-
Emerging Infectious Diseases Jan 2020A 60-year-old man from South Korea underwent a colonoscopy. A juvenile female worm showing 3 pairs of teeth in the buccal cavity was recovered from the descending colon....
A 60-year-old man from South Korea underwent a colonoscopy. A juvenile female worm showing 3 pairs of teeth in the buccal cavity was recovered from the descending colon. Partial sequencing of the internal transcribed spacer region showed 100% identity with Ancylostoma caninum, the dog hookworm.
Topics: Ancylostoma; Ancylostomiasis; Animals; Humans; Male; Middle Aged; Phylogeny; Polymerase Chain Reaction; Republic of Korea; Sequence Analysis, DNA
PubMed: 31855538
DOI: 10.3201/eid2601.191335 -
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 -
Iranian Journal of Public Health Sep 2019Ancylostomiasis is a prevalent and global parasitic disease, including China. A systematic review is significant to understand the epidemiological features of hookworm... (Review)
Review
BACKGROUND
Ancylostomiasis is a prevalent and global parasitic disease, including China. A systematic review is significant to understand the epidemiological features of hookworm and provide guidance for prevention and treatment.
METHODS
We systematically searched academic databases and assessed 944 papers published from 1955-2015 to establish the comprehensive analysis of prevalence of hookworm disease in China. We searched Chinese databases, including CNKI, Wanfang and VIP, for literature with the subject word "Ancylostomiasis and hookworm". The data were analyzed with SPSS 19.0 software using Spearman correlation analysis. Results were statistically significant for a -value of <0.01.
RESULTS
The search yielded 532,151 cases from epidemiological investigation and 7294 cases based on hospital diagnosis. Hookworm infection was highest (15.83%) in Fujian province, with high rates also found in East China, Southwest China, Central China and Southern China and lower rates in Northwest China, North China and Northeast China. In terms of occupation, farmers had the highest proportion of infections (72.54%). There was no correlation between epidemiological investigations and hospital-diagnosed cases. However, there was significant positive correlation between hospital-diagnosed cases and misdiagnosed cases. The proportion of hospital-misdiagnosed cases was 32.80%.
CONCLUSION
Ancylostomiasis is a serious public health problem that negatively influences health and hinders socioeconomic development. Positive measures are required by both health services and individuals to prevent and control hookworm disease.
PubMed: 31700811
DOI: No ID Found -
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 -
The Brazilian Journal of Infectious... 2019
Topics: Albendazole; Ancylostoma; Ancylostomiasis; Animals; Anthelmintics; Antinematodal Agents; Gastrointestinal Hemorrhage; Humans; Intestinal Diseases, Parasitic; Mebendazole
PubMed: 31622567
DOI: 10.1016/j.bjid.2019.09.002 -
The American Journal of Case Reports Sep 2019BACKGROUND Cutaneous larva migrans (CLM) is caused by nematode parasites of the hookworm family of Ancylostomatidae. Ancylostomiasis is a zoonosis found in cats and...
BACKGROUND Cutaneous larva migrans (CLM) is caused by nematode parasites of the hookworm family of Ancylostomatidae. Ancylostomiasis is a zoonosis found in cats and dogs, and humans are an accidental host. This report presents a case of CLM in an 8-year-old boy, which was due to the zoonotic transmission of Ancylostoma caninum from domestic dogs in an urban area of Vinces, Ecuador, and demonstrates how awareness and early diagnosis contributed to the timely treatment of CLM. CASE REPORT An 8-year-old boy from the urban area of Vinces city in the Los Ríos province of Ecuador presented with a serpiginous palpable lesion on the sole of the right foot, consistent with a diagnosis of cutaneous larva migrans (CLM). He was infected through contact with the soil where canine Ancylostoma larvae were found. Twenty samples of feces were analyzed from the soil, and Ancylostoma larvae were found in 100% of these samples. Also, 120 dog stool samples were examined, and 75 (62.5%) contained Ancylostoma larvae, which were identified using the modified Willis and Baermann method. CONCLUSIONS CLM is a zoonotic disease that can affect the population in endemic areas. In this case, CLM was identified in the sole of the foot of a child. The presence of Ancylostoma larvae were identified in the soil and in the feces of dogs, indicating that the community was exposed to a significant environmental risk from this zoonotic disease.
Topics: Ancylostoma; Ancylostomiasis; Animals; Child; Dogs; Ecuador; Endemic Diseases; Feces; Humans; Larva Migrans; Male; Soil; Zoonoses
PubMed: 31543509
DOI: 10.12659/AJCR.915154 -
Mitochondrial DNA. Part B, Resources Sep 2019The dog hookworm (Nematoda, Ancylostomatidae) is a blood-feeding intestinal parasitic nematode and can cause ancylostomiasis in humans. In this study, the complete...
The dog hookworm (Nematoda, Ancylostomatidae) is a blood-feeding intestinal parasitic nematode and can cause ancylostomiasis in humans. In this study, the complete mitochondrial genome of this anthropozoonotic hookworm was sequenced through Illumina deep sequencing technology. The whole genome was 13,721 bp in length and encoded 36 genes including 12 protein-coding genes, 22 transfer RNAs, and 2 ribosomal RNAs. Phylogeny revealed that grouped with species from Ancylostomatinae and separated from species of Bunostominae in the family Ancylostomatidae. Amongst the subfamily Ancylostomatinae, three dog-originated , regardless of isolate origins, clustered together and were more closely related to the cat hookworm and the human hookworm than to the dog/cat hookworm and the sea lion hookworm . Taken together, the cumulative mitochondrial DNA data provides insights into phylogenetic studies among Ancylostomatidae nematodes.
PubMed: 33365829
DOI: 10.1080/23802359.2019.1666048 -
Invertebrate Neuroscience : IN Sep 2019Parasitic nematode infections are treated using anthelmintic drugs, some of which target nicotinic acetylcholine receptors (nAChRs) located in different parasite...
Parasitic nematode infections are treated using anthelmintic drugs, some of which target nicotinic acetylcholine receptors (nAChRs) located in different parasite tissues. The limited arsenal of anthelmintic agents and the prevalence of drug resistance imply that future defense against parasitic infections will depend on the discovery of novel targets and therapeutics. Previous studies have suggested that Ascaris suum ACR-16 nAChRs are a suitable target for the development of antinematodal drugs. In this study, we characterized the pharmacology of the Ancylostoma caninum ACR-16 receptor using two-electrode voltage-clamp electrophysiology. This technique allowed us to study the effects of cholinergic agonists and antagonists on the nematode nAChRs expressed in Xenopus laevis oocytes. Aca-ACR-16 was not sensitive to many of the existing cholinomimetic anthelmintics (levamisole, oxantel, pyrantel, and tribendimidine). 3-Bromocytisine was the most potent agonist (> 130% of the control acetylcholine current) on the Aca-ACR-16 nAChR but, unlike Asu-ACR-16, oxantel did not activate the receptor. The mean time constants of desensitization for agonists on Aca-ACR-16 were longer than the rates observed in Asu-ACR-16. In contrast to Asu-ACR-16, the A. caninum receptor was completely inhibited by DHβE and moderately inhibited by α-BTX. In conclusion, we have successfully reconstituted a fully functional homomeric nAChR, ACR-16, from A. caninum, a model for human hookworm infections. The pharmacology of the receptor is distinct from levamisole-sensitive nematode receptors. The ACR-16 homologue also displayed some pharmacological differences from Asu-ACR-16. Hence, A. caninum ACR-16 may be a valid target site for the development of anthelmintics against hookworm infections.
Topics: Ancylostoma; Ancylostomiasis; Animals; Anthelmintics; Cholinergic Agents; Helminth Proteins; Receptors, Nicotinic
PubMed: 31486912
DOI: 10.1007/s10158-019-0231-0 -
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 -
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