The Experts below are selected from a list of 1677 Experts worldwide ranked by ideXlab platform
Lisette Van Lieshout - One of the best experts on this subject based on the ideXlab platform.
-
real time pcr demonstrates Ancylostoma Duodenale is a key factor in the etiology of severe anemia and iron deficiency in malawian pre school children
PLOS Neglected Tropical Diseases, 2012Co-Authors: Femkje A M Jonker, Job C J Calis, Kamija S Phiri, Eric A T Brienen, Harriet Khoffi, Bernard J Brabin, Jaco J Verweij, Michael Boele Van Hensbroek, Lisette Van LieshoutAbstract:Background Hookworm infections are an important cause of (severe) anemia and iron deficiency in children in the tropics. Type of hookworm species (Ancylostoma Duodenale or Necator americanus) and infection load are considered associated with disease burden, although these parameters are rarely assessed due to limitations of currently used diagnostic methods. Using multiplex real-time PCR, we evaluated hookworm species-specific prevalence, infection load and their contribution towards severe anemia and iron deficiency in pre-school children in Malawi.
-
simultaneous detection and quantification of Ancylostoma Duodenale necator americanus and oesophagostomum bifurcum in fecal samples using multiplex real time pcr
American Journal of Tropical Medicine and Hygiene, 2007Co-Authors: Jaco J Verweij, Eric A T Brienen, Juventus B Ziem, Lawrence Yelifari, A M Polderman, Lisette Van LieshoutAbstract:A multiplex real-time PCR was developed and evaluated for the simultaneous detection of Ancylostoma Duodenale, Necator americanus, and Oesophagostomum bifurcum in fecal samples. Using well-defined control samples (N = 150), known positive fecal samples (N = 50), and fecal samples from an area in Ghana where human infections with all 3 nematode species are endemic (N = 339), the method proved to be highly specific and sensitive. Cycle threshold (Ct) values, reflecting parasite-specific DNA load, showed significant correlation with the intensity of infection as measured by microscopy using Kato-Katz fecal smears or by species specific third-stage larval count after coproculture. The multiplex real-time PCR described combined with the simple fecal sample collection procedure and the potential for high throughput makes this approach a powerful diagnostic tool to study species-specific transmission patterns of human hookworm-like infections. Moreover, this procedure facilitates monitoring of intervention programs and allows species-specific detection of treatment failure following rounds of mass treatment.
-
polymerase chain reaction based differential diagnosis of Ancylostoma Duodenale and necator americanus infections in humans in northern ghana
Tropical Medicine & International Health, 2005Co-Authors: Johanna M De Gruijter, Robin B Gasser, Eric A T Brienen, Jaco J Verweij, Lisette Van Lieshout, Juventus B Ziem, Lawrence Yelifari, A M PoldermanAbstract:We evaluated a two-step semi-nested polymerase chain reaction (PCR)-based approach for the specific detection of Ancylostoma Duodenale DNA in human faeces. The test was used to determine to what extent this species of hookworm is present in the regions of Bolgatanga and Garu of northern Ghana. Initially, the sensitivity and specificity of the PCR were tested using a range of well-defined control samples. Subsequently, a total of 378 human faecal DNA samples from Bolgatanga and Garu were subjected to the PCR. The results were compared with those obtained using a previously established PCR for the specific detection of Necator americanus DNA in human faeces. Infection with A. Duodenale was recorded in 74 (19.6%) samples and N. americanus in 278 (73.5%), of which 64 (16.9%), represented co-infections with both species. While A. Duodenale was predominantly detected in the samples from Bolgatanga, infections in Garu related almost exclusively to N. americanus. The results showed that the present PCR approach is a valuable complementary tool for the diagnosis of A. Duodenale infection in humans in Ghana, having implications for epidemiological studies and for the monitoring of the success of control programmes in regions in Africa.
Jaco J Verweij - One of the best experts on this subject based on the ideXlab platform.
-
real time pcr demonstrates Ancylostoma Duodenale is a key factor in the etiology of severe anemia and iron deficiency in malawian pre school children
PLOS Neglected Tropical Diseases, 2012Co-Authors: Femkje A M Jonker, Job C J Calis, Kamija S Phiri, Eric A T Brienen, Harriet Khoffi, Bernard J Brabin, Jaco J Verweij, Michael Boele Van Hensbroek, Lisette Van LieshoutAbstract:Background Hookworm infections are an important cause of (severe) anemia and iron deficiency in children in the tropics. Type of hookworm species (Ancylostoma Duodenale or Necator americanus) and infection load are considered associated with disease burden, although these parameters are rarely assessed due to limitations of currently used diagnostic methods. Using multiplex real-time PCR, we evaluated hookworm species-specific prevalence, infection load and their contribution towards severe anemia and iron deficiency in pre-school children in Malawi.
-
simultaneous detection and quantification of Ancylostoma Duodenale necator americanus and oesophagostomum bifurcum in fecal samples using multiplex real time pcr
American Journal of Tropical Medicine and Hygiene, 2007Co-Authors: Jaco J Verweij, Eric A T Brienen, Juventus B Ziem, Lawrence Yelifari, A M Polderman, Lisette Van LieshoutAbstract:A multiplex real-time PCR was developed and evaluated for the simultaneous detection of Ancylostoma Duodenale, Necator americanus, and Oesophagostomum bifurcum in fecal samples. Using well-defined control samples (N = 150), known positive fecal samples (N = 50), and fecal samples from an area in Ghana where human infections with all 3 nematode species are endemic (N = 339), the method proved to be highly specific and sensitive. Cycle threshold (Ct) values, reflecting parasite-specific DNA load, showed significant correlation with the intensity of infection as measured by microscopy using Kato-Katz fecal smears or by species specific third-stage larval count after coproculture. The multiplex real-time PCR described combined with the simple fecal sample collection procedure and the potential for high throughput makes this approach a powerful diagnostic tool to study species-specific transmission patterns of human hookworm-like infections. Moreover, this procedure facilitates monitoring of intervention programs and allows species-specific detection of treatment failure following rounds of mass treatment.
-
polymerase chain reaction based differential diagnosis of Ancylostoma Duodenale and necator americanus infections in humans in northern ghana
Tropical Medicine & International Health, 2005Co-Authors: Johanna M De Gruijter, Robin B Gasser, Eric A T Brienen, Jaco J Verweij, Lisette Van Lieshout, Juventus B Ziem, Lawrence Yelifari, A M PoldermanAbstract:We evaluated a two-step semi-nested polymerase chain reaction (PCR)-based approach for the specific detection of Ancylostoma Duodenale DNA in human faeces. The test was used to determine to what extent this species of hookworm is present in the regions of Bolgatanga and Garu of northern Ghana. Initially, the sensitivity and specificity of the PCR were tested using a range of well-defined control samples. Subsequently, a total of 378 human faecal DNA samples from Bolgatanga and Garu were subjected to the PCR. The results were compared with those obtained using a previously established PCR for the specific detection of Necator americanus DNA in human faeces. Infection with A. Duodenale was recorded in 74 (19.6%) samples and N. americanus in 278 (73.5%), of which 64 (16.9%), represented co-infections with both species. While A. Duodenale was predominantly detected in the samples from Bolgatanga, infections in Garu related almost exclusively to N. americanus. The results showed that the present PCR approach is a valuable complementary tool for the diagnosis of A. Duodenale infection in humans in Ghana, having implications for epidemiological studies and for the monitoring of the success of control programmes in regions in Africa.
Eric A T Brienen - One of the best experts on this subject based on the ideXlab platform.
-
real time pcr demonstrates Ancylostoma Duodenale is a key factor in the etiology of severe anemia and iron deficiency in malawian pre school children
PLOS Neglected Tropical Diseases, 2012Co-Authors: Femkje A M Jonker, Job C J Calis, Kamija S Phiri, Eric A T Brienen, Harriet Khoffi, Bernard J Brabin, Jaco J Verweij, Michael Boele Van Hensbroek, Lisette Van LieshoutAbstract:Background Hookworm infections are an important cause of (severe) anemia and iron deficiency in children in the tropics. Type of hookworm species (Ancylostoma Duodenale or Necator americanus) and infection load are considered associated with disease burden, although these parameters are rarely assessed due to limitations of currently used diagnostic methods. Using multiplex real-time PCR, we evaluated hookworm species-specific prevalence, infection load and their contribution towards severe anemia and iron deficiency in pre-school children in Malawi.
-
simultaneous detection and quantification of Ancylostoma Duodenale necator americanus and oesophagostomum bifurcum in fecal samples using multiplex real time pcr
American Journal of Tropical Medicine and Hygiene, 2007Co-Authors: Jaco J Verweij, Eric A T Brienen, Juventus B Ziem, Lawrence Yelifari, A M Polderman, Lisette Van LieshoutAbstract:A multiplex real-time PCR was developed and evaluated for the simultaneous detection of Ancylostoma Duodenale, Necator americanus, and Oesophagostomum bifurcum in fecal samples. Using well-defined control samples (N = 150), known positive fecal samples (N = 50), and fecal samples from an area in Ghana where human infections with all 3 nematode species are endemic (N = 339), the method proved to be highly specific and sensitive. Cycle threshold (Ct) values, reflecting parasite-specific DNA load, showed significant correlation with the intensity of infection as measured by microscopy using Kato-Katz fecal smears or by species specific third-stage larval count after coproculture. The multiplex real-time PCR described combined with the simple fecal sample collection procedure and the potential for high throughput makes this approach a powerful diagnostic tool to study species-specific transmission patterns of human hookworm-like infections. Moreover, this procedure facilitates monitoring of intervention programs and allows species-specific detection of treatment failure following rounds of mass treatment.
-
polymerase chain reaction based differential diagnosis of Ancylostoma Duodenale and necator americanus infections in humans in northern ghana
Tropical Medicine & International Health, 2005Co-Authors: Johanna M De Gruijter, Robin B Gasser, Eric A T Brienen, Jaco J Verweij, Lisette Van Lieshout, Juventus B Ziem, Lawrence Yelifari, A M PoldermanAbstract:We evaluated a two-step semi-nested polymerase chain reaction (PCR)-based approach for the specific detection of Ancylostoma Duodenale DNA in human faeces. The test was used to determine to what extent this species of hookworm is present in the regions of Bolgatanga and Garu of northern Ghana. Initially, the sensitivity and specificity of the PCR were tested using a range of well-defined control samples. Subsequently, a total of 378 human faecal DNA samples from Bolgatanga and Garu were subjected to the PCR. The results were compared with those obtained using a previously established PCR for the specific detection of Necator americanus DNA in human faeces. Infection with A. Duodenale was recorded in 74 (19.6%) samples and N. americanus in 278 (73.5%), of which 64 (16.9%), represented co-infections with both species. While A. Duodenale was predominantly detected in the samples from Bolgatanga, infections in Garu related almost exclusively to N. americanus. The results showed that the present PCR approach is a valuable complementary tool for the diagnosis of A. Duodenale infection in humans in Ghana, having implications for epidemiological studies and for the monitoring of the success of control programmes in regions in Africa.
Peter J. Hotez - One of the best experts on this subject based on the ideXlab platform.
-
hookworm burden reductions in balb c mice vaccinated with recombinant Ancylostoma secreted proteins asps from Ancylostoma Duodenale Ancylostoma caninum and necator americanus
Vaccine, 2000Co-Authors: Liu Sen, Kashinath Ghosh, Zhan Bin, Shan Qiang, M. G. Thompson, Raymond A. Koski, Xiao Shuhua, Peter J. HotezAbstract:Vaccination of mice with alum-precipitated recombinant Ancylostoma secreted protein-1 from the canine hookworm Ancylostoma caninum (Ac-ASP-1) results in protection against A. caninum larval challenge. Vaccine protection is manifested by host reductions in hookworm burden compared to control mice. The goal of this study was to determine whether ASP antigens cloned and expressed from different hookworm species will cross protect against A. caninum larval challenge. Cross-species protection against A. caninum challenge infections was observed with immunizations using recombinant ASP-1 from the human hookworms Ancylostoma Duodenale and Necator americanus. However, the degree of protection was proportional to the extent of amino acid sequence homology between the ASP immunogen used for vaccination and the Ac-ASP-1 produced by the challenge larval strain. Vaccine protection was noted to decrease significantly as amino acid sequence homologies diverged 10% or more. It was also determined that Ac-ASP-2, a molecule cloned from A. caninum having 55% amino acid sequence homology to the C-terminus of Ac-ASP-1, did not elicit vaccine protection. These observations were partly reflected in the titer of antibodies that recognize Ac-ASP-1. The studies reported here will help to design immunogenic peptide vaccines based on the sequence divergence of hookworm ASPs.
-
Sequencing of cytochrome C oxidase 1 gene of Ancylostoma Duodenale and Necator americanus
Chinese Journal of Parasitology and Parasitic Diseases, 1999Co-Authors: Li Th, Gong X, Shu-hua Xiao, Bin Zhan, Feng Z, Q. Shan, Peter J. HotezAbstract:AIM: To identify the genetic diversity between Ancylostoma Duodenale and Necator americanus. METHODS : Mitochondrial cytochrome C oxidase subunit 1 (CO1) gene was amplified from genomic DNA of human hookworms collected from infected patients in Hejiang County, Sichuan Province , and the purified PCR products were directly sequenced by using Licor auto sequencer. RESULTS: The PCR products were about 700 bp. Alignment of CO1 gene fragment sequences showed 89 7% similarity between Ancylostoma Duodenale and Necator americanus, but still certain nucleotide variations (10 3%) existed. CONCLUSION: CO1 gene sequence can be used as a marker to identify the two species of human hookworms.
-
hookworms necator americanus stiles 1902 and Ancylostoma Duodenale dubini 1843
1995Co-Authors: Dickson D. Despommier, Robert W. Gwadz, Peter J. HotezAbstract:Two major species of hookworm infect humans: Necator americanus (New World hookworm) and Ancylostoma Duodenale (Old World hookworm). Adults of both species inhabit the small intestine and feed on intestinal mucosa and blood.
Gabriella Cancrini - One of the best experts on this subject based on the ideXlab platform.
-
epidemiological evidence for a differential effect of hookworm species Ancylostoma Duodenale or necator americanus on iron status of children
International Journal of Epidemiology, 1998Co-Authors: Marco Albonico, Enrico Ercole, Rebecca J Stoltzfus, Hababu M Chwaya, Lorenzo Savioli, James M Tielsch, Gabriella CancriniAbstract:Hookworms infect 1.3 billion people annually. Iron-deficiency anemia caused or exacerbated by intestinal blood loss is the major feature of hookworm infection with such loss caused by the feeding of hookworms upon the intestinal mucosa. The hookworms Ancylostoma Duodenale and Necator americanus cause major gastrointestinal blood loss. While relatively greater blood loss has been reported in clinical studies due to infection with A. Duodenale there has been no evidence that endemic A. Duodenale infection has a greater impact than N. americanus infection upon the iron status of populations. The authors compared the degree of anemia and iron deficiency associated with these 2 hookworm species at the individual and community levels using a sample of 525 school children in grades 1-4 in Pemba Island Tanzania and controlling for infection intensities and other child characteristics through multiple regression. In the 492 children with hookworm-positive fecal cultures hemoglobin and ferritin concentrations decreased with increasing proportions of A. Duodenale. Among children with only N. americanus larvae the prevalence of anemia was 60.5% and the prevalence of ferritin under 12 mcg/l was 33.1%. In children with 50% or higher proportions of A. Duodenale larvae the respective prevalences were 80.6% and 58.9%. Children from schools with high prevalences of A. Duodenale infection had significantly worse iron deficiency and anemia than did children from low prevalence schools.