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The Korean Journal of Parasitology Feb 2019Melting temperature shift (Tm-shift) is a new detection method that analyze the melting curve on real-time PCR thermocycler using SYBR Green I fluorescent dye. To...
Melting temperature shift (Tm-shift) is a new detection method that analyze the melting curve on real-time PCR thermocycler using SYBR Green I fluorescent dye. To establish a Tm-shift method for the detection of Ancylostoma ceylanicum and A. tubaeforme in cats, specific primers, with GC tail of unequal length attached to their 5 ́ end, were designed based on 2 SNP loci (ITS101 and ITS296) of the internal transcribed spacer 1 (ITS1) sequences. The standard curve of Tm-shift was established using the standard plasmids of A. ceylanicum (AceP) and A. tubaeforme (AtuP). The Tm-shift method stability, sensitivity, and accuracy were tested with reference to the standard curve, and clinical fecal samples were also examined. The results demonstrated that the 2 sets of primers based on the 2 SNPs could accurately distinguish between A. ceylanicum and A. tubaeforme. The coefficient of variation (CV) of Tm-values of AceP and AtuP was 0.07% and 0.06% in ITS101 and was 0.06% and 0.08% in ITS296, respectively. The minimum detectable DNA concentration was 5.22×10-6 and 5.28×10-6 ng/μl samples of AceP and AtuP, respectively. The accuracy of Tm-shift method reached 100% based on examination of 10 hookworm DNA samples with known species. In the clinical detection of hookworm in 69 stray cat fecal sample, the Tm-shift detection results were consistent with the microscopic examination and successfully differentiated between the 2-hookworm species. In conclusion, the developed method is a rapid, sensitive and accurate technique and can provide a promising tool for clinical detection and epidemiological investigation of cat-derived hookworms.
Topics: Ancylostoma; Ancylostomiasis; Animals; Cat Diseases; Cats; DNA Primers; DNA, Helminth; DNA, Ribosomal Spacer; Feces; Molecular Diagnostic Techniques; Real-Time Polymerase Chain Reaction; Reproducibility of Results; Sensitivity and Specificity; Transition Temperature
PubMed: 30840793
DOI: 10.3347/kjp.2019.57.1.9 -
International Journal For Parasitology.... Aug 2023Reports of anthelmintic resistance in Ancylostoma caninum are increasing in frequency in the United States of America (USA). In the last few years in vitro and in vivo... (Review)
Review
Reports of anthelmintic resistance in Ancylostoma caninum are increasing in frequency in the United States of America (USA). In the last few years in vitro and in vivo studies characterized individual isolates, demonstrating multiple anthelmintic drug resistance (MADR). In 2021, the American Association of Veterinary Parasitologists initiated a hookworm task force to address this issue. The first report of drug resistant A. caninum occurred in 1987 in Australian racing Greyhounds. In the last five years multiple case reports and investigations show drug resistant A. caninum is becoming a much greater problem in the USA and now extends beyond racing Greyhounds into the general companion animal dog population. The literature, regarding drug resistance in livestock and equine nematodes, provides helpful guidance along with diagnostic methods to better understand the evolution and selection of canine MADR hookworms; however, there are limitations and caveats due to A. caninum's unique biology and zoonotic potential. Mass drug administration (MDA) of anthelminthic drugs to humans to reduce morbidity associated with human hookworms (Necator americanus) should consider the factors that contributed to the development of MADR A. caninum. Finally, as Greyhound racing undergoes termination in some regions and the retired dogs undergo subsequent rehoming, drug resistant parasites, if present, are carried with them. Drug resistant A. caninum requires greater recognition by the veterinary community, and small animal practitioners need to be aware of the spread into current pet dog populations. The current understanding of anthelmintic resistance, available treatments, and environmental mitigation for these drug resistant A. caninum isolates must be monitored for horizontal spread. A major goal in this emerging problem is to prevent continued dissemination.
Topics: Animals; Dogs; Horses; Humans; Ancylostoma; Ancylostomiasis; Dog Diseases; Australia; Anthelmintics; Ancylostomatoidea
PubMed: 37229949
DOI: 10.1016/j.ijpddr.2023.04.003 -
American Journal of Human Biology : the... Mar 2020Despite public health concerns about hookworm infection in pregnancy, little is known about immune profiles associated with hookworm (Necator americanus and Ancylostoma...
OBJECTIVES
Despite public health concerns about hookworm infection in pregnancy, little is known about immune profiles associated with hookworm (Necator americanus and Ancylostoma duodenale) infection during pregnancy. Fetal tolerance requirements may constrain maternal immune response to hookworm, thereby increasing susceptibility to new infections or increasing hemoglobin loss. To explore this possibility, we study systemic immune response and hemoglobin levels in a natural fertility population with endemic helminthic infection.
METHODS
We used Bayesian multilevel models to analyze mixed longitudinal data on hemoglobin, hookworm infection, reproductive state, eosinophils, and erythrocyte sedimentation rate (ESR) to examine the effects of pregnancy and hookworm infection on nonspecific inflammation, cellular parasite response, and hemoglobin among 612 Tsimane women aged 15-45 (1016 observations).
RESULTS
Pregnancy is associated with lower eosinophil counts and lower eosinophil response to hookworm, particularly during the second and third trimesters. Both hookworm and pregnancy are associated with higher ESR, with evidence for an interaction between the two causing further increases in the first trimester. Pregnancy is moderately associated with higher odds of hookworm infection (OR: 1.23, 95% CI: 0.83 to 1.83). Pregnancy and hookworm both decrease hemoglobin and may interact to accentuate this effect in the first-trimester of pregnancy (Interaction: β: -0.30 g/dL; CI: -0.870 to 0.24).
CONCLUSIONS
Our findings are consistent with a possible trade-off between hookworm immunity and successful pregnancy, and with the suggestion that hookworm and pregnancy may have synergistic effects, particularly in the first trimester.
Topics: Adolescent; Adult; Ancylostoma; Ancylostomiasis; Animals; Bolivia; Female; Horticulture; Humans; Indians, South American; Middle Aged; Necator americanus; Necatoriasis; Occupational Diseases; Pregnancy; Prevalence; Young Adult
PubMed: 31642576
DOI: 10.1002/ajhb.23337 -
Veterinary Parasitology Aug 1999Nematode parasites of warm-blooded hosts use chemical and thermal signals in host-finding and in the subsequent resumption of development. The free-living nematode... (Review)
Review
Nematode parasites of warm-blooded hosts use chemical and thermal signals in host-finding and in the subsequent resumption of development. The free-living nematode Caenorhabditis elegans is a useful model for investigating the chemo- and thermosensory neurons of such parasites, because the functions of its amphidial neurons are well known from laser microbeam ablation studies. The neurons found in the amphidial channel detect aqueous chemoattractants and repellants; the wing cells-flattened amphidial neurons-detect volatile odorants. The finger cells-digitiform amphidial neurons-are the primary thermoreceptors. Two neuron classes, named ADF and ASI, control entry into the environmentally resistant resting and dispersal dauer larval stage, while the paired ASJ neurons control exit from this stage. Skin-penetrating nematode parasites, i.e. the dog hookworm Ancylostoma caninum, and the threadworm, Strongyloides stercoralis, use thermal and chemical signals for host-finding, while the passively ingested sheep stomach worm, Haemonchus contortus, uses environmental signals to position itself for ingestion. Amphidial neurons presumably recognize these signals. In all species, resumption of development, on entering a host, is probably triggered by host signals also perceived by amphidial neurons. In the amphids of the A. caninum infective larva, there are wing- and finger-cell neurons, as well as neurons ending in cilia-like dendritic processes, some of which presumably recognize a sequence of signals that stimulate these larvae to attach to suitable hosts. The functions of these neurons can be postulated, based on the known functions of their homologs in C. elegans. The threadworm, S. stercoralis, has a complex life cycle. After leaving the host, soil-dwelling larvae may develop either to infective larvae (the life-stage equivalent of dauer larvae) or to free-living adults. As with the dauer larva of C. elegans, two neuron classes control this developmental switch. Amphidial neurons control chemotaxis to a skin extract, and a highly modified amphidial neuron, the lamellar cell, appears to be the primary thermoreceptor, in addition to having chemosensory function. The stomach worm, Haemonchus contortus, depends on ingestion by a grazing host. Once ingested, the infective larva is exposed to profound environmental changes in the rumen. These changes stimulate resumption of development in this species. We hypothesize that resumption of development is under the control of the ASJ neuronal pair. Identification of the neurons that control the infective process could provide the basis for entirely new approaches to parasite control involving interference with development at the time and place of initial host-contact.
Topics: Ancylostoma; Ancylostomiasis; Animals; Caenorhabditis elegans; Dog Diseases; Dogs; Haemonchiasis; Haemonchus; Humans; Neurons; Sheep; Sheep Diseases; Strongyloides stercoralis; Strongyloidiasis
PubMed: 10456420
DOI: 10.1016/s0304-4017(99)00037-0 -
Revista Da Sociedade Brasileira de... 2001In the beginning of the XX century, ancylostomiasis was considered a serious public health problem and governments started the first systematic planning for the control... (Review)
Review
In the beginning of the XX century, ancylostomiasis was considered a serious public health problem and governments started the first systematic planning for the control of an endemic disease, in large scale. Thereafter, ancylostomiasis was considered a less important subject, because efficient anti-helminthic drugs were introduced, this in combination with the economic development in rich countries, reduced undernourishment and improved housing and sanitary conditions. Consequently, the residual cases of the infection became in general asymptomatic. However, in the third world the problem is still present, and must be considered with realism and managed accordingly. Various suggestions for controling the disease are presented in this paper.
Topics: Ancylostomiasis; Humans
PubMed: 11340499
DOI: 10.1590/s0037-86822001000100010 -
Veterinary Parasitology Jun 2019A new topical formulation of selamectin plus sarolaner (Revolution Plus/Stronghold Plus, Zoetis) was evaluated in the treatment and control of naturally occurring...
Efficacy and safety of a new topical formulation of selamectin plus sarolaner in the treatment and control of natural infections of Ancylostoma tubaeforme and Toxocara cati in cats presented as veterinary patients in the United States.
A new topical formulation of selamectin plus sarolaner (Revolution Plus/Stronghold Plus, Zoetis) was evaluated in the treatment and control of naturally occurring infections of Ancylostoma tubaeforme and Toxocara cati in cats presented as veterinary patients in the United States. Three thousand three hundred three (3303) cats were screened in 25 veterinary practices in 15 states and 153 hookworm-positive cats (A. tubaeforme and/or A. braziliense), mainly from Alabama, Mississippi, Texas, and Hawaii, were identified; 135 cats met all the criteria for enrollment and were included on study. The cats were randomly assigned to treatment with Revolution (at the label dosage, to provide a minimum dosage of 6 mg/kg selamectin) or selamectin plus sarolaner (at a dosage of 6-12 mg/kg plus 1-2 mg/kg, respectively). Treatments were administered at the time of enrollment and repeated 30 days later. Fecal samples were collected for differential fecal egg count prior to the first treatment (Day 0), prior to the second treatment (Day 30), and approximately 30 days later (Day 60). Efficacy was based on the percentage reductions in geometric mean fecal egg count for A. tubaeforme on Day 30 and Day 60 compared with Day 0. Where cats were co-infected with T. cati, efficacy against this species was also evaluated. Efficacy data were evaluated for A. tubaeforme for 40 cats on both Day 30 and Day 60 for the group treated with the selamectin/sarolaner combination and reductions in geometric mean fecal egg counts of 99.4% and 99.7% were demonstrated for Day 30 and Day 60, respectively. For the group treated with selamectin alone, 44 and 40 cats were evaluated and percent reductions for Day 30 and Day 60 were 99.5% and 99.9%, respectively. For T. cati, 14 cats were evaluated in the selamectin/sarolaner-treated group for Day 30 and for Day 60, and the reduction in geometric mean fecal egg count was 100% for both days. There were 11 and 9 cats evaluated for Day 30 and Day 60, respectively, for the selamectin-treated group and the reduction was again 100% for both days. The geometric mean fecal egg counts post-treatment were significantly lower than pre-treatment for both A. tubaeforme and T. cati, for both treatments, and for both periods of interest (P < 0.0001). No serious adverse events related to treatment with either product occurred during the study. Thus, both selamectin alone and the combination product of selamectin/sarolaner were safe and effective when administered on a monthly basis for the treatment and control of natural infections of A. tubaeforme and T. cati. The addition of sarolaner to the formulation did not interfere with the efficacy of selamectin against these nematodes.
Topics: Ancylostoma; Ancylostomiasis; Animals; Antiparasitic Agents; Azetidines; Cat Diseases; Cats; Female; Ivermectin; Male; Random Allocation; Spiro Compounds; Toxocara; Toxocariasis; Treatment Outcome; United States
PubMed: 30470638
DOI: 10.1016/j.vetpar.2018.10.012 -
World Journal of Gastroenterology Sep 2018To provide a clear understanding of viral hepatitis epidemiology and their clinical burdens in Somalia. (Meta-Analysis)
Meta-Analysis Review
AIM
To provide a clear understanding of viral hepatitis epidemiology and their clinical burdens in Somalia.
METHODS
A systematic review and meta-analysis was conducted as Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive literature search of published studies on viral hepatitis was performed from 1977-2016 in PubMed, Google Scholar, Science Direct, World Health Organization African and the Africa Journals Online databases, as well as on the Ministry of Health website. We also captured unpublished articles that were not available on online systems.
RESULTS
Twenty-nine studies from Somalia and Somali immigrants (United Kingdom, United States, Italy, Libya) with a combined sample size for each type of viral hepatitis [hepatitis A virus (HAV): 1564, hepatitis B virus (HBV): 8756, hepatitis C virus (HCV): 6257, hepatitis D virus (HDV): 375 and hepatitis E virus (HEV): 278] were analyzed. The overall pooled prevalence rate of HAV was 90.2% (95%CI: 77.8% to 96%). The HAV prevalence among different age groups was as follows: < 1 year old, 61.54% (95%CI: 40.14% to 79.24%); 1-10 years old, 91.91% (95%CI: 87.76% to 94.73%); 11-19 years old, 96.31% (95%CI: 92.84% to 98.14%); 20-39 years old, 91.3% (95%CI: 83.07% to 95.73%); and > 40 years old, 86.96% (95%CI: 75.68% to 93.47%). The overall pooled prevalence of HBV was 18.9% (95%CI: 14% to 29%). The overall pooled prevalence among subgroups of HBV was 20.5% (95%CI: 5.1% to 55.4%) in pregnant women; 5.7% (95%CI: 2.7% to 11.5%) in children; 39.2% (95%CI: 33.4% to 45.4%) in patients with chronic liver disease, including hepatocellular carcinoma (HCC); 7.7% (95%CI: 4.2% to 13.6%), 12.4% (95%CI: 6.3% to 23.0%) and 11.8% (95%CI: 5.3% to 24.5%) in age groups < 20 years old, 20-39 years old and > 40 years old, respectively. The HBV prevalence among risk groups was 20% (95%CI: 7.19% to 44.64%) in female prostitutes, 21.28% (95%CI: 7.15% to 48.69%) in hospitalized adults, 5.56% (95%CI: 0.99% to 25.62%) in hospitalized children, 60% (95%CI: 31.66% to 82.92%) in patients with acute hepatitis, 33.55% (95%CI: 14.44% to 60.16%) in patients with ancylostomiasis, 12.34% (95%CI: 7.24% to 20.26%) in patients with leprosy and 20.19% (95%CI: 11.28% to 33.49%) in schistosomiasis patients. The overall pooled prevalence of HCV was estimated as 4.84% (95%CI: 3.02% to 7.67%). The prevalence rates among blood donors, risk groups, children and patients chronic liver disease (including HCC) was 0.87% (95%CI: 0.33% to 2.30%), 2.43% (95%CI: 1.21% to 4.8%), 1.37% (95%CI: 0.76% to 2.46%) and 29.82% (95%CI: 15.84% to 48.98%), respectively. The prevalence among genotypes of HCV was 21.9% (95%CI: 15.36% to 30.23%) in genotype 1, 0.87% (95%CI: 0.12% to 5.9%) in genotype 2, 25.21% (95%CI: 18.23% to 33.77%) in genotype 3, 46.24% (95%CI: 37.48% to 55.25%) in genotype 4, 2.52% (95%CI: 0.82% to 7.53%) in genotype 5, and 1.19% (95%CI: 0.07% to 16.38%) in genotype 6. The overall pooled prevalence of HDV was 28.99% (95%CI: 16.38% to 45.96%). The HDV prevalence rate among patients with chronic liver disease, including HCC, was 43.77% (95%CI: 35.09% to 52.84%). The overall pooled prevalence of HEV was 46.86% (95%CI: 5.31% to 93.28%).
CONCLUSION
Our study demonstrates a high prevalence of all forms of viral hepatitis in Somalia and it also indicates that chronic HBV was the commonest cause of chronic liver disease. This highlights needs for urgent public health interventions and strategic policy directions to controlling the burden of the disease.
Topics: Chronic Disease; Emigrants and Immigrants; Genotype; Hepatitis, Viral, Human; Humans; Italy; Libya; Prevalence; Somalia; United Kingdom; United States; Viruses
PubMed: 30228786
DOI: 10.3748/wjg.v24.i34.3927 -
Current Opinion in Genetics &... Oct 1996Hookworms cause severe anemia and malnutrition in developing countries of the tropics, with an estimated one billion people infected worldwide. An in vitro system that... (Comparative Study)
Comparative Study Review
Hookworms cause severe anemia and malnutrition in developing countries of the tropics, with an estimated one billion people infected worldwide. An in vitro system that models the early events of infection has provided new information about the linkage between the infectious process and the parasite's developmental biology. The cloning and expression of Ancylostoma secreted protein, ASP 1 - a secreted molecule associated with these developmental processes - is an example of how this system allows us to dissect the infectious process at the molecular level.
Topics: Amino Acid Sequence; Ancylostoma; Ancylostomiasis; Animals; Helminth Proteins; Humans; Kinetics; Larva; Molecular Sequence Data; Sequence Homology, Amino Acid
PubMed: 8939719
DOI: 10.1016/s0959-437x(96)80092-x -
Immunology Jun 2016Cellular and molecular investigation of parasitic helminth infections has greatly accelerated the understanding of type 2 immune responses. However, there remains... (Review)
Review
Cellular and molecular investigation of parasitic helminth infections has greatly accelerated the understanding of type 2 immune responses. However, there remains considerable debate regarding the specific leucocytes that kill parasites and whether these mechanisms are distinct from those responsible for tissue repair. Herein, we chronicle discoveries over the past decade highlighting current paradigms in type 2 immunity with a particular emphasis upon how CD4(+) T helper type 2 cells, type 2 innate lymphoid cells and alternatively activated macrophages coordinately control helminth-induced parasitism. Primarily, this review will draw from studies of the murine nematode parasite Nippostrongylus brasiliensis, which bears important similarities to the human hookworms Ancylostoma duodenale and Necator americanus. Given that one or more hookworm species currently infect millions of individuals across the globe, we propose that vaccine and/or pharmaceutical-based cure strategies targeting these affected human populations should incorporate the conceptual advances outlined herein.
Topics: Ancylostoma; Ancylostomiasis; Animals; Antigens, Helminth; Cell Differentiation; Complement Pathway, Alternative; Humans; Immunity, Innate; Macrophage Activation; Macrophages; Necator americanus; Necatoriasis; Nippostrongylus; Strongylida Infections; Th2 Cells
PubMed: 26928141
DOI: 10.1111/imm.12601 -
International Journal For Parasitology.... Aug 2018Hookworms are intestinal nematode parasites that infect nearly half a billion people and are globally one of the most important contributors to iron-deficiency anemia....
Hookworms are intestinal nematode parasites that infect nearly half a billion people and are globally one of the most important contributors to iron-deficiency anemia. These parasites have significant impacts in developing children, pregnant women and working adults. Of all the soil-transmitted helminths or nematodes (STNs), hookworms are by far the most important, with disease burdens conservatively estimated at four million DALYs (Disability-Adjusted Life Years) and with productivity losses of up to US$139 billion annually. To date, mainly one drug, albendazole is used for hookworm therapy in mass drug administration, which has on average ∼80% cure rate that is lower (<40%) in some places. Given the massive numbers of people needing treatment, the threat of parasite resistance, and the inadequacy of current treatments, new and better cures against hookworms are urgently needed. Cry5B, a pore-forming protein produced by the soil bacterium Bacillus thuringiensis (Bt) has demonstrated good efficacy against Ancylostoma ceylanicum hookworm infections in hamsters. Here we broaden studies of Cry5B to include tests against infections of Ancylostoma caninum hookworms in dogs and against infections of the dominant human hookworm, Necator americanus, in hamsters. We show that Cry5B is highly effective against all hookworm parasites tested in all models. Neutralization of stomach acid improves Cry5B efficacy, which will aid in practical application of Cry5B significantly. Importantly, we also demonstrate that the anti-nematode therapeutic efficacy of Cry5B is independent of the host immune system and is not itself negated by repeated dosing. This study indicates that Bt Cry5B is a pan-hookworm anthelmintic with excellent properties for use in humans and other animals.
Topics: Ancylostoma; Ancylostomatoidea; Ancylostomiasis; Animals; Anthelmintics; Bacillus thuringiensis; Bacillus thuringiensis Toxins; Bacterial Proteins; Cricetinae; Dogs; Endotoxins; Hemolysin Proteins; Hookworm Infections; Intestinal Diseases, Parasitic; Necator americanus; Necatoriasis
PubMed: 29772478
DOI: 10.1016/j.ijpddr.2018.05.001