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Parasite Immunology Jun 2010Hookworm infection is associated with anaemia and malnutrition in many resource-limited countries. Ancylostoma hookworms have previously been shown to modulate host...
Hookworm infection is associated with anaemia and malnutrition in many resource-limited countries. Ancylostoma hookworms have previously been shown to modulate host cellular immune responses through multiple mechanisms, including reduced mitogen-mediated lymphocyte proliferation, impaired antigen presentation/processing, and relative reductions in CD4(+) T cells in the spleen and mesenteric lymph nodes. Syrian hamsters were depleted of CD4(+) for up to 9 days following intraperitoneal injection (200 microg) of a murine anti-mouse CD4 monoclonal IgG (clone GK1.5). CD4(+) T-cell-depleted hamsters infected with the hookworm Ancylostoma ceylanicum exhibited a threefold higher mean intestinal worm burden and more severe anaemia than animals that received isotype control IgG. In addition, depletion of CD4(+) T cells was associated with impaired cellular and humoral (serum and mucosal) immune responses to hookworm antigens. These data demonstrate an effector role for CD4(+) T cells in hookworm immunity and disease pathogenesis. Ultimately, these studies may yield important insights into the relationship between intestinal nematode infections and diseases that are associated with CD4(+) T-cell depletion, including HIV.
Topics: Ancylostoma; Ancylostomiasis; Anemia; Animals; Antibodies, Helminth; Antibodies, Monoclonal; CD4-Positive T-Lymphocytes; Cricetinae; Immunity, Mucosal; Intestines; Lymphocyte Depletion; Mesocricetus
PubMed: 20500671
DOI: 10.1111/j.1365-3024.2010.01204.x -
Infectious Diseases of Poverty Jul 2019Baseline mapping of soil-transmitted helminth (STH) infections among school age children (SAC) in 2008-2009 found high or moderate prevalence in 13 of the 14 districts...
BACKGROUND
Baseline mapping of soil-transmitted helminth (STH) infections among school age children (SAC) in 2008-2009 found high or moderate prevalence in 13 of the 14 districts in Sierra Leone. Following these surveys, mass drug administration (MDA) of mebendazole/albendazole was conducted biannually at national level targeting pre-school children (PSC) aged 12-59 months and intermittently at sub-national level targeting SAC. In addition, MDA with ivermectin and albendazole for eliminating lymphatic filariasis (LF) has been conducted nationwide since 2010 targeting individuals over 5 years of age. Each MDA achieved high coverage, except in 2014 when all but one round of MDA for PSC was cancelled due to the Ebola emergency. The objective of the current study was to determine the prevalence and intensity of STH infections among SAC after a decade of these deworming campaigns.
METHODS
Seventy-three schools in 14 districts were purposefully selected, including 39 schools from the baseline surveys, with approximately two sites from each of low, moderate and high prevalence categories at baseline per district. Fresh stool samples were collected from 3632 children aged 9-14 years (male 51%, female 49%) and examined using the Kato Katz technique.
RESULTS
The prevalence of STH infections in Sierra Leone decreased in 2016 compared to 2008: Ascaris lumbricoides 4.4% (95% confidence interval [CI]: 3.7-5.1%) versus 6.6% (95% CI: 0-25%), Trichuris trichiura 0.7% (95% CI: 0.5-1.1%) versus 1.8% (95% CI: 0-30.2%), hookworm 14.9% (95% CI: 13.8-16.1) versus 38.5% (95% CI: 5.4-95.1%), and any STH 18.3% (95% CI:17.0-19.5%) versus 48.3% (CI: 5.4-96.3%), respectively. In 2016, no district had high hookworm prevalence and four districts had moderate prevalence, compared with eight and four districts respectively in 2008. In 2016, the arithmetic mean hookworm egg count in all children examined was light: 45.5 eggs per gram (EPG) of faeces, (95% CI:\ 35.96-55.07 EPG); three (0.08%) children had heavy infections and nine (0.25%) children had moderate infections.
CONCLUSIONS
Sierra Leone has made considerable progress toward controlling STH as a public health problem among SAC. As LF MDA phases out (between 2017 and 2021), transition of deworming to other platforms and water and sanitation strategies need to be strengthened to maintain STH control and ultimately interrupt transmission.
Topics: Adolescent; Ancylostoma; Ancylostomiasis; Animals; Ascariasis; Ascaris lumbricoides; Chemoprevention; Child; Feces; Female; Helminthiasis; Humans; Male; Prevalence; Schools; Sierra Leone; Soil; Trichuriasis; Trichuris
PubMed: 31262367
DOI: 10.1186/s40249-019-0553-5 -
Parasites & Vectors Jan 2020Japan is one of the few countries believed to have eliminated soil-transmitted helminths (STHs). In 1949, the national prevalence of Ascaris lumbricoides was 62.9%,...
BACKGROUND
Japan is one of the few countries believed to have eliminated soil-transmitted helminths (STHs). In 1949, the national prevalence of Ascaris lumbricoides was 62.9%, which decreased to 0.6% in 1973 due to improvements in infrastructure, socioeconomic status, and the implementation of national STH control measures. The Parasitosis Prevention Law ended in 1994 and population-level screening ceased in Japan; therefore, current transmission status of STH in Japan is not well characterized. Sporadic cases of STH infections continue to be reported, raising the possibility of a larger-scale recrudescence of STH infections. Given that traditional microscopic detection methods are not sensitive to low-intensity STH infections, we conducted targeted prevalence surveys using sensitive PCR-based assays to evaluate the current STH-transmission status and to describe epidemiological characteristics of areas of Japan believed to have achieved historical elimination of STHs.
METHODS
Stool samples were collected from 682 preschool- and school-aged children from six localities of Japan with previously high prevalence of STH. Caregivers of participants completed a questionnaire to ascertain access to water, sanitation and hygiene (WASH), and potential exposures to environmental contamination. For fecal testing, multi-parallel real-time PCR assays were used to detect infections of Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale and Trichuris trichiura.
RESULTS
Among the 682 children, no positive samples were identified, and participants reported high standards of WASH.
CONCLUSIONS
To our knowledge, this is the first STH-surveillance study in Japan to use sensitive molecular techniques for STH detection. The results suggest that recrudescence of STH infections has not occurred, and that declines in prevalence have been sustained in the sampled areas. These findings suggest that reductions in prevalence below the elimination thresholds, suggestive of transmission interruption, are possible. Additionally, this study provides circumstantial evidence that multi-parallel real-time PCR methods are applicable for evaluating elimination status in areas where STH prevalence is extremely low.
Topics: Adolescent; Ancylostoma; Ancylostomiasis; Animals; Ascariasis; Ascaris lumbricoides; Child; Child, Preschool; Feces; Female; Helminths; Humans; Hygiene; Japan; Male; Necator americanus; Necatoriasis; Soil; Surveys and Questionnaires; Trichuriasis; Trichuris
PubMed: 31915050
DOI: 10.1186/s13071-019-3875-z -
Infection and Immunity Jan 2006Hookworm infection is associated with growth delay and iron deficiency anemia in developing countries. A series of experiments were designed in order to test the...
Hookworm infection is associated with growth delay and iron deficiency anemia in developing countries. A series of experiments were designed in order to test the hypothesis that host dietary iron restriction mediates susceptibility to hookworm infection using the hamster model of Ancylostoma ceylanicum. Animals were maintained on diets containing either 10 ppm iron (iron restricted) or 200 ppm iron (standard/high iron), followed by infection with A. ceylanicum third-stage larvae. Infected animals fed the standard diet exhibited statistically significant growth delay and reduced blood hemoglobin levels compared to uninfected controls on day 20 postinfection. In contrast, no statistically significant differences in weight or hemoglobin concentration were observed between infected and uninfected animals fed the iron-restricted diet. Moreover, iron-restricted animals were observed to have reduced intestinal worm burdens on day 10 and day 20 postinfection compared to those of animals maintained on the standard/high-iron diet. In a subsequent study, animals equilibrated on diets containing a range of iron levels (10 ppm, 40 ppm, 100 ppm, or 200 ppm) were infected with A. ceylanicum and followed for evidence of hookworm disease. Infected animals from the intermediate-dietary iron (40- and 100-ppm) groups exhibited greater weight loss and anemia than those in the low (10-ppm)- or high (200-ppm)-iron diet groups. Mortality was also significantly higher in the intermediate-dietary-iron groups. These data suggest that severe dietary iron restriction impairs hookworm development in vivo but that moderate iron restriction enhances host susceptibility to severe disease.
Topics: Ancylostoma; Ancylostomiasis; Animals; Cricetinae; Genetic Predisposition to Disease; Iron, Dietary; Male
PubMed: 16368983
DOI: 10.1128/IAI.74.1.289-295.2006 -
Scientific Reports Jun 2018Camp dogs in indigenous communities in the Western Australian Kimberley Region, share the domestic environment with humans and have the potential to act as carriers of,...
Camp dogs in indigenous communities in the Western Australian Kimberley Region, share the domestic environment with humans and have the potential to act as carriers of, and sentinels for, a wide range of zoonotic agents, including intestinal parasites and antimicrobial resistant bacteria. In this study, we investigated the carriage of extended-spectrum-cephalosporin-resistant (ESC-resistant) Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA) and species of hookworm and Giardia among camp dogs in remote Western Australian Aboriginal communities. A total of 141 canine faecal samples and 156 nasal swabs were collected from dogs in four communities of the Western Australian Kimberley region. Overall, ESC-resistant E. coli was detected in 16.7% of faecal samples and MRSA was isolated from 2.6% of nasal swabs. Of most significance was the presence of the community-associated Panton-Valentine leucocidin (PVL)-positive MRSA ST93 and ST5 clones and ESC-resistant E. coli ST38 and ST131. The most prevalent zoonotic intestinal parasite infection was Ancylostoma caninum (66%). The prevalence of Giardia was 12.1%, with the main genotypes of Giardia detected being dog specific assemblages C and D, which are unlikely to cause disease in humans.
Topics: Ancylostoma; Ancylostomiasis; Animals; Australia; Dog Diseases; Dogs; Giardia; Giardiasis; Methicillin-Resistant Staphylococcus aureus; Prevalence; Staphylococcal Infections; Zoonoses
PubMed: 29880792
DOI: 10.1038/s41598-018-26920-5 -
The Korean Journal of Parasitology Mar 2007Trichostrongylus eggs observed in cellophane-thick smears are difficult, in practice, to distinguish from hookworm eggs. In order to overcome these limitations, a...
Trichostrongylus eggs observed in cellophane-thick smears are difficult, in practice, to distinguish from hookworm eggs. In order to overcome these limitations, a molecular approach was conducted. A Trichostrongylus colubriformis adult worm was obtained from a human in Laos, which was identified morphologically. ITS-1 sequence of this worm was determined, and found to be most similar with that of T. colubriformis among the Trichostrongylus spp. reported so far. Then, this sequence was compared with those of human hookworm species, Ancylostoma duodenale and Necator americanus, and species-specific oligonucleotide primers were designed. Polymerase chain reaction (PCR) using these primers evidenced specifically amplified PCR products of Trichostrongylus sp., A. duodenale and N. americanus from the eggs of each (520 bp, 690 bp, and 870 bp, respectively). A species-specific PCR technique can be developed in order to study the epidemiology of Trichostrongylus spp. and hookworms in endemic areas.
Topics: Ancylostoma; Ancylostomiasis; Animals; Base Sequence; DNA, Intergenic; DNA, Protozoan; DNA, Ribosomal Spacer; Diagnosis, Differential; Humans; Molecular Sequence Data; Necator americanus; Phylogeny; Polymerase Chain Reaction; Sequence Alignment; Trichostrongylosis; Trichostrongylus
PubMed: 17374982
DOI: 10.3347/kjp.2007.45.1.69 -
PLoS Neglected Tropical Diseases Jan 2022Hundreds of millions of people in poor countries continue to suffer from disease caused by bloodfeeding hookworms. While mice and rats are not reliably permissive hosts... (Comparative Study)
Comparative Study
BACKGROUND
Hundreds of millions of people in poor countries continue to suffer from disease caused by bloodfeeding hookworms. While mice and rats are not reliably permissive hosts for any human hookworm species, adult Golden Syrian hamsters are fully permissive for the human and animal pathogen Ancylostoma ceylanicum. Similar to humans, hamsters may be infected with A. ceylanicum third-stage larvae orally or percutaneously. Oral infection typically leads to consistent worm yields in hamsters but may not accurately reflect the clinical and immunological manifestations of human infection resulting from skin penetration.
METHODOLOGY/PRINCIPAL FINDINGS
In this study we compared host responses following percutaneous infection to those utilizing an established oral infection protocol. Infected hamsters exhibited a dose-dependent pathology, with 1000 percutaneous larvae (L3) causing anemia and adult worm recovery comparable to that of 50 orally administered L3. A delayed arrival and maturity of worms in the intestine was observed, as was variation in measured cellular immune responses. A long-term study found that the decline in blood hemoglobin was more gradual and did not reach levels as low, with the nadir of disease coming later in percutaneously infected hamsters. Both groups exhibited moderate growth delay, an effect that was more persistent in the percutaneously infected group. Fecal egg output also peaked later and at lower levels in the percutaneously infected animals. In contrast to orally infected hamsters, antibody titers to larval antigens continued to increase throughout the course of the experiment in the percutaneous group.
CONCLUSIONS/SIGNIFICANCE
These results demonstrate that the route of infection with A. ceylanicum impacts disease pathogenesis, as well as humoral and cellular immune responses in an experimental setting. These data further validate the utility of the Golden Syrian hamster as a model of both oral and percutaneous infection with human hookworms.
Topics: Ancylostoma; Ancylostomiasis; Animals; Cricetinae; Disease Models, Animal; Hemoglobins; Male; Mesocricetus; Mouth; Skin
PubMed: 34986139
DOI: 10.1371/journal.pntd.0010098 -
PLoS Neglected Tropical Diseases 2012Hookworm infections are one of the most important parasitic infections of humans worldwide, considered by some second only to malaria in associated disease burden....
BACKGROUND
Hookworm infections are one of the most important parasitic infections of humans worldwide, considered by some second only to malaria in associated disease burden. Single-dose mass drug administration for soil-transmitted helminths, including hookworms, relies primarily on albendazole, which has variable efficacy. New and better hookworm therapies are urgently needed. Bacillus thuringiensis crystal protein Cry5B has potential as a novel anthelmintic and has been extensively studied in the roundworm Caenorhabditis elegans. Here, we ask whether single-dose Cry5B can provide therapy against a hookworm infection and whether C. elegans mechanism-of-action studies are relevant to hookworms.
METHODOLOGY/PRINCIPAL FINDINGS
To test whether the C. elegans invertebrate-specific glycolipid receptor for Cry5B is relevant in hookworms, we fed Ancylostoma ceylanicum hookworm adults Cry5B with and without galactose, an inhibitor of Cry5B-C. elegans glycolipid interactions. As with C. elegans, galactose inhibits Cry5B toxicity in A. ceylanicum. Furthermore, p38 mitogen-activated protein kinase (MAPK), which controls one of the most important Cry5B signal transduction responses in C. elegans, is functionally operational in hookworms. A. ceylanicum hookworms treated with Cry5B up-regulate p38 MAPK and knock down of p38 MAPK activity in hookworms results in hypersensitivity of A. ceylanicum adults to Cry5B attack. Single-dose Cry5B is able to reduce by >90% A. ceylanicum hookworm burdens from infected hamsters, in the process eliminating hookworm egg shedding in feces and protecting infected hamsters from blood loss. Anthelmintic activity is increased about 3-fold, eliminating >97% of the parasites with a single 3 mg dose (∼30 mg/kg), by incorporating a simple formulation to help prevent digestion in the acidic stomach of the host mammal.
CONCLUSIONS/SIGNIFICANCE
These studies advance the development of Cry5B protein as a potent, safe single-dose anthelmintic for hookworm therapy and make available the information of how Cry5B functions in C. elegans in order to study and improve Cry5B function against hookworms.
Topics: Ancylostoma; Ancylostomiasis; Animals; Anthelmintics; Bacillus thuringiensis Toxins; Bacterial Proteins; Cricetinae; Disease Models, Animal; Endotoxins; Feces; Female; Hemolysin Proteins; Male; Mesocricetus; Parasite Egg Count; Treatment Outcome
PubMed: 23145203
DOI: 10.1371/journal.pntd.0001900 -
Revista de Saude Publica Dec 2012To analyze the effects of a pedagogical intervention on the learning of children and teenagers participating in a clinical research.
OBJECTIVE
To analyze the effects of a pedagogical intervention on the learning of children and teenagers participating in a clinical research.
METHODS
Quantitative, quasi-experimental and longitudinal study, part of a group of studies conducted to test a vaccine against ancylostomiasis. Convenience sample with 133 students aged 10-17 years, of both sexes, from the school Escola Municipal de Maranhão (Southeastern Brazil), 2009. A structured questionnaire was used, which was administered before and after the intervention. The pedagogical device was the "Theater of the Oppressed". The dependent variables were specific and global knowledge about clinical research and about parasitic worms; the independent variable was participation in the educational intervention.
RESULTS
There was an increase in knowledge about signals and symptoms, susceptibility to reinfection and way of contagion after the educational intervention. We observed an increase in the number of right answers concerning duration of clinical research, procedures, the possibility of quitting participation, and occurrence of adverse events. The notion that the research's primary purpose is therapeutic remained, but the percentage of participants who associated the research with medical treatment decreased. The "Theater of the Oppressed" enabled that the discussions about helminthiasis and clinical research were contextualized and materialized. The subjects could dispose of or reduce their previous representations.
CONCLUSIONS
Participation of children and adolescents in clinical trials must be preceded by an educational intervention, since individuals of that age group do not even recognize they have the right to decide for themselves.
Topics: Adolescent; Ancylostomiasis; Art; Brazil; Child; Clinical Trials as Topic; Female; Health Education; Health Knowledge, Attitudes, Practice; Humans; Informed Consent; Male; Patient Education as Topic; Patient Participation; Personal Autonomy; Vaccines
PubMed: 23503538
DOI: No ID Found -
The Journal of Biological Chemistry Jun 1985The adult hookworm Ancylostoma caninum releases a proteolytic enzyme which is thought to be essential for its adaption to parasitism. The protease was purified from...
The adult hookworm Ancylostoma caninum releases a proteolytic enzyme which is thought to be essential for its adaption to parasitism. The protease was purified from parasite extracts by ion-exchange chromatography followed by gel filtration and hydrophobic interaction chromatography. The purified enzyme exhibited a molecular weight of 37,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and had an NH2-terminal sequence of Arg-His-His-Gln-Pro-Lys-Val-Ala-Leu-Leu-Gly-Ala-His-Gly-Gly-Ile. Using 125I-fibrin as substrate, the enzyme displayed optimal activity at pH 9-11 and was inactivated by dialysis against EDTA. The enzyme degraded [3H]elastin and both elastin and trypsin-labile glycoproteins in a rat vascular smooth muscle extracellular matrix. Antiserum raised to the protease in rabbits cross-reacted with extracts from the infective larval stage of A. caninum, suggesting that the production of the enzyme begins in an earlier developmental stage of the parasite life cycle. The role of the protease in the histolytic and anticlotting processes of the hookworm and its importance in immunity to ancylostomiasis is discussed.
Topics: Amino Acid Sequence; Amino Acids; Ancylostoma; Animals; Hydrogen-Ion Concentration; Kinetics; Molecular Weight; Peptide Hydrolases; Protease Inhibitors
PubMed: 3888998
DOI: No ID Found