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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 We also captured unpublished articles that were not available on online systems.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 -
Journal of Postgraduate Medicine Apr 1982
Topics: Adult; Ancylostomiasis; Anemia; Female; Gastrointestinal Diseases; Humans; Male
PubMed: 7131345
DOI: No ID Found -
The American Journal of Tropical... Jul 2020Hookworm infections are classified as the most impactful of the human soil-transmitted helminth (STH) infections, causing a disease burden of ∼4 million...
Hookworm infections are classified as the most impactful of the human soil-transmitted helminth (STH) infections, causing a disease burden of ∼4 million disability-adjusted life years, with a global prevalence of 406-480 million infections. Until a decade ago, epidemiological surveys largely assumed and as the relevant human hookworm species implicated as contributing to iron-deficiency anemia. This assumption was based on the indistinguishable morphology of the spp. eggs in stool and the absence of awareness of a third zoonotic hookworm species, . The expanded use of molecular diagnostic assays for differentiating hookworm species infections during STH surveys has now implicated , a predominant hookworm of dogs in Asia, as the second most common hookworm species infecting humans in Southeast Asia and the Pacific. Despite this, with the exception of sporadic case reports, there is a paucity of data available on the impact of this emerging zoonosis on human health at a population level. This situation also challenges the current paradigm, necessitating a One Health approach to hookworm control in populations in which this zoonosis is endemic. Here, we have summarized the available research studies and case reports on human infections in Southeast Asia and the Pacific after 2013 using a systematic review approach. We summarized eight research articles and five clinical case studies, highlighting the importance of future in-depth investigation of zoonotic infections using sensitive and cost-effective diagnostic tools.
Topics: Ancylostoma; Ancylostomiasis; Animals; Asia, Southeastern; Dog Diseases; Dogs; Feces; Humans; Neglected Diseases; One Health; Pacific Islands; Parasite Egg Count; Zoonoses
PubMed: 32342850
DOI: 10.4269/ajtmh.20-0060 -
Scientific Reports May 2019Hookworms are one of the most prevalent and important parasites, infecting ~500 million people worldwide. Hookworm disease is among the leading causes of iron-deficiency...
Hookworms are one of the most prevalent and important parasites, infecting ~500 million people worldwide. Hookworm disease is among the leading causes of iron-deficiency anemia in the developing world and is associated with significant growth stunting and malnutrition. In humans, hookworms appear to impair memory and other forms of cognition, although definitive data are hard to come by. Here we study the impact of a human hookworm parasite, Ancylostoma ceylanicum, on cognition in hamsters in a controlled laboratory setting. We developed tests that measure long-term memory in hamsters. We find that hookworm-infected hamsters were fully capable of detecting a novel object. However, hookworm-infected hamsters were impaired in detecting a displaced object. Defects could be discerned at even at low levels of infection, whereas at higher levels of infection, hamsters were statistically unable to distinguish between displaced and non-displaced objects. These spatial memory deficiencies could not be attributed to defects in infected hamster mobility or to lack of interest. We also found that hookworm infection resulted in reproducible reductions in diversity and changes in specific taxanomic groups in the hamster gut microbiome. These data demonstrate that human hookworm infection in a laboratory mammal results in a specific, rapid, acute, and measurable deficit in spatial memory, and we speculate that gut alterations could play some role in these cognitive deficits. Our findings highlight the importance of hookworm elimination and suggest that finer tuned spatial memory studies be carried out in humans.
Topics: Ancylostoma; Ancylostomiasis; Animals; Cognition; Cricetinae; Disease Models, Animal; Female; Gastrointestinal Microbiome; Humans; Male; Memory, Long-Term
PubMed: 31133690
DOI: 10.1038/s41598-019-44301-4 -
Current Biology : CB Jul 2018Skin-penetrating parasitic nematodes infect approximately one billion people worldwide and are a major source of neglected tropical disease [1-6]. Their life cycle...
Skin-penetrating parasitic nematodes infect approximately one billion people worldwide and are a major source of neglected tropical disease [1-6]. Their life cycle includes an infective third-larval (iL3) stage that searches for hosts to infect in a poorly understood process that involves both thermal and olfactory cues. Here, we investigate the temperature-driven behaviors of skin-penetrating iL3s, including the human-parasitic threadworm Strongyloides stercoralis and the human-parasitic hookworm Ancylostoma ceylanicum. We show that human-parasitic iL3s respond robustly to thermal gradients. Like the free-living nematode Caenorhabditis elegans, human-parasitic iL3s show both positive and negative thermotaxis, and the switch between them is regulated by recent cultivation temperature [7]. When engaging in positive thermotaxis, iL3s migrate toward temperatures approximating mammalian body temperature. Exposing iL3s to a new cultivation temperature alters the thermal switch point between positive and negative thermotaxis within hours, similar to the timescale of thermal plasticity in C. elegans [7]. Thermal plasticity in iL3s may enable them to optimize host finding on a diurnal temperature cycle. We show that temperature-driven responses can be dominant in multisensory contexts such that, when thermal drive is strong, iL3s preferentially engage in temperature-driven behaviors despite the presence of an attractive host odorant. Finally, targeted mutagenesis of the S. stercoralis tax-4 homolog abolishes heat seeking, providing the first evidence that parasitic host-seeking behaviors are generated through an adaptation of sensory cascades that drive environmental navigation in C. elegans [7-10]. Together, our results provide insight into the behavioral strategies and molecular mechanisms that allow skin-penetrating nematodes to target humans.
Topics: Ancylostoma; Ancylostomiasis; Animals; Host-Seeking Behavior; Humans; Larva; Strongyloides stercoralis; Strongyloidiasis; Taxis Response; Thermosensing
PubMed: 30017486
DOI: 10.1016/j.cub.2018.05.063 -
Parasites & Vectors Jun 2017Hookworms belonging to the genus Ancylostoma (Dubini, 1843) cause ancylostomiasis, a disease of considerable concern in humans and domestic and wild animals. Molecular...
BACKGROUND
Hookworms belonging to the genus Ancylostoma (Dubini, 1843) cause ancylostomiasis, a disease of considerable concern in humans and domestic and wild animals. Molecular and epidemiological data support evidence for the zoonotic potential among species of Ancylostoma where transmission to humans is facilitated by rapid urbanization and increased human-wildlife interactions. It is important to assess and describe these potential zoonotic parasite species in wildlife, especially in hosts that have physiological similarities to humans and share their habitat. Moreover, defining species diversity within parasite groups that can circulate among free-ranging host species and humans also provides a pathway to understanding the distribution of infection and disease. In this study, we describe a previously unrecognized species of hookworm in the genus Ancylostoma in the giant panda, including criteria for morphological and molecular characterization.
METHODS
The hookworm specimens were obtained from a wild giant panda that died in the Fengtongzai Natural Reserve in Sichuan Province of China in November 2013. They were microscopically examined and then genetically analyzed by sequencing the nuclear internal transcribed spacer (ITS, ITS1-5.8S-ITS2) and mitochondrial cytochrome c oxidase subunit 1 (cox1) genes in two representative specimens (one female and one male, FTZ1 and FTZ2, respectively).
RESULTS
Ancylostoma ailuropodae n. sp. is proposed for these hookworms. Morphologically the hookworm specimens differ from other congeneric species primarily based on the structure of the buccal capsule in males and females, characterized by 2 pairs of ventrolateral and 2 pairs of dorsolateral teeth; males differ in the structure and shape of the copulatory bursa, where the dorsal ray possesses 2 digitations. Pairwise nuclear and mitochondrial DNA comparisons, genetic distance analysis, and phylogenetic data strongly indicate that A. ailuropodae from giant pandas is a separate species which shared a most recent common ancestor with A. ceylanicum Looss, 1911 in the genus Ancylostoma (family Ancylostomatidae).
CONCLUSION
Ancylostoma ailuropodae n. sp. is the fourth species of hookworm described from the Ursidae and the fifteenth species assigned to the genus Ancylostoma. A sister-species association with A. ceylanicum and phylogenetic distinctiveness from the monophyletic Uncinaria Frölich, 1789 among ursids and other carnivorans indicate a history of host colonization in the evolutionary radiation among ancylostomatid hookworms. Further, phylogenetic relationships among bears and a history of ecological and geographical isolation for giant pandas may be consistent with two independent events of host colonization in the diversification of Ancylostoma among ursid hosts. A history for host colonization within this assemblage and the relationship for A. ailuropodae n. sp. demonstrate the potential of this species as a zoonotic parasite and as a possible threat to human health. The cumulative morphological, molecular and phylogenetic data presented for A. ailuropodae n. sp. provides a better understanding of the taxonomy, diagnostics and evolutionary biology of the hookworms.
Topics: Ancylostoma; Ancylostomiasis; Animals; Base Sequence; China; DNA, Helminth; DNA, Mitochondrial; Female; Male; Phylogeny; Sequence Alignment; Sequence Analysis, DNA; Ursidae
PubMed: 28576124
DOI: 10.1186/s13071-017-2209-2 -
Nature Genetics Apr 2015Hookworms infect over 400 million people, stunting and impoverishing them. Sequencing hookworm genomes and finding which genes they express during infection should help...
Hookworms infect over 400 million people, stunting and impoverishing them. Sequencing hookworm genomes and finding which genes they express during infection should help in devising new drugs or vaccines against hookworms. Unlike other hookworms, Ancylostoma ceylanicum infects both humans and other mammals, providing a laboratory model for hookworm disease. We determined an A. ceylanicum genome sequence of 313 Mb, with transcriptomic data throughout infection showing expression of 30,738 genes. Approximately 900 genes were upregulated during early infection in vivo, including ASPRs, a cryptic subfamily of activation-associated secreted proteins (ASPs). Genes downregulated during early infection included ion channels and G protein-coupled receptors; this downregulation was observed in both parasitic and free-living nematodes. Later, at the onset of heavy blood feeding, C-lectin genes were upregulated along with genes for secreted clade V proteins (SCVPs), encoding a previously undescribed protein family. These findings provide new drug and vaccine targets and should help elucidate hookworm pathogenesis.
Topics: Ancylostoma; Ancylostomatoidea; Ancylostomiasis; Animals; Base Sequence; Female; Genome, Helminth; Humans; Male; Molecular Sequence Data; Multigene Family; Phylogeny; Species Specificity; Transcriptome; Zoonoses
PubMed: 25730766
DOI: 10.1038/ng.3237 -
PLoS Neglected Tropical Diseases May 2018The soil-transmitted nematodes (STNs) or helminths (hookworms, whipworms, large roundworms) infect the intestines of ~1.5 billion of the poorest peoples and are leading...
In vivo and in vitro studies of Cry5B and nicotinic acetylcholine receptor agonist anthelmintics reveal a powerful and unique combination therapy against intestinal nematode parasites.
BACKGROUND
The soil-transmitted nematodes (STNs) or helminths (hookworms, whipworms, large roundworms) infect the intestines of ~1.5 billion of the poorest peoples and are leading causes of morbidity worldwide. Only one class of anthelmintic or anti-nematode drugs, the benzimidazoles, is currently used in mass drug administrations, which is a dangerous situation. New anti-nematode drugs are urgently needed. Bacillus thuringiensis crystal protein Cry5B is a powerful, promising new candidate. Drug combinations, when properly made, are ideal for treating infectious diseases. Although there are some clinical trials using drug combinations against STNs, little quantitative and systemic work has been performed to define the characteristics of these combinations in vivo.
METHODOLOGY/PRINCIPAL FINDINGS
Working with the hookworm Ancylostoma ceylanicum-hamster infection system, we establish a laboratory paradigm for studying anti-nematode combinations in vivo using Cry5B and the nicotinic acetylcholine receptor (nAChR) agonists tribendimidine and pyrantel pamoate. We demonstrate that Cry5B strongly synergizes in vivo with both tribendimidine and pyrantel at specific dose ratios against hookworm infections. For example, whereas 1 mg/kg Cry5B and 1 mg/kg tribendimidine individually resulted in only a 0%-6% reduction in hookworm burdens, the combination of the two resulted in a 41% reduction (P = 0.020). Furthermore, when mixed at synergistic ratios, these combinations eradicate hookworm infections at doses where the individual doses do not. Using cyathostomin nematode parasites of horses, we find based on inhibitory concentration 50% values that a strongylid parasite population doubly resistant to nAChR agonists and benzimidazoles is more susceptible or "hypersusceptible" to Cry5B than a cyathostomin population not resistant to nAChR agonists, consistent with previous Caenhorhabditis elegans results.
CONCLUSIONS/SIGNIFICANCE
Our study provides a powerful means by which anthelmintic combination therapies can be examined in vivo in the laboratory. In addition, we demonstrate that Cry5B and nAChR agonists have excellent combinatorial properties-Cry5B combined with nAChR agonists gives rise to potent cures that are predicted to be recalcitrant to the development of parasite resistance. These drug combinations highlight bright spots in new anthelmintic development for human and veterinary animal intestinal nematode infections.
Topics: Ancylostoma; Ancylostomiasis; Animals; Anthelmintics; Bacillus thuringiensis Toxins; Bacterial Proteins; Cricetinae; Drug Therapy, Combination; Endotoxins; Female; Hemolysin Proteins; Horse Diseases; Horses; Humans; Intestinal Diseases, Parasitic; Male; Mesocricetus; Nicotinic Antagonists; Receptors, Nicotinic
PubMed: 29775454
DOI: 10.1371/journal.pntd.0006506 -
Parasites & Vectors Dec 2019The canine hookworm, Ancylostoma caninum is the most prevalent and important intestinal nematode parasite of dogs in the USA. Hookworms are typically well controlled by...
BACKGROUND
The canine hookworm, Ancylostoma caninum is the most prevalent and important intestinal nematode parasite of dogs in the USA. Hookworms are typically well controlled by treatment with all commonly used anthelmintics that are approved for this use in dogs. However, in the past few years, cases of recurrent/persistent canine hookworm infections appear to have dramatically increased, suggesting that anthelmintic resistance (AR) may have evolved in this parasite. These cases are highly overrepresented by greyhounds, but multiple other breeds are also represented. The aim of this study was to characterize several of these suspected resistant isolates using in vitro, genetic and clinical testing to determine if these cases represent true anthelmintic resistance in A. caninum.
METHODS
Fecal samples containing hookworm eggs from three cases of persistent hookworm infections; one from a greyhound, one from a miniature schnauzer and one from a hound-mix, were received by our laboratory. These were then used to establish infections in laboratory dogs and to perform egg hatch assays (EHA) and larval development assays (LDA) for detecting resistance to benzimidazoles and macrocyclic lactones, respectively. Additional EHA and LDA were performed on eggs recovered from the laboratory-induced infections. Fecal egg count reduction tests were performed to detect resistance to pyrantel. Deep amplicon sequencing assays were developed to measure the frequency of non-synonymous single nucleotide polymorphisms (SNP) at codons 167, 198 and 200 of the A. caninum isotype-1 β-tubulin gene.
RESULTS
Resistance ratios for the three A. caninum isolates tested ranged from 6.0 to > 100 and 5.5 to 69.8 for the EHA and LDA, respectively. Following treatment with pyrantel, reduction in faecal egg counts was negative or 0%. Deep amplicon sequencing of the isotype-1 β-tubulin gene identified a high frequency of resistance-associated SNPs at codon 167 in all three resistant isolates and in two additional clinical cases.
CONCLUSIONS
These data conclusively demonstrate multiple anthelmintic resistance in multiple independent isolates of A. caninum, strongly suggesting that this is an emerging problem in the USA. Furthermore, evidence suggest that these resistant hookworms originate from racing greyhound farms and kennels, though additional research is needed to confirm this.
Topics: Ancylostoma; Ancylostomiasis; Animals; Anthelmintics; Breeding; Dog Diseases; Dogs; Drug Resistance, Multiple; Feces; Parasite Egg Count; Polymorphism, Single Nucleotide; Pyrantel; United States
PubMed: 31818311
DOI: 10.1186/s13071-019-3828-6 -
PLoS Neglected Tropical Diseases Sep 2015The implementation of soil-transmitted helminth (STH) treatment programmes occurs in varied environmental, social and economic contexts. Programme impact will be...
BACKGROUND
The implementation of soil-transmitted helminth (STH) treatment programmes occurs in varied environmental, social and economic contexts. Programme impact will be influenced by factors that affect the reduction in the prevalence and intensity of infections following treatment, as well as the subsequent rate of reinfection. To better understand the heterogeneity of programme impact and its underlying reasons, we investigated the influence of contextual factors on reduction in STH infection as part of the national school based deworming (SBD) programme in Kenya.
MATERIALS AND METHODS
Data on the prevalence and intensity of infection were collected within the monitoring and evaluation component of the SBD programme at baseline and after delivery of two annual treatment rounds in 153 schools in western Kenya. Using a framework that considers STH epidemiology and transmission dynamics, capacity to deliver treatment, operational feasibility and financial capacity, data were assembled at both school and district (county) levels. Geographic heterogeneity of programme impact was assessed by descriptive and spatial analyses. Factors associated with absolute reductions of Ascaris lumbricoides and hookworm infection prevalence and intensity were identified using mixed effects linear regression modelling adjusting for baseline infection levels.
PRINCIPAL FINDINGS
The reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school. Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community. Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores.
CONCLUSIONS
The study identifies factors associated with the impact of school-based deworming and in particular highlights how access to water, sanitation and hygiene and environmental conditions influence the impact of deworming programmes.
Topics: Ancylostomiasis; Animals; Antinematodal Agents; Ascariasis; Delivery of Health Care; Humans; Kenya; Neglected Diseases; Nematode Infections; Prevalence; Program Evaluation; Public Health; School Health Services; Socioeconomic Factors; Trichuriasis; Water
PubMed: 26421808
DOI: 10.1371/journal.pntd.0004108