasis/tratamiento farmacológico , Ascariasis/parasitología , Costos de los Medicamentos/tendencias , Gastos en Salud/estadística & datos numéricos , Infecciones por Uncinaria/diagnóstico , Infecciones por Uncinaria/tratamiento farmacológico , Infecciones por Uncinaria/parasitología , Humanos , Ivermectina/uso terapéutico , Mebendazol/uso terapéutico , Pacientes Ambulatorios , Suelo/parasitología , Nivel de Atención/tendencias , Tricuriasis/diagnóstico , Tricuriasis/tratamiento farmacológico , Tricuriasis/parasitología , Estados UnidosRESUMEN
BACKGROUND: Soil-transmitted helminth (STH) infections remain a public health concern in sub-Saharan Africa. School-based mass drug administration (MDA) using the anthelminthic drug Mebendazole/Albendazole have succeeded in controlling morbidity associated to these diseases but failed to interrupt their transmission. In areas were filarial diseases are co-endemic, another anthelminthic drug (Ivermectin) is distributed to almost the entire population, following the community-directed treatment with ivermectin (CDTI) strategy. Since Ivermectin is a broad spectrum anthelmintic known to be effective against STH, we conducted cross-sectional surveys in two health districts with very contrasting histories of Ivermectin/Albendazole-based PC in order to investigate whether CDTI might have contributed in STH transmission interruption. METHODOLOGY: Cross-sectional surveys were conducted in two health districts with similar socio-environmental patterns but with very contrasting CDTI histories (Akonolinga health district where CDTI was yet to be implemented vs. Yabassi health district where CDTI has been ongoing for two decades). Stool samples were collected from all volunteers aged >2 years old and analyzed using the Kato-Katz technique. Infections by different STH species were compared between Akonolinga and Yabassi health districts to decipher the impact of Ivermectin/Albendazole-based MDA on STH transmission. PRINCIPAL FINDINGS: A total of 610 and 584 participants aged 2-90 years old were enrolled in Akonolinga and Yabassi health districts, respectively. Two STH species (Ascaris lumbricoides and Trichuris trichiura) were found, with prevalence significantly higher in Akonolinga health district (43.3%; 95% CI: 38.1-46.6) compared to Yabassi health district (2.5%; 95% CI: 1.1-5.1) (chi-square: 90.8; df: 1; p < 0.001). CONCLUSION/SIGNIFICANCE: These findings (i) suggest that Mebendazole- or Albendazole-based MDA alone distributed only to at-risk populations might not be enough to eliminate STH, (ii) support the collateral impact of Ivermectin/Albendazole MDA on A. lumbricoides and T. trichiura infections, and (iii) suggest that Ivermectin/Albendazole-based PC could accelerate STH transmission interruption.
Asunto(s)
Albendazol/uso terapéutico , Antihelmínticos/uso terapéutico , Antiparasitarios/uso terapéutico , Helmintiasis/epidemiología , Ivermectina/uso terapéutico , Mebendazol/uso terapéutico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Ancylostomatoidea/efectos de los fármacos , Animales , Ascariasis/tratamiento farmacológico , Ascariasis/epidemiología , Ascariasis/prevención & control , Ascaris lumbricoides/efectos de los fármacos , Ascaris lumbricoides/aislamiento & purificación , Camerún/epidemiología , Niño , Preescolar , Estudios Transversales , Heces/parasitología , Femenino , Helmintiasis/tratamiento farmacológico , Helmintiasis/prevención & control , Infecciones por Uncinaria/tratamiento farmacológico , Infecciones por Uncinaria/epidemiología , Infecciones por Uncinaria/prevención & control , Humanos , Masculino , Administración Masiva de Medicamentos , Persona de Mediana Edad , Suelo/parasitología , Tricuriasis/tratamiento farmacológico , Tricuriasis/epidemiología , Tricuriasis/prevención & control , Trichuris/efectos de los fármacos , Trichuris/aislamiento & purificación , Adulto JovenRESUMEN
BACKGROUND: The effect of nutritional supplements on the re-infection rate of species-specific soil-transmitted helminth infections in school-aged children remains complex and available evidence on the subject matter has not been synthesized. METHODS: The review included randomised controlled trials (RCTs) and cluster RCTs investigating food supplements on school-aged children between the age of 4-17 years. A search for RCTs was conducted on eight databases from inception to 12th June 2019. Cochrane Risk of Bias tool was used to assess the risk of bias in all included studies. Meta-analysis and narrative synthesis were conducted to describe and analyze the results of the review. Outcomes were summarized using the mean difference or standardized mean difference where appropriate. RESULTS: The search produced 1,816 records. Six studies met the inclusion criteria (five individually RCTs and one cluster RCT). Four studies reported data on all three STH species, while one study only reported data on Ascaris lumbricoides infections and the last study reported data on only hookworm infections. Overall, the risk of bias in four individual studies was low across most domains. Nutritional supplementation failed to statistically reduce the re-infection rates of the three STH species. The effect of nutritional supplements on measures of physical wellbeing in school-aged children could not be determined. CONCLUSIONS: The findings from this systematic review suggest that nutritional supplements for treatment of STH in children should not be encouraged unless better evidence emerges. Conclusion of earlier reviews on general populations may not necessarily apply to children since children possibly have a higher re-infection rate.
Asunto(s)
Ascariasis/prevención & control , Suplementos Dietéticos , Micronutrientes/uso terapéutico , Tricuriasis/prevención & control , Vitaminas/uso terapéutico , Ascariasis/tratamiento farmacológico , Ascariasis/epidemiología , Ascariasis/parasitología , Niño , Humanos , Micronutrientes/administración & dosificación , Ensayos Clínicos Controlados Aleatorios como Asunto , Suelo/parasitología , Tricuriasis/tratamiento farmacológico , Tricuriasis/epidemiología , Tricuriasis/parasitología , Vitaminas/administración & dosificaciónRESUMEN
BACKGROUND: School-based deworming programmes can reduce morbidity attributable to soil-transmitted helminths in children but do not interrupt transmission in the wider community. We assessed the effects of alternative mass treatment strategies on community soil-transmitted helminth infection. METHODS: In this cluster-randomised controlled trial, 120 community units (clusters) serving 150â000 households in Kenya were randomly assigned (1:1:1) to receive albendazole through annual school-based treatment targeting 2-14 year olds or annual or biannual community-wide treatment targeting all ages. The primary outcome was community hookworm prevalence, assessed at 12 and 24 months through repeat cross-sectional surveys. Secondary outcomes were Ascaris lumbricoides and Trichuris trichiura prevalence, infection intensity of each soil-transmitted helminth species, and treatment coverage and costs. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT02397772. FINDINGS: After 24 months, prevalence of hookworm changed from 18·6% (95% CI 13·9-23·2) to 13·8% (10·5-17·0) in the annual school-based treatment group, 17·9% (13·7-22·1) to 8·0% (6·0-10·1) in the annual community-wide treatment group, and 20·6% (15·8-25·5) to 6·2% (4·9-7·5) in the biannual community-wide treatment group. Relative to annual school-based treatment, the risk ratio for annual community-wide treatment was 0·59 (95% CI 0·42-0·83; p<0·001) and for biannual community-wide treatment was 0·46 (0·33-0·63; p<0·001). More modest reductions in risk were observed after 12 months. Risk ratios were similar across demographic and socioeconomic subgroups after 24 months. No adverse events related to albendazole were reported. INTERPRETATION: Community-wide treatment was more effective in reducing hookworm prevalence and intensity than school-based treatment, with little additional benefit of treating every 6 months, and was shown to be remarkably equitable in coverage and effects. FUNDING: Bill & Melinda Gates Foundation, the Joint Global Health Trials Scheme of the Medical Research Council, the UK Department for International Development, the Wellcome Trust, and the Children's Investment Fund Foundation.
Asunto(s)
Albendazol/uso terapéutico , Antihelmínticos/uso terapéutico , Ascariasis/tratamiento farmacológico , Infecciones por Uncinaria/tratamiento farmacológico , Suelo/parasitología , Tricuriasis/tratamiento farmacológico , Adolescente , Adulto , Animales , Ascariasis/diagnóstico , Ascariasis/epidemiología , Ascaris lumbricoides , Niño , Preescolar , Estudios Transversales , Femenino , Infecciones por Uncinaria/diagnóstico , Infecciones por Uncinaria/epidemiología , Humanos , Análisis de Intención de Tratar , Kenia/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Salud Pública/economía , Salud Pública/estadística & datos numéricos , Servicios de Salud Escolar/economía , Servicios de Salud Escolar/estadística & datos numéricos , Tricuriasis/diagnóstico , Tricuriasis/epidemiología , Trichuris , Adulto JovenRESUMEN
BACKGROUND: Mass drug administration (MDA), targeted at school-aged children (SAC) is the method recommended by the World Health Organization for the control of morbidity induced by soil-transmitted helminth (STH) infection in endemic countries. However, MDA does not prevent reinfection between treatment rounds and research suggests that only treating SAC will not be sufficient to bring prevalence to low levels and possibly interrupt transmission of STH. In countries with endemic infection, such as Myanmar, the coverage, who is targeted, and rates of reinfection will determine how effective MDA is in suppressing transmission in the long-term. METHODS/PRINCIPAL FINDINGS: In this paper, data from an epidemiological study on STH, comprising three surveys conducted between June 2015 and June 2016 in the delta region of Myanmar, are analysed to determine how STH prevalence and intensity in the study community changes over the course of a year, including reinfection after two MDA rounds in which the whole study sample (all age groups, n = 523) were treated with albendazole. Prevalence in the first survey (August 2015) was 27.92% for any STH, 5.54% for Ascaris lumbricoides, 17.02% for Trichuris trichiura and 9.75% for hookworm. Over the year (survey one to survey three), prevalence of any STH decreased by 8.99% (P < 0.001) and mean EPG significantly decreased for T. trichiura (P < 0.01) and hookworm (P < 0.001). Risk ratios (RRs) for a four-month reinfection period (August to December) were statistically significant and were below one, indicating that STH prevalence had not bounced back to the prevalence levels recorded immediately prior to the last round of treatment (any STH RR = 0.67, 95% CI 0.56-0.81; A. lumbricoides RR = 0.31, 95% CI 0.16-0.59; T. trichiura RR = 0.70, 95% CI 0.55-0.88; hookworm RR = 0.69, 95% CI 0.50-0.95). The only statistically significant RR for the six-month reinfection period (December to June) was for A. lumbricoides infection in SAC (RR = 2.67, 95% CI 1.37-5.21). All six-month RRs were significantly higher than four-month RRs (P < 0.05). Evidence of predisposition to infection (low and high), as measured by the Kendall Tau-b statistic, was found for all species overall and within most age groups stratifications, except for hookworm infection in preschool-aged children. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that, for certain demographic groups, a six-month gap between MDA in these communities is enough time for STH infection to return to STH prevalence levels recorded immediately before the previous MDA round, and that on average the same individuals are being consistently infected between MDA rounds.
Asunto(s)
Albendazol/uso terapéutico , Antihelmínticos/uso terapéutico , Ascariasis/tratamiento farmacológico , Infecciones por Uncinaria/tratamiento farmacológico , Administración Masiva de Medicamentos , Tricuriasis/tratamiento farmacológico , Adolescente , Adulto , Albendazol/administración & dosificación , Antihelmínticos/administración & dosificación , Ascariasis/epidemiología , Niño , Femenino , Infecciones por Uncinaria/epidemiología , Humanos , Masculino , Mianmar/epidemiología , Factores de Riesgo , Suelo/parasitología , Tricuriasis/epidemiología , Adulto JovenRESUMEN
BACKGROUND: Mass anthelmintic drug administration is recommended in developing countries to address infection by soil-transmitted helminthiases (STH). We quantified the public health benefit of treatment with mebendazole in eight million Vietnamese children aged 5-14 years from 2006 to 2011. This was compared to the environmental impact of the pharmaceutical supply chain of mebendazole, as the resource use and emissions associated with pharmaceutical production can be associated with a public health burden, e.g. through emissions of fine particulate matter. METHODOLOGY: Through Markov modelling the disability due to STH was quantified for hookworm, Ascaris lumbricoides and Trichuris trichiura. For each worm type, four levels of intensity of infection were included: none, light, medium and heavy. The treatment effect on patients was quantified in Disability-Adjusted Life Years (DALYs). The public health burden induced by the pharmaceutical supply chain of mebendazole was quantified in DALYs through Life Cycle Assessment. PRINCIPAL FINDINGS: Compared to 'no treatment', the modelled results of five-year treatment averted 116,587 DALYs (68% reduction) for the three worms combined and largely driven by A. lumbricoides. The main change in DALYs occurred in the first year of treatment, after which the results stabilized. The public health burden associated with the pharmaceutical supply chain was 6 DALYs. CONCLUSIONS: The public health benefit of the Mass Drug Administration (MDA) averted substantially more DALYs than those induced by the pharmaceutical supply chain. These results were verified in a sensitivity analysis. The starting prevalence for each worm was the most sensitive model parameter. This methodology is useful for policymakers interested in a holistic approach towards the public health performance of MDA programs, enveloping both the treatment benefit received by the patient and the public health burden associated with the resource consumption and environmental emissions of the pharmaceutical production and supply chain.
Asunto(s)
Antinematodos/administración & dosificación , Helmintiasis/tratamiento farmacológico , Administración Masiva de Medicamentos/estadística & datos numéricos , Mebendazol/administración & dosificación , Salud Pública/estadística & datos numéricos , Adolescente , Animales , Antinematodos/efectos adversos , Antinematodos/uso terapéutico , Ascariasis/tratamiento farmacológico , Ascariasis/epidemiología , Ascaris lumbricoides/efectos de los fármacos , Niño , Preescolar , Costo de Enfermedad , Femenino , Helmintiasis/epidemiología , Helmintiasis/transmisión , Humanos , Masculino , Cadenas de Markov , Mebendazol/efectos adversos , Mebendazol/uso terapéutico , Salud Pública/métodos , Años de Vida Ajustados por Calidad de Vida , Suelo/parasitología , Tricuriasis/tratamiento farmacológico , Tricuriasis/epidemiología , Trichuris/efectos de los fármacos , Vietnam/epidemiologíaRESUMEN
Risk maps facilitate discussion among different stakeholders and provide a tool for spatial targeting of health interventions. We present maps documenting shrinking risk profiles after deworming with respect to soil-transmitted helminthiasis among schoolchildren from disadvantaged neighbourhoods in Port Elizabeth, South Africa. Children were examined for soil-transmitted helminth infections using duplicate Kato-Katz thick smears in March 2015, October 2015 and May 2016, and subsequently treated with albendazole after each survey. The mean infection intensities for Ascaris lumbricoides were 9,554 eggs per gram of stool (EPG) in March 2015, 4,317 EPG in October 2015 and 1,684 EPG in March 2016. The corresponding figures for Trichuris trichiura were 664 EPG, 331 EPG and 87 EPG. Repeated deworming shrank the risk of soil-transmitted helminthiasis, but should be complemented by other public health measures.
Asunto(s)
Albendazol/uso terapéutico , Antihelmínticos/uso terapéutico , Ascariasis/tratamiento farmacológico , Ascariasis/epidemiología , Tricuriasis/tratamiento farmacológico , Tricuriasis/epidemiología , Animales , Ascaris lumbricoides , Niño , Estudios Transversales , Heces/parasitología , Femenino , Mapeo Geográfico , Humanos , Estudios Longitudinales , Masculino , Factores de Riesgo , Suelo/parasitologíaRESUMEN
BACKGROUND: Whipworms and blood flukes combined infect almost one billion people in developing countries. Only a handful of anthelmintic drugs are currently available to treat these infections effectively; there is therefore an urgent need for new generations of anthelmintic compounds. Medicinal plants have presented as a viable source of new parasiticides. Ajania nubigena, the Bhutanese daisy, has been used in Bhutanese traditional medicine for treating various diseases and our previous studies revealed that small molecules from this plant have antimalarial properties. Encouraged by these findings, we screened four major compounds isolated from A. nubigena for their anthelmintic properties. METHODOLOGY/PRINCIPAL FINDINGS: Here we studied four major compounds derived from A. nubigena for their anthelmintic properties against the nematode whipworm Trichuris muris and the platyhelminth blood fluke Schistosoma mansoni using the xWORM assay technique. Of four compounds tested, two compounds-luteolin (3) and (3R,6R)-linalool oxide acetate (1)-showed dual anthelmintic activity against S. mansoni (IC50 range = 5.8-36.9 µg/mL) and T. muris (IC50 range = 9.7-20.4 µg/mL). Using scanning electron microscopy, we determined luteolin as the most efficacious compound against both parasites and additionally was found effective against the schistosomula, the infective stage of S. mansoni (IC50 = 13.3 µg/mL). Luteolin induced tegumental damage to S. mansoni and affected the cuticle, bacillary bands and bacillary glands of T. muris. Our in vivo assessment of luteolin (3) against T. muris infection at a single oral dosing of 100 mg/kg, despite being significantly (27.6%) better than the untreated control group, was markedly weaker than mebendazole (93.1%) in reducing the worm burden in mice. CONCLUSIONS/SIGNIFICANCE: Among the four compounds tested, luteolin demonstrated the best broad-spectrum activity against two different helminths-T. muris and S. mansoni-and was effective against juvenile schistosomes, the stage that is refractory to the current gold standard drug, praziquantel. Medicinal chemistry optimisation including cytotoxicity analysis, analogue development and structure-activity relationship studies are warranted and could lead to the identification of more potent chemical entities for the control of parasitic helminths of humans and animals.
Asunto(s)
Antihelmínticos/farmacología , Extractos Vegetales/farmacología , Schistosoma mansoni/efectos de los fármacos , Esquistosomiasis mansoni/tratamiento farmacológico , Tricuriasis/tratamiento farmacológico , Trichuris/efectos de los fármacos , Animales , Asteraceae/química , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Microscopía Electrónica de Rastreo , Plantas Medicinales/química , Praziquantel/farmacología , Relación Estructura-ActividadRESUMEN
The current treatments against Trichuris trichiura, albendazole and mebendazole, are only poorly efficacious. Therefore, combination chemotherapy was recommended for treating soil-transmitted helminthiasis. Albendazole-mebendazole and albendazole-oxantel pamoate have shown promising results in clinical trials. However, in vitro and in vivo drug interaction studies should be performed before their simultaneous treatment can be recommended. Inhibition of human recombinant cytochromes P450 (CYPs) CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4 was tested by exposure to albendazole, albendazole sulfoxide, mebendazole, and oxantel pamoate, as well as albendazole-mebendazole, albendazole sulfoxide-mebendazole, albendazole-oxantel pamoate, and albendazole sulfoxide-oxantel pamoate. A high-pressure liquid chromatography (HPLC)-UV/visible spectroscopy method was developed and validated for simultaneous quantification of albendazole sulfoxide, albendazole sulfone, mebendazole, and oxantel pamoate in plasma. Albendazole, mebendazole, oxantel pamoate, albendazole-mebendazole, and albendazole-oxantel pamoate were orally applied to rats (100 mg/kg) and pharmacokinetic parameters calculated. CYP1A2 showed a 2.6-fold increased inhibition by albendazole-oxantel pamoate (50% inhibitory concentration [IC50] = 3.1 µM) and a 3.9-fold increased inhibition by albendazole sulfoxide-mebendazole (IC50 = 3.8 µM) compared to the single drugs. In rats, mebendazole's area under the concentration-time curve (AUC) and maximal plasma concentration (Cmax) were augmented 3.5- and 2.8-fold, respectively (P = 0.02 for both) when coadministered with albendazole compared to mebendazole alone. Albendazole sulfone was slightly affected by albendazole-mebendazole, displaying a 1.3-fold-elevated AUC compared to albendazole alone. Oxantel pamoate could not be quantified, translating to a bioavailability below 0.025% in rats. Elevated plasma levels of albendazole sulfoxide, albendazole sulfone, and mebendazole in coadministrations are probably not mediated by CYP-based drug-drug interaction. Even though this study indicates that it is safe to coadminister albendazole-oxantel pamoate and albendazole-mebendazole, human pharmacokinetic studies are recommended.
Asunto(s)
Albendazol/farmacocinética , Antihelmínticos/farmacocinética , Mebendazol/farmacocinética , Pamoato de Pirantel/análogos & derivados , Tricuriasis/tratamiento farmacológico , Trichuris/efectos de los fármacos , Administración Oral , Albendazol/sangre , Animales , Antihelmínticos/sangre , Área Bajo la Curva , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Combinación de Medicamentos , Interacciones Farmacológicas , Expresión Génica , Isoenzimas/genética , Isoenzimas/metabolismo , Mebendazol/sangre , Ratones , Pruebas de Sensibilidad Microbiana , Pamoato de Pirantel/sangre , Pamoato de Pirantel/farmacocinética , Ratas , Ratas Sprague-Dawley , Suelo/parasitología , Tricuriasis/sangre , Tricuriasis/parasitología , Tricuriasis/transmisión , Trichuris/crecimiento & desarrolloRESUMEN
Implementation of mass drug administration (MDA) with ivermectin plus albendazole (ALB) for lymphatic filariasis (LF) has been delayed in central Africa because of the risk of serious adverse events in subjects with high Loa loa microfilaremia. We conducted a community trial to assess the impact of semiannual MDA with ALB (400 mg) alone on LF and soil-transmitted helminth (STH) infections in the Republic of Congo. Evaluation at 12 months showed that ALB MDA had not significantly reduced Wuchereria bancrofti antigenemia or microfilaria (mf) rates in the community (from 17.3% to 16.6% and from 5.3% to 4.2%, respectively). However, the geometric mean mf count in mf-positive subjects was reduced from 202.2 to 80.9 mf/mL (60% reduction, P = 0.01). The effect of ALB was impressive in 38 subjects who were mf-positive at baseline and retested at 12 months: 37% had total mf clearance, and individual mf densities were reduced by 73.0%. MDA also dramatically reduced the hookworm infection rate in the community from 6.5% to 0.6% (91% reduction), with less impressive effects on Ascaris and Trichuris. These preliminary results suggest that semiannual community MDA with ALB is a promising strategy for controlling LF and STH in areas with coendemic loiasis.
Asunto(s)
Albendazol/uso terapéutico , Antihelmínticos/uso terapéutico , Filariasis Linfática/tratamiento farmacológico , Helmintiasis/tratamiento farmacológico , Wuchereria bancrofti/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Antígenos Helmínticos/inmunología , Ascariasis/tratamiento farmacológico , Ascariasis/epidemiología , Ascaris lumbricoides/efectos de los fármacos , Ascaris lumbricoides/aislamiento & purificación , Niño , Preescolar , Congo/epidemiología , Filariasis Linfática/epidemiología , Femenino , Helmintiasis/epidemiología , Helmintiasis/parasitología , Infecciones por Uncinaria/tratamiento farmacológico , Infecciones por Uncinaria/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Suelo/parasitología , Tricuriasis/tratamiento farmacológico , Tricuriasis/epidemiología , Trichuris/efectos de los fármacos , Trichuris/aislamiento & purificación , Wuchereria bancrofti/efectos de los fármacos , Adulto JovenRESUMEN
Post-treatment soil-transmitted helminth re-infection patterns were studied as part of a randomized controlled trial among school-aged children from an ethnic minority group in Yunnan province, People's Republic of China. Children with a soil-transmitted helminth infection (N = 194) were randomly assigned to triple-dose albendazole or placebo and their infection status monitored over a 6-month period using the Kato-Katz and Baermann techniques. Baseline prevalence of Trichuris trichiura, Ascaris lumbricoides, hookworm, and Strongyloides stercoralis were 94.5%, 93.3%, 61.3%, and 3.1%, respectively, with more than half of the participants harboring triple-species infections. For the intervention group (N = 99), the 1-month post-treatment cure rates were 96.7%, 91.5%, and 19.6% for hookworm, A. lumbricoides, and T. trichiura, respectively. Egg reduction rates were above 88% for all three species. Rapid re-infection with A. lumbricoides was observed: the prevalence 4 and 6 months post-treatment was 75.8% and 83.8%, respectively. Re-infection with hookworm and T. trichiura was considerably slower.
Asunto(s)
Albendazol/uso terapéutico , Antihelmínticos/uso terapéutico , Helmintiasis/tratamiento farmacológico , Albendazol/administración & dosificación , Ancylostomatoidea , Animales , Antihelmínticos/administración & dosificación , Ascariasis/tratamiento farmacológico , Ascariasis/epidemiología , Ascaris lumbricoides , Niño , China/epidemiología , Método Doble Ciego , Heces/parasitología , Femenino , Helmintiasis/epidemiología , Infecciones por Uncinaria/tratamiento farmacológico , Infecciones por Uncinaria/epidemiología , Humanos , Masculino , Recuento de Huevos de Parásitos , Prevalencia , Suelo/parasitología , Strongyloides stercoralis , Estrongiloidiasis/tratamiento farmacológico , Estrongiloidiasis/epidemiología , Resultado del Tratamiento , Tricuriasis/tratamiento farmacológico , Tricuriasis/epidemiología , TrichurisRESUMEN
BACKGROUND: Schistosome and soil-transmitted helminth (STH) infections are recognized as major global public health problems, causing severe and subtle morbidity, including significant educational and nutritional effects in children. Although effective and safe drugs are available, ensuring access to these drugs by all those at risk of schistosomiasis and STHs is still a challenge. Community-directed intervention (CDI) has been used successfully for mass distribution of drugs for other diseases such as onchocerciasis and lymphatic filariasis. A national control programme is yet to be instituted in Kenya and evidence for cost-effective strategies for reaching most affected communities is needed. This study evaluated the effectiveness and feasibility of the CDI strategy in the control of schistosomiasis and STHs, in East Uyoma location, Rarieda district, a community of western Kenya that is highly endemic for both infections. RESULTS: Pre-treatment prevalence of S. mansoni averaged 17.4% (range 5-43%) in the entire location. Treatment coverage in different villages ranged from 54.19 to 96.6% by community drug distributor (CDD) records. Assessment from a household survey showed coverage of 52.3 -91.9% while the proportion of homesteads (home compounds) covered ranged from 54.9-98.5%. Six months after one round of drug distribution, the prevalence levels of S. mansoni, hookworm and Trichuris trichura infections were reduced by 33.2%, 69.4% and 42.6% respectively. CONCLUSIONS: This study shows that CDI is an accepted and effective strategy in the mass treatment of schistosomiasis and STH infections in resource constrained communities in Kenya and may be useful in similar communities elsewhere. A controlled trial comparing CDI and school based mass drug administration to demonstrate their relative advantages is ongoing.
Asunto(s)
Antihelmínticos/uso terapéutico , Atención a la Salud/métodos , Helmintiasis/tratamiento farmacológico , Infecciones por Uncinaria/tratamiento farmacológico , Esquistosomiasis/tratamiento farmacológico , Tricuriasis/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Albendazol/efectos adversos , Albendazol/economía , Albendazol/uso terapéutico , Animales , Antihelmínticos/efectos adversos , Antihelmínticos/economía , Niño , Preescolar , Análisis Costo-Beneficio , Estudios de Factibilidad , Femenino , Helmintiasis/epidemiología , Helmintiasis/parasitología , Infecciones por Uncinaria/epidemiología , Infecciones por Uncinaria/parasitología , Humanos , Kenia/epidemiología , Masculino , Persona de Mediana Edad , Proyectos Piloto , Praziquantel/efectos adversos , Praziquantel/economía , Praziquantel/uso terapéutico , Prevalencia , Esquistosomiasis/epidemiología , Esquistosomiasis/parasitología , Factores Socioeconómicos , Suelo/parasitología , Tricuriasis/epidemiología , Tricuriasis/parasitologíaRESUMEN
OBJECTIVE: There is limited information on the acceptability and safety of praziquantel for treatment of schistosomiasis in children below the age of four years. In addition, although mebendazole has been extensively used together with praziquantel against infections with schistosomiasis and soil-transmitted helminthiasis (STH) in school-aged children, no specific acceptability or safety studies have been published on this drug combination in younger children. METHODS: A randomized clinical trial was conducted to determine the safety of praziquantel alone and in combination with mebendazole in the treatment of Schistosoma mansoni and STH in children aged 1 to 4 years. RESULTS: A total of 596 children from Bwondha fishing community in Mayuge district and Wang-Kado fishing community in Nebbi district were investigated using duplicate Kato-Katz thick smears of two stool samples and 130 (21·8%) were found infected with S. mansoni. Of these, 19·2% (25) had heavy intensity of infections. Of the infected children, 82 were included and randomised into praziquantel (40 mg/kg) + mebendazole (500 mg) or praziquantel (40 mg/kg) alone. CONCLUSION: Many symptoms were reported before treatment while very few were reported after treatment and all on treatment day. No serious adverse events were reported or observed after treatment. Praziquantel with or without mebendazole was well tolerated in small children in the study area.
Asunto(s)
Antihelmínticos/administración & dosificación , Helmintiasis/tratamiento farmacológico , Mebendazol/administración & dosificación , Praziquantel/administración & dosificación , Esquistosomiasis mansoni/tratamiento farmacológico , Animales , Antihelmínticos/efectos adversos , Ascariasis/tratamiento farmacológico , Ascariasis/parasitología , Ascaris lumbricoides/aislamiento & purificación , Preescolar , Quimioterapia Combinada , Heces/parasitología , Femenino , Helmintiasis/complicaciones , Helmintiasis/epidemiología , Infecciones por Uncinaria/tratamiento farmacológico , Infecciones por Uncinaria/epidemiología , Humanos , Lactante , Masculino , Mebendazol/efectos adversos , Recuento de Huevos de Parásitos , Praziquantel/efectos adversos , Prevalencia , Schistosoma mansoni/aislamiento & purificación , Esquistosomiasis mansoni/complicaciones , Esquistosomiasis mansoni/epidemiología , Método Simple Ciego , Suelo/parasitología , Encuestas y Cuestionarios , Resultado del Tratamiento , Tricuriasis/tratamiento farmacológico , Tricuriasis/epidemiología , Uganda/epidemiologíaRESUMEN
The anthelminthic efficacy of some differently obtained extracts of several plants was tested in vivo in laboratory animals and in vitro. The extracts were obtained by ethanolic, methanolic, aqueous, or chloroform, respectively, acetonitrile polyethylenglycol (PEG) and/or propylencarbonate (PC) elution at room temperature or at 37°C. The plants used were bulbs of onions, garlic, chives, coconut, birch tree, ananas, cistrose, banana, chicory, date palm fruit, fig, pumpkin, and neem tree seeds. The worm systems tested both in vivo and in vitro were Trichuris muris and Angiostrongylus cantonensis but only in vivo Toxocara cati. The tests clearly showed that the different extraction methods eluted different components and different mass amounts, which had different efficacies against the above-cited worms. In vitro effects against A. cantonensis and T.muris were best with aqueous extracts, followed by chloroform extracts. The other plant extracts showed only low or no effects on A. cantonensis in vitro. In the case of T. muris, best results were obtained in vivo and in vitro with PEG/PC extracts of the onion followed by the aqueous extract of coconut. The complete elimination of worms in the in vivo experiments with T. muris was obtained when infected mice were treated with a 1:1 mixture of extracts of coconut and onion being produced by elutions with a mixture of 1:1 PEG and PC and fed daily for 8 days. T. cati in a naturally infected cat was eliminated by daily oral application of 6 ml coco's fluid for 5 days. This study shows that a broad spectrum of plants has anti-nematodal activities, the intensity of which, however, depends on the mode of extraction. This implicates that, if results should be really comparable, the same extraction methods at the same temperatures have to be used. Furthermore, efficacy in in vitro systems does not guarantee as good--if at all--efficacy in vivo.
Asunto(s)
Angiostrongylus cantonensis/efectos de los fármacos , Antihelmínticos/administración & dosificación , Antihelmínticos/farmacología , Extractos Vegetales/administración & dosificación , Extractos Vegetales/farmacología , Toxocara/efectos de los fármacos , Trichuris/efectos de los fármacos , Animales , Antihelmínticos/aislamiento & purificación , Gatos , Modelos Animales de Enfermedad , Ratones , Pruebas de Sensibilidad Parasitaria , Extractos Vegetales/aislamiento & purificación , Ratas , Infecciones por Strongylida/tratamiento farmacológico , Toxocariasis/tratamiento farmacológico , Resultado del Tratamiento , Tricuriasis/tratamiento farmacológicoAsunto(s)
Albendazol/uso terapéutico , Antihelmínticos/uso terapéutico , Ascariasis/tratamiento farmacológico , Levamisol/uso terapéutico , Tricuriasis/tratamiento farmacológico , Animales , Ascariasis/transmisión , Preescolar , Heces/parasitología , Helmintos/aislamiento & purificación , Infecciones por Uncinaria/tratamiento farmacológico , Infecciones por Uncinaria/transmisión , Humanos , Recuento de Huevos de Parásitos , Suelo/parasitología , Tanzanía , Tricuriasis/transmisiónRESUMEN
This study aimed to assess the current situation of STH in pregnant women, explore factors associated with STH and evaluate the effects of its treatment. A cohort study was conducted in four southernmost provinces. All pregnant women who presented at their first prenatal care visit at participating hospitals were interviewed by trained health care providers and their stool specimens were examined for Ascaris lumbricoides, Trichuris trichiura and hookworm eggs. Women with STH were treated with 400 mg of albendazole after 14 weeks of gestation and treatment outcomes were evaluated three weeks after treatment. Of 1,063 pregnant women, STH were detected in 190 patients (17.9%) without seasonal variation for a combined infection of 21.6%. Ascaris, hookworm and Trichuris were detected in 10.3, 5.7 and 6.3%, respectively. The cure rate with a single dose was 92% but was 100% when repeated treatment was given as a three-day course. The risk of infection was higher in Muslim women, those with a family income < or = USD300/month, those bathing outside the house and those with no knowledge of STH. These results showed that southern Thailand is still an endemic area for STH and there appears to be no seasonal variation in incidence. Although the cure rate for treatment with albendazole was good, the low cure rate and egg reduction rate for trichuriasis needs to be considered.
Asunto(s)
Albendazol/uso terapéutico , Antihelmínticos/uso terapéutico , Ascariasis/tratamiento farmacológico , Infecciones por Uncinaria/tratamiento farmacológico , Complicaciones Parasitarias del Embarazo/tratamiento farmacológico , Tricuriasis/tratamiento farmacológico , Adolescente , Adulto , Albendazol/farmacología , Ancylostomatoidea/efectos de los fármacos , Animales , Antihelmínticos/farmacología , Ascariasis/epidemiología , Ascariasis/transmisión , Ascaris lumbricoides/efectos de los fármacos , Estudios de Cohortes , Heces/parasitología , Femenino , Infecciones por Uncinaria/epidemiología , Humanos , Persona de Mediana Edad , Recuento de Huevos de Parásitos , Embarazo , Complicaciones Parasitarias del Embarazo/epidemiología , Prevalencia , Factores de Riesgo , Factores Socioeconómicos , Suelo/parasitología , Tailandia/epidemiología , Resultado del Tratamiento , Tricuriasis/epidemiología , Trichuris/efectos de los fármacos , Adulto JovenRESUMEN
CONTEXT: More than a quarter of the human population is likely infected with soil-transmitted helminths (Ascaris lumbricoides, hookworm, and Trichuris trichiura) in highly endemic areas. Preventive chemotherapy is the mainstay of control, but only 4 drugs are available: albendazole, mebendazole, levamisole, and pyrantel pamoate. OBJECTIVE: To assess the efficacy of single-dose oral albendazole, mebendazole, levamisole, and pyrantel pamoate against A lumbricoides, hookworm, and T trichiura infections. DATA SOURCES: A systematic search of PubMed, ISI Web of Science, ScienceDirect, the World Health Organization library database, and the Cochrane Central Register of Controlled Trials (1960 to August 2007). STUDY SELECTION: From 168 studies, 20 randomized controlled trials were included. DATA EXTRACTION AND DATA SYNTHESIS: Information on study year and country, sample size, age of study population, mean infection intensity before treatment, diagnostic method used, time between evaluations before and after treatment, cure rate (the percentage of individuals who became helminth egg negative following treatment with an anthelminthic drug), egg reduction rate, adverse events, and trial quality was extracted. Relative risk, including a 95% confidence interval (CI), was used to measure the effect of the drugs on the risk of infection prevalence with a random-effects model. RESULTS: Single-dose oral albendazole, mebendazole, and pyrantel pamoate for infection with A lumbricoides resulted in cure rates of 88% (95% CI, 79%-93%; 557 patients), 95% (95% CI, 91%-97%; 309 patients), and 88% (95% CI, 79%-93%; 131 patients), respectively. Cure rates for infection with T trichiura following treatment with single-dose oral albendazole and mebendazole were 28% (95% CI, 13%-39%; 735 patients) and 36% (95% CI, 16%-51%; 685 patients), respectively. The efficacy of single-dose oral albendazole, mebendazole, and pyrantel pamoate against hookworm infections was 72% (95% CI, 59%-81%; 742 patients), 15% (95% CI, 1%-27%; 853 patients), and 31% (95% CI, 19%-42%; 152 patients), respectively. No pooled relative risks could be calculated for pyrantel pamoate against T trichiura and levamisole for any of the parasites investigated. CONCLUSIONS: Single-dose oral albendazole, mebendazole, and pyrantel pamoate show high cure rates against A lumbricoides. For hookworm infection, albendazole was more efficacious than mebendazole and pyrantel pamoate. Treatment of T trichiura with single oral doses of current anthelminthics is unsatisfactory. New anthelminthics are urgently needed.