213 research outputs found

    Systematic review of studies generating individual participant data on the efficacy of drugs for treating soil-transmitted helminthiases and the case for data-sharing

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    Preventive chemotherapy and transmission control (PCT) by mass drug administration is the cornerstone of the World Health Organization (WHO)’s policy to control soil-transmitted helminthiases (STHs) caused by Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm) and hookworm species (Necator americanus and Ancylostama duodenale) which affect over 1 billion people globally. Despite consensus that drug efficacies should be monitored for signs of decline that could jeopardise the effectiveness of PCT, systematic monitoring and evaluation is seldom implemented. Drug trials mostly report aggregate efficacies in groups of participants, but heterogeneities in design complicate classical meta-analyses of these data. Individual participant data (IPD) permit more detailed analysis of drug efficacies, offering increased sensitivity to identify atypical responses potentially caused by emerging drug resistance

    Mapping Asbestos-Cement Roofing with Hyperspectral Remote Sensing over a Large Mountain Region of the Italian Western Alps

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    The World Health Organization estimates that 100 thousand people in the world die every year from asbestos-related cancers and more than 300 thousand European citizens are expected to die from asbestos-related mesothelioma by 2030. Both the European and the Italian legislations have banned the manufacture, importation, processing and distribution in commerce of asbestos-containing products and have recommended action plans for the safe removal of asbestos from public and private buildings. This paper describes the quantitative mapping of asbestos-cement covers over a large mountainous region of Italian Western Alps using the Multispectral Infrared and Visible Imaging Spectrometer sensor. A very large data set made up of 61 airborne transect strips covering 3263 km2 were processed to support the identification of buildings with asbestos-cement roofing, promoted by the Valle d’Aosta Autonomous Region with the support of the Regional Environmental Protection Agency. Results showed an overall mapping accuracy of 80%, in terms of asbestos-cement surface detected. The influence of topography on the classification’s accuracy suggested that even in high relief landscapes, the spatial resolution of data is the major source of errors and the smaller asbestos-cement covers were not detected or misclassified

    A Comparison of the Sensitivity and Fecal Egg Counts of the McMaster Egg Counting and Kato-Katz Thick Smear Methods for Soil-Transmitted Helminths

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    Currently, in public health, the reduction in the number of eggs excreted in stools after drug administration is used to monitor the efficacy of drugs against parasitic worms. Yet, studies comparing diagnostic methods for the enumeration of eggs in stool are few. We compared the Kato-Katz thick smear (Kato-Katz) and McMaster egg counting (McMaster) methods, which are commonly used diagnostic methods in public and animal health, respectively, for the diagnosis and enumeration of eggs of roundworms, whipworms and hookworms in 1,536 stool samples from children in five trials across Africa, Asia and South America. The Kato-Katz method was the most sensitive for the detection of roundworms, but there was no significant difference in sensitivity between the methods for hookworms and whipworms. The sensitivity of the methods differed across the trials and magnitude of egg counts. The Kato-Katz method resulted in significantly higher egg counts, but these were subject to lack of accuracy caused by intrinsic properties of this method. McMaster provided more reliable estimates of drug efficacies. We conclude that the McMaster is an alternative method for monitoring large-scale treatment programs. It allows accurate monitoring of drug efficacy and can be easily performed under field conditions

    Enhanced diagnostic protocol to identify E.coli VTEC from milk filters

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    The EHEC (enterohemorrhagic E. coli) are a subgroup of VTEC with strong pathogenicity. The most well-known EHEC serotype is E. coli O157:H7, which has been implicated in many large outbreaks of deadly human diseases. However, EHEC strains of other serotypes have increasingly been implicated in sporadic cases and outbreaks of serious illness in humans, e.g., serotypes O26, O45, O103, O111, O121 and O145. Epidemics studied from 1982 to date have shown that ruminants, and in particular bovine, appear almost always involved in the transmission of these bacteria to humans through direct or indirect fecal contamination of foods. Unpasteurized milk and milk products are considered minor, but important sources of infection. The possible ways to the entrance of VTEC in milk are fecal contamination and mammary excretion during E.coli mastitis. Between the two ways, the first is considered much more frequent in practice, but it cannot be excluded that a small part of EHEC found in milk resulting from mammary gland, as reported. Previous investigation suggested that milk filters used in milking machines could be a useful control point to identify the presence of EHEC in dairy herds. However, conventional methods to identify the presence of EHEC have a poor sensitivity due the high content of fecal bacteria of these filters. In order to set up a monitoring scheme to identify herds at risk, we developed and tested a diagnostic protocol involving VIDAS\uae UP E.coli serogroups (ESPT) which is a method using phage recombinant proteins for the immuno-concentration (IC) of E.coli serogroups O157, O26, O103, O111, O145, O45 and O121 from food, multiplex PCR and high resolution melting analysis (HRMA). Practically, bulk tank milk or washing solution obtained from milk filters after stomacher mixing were analyzed by Vidas ESPT. After incubation, the solution obtained was analyzed by multiplex PCR based on serotype-specific primers coding for O-antigen regions of the seven major VTEC serogroups available in literature. If PCR was positive for any of the seven serogroups, a HRMA-based protocol to detect virulence-predictive SNPs, as discovered by Norman et al., 2012, was applied to confirm the presence of a EHEC strain. The protocol was preliminary validated by inoculation of milk and milk filters with a known concentration of the seven EHEC serotypes (O26, O45, O103, O111, O121, O145, O157). The results confirmed that this protocol was able to identify as low as 101 UFC in both milk and milk filters. The protocol applied to milk and milk filters obtained from 70 dairy herds allow to identify 2 EHEC from milk and 17 from milk filters for one or more of the EHEC serogroups considered. The proposed protocol confirmed to be useful in detecting the presence of EHEC and that milk filters are an important critical control point to identify herd at risk

    A new integrated approach to analyze bulk tank milk and raw milk filters for the presence of the E. coli serogroups frequently associated with VTEC status

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    We optimized a combination of microbiological and molecular methods to quickly identify the presence of the O157 and the six non-O157 serogroups (O26, O45, O103, O111, O121 and O145) most frequently associated with VTEC status, at herd level. The lower detection limit of this methodology is 101 CFU/ml for each of the serogroups tested. We tested 67 bulk tank milk (BTM) and raw milk filters (RMF) derived from dairy herds located in Lombardy and Trentino Alto Adige. We identified 3 positive samples and 20 positive samples out of 67 respectively in the BTM and RMF. Interestingly, several samples showed positivity for more than one serogroups at the same time. We also identified the presence of E. coli O45 and O121 for the first time in raw milk and raw milk filters. Once screened the seven serogroups of interest in our samples, we evaluated the real pathogenicity of our positive, non-O157 samples through two parallel molecular biology methods: virulence gene research by PCR, and HRMA and sequencing. The most frequently isolated serogroups in milk were O157 (2.64%), O103 (2.11%), and O145 (1.06%), while in RMF the frequencies were, respectively 14.92%, 4.48%, and 2.98%. Moreover, this is the first published report in Italy of positive recovery of O45 and O121 serogroups in milk and milk filters. The new diagnostic approach proposed investigate the presence of the O157 and big six non-O157 serogroups at farm level and not to identify VTEC hazard only once the product is processed and/or is ready to be consumed

    Prevalence of soil transmitted nematodes on Nukufetau, a remote Pacific island in Tuvalu

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    BACKGROUND: The population of Nukufetau, a remote coral atoll island in Tuvalu in the Western Pacific, received annual mass drug administration (MDA) of diethylcarbamazine and albendazole under the Pacific Elimination of Lymphatic Filariasis program in 2001, 2002 and 2003, with the last MDA occurring six months before a cross-sectional survey of the whole population for soil transmitted helminths (STH). METHODS: A cross-sectional survey in May 2004 recruited 206 residents (35.2% of the population) who provided a single faecal sample that was preserved, concentrated and examined microscopically. RESULTS: Overall prevalence of STH was 69.9%; only hookworm and Trichuris trichiura were diagnosed. Trichuris was present in 68.4% with intensity of infection being light in 56.3%, medium in 11.7% and heavy in 0.5%. Hookworm occurred in 11.7% with intensity of infection 11.2% being light and medium in 0.5%. Twenty individuals (9.7%) had dual infections. The prevalence of Trichuris was constant across all ages while the prevalence of hookworm was significantly lower in residents below 30 years of age. In the age group 5–12 years comparison of results with a 2001 survey [1] suggested that the prevalence of STH has declined minimally, due to sustained high prevalence of Trichuris, while hookworm has declined dramatically from 34.4% to 1.6%. CONCLUSION: The results of this survey suggest that although the MDA appears to have reduced hookworm prevalence in residents below 30 years of age, there has been minimal effect on Trichuris prevalence. An integrated program to control STH is required

    Assessment of the Anthelmintic Efficacy of Albendazole in School Children in Seven Countries Where Soil-Transmitted Helminths Are Endemic

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    Soil-transmitted helminths (roundworms, whipworms and hookworms) infect millions of children in (sub)tropical countries, resulting in malnutrition, growth stunting, intellectual retardation and cognitive deficits. Currently, there is a need to closely monitor anthelmintic drug efficacy and to develop standard operating procedures, as highlighted in a World Health Organization–World Bank meeting on “Monitoring of Drug Efficacy in Large Scale Treatment Programs for Human Helminthiasis” in Washington DC at the end of 2007. Therefore, we have evaluated the efficacy of a commonly used treatment against these parasitic infections in school children in Africa, Asia and South-America using a standardized protocol. In addition, different statistical approaches to analyzing the data were evaluated in order to develop standardized procedures for data analysis. The results demonstrate that the applied treatment was highly efficacious against round- and hookworms, but not against whipworms. However, there was large variation in efficacy across the different trials which warrants further attention. This study also provides new insights into the statistical analysis of efficacy data, which should be considered in future monitoring and evaluation studies of large scale anthelmintic treatment programs. Finally, our findings emphasize the need to update the World Health Organization recommended efficacy threshold for the treatment of STH

    Early, incomplete, or preclinical autoimmune systemic rheumatic diseases and pregnancy outcome

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    OBJECTIVE: To evaluate the impact of preclinical systemic autoimmune rheumatic disorders on pregnancy outcome. METHODS: In this longitudinal cohort study, patients were enrolled during the first trimester of pregnancy if they reported having had connective tissue disorder symptoms, were found to be positive for circulating autoantibodies, and on clinical evaluation were judged to have a preclinical or incomplete rheumatic disorder. The incidence of fetal growth restriction (FGR), preeclampsia, and adverse pregnancy outcomes in patients with preclinical rheumatic disorders was compared with that in selected controls, after adjustment for confounders by penalized logistic regression. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. RESULTS: Of 5,232 women screened, 150 (2.9%) were initially diagnosed as having a suspected rheumatic disorder. After a mean\u2009\ub1\u2009SD postpartum follow-up of 16.7\u2009\ub1\u20095.5 months, 64 of these women (42.7%) had no clinically apparent rheumatic disease and 86 (57.3%) had persistent symptoms and positive autoantibody results, including 10 (6.7%) who developed a definitive rheumatic disease. The incidences of preeclampsia/FGR and of small for gestational age (SGA) infants were 5.1% (23 of 450) and 9.3% (42 of 450), respectively, among controls, 12.5% (8 of 640) (OR 2.7 [95% CI 1.1-6.4]) and 18.8% (12 of 64) (OR 2.2 [95% CI 1.1-4.5]), respectively, among women with no clinically apparent disease, and 16.3% (14 of 86) (OR 3.8 [95% CI 1.9-7.7]) and 18.6% (16 of 86) (OR 2.3 [95% CI 1.2-4.3]), respectively, among those with persisting symptoms at follow-up. Mean\u2009\ub1\u2009SD umbilical artery Doppler pulsatility indices were higher among women with no clinically apparent disease (0.95\u2009\ub1\u20090.2) and those with persisting symptoms (0.96\u2009\ub1\u20090.21) than in controls (0.89\u2009\ub1\u20090.12) (P\u2009=\u20090.01 and P\u2009<\u20090.001, respectively). CONCLUSION: In our study population, preclinical rheumatic disorders were associated with an increased risk of FGR/preeclampsia and SGA. The impact of these findings and their utility in screening for FGR/preeclampsia need to be confirmed in population studies

    Risk Factors for Soil-Transmitted Helminth Infections during the First 3 Years of Life in the Tropics; Findings from a Birth Cohort.

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    Background: Soil-transmitted helminths (STH) infect more than 2 billion humans worldwide, causing significant morbidity in children. There are few data on the epidemiology and risk factors for infection in pre-school children. To investigate risk factors for infection in early childhood, we analysed data prospectively collected in the ECUAVIDA birth cohort in Ecuador. Methods and Findings: Children were recruited at birth and followed up to 3 years of age with periodic collection of stool samples that were examined microscopically for STH parasites. Data on social, demographic, and environmental risk factors were collected from the mother at time of enrolment. Associations between exposures and detection of STH infections were analysed by multivariable logistic regression. Data were analysed from 1,697 children for whom a stool sample was obtained at 3 years. 42.3% had at least one STH infection in the first 3 years of life and the most common infections were caused by A. lumbricoides (33.2% of children) and T. trichiura (21.2%). Hookworm infection was detected in 0.9% of children. Risk of STH infection was associated with factors indicative of poverty in our study population such as Afro-Ecuadorian ethnicity and low maternal educational level. Maternal STH infections during pregnancy were strong risk factors for any childhood STH infection, infections with either A. lumbricoides or T. trichiura, and early age of first STH infection. Children of mothers with moderate to high infections intensities with A. lumbricoides were most at risk. Conclusions: Our data show high rates of infection with STH parasites during the first 3 years of life in an Ecuadorian birth cohort, an observation that was strongly associated with maternal STH infections during pregnancy. The targeted treatment of women of childbearing age, in particular before pregnancy, with anthelmintic drugs could offer a novel approach to the prevention of STH infections in pre-school children

    Evaluation of virulence factors profiles and antimicrobials resistance of Escherichia coli isolated from bulk tank milk and raw milk filters

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    Data on the presence of pathogenic Escherichia coli in bulk tank milk (BTM) and raw milk filters (RMF) are not available in Italy and there are few studies worldwide. Therefore, a study under field condition was conducted to assess the presence of E.coli pathogenic and commensal (CoEC) strains in BTM and RMF samples and their associated AMR pattern. One hundred forty-nine E.coli isolates were characterized. Among all the isolates, 53 (35.6%) were classified as pathogenic while the other ones were classified as CoEC. Among the pathogenic ones, 23 (54.7%) were classified as enterotoxigenic E.coli (ETEC), 6 (11.3%) as enteroinvasive E.coli (EIEC), 2 (3.8%) as enteroaggregative E.coli (EAEC), 12 (22.6%) harboured virulence factors (VF) common to ETEC+EIEC, and 2 (3.8%) common to ETEC+EAEC. To our knowledge, it is the first time that ETEC isolates harboring VF associated with EAEC or EIEC are observed in raw milk. These data support the presence of transmission of VFs genes among isolates. None of the isolates showed resistance to three or more antimicrobials. The CoEC role as a vector of AMR was confirmed by the presence of 18% ampicillin- and cephalexin-resistant isolates. The presence of AMR in CoEC supports the role of these bacteria as source of resistance genes. Monitoring raw milk by either BTM or RMF analysis, and the relatively cheap procedure applied to identify E.coli pathotypes can be useful to identify hazards related to the spread of enteric diseases and antimicrobial resistance
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