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The American Journal of Tropical... Mar 2008Iron deficiency anemia poses an important public health problem for women of reproductive age living in developing countries. We assessed the prevalence of iron...
Iron deficiency anemia poses an important public health problem for women of reproductive age living in developing countries. We assessed the prevalence of iron deficiency and anemia and associated risk factors in a community-based sample of women living in a rural province of northwest Vietnam. A cross-sectional survey, comprised of written questionnaires and laboratory analysis of hemoglobin (Hb), ferritin, transferrin receptor, and stool hookworm egg count, was undertaken, and the soluble transferrin receptor/log ferritin index was calculated. Of 349 non-pregnant women, 37.53% were anemic (Hb < 12 g/dL), and 23.10% were iron deficient (ferritin < 15 ng/L). Hookworm infection was present in 78.15% of women, although heavy infection was uncommon (6.29%). Iron deficiency was more prevalent in anemic than non-anemic women (38.21% versus 14.08%, P < 0.001). Consumption of meat at least three times a week was more common in non-anemic women (51.15% versus 66.67%, P = 0.042). Mean ferritin was lower in anemic women (18.99 versus 35.66 ng/mL, P < 0.001). There was no evidence of a difference in prevalence (15.20% versus 17.23%, P = 0.629) or intensity (171.07 versus 129.93 eggs/g, P = 0.412) of hookworm infection between anemic and non-anemic women. Although intensity of hookworm infection and meat consumption were associated with indices of iron deficiency in a multiple regression model, their relationship with hemoglobin was not significant. Anemia, iron deficiency, and hookworm infection were prevalent in this population. Intake of meat was more clearly associated with hemoglobin and iron indices than hookworm. An approach to addressing iron deficiency in this population should emphasize both iron supplementation and deworming.
Topics: Adult; Anemia; Cross-Sectional Studies; Feces; Female; Hookworm Infections; Humans; Iron Deficiencies; Logistic Models; Maternal Age; Meat; Odds Ratio; Parasite Egg Count; Risk Factors; Vietnam
PubMed: 18337329
DOI: No ID Found -
PLoS Neglected Tropical Diseases May 2017Necator americanus Glutathione-S-Transferase-1 (Na-GST-1) plays a role in the digestion of host hemoglobin by adult N. americanus hookworms. Vaccination of laboratory...
UNLABELLED
Necator americanus Glutathione-S-Transferase-1 (Na-GST-1) plays a role in the digestion of host hemoglobin by adult N. americanus hookworms. Vaccination of laboratory animals with recombinant Na-GST-1 is associated with significant protection from challenge infection. Recombinant Na-GST-1 was expressed in Pichia pastoris and adsorbed to aluminum hydroxide adjuvant (Alhydrogel) according to current Good Manufacturing Practice. Two Phase 1 trials were conducted in 142 healthy adult volunteers in the United States and Brazil, first in hookworm-naïve individuals and then in residents of a N. americanus endemic area in Brazil. Volunteers received one of three doses of recombinant Na-GST-1 (10, 30, or 100 μg) adjuvanted with Alhydrogel, adjuvanted with Alhydrogel and co-administered with an aqueous formulation of Glucopyranosyl Lipid A (GLA-AF), or the hepatitis B vaccine. Vaccinations were administered via intramuscular injection on days 0, 56, and 112. Na-GST-1/Alhydrogel was well tolerated in both hookworm-naïve and hookworm-exposed adults, with the most common adverse events being mild to moderate injection site pain and tenderness, and mild headache and nausea; no vaccine-related severe or serious adverse events were observed. Antigen-specific IgG antibodies were induced in a dose-dependent fashion, with increasing levels observed after each vaccination in both trials. The addition of GLA-AF to Na-GST-1/Alhydrogel did not result in significant increases in specific IgG responses. In both the US and Brazil studies, the predominant IgG subclass induced against Na-GST-1 was IgG1, with lesser amounts of IgG3. Vaccination of both hookworm-naïve and hookworm-exposed adults with recombinant Na-GST-1 was safe, well tolerated, and resulted in significant antigen-specific IgG responses. Based on these results, this vaccine will be advanced into clinical trials in children and eventual efficacy studies.
TRIAL REGISTRATION
ClinicalTrials.gov (NCT01261130 for the Brazil trial and NCT01385189 for the US trial).
Topics: Adjuvants, Immunologic; Adolescent; Adult; Aluminum Hydroxide; Ancylostomatoidea; Animals; Antibodies, Helminth; Antigens, Helminth; Brazil; Drug-Related Side Effects and Adverse Reactions; Female; Glucosides; Glutathione Transferase; Healthy Volunteers; Hepatitis B Vaccines; Hookworm Infections; Humans; Immunoglobulin G; Injections, Intramuscular; Lipid A; Male; Middle Aged; Treatment Outcome; United States; Vaccines, Synthetic; Young Adult
PubMed: 28464026
DOI: 10.1371/journal.pntd.0005574 -
Veterinary Parasitology, Regional... Jun 2024Recent studies demonstrated that Greyhounds are commonly infected with Ancylostoma caninum and these infections have been shown to be resistant to anthelmintics. This...
Recent studies demonstrated that Greyhounds are commonly infected with Ancylostoma caninum and these infections have been shown to be resistant to anthelmintics. This study evaluated samples submitted to a commercial reference laboratory (IDEXX Laboratories) for canine fecal flotation zinc sulfate centrifugation and coproantigen immunoassay between January 1, 2019, and July 30, 2023 for evidence that Greyhounds were more often positive for Ancylostoma spp. (hookworms) compared to other breeds. The purpose of the study was to determine if Greyhounds were more likely to be hookworm-positive compared to other breeds, if Greyhounds on preventives with efficacy against hookworm infections are more likely to test positive than other breeds, if their infections take longer to resolve, to estimate how long this takes and to assess whether the proportion of hookworm positive tests for all breeds is increasing over time. Records of 25,440,055 fecal results were obtained representing 17,671,724 unique dogs. Of these, 49,795 (∼0.3%) were Greyhounds. The overall odds ratio (OR) of 15.3 (p < 0.001) suggests that Greyhounds are at significantly higher risk than other breeds for hookworm positive float findings, and the OR of 14.3 (p < 0.001) suggests significantly higher risk for hookworm antigen positive results. The median time to negative testing event from the Turnbull distribution estimate was in the interval of 1-2 days for other breeds and 71-72 days for Greyhounds. These results provide evidence that anthelmintic resistant A. caninum strains may be having population-level impacts on the frequency and duration of infections in Greyhounds. The findings have broader health implications beyond Greyhounds as MADR A. caninum strains could spread to other breeds and even pet owners.
Topics: Animals; Dogs; Dog Diseases; Feces; Retrospective Studies; Ancylostoma; Hookworm Infections; Immunoassay; Ancylostomiasis; Antigens, Helminth; Female; Male
PubMed: 38772642
DOI: 10.1016/j.vprsr.2024.101026 -
Epidemics Mar 2017The predictions of two mathematical models of the transmission dynamics of Ascaris lumbricoides and hookworm infection and the impact of mass drug administration (MDA)... (Comparative Study)
Comparative Study
The predictions of two mathematical models of the transmission dynamics of Ascaris lumbricoides and hookworm infection and the impact of mass drug administration (MDA) are compared, using data from India. One model has an age structured partial differential equation (PDE) deterministic framework for the distribution of parasite numbers per host and sexual mating. The second model is an individual-based stochastic model. Baseline data acquired prior to treatment are used to estimate key transmission parameters, and forward projections are made, given the known MDA population coverage. Predictions are compared with observed post-treatment epidemiological patterns. The two models could equally well predict the short-term impact of deworming on A. lumbricoides and hookworm infection levels, despite being fitted to different subsets and/or summary statistics of the data. As such, the outcomes give confidence in their use as aids to policy formulation for the use of PCT to control A. lumbricoides and hookworm infection. The models further largely agree in a qualitative sense on the added benefit of semi-annual vs. annual deworming and targeting of the entire population vs. only children, as well as the potential for interruption of transmission. Further, this study also illustrates that long-term predictions are sensitive to modelling assumptions about which age groups contribute most to transmission, which depends on human demography and age-patterns in exposure and contribution to the environmental reservoir of infection, the latter being notoriously difficult to empirically quantify.
Topics: Animals; Anthelmintics; Ascariasis; Ascaris lumbricoides; Hookworm Infections; Humans; India; Mass Drug Administration; Models, Theoretical; Reproducibility of Results
PubMed: 28279454
DOI: 10.1016/j.epidem.2017.02.001 -
PloS One 2022Large-scale deworming programs have been successful in reducing the burden of disease due to soil-transmitted helminth (STH; Ascaris lumbricloides, Trichuris trichiura...
BACKGROUND
Large-scale deworming programs have been successful in reducing the burden of disease due to soil-transmitted helminth (STH; Ascaris lumbricloides, Trichuris trichiura and hookworm) infections, but re-infection in absence of other measures is unavoidable. We assessed the role of nail contamination as a source of infection with the goal to evaluate the potential of nail clipping as a simple measure to further reduce STH-attributable morbidity.
METHODS
A cross-sectional study was conducted in Jimma Town (Ethiopia). Both stool samples and clipped nails were collected from 600 schoolchildren and microscopically screened for the presence of STHs. We also interviewed the children to gain insights into their hygiene practices. Subsequently, we explored any associations between infection, nail contamination and personal hygiene.
RESULTS
Any STH infections were observed in 24.3% of the children (A. lumbricoides: 18.5%; T. trichiura: 9.8%; hookworm: 0.5%). The intensity of the infections was mainly low, only in a few cases a moderate-to-heavy intensity infection was observed (A. lumbricoides: 4.3%; T. trichiura: 0.2%). Other helminth species observed were Schistosoma mansoni (5.0%), Hymenolepis nana (2.7%), Taenia spp. and Enterobius vermicularis (<1.0%). The analysis of the nail material revealed the presence of A. lumbricoides (1.7%), Taenia spp. (1.0%), T. trichiura (0.5%), E. vermicularis (0.5%) and H. nana (0.2%). The odds of infection with any STH increased as the frequency of trimming decreased. The odds of nail contamination with any STH and A. lumbricoides were higher for younger children.
CONCLUSIONS
The presence of helminth eggs under the nails of children highlights a poor personal hygiene. The association between any STH infection and frequency of nail trimming needs to be explored in an intervention study. The recent prevalence of any STH infections indicated that scaling down of the frequency of deworming is justified but that STH is still a public health problem.
Topics: Ancylostomatoidea; Animals; Ascaris lumbricoides; Child; Cross-Sectional Studies; Ethiopia; Feces; Helminthiasis; Helminths; Hookworm Infections; Humans; Nails; Prevalence; Soil
PubMed: 35767573
DOI: 10.1371/journal.pone.0268792 -
The Journal of Infectious Diseases May 2022Hookworm infection is associated with poor nutritional outcomes, anemia, and impaired cognitive performance. We examined the association between maternal hookworm...
Hookworm infection is associated with poor nutritional outcomes, anemia, and impaired cognitive performance. We examined the association between maternal hookworm infection and birth outcomes in a cohort of women in Leyte, Philippines. We observed poor intrauterine growth characteristics associated with maternal hookworm only among male offspring, with lower birth weight, head circumference, and placental surface area. Male neonates also had higher insulin-like growth factor 2 (IGF-2) and lower adiponectin in cord blood. These data intriguingly suggest nutritional impacts of maternal hookworm infection during pregnancy may be divergent based on sex of the offspring.
Topics: Birth Weight; Female; Fetal Blood; Hookworm Infections; Humans; Infant, Newborn; Insulin-Like Growth Factor I; Male; Placenta; Pregnancy
PubMed: 35091745
DOI: 10.1093/infdis/jiac025 -
PLoS Neglected Tropical Diseases Oct 2022Hookworm infections, caused by Ancylostoma duodenale and Necator americanus, are of considerable public health importance. The World Health Organization recommends...
BACKGROUND
Hookworm infections, caused by Ancylostoma duodenale and Necator americanus, are of considerable public health importance. The World Health Organization recommends preventive chemotherapy as the key strategy for morbidity control. Meta-analyses have been conducted to estimate treatment efficacy of available drugs and drug combinations. However, in most studies, the relation between the diagnostic error and infection intensity have not been considered, resulting in an overestimation of cure rates (CRs).
METHODOLOGY
A Bayesian model was developed to compare the 'true' CR and egg reduction rate of different treatment regimens for hookworm infections taking into account the error of the recommended Kato-Katz thick smear diagnostic technique. It was fitted to the observed egg count data which was linked to the distribution of worms, considered the day-to-day variation of hookworm egg excretion and estimated the infection intensity-dependent sensitivity. The CR was obtained by defining the prevalence of infection at follow-up as the probability of having at least one fertilized female worm. The model was applied to individual-level egg count data available from 17 treatments and six clinical trials.
PRINCIPAL FINDINGS
Taking the diagnostic error into account resulted in considerably lower CRs than previously reported. Overall, of all treatments analyzed, mebendazole administered in six dosages of 100 mg each was the most efficacious treatment with a CR of 88% (95% Bayesian credible interval: 79-95%). Furthermore, diagnostic sensitivity varied with the infection intensity and sampling effort. For an infection intensity of 50 eggs per gram of stool, the sensitivity is close to 60%; for two Kato-Katz thick smears it increased to approximately 76%.
CONCLUSIONS/SIGNIFICANCE
Our model-based estimates provide the true efficacy of different treatment regimens against hookworm infection taking into account the diagnostic error of the Kato-Katz method. Estimates of the diagnostic sensitivity for different number of stool samples and thick smears are obtained. To accurately assess efficacy in clinical trials with the Kato-Katz method, at least two stool samples on consecutive days should be collected.
Topics: Animals; Female; Humans; Ancylostomatoidea; Parasite Egg Count; Mebendazole; Bayes Theorem; Hookworm Infections; Feces; Diagnostic Errors; Sensitivity and Specificity
PubMed: 36194622
DOI: 10.1371/journal.pntd.0010810 -
Infectious Diseases of Poverty Feb 2017School-based deworming is widely implemented in various countries to reduce the burden of soil-transmitted helminths (STHs), however, the frequency of drug... (Randomized Controlled Trial)
Randomized Controlled Trial
Impact of single annual treatment and four-monthly treatment for hookworm and Ascaris lumbricoides, and factors associated with residual infection among Kenyan school children.
BACKGROUND
School-based deworming is widely implemented in various countries to reduce the burden of soil-transmitted helminths (STHs), however, the frequency of drug administration varies in different settings. In this study, we compared the impact of a single annual treatment and 4-monthly treatment over a follow-up among Kenyan school children, and investigated the factors associated with residual infection.
METHODS
We performed a secondary analysis of data from a randomized trial investigating whether deworming for STHs alters risk of acquiring malaria. Children received either a single treatment or 4-monthly albendazole treatments were followed longitudinally from February 2014 to October 2014. The relative impact of treatment and factors associated with residual infections were investigated using mixed-effects regression models. Predisposition to infection was assessed based on Spearman's rank and Kendall's Tau correlation coefficients.
RESULTS
In the 4-monthly treatment group, the proportion of children infected with hookworm decreased from 59.9 to 5.7%, while Ascaris lumbricoides infections dropped from 55.7 to 6.2%. In the single treatment group, hookworm infections decreased over the same time period from 58.7 to 18.3% (12.6% absolute difference in reduction, 95% CI: 8.9-16.3%), and A. lumbricoides from 56.7 to 23.3% (17.1% absolute difference in reduction, 95% CI: 13.1-21.1%). There was strong evidence for predisposition to both STH types. Residual hookworm infection among children on 4-monthly treatment were associated with male sex and baseline nutritional status, whereas A. lumbricoides infection was associated with individual and school-level infection at baseline, latrine cleanliness at schools.
CONCLUSIONS
This study found that 4-monthly treatment w more effective than single annual treatment. Repeated treatments led to dramatic reductions in the intensities of STHs, but did not completely clear infections among school children in Kenya, a presumed reflection of reinfection in a setting where there is ongoing transmission.
Topics: Adolescent; Albendazole; Ancylostomatoidea; Animals; Anthelmintics; Ascariasis; Ascaris lumbricoides; Child; Child, Preschool; Female; Hookworm Infections; Humans; Kenya; Longitudinal Studies; Male; Schools; Students; Treatment Outcome
PubMed: 28179024
DOI: 10.1186/s40249-017-0244-z -
Drugs Jun 2021Soil-transmitted helminths (Ascaris lumbricoides, hookworm and Trichuris trichiura) infect about one-fifth of the world's population. The currently available drugs are... (Review)
Review
Soil-transmitted helminths (Ascaris lumbricoides, hookworm and Trichuris trichiura) infect about one-fifth of the world's population. The currently available drugs are all highly efficacious against A. lumbricoides. However, they are only moderately efficacious against hookworm and poorly efficacious against T. trichiura. Oxantel, a tetrahydropyrimidine derivative discovered in the 1970s, has recently been brought back to our attention given its high efficacy against T. trichiura infections (estimated 76% cure rate and 85% egg reduction rate at a 20 mg/kg dose). This review summarizes the current knowledge on oxantel pamoate and its use against T. trichiura infections in humans. Oxantel pamoate acts locally in the human gastrointestinal tract and binds to the parasite's nicotinic acetylcholine receptor (nAChR), leading to a spastic paralysis of the worm and subsequent expulsion. The drug is metabolically stable, shows low permeability and low systemic bioavailability after oral use. Oxantel pamoate was found to be safe in humans, with only a few mild adverse events reported. Several clinical trials have investigated the efficacy of this drug against T. trichiura and suggest that oxantel pamoate is more efficacious against T. trichiura than the currently recommended drugs, which makes it a strong asset to the depleted drug armamentarium and could help delay or even prevent the development of resistance to existing drugs. We highlight existing data to support the use of oxantel pamoate against T. trichiura infections.
Topics: Animals; Antinematodal Agents; Dose-Response Relationship, Drug; Drug Interactions; Hookworm Infections; Humans; Pyrantel Pamoate; Trichuris
PubMed: 33929716
DOI: 10.1007/s40265-021-01505-1 -
Parasites & Vectors Nov 2022The Geshiyaro project is a 5-year intervention to assess the impact of community- and school-based water, sanitation, and hygiene (WaSH) interventions on reducing...
BACKGROUND
The Geshiyaro project is a 5-year intervention to assess the impact of community- and school-based water, sanitation, and hygiene (WaSH) interventions on reducing infection with soil-transmitted helminths (STH) and schistosome parasites in combination with deworming in Wolayita zone, Ethiopia.
METHODS
A population-based, cross-sectional census and parasitological mapping activity was conducted between 2018 and 2019. Individuals in the census were identified using either a registered study ID card or biometric fingerprint to enable linkage of their household WaSH data with baseline STH and schistosome prevalence for risk analysis.
RESULTS
Prevalence of STH was 15.5% for any STH species, 9.47% for Ascaris lumbricoides, 1.78% for Trichuris trichiura, and 7.24% for hookworm. Intestinal schistosomiasis (Schistosoma mansoni) infection prevalence was 0.85% by Kato Katz, 21.6% by POC-CCA trace positive (Tr +), and 13.3% trace negative (Tr-). Microhaematuria was 2.77%, with 0.13% of people examined with S. haematobium eggs detected by urine filtration. At the household level, increased (> 30 min) time taken to collect drinking water, sharing a latrine, and lack of handwashing facilities were all associated with a greater risk of A. lumbricoides, hookworm, and S. mansoni infection. Not disposing of infant stool at the household and clothes washing/recreational freshwater contact were significantly associated with higher risk of schistosomiasis infection. Aggregating WaSH data at the community level showed odds of A. lumbricoides, hookworm, and T. trichiura infection were significantly lower as both community sanitation coverage and access to improved drinking water improved.
CONCLUSIONS
The principal finding of this study is that lack of access to WaSH, such as improved drinking water and shared toilet and hand-washing facilities, were linked to an increased risk of infection with STH and schistosome parasites. These associations are difficult to establish at an individual household level because of wide variability in access between houses but are detectable when coverage is aggregated at the community level. Maintenance of WaSH facilities as well as increased access within the whole community is important in influencing the community-wide prevalence of infection with STH and schistosome parasites.
Topics: Infant; Animals; Humans; Sanitation; Soil; Prevalence; Cross-Sectional Studies; Drinking Water; Ethiopia; Hygiene; Helminths; Hookworm Infections; Ancylostomatoidea; Schistosoma mansoni; Feces; Schistosomatidae; Helminthiasis
PubMed: 36333779
DOI: 10.1186/s13071-022-05465-7