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Journal of Tropical Medicine 2023School-age children (SAC) are at a higher risk of geohelminth or soil-transmitted helminth (STH) infections due to their practice of walking and playing barefoot, lack...
School-age children (SAC) are at a higher risk of geohelminth or soil-transmitted helminth (STH) infections due to their practice of walking and playing barefoot, lack of adequate sanitary facilities, and poor personal hygiene. In Ethiopia, periodic deworming has been implemented since 2013 with the aim of interrupting the transmission of STH in children by 2025. To evaluate the likely success of such a control program, it is crucial to monitor the transmission of STH, especially in peri-urban settings where environmental sanitation is modest. The aim of this study was to determine the prevalence and determinants of STH infections among SAC in peri-urban areas of Jimma City, Southwestern Ethiopia. A community-based cross-sectional study was conducted in five peri-urban of Jimma City from July to September, 2021. Systematic random sampling was used to select 522 households with at least one child, and 478 children (5-15 years old) were recruited randomly from the households. Data on sociodemographic and potential risk factors were collected using a structured questionnaire. Stool samples from each study participant were collected and examined microscopically using the Kato-Katz technique. Multivariate logistic regression model was used to identify risk factors associated with STH infections. The prevalence of any STH among SAC was 23.4%, with being the predominant STH species (15.7%), followed by (9%) and hookworm (2.1%). Most (86.6%) of the STH-positive SAC had a single infection and a light infection intensity (88.2%), with a mean intensity of 367.4 eggs per gram. Location of (AOR = 2.73; 95% CI: 1.21-6.16, =0.016), lack of hand washing after defecation (AOR = 6.39; 95% CI: 3.16-12.95, < 0.001), untrimmed fingernails (AOR = 2.65; 95% CI: 1.56-4.51, < 0.001), and lack of previous deworming (AOR = 2.90; 95% CI: 1.47-5.74, =0.002) were significant predictors for STH infections among SAC. In conclusion, the study revealed that STH infections are significant health problem in the peri-urban areas of Jimma City. Strengthening periodic deworming and improving children's hygiene through health education are required to reduce the transmission.
PubMed: 38058563
DOI: 10.1155/2023/8811795 -
The Lancet. Microbe Dec 2023Vaccine development against hookworm is hampered by the absence of the development of protective immunity in populations repeatedly exposed to hookworm, limiting... (Randomized Controlled Trial)
Randomized Controlled Trial
Protective efficacy of short-term infection with Necator americanus hookworm larvae in healthy volunteers in the Netherlands: a single-centre, placebo-controlled, randomised, controlled, phase 1 trial.
BACKGROUND
Vaccine development against hookworm is hampered by the absence of the development of protective immunity in populations repeatedly exposed to hookworm, limiting identification of mechanisms of protective immunity and new vaccine targets. Immunisation with attenuated larvae has proven effective in dogs and partial immunity has been achieved using an irradiated larvae model in healthy volunteers. We aimed to investigate the protective efficacy of immunisation with short-term larval infection against hookworm challenge.
METHODS
We did a single-centre, placebo-controlled, randomised, controlled, phase 1 trial at Leiden University Medical Center (Leiden, Netherlands). Healthy volunteers (aged 18-45 years) were recruited using advertisements on social media and in publicly accessible areas. Volunteers were randomly assigned (2:1) to receive three short-term infections with 50 infectious Necator americanus third-stage filariform larvae (50L3) or placebo. Infection was abrogated with a 3-day course of albendazole 400 mg, 2 weeks after each exposure. Subsequently all volunteers were challenged with two doses of 50L3 at a 2-week interval. The primary endpoint was egg load (geometric mean per g faeces) measured weekly between weeks 12 and 16 after first challenge, assessed in the per-protocol population, which included all randomly assigned volunteers with available data on egg counts at week 12-16 after challenge. This study is registered with ClinicalTrials.gov, NCT03702530.
FINDINGS
Between Nov 8 and Dec 14, 2018, 26 volunteers were screened, of whom 23 enrolled in the trial. The first immunisation was conducted on Dec 18, 2018. 23 volunteers were randomly assigned (15 to the intervention group and eight to the placebo group). Egg load after challenge was lower in the intervention group than the placebo group (geometric mean 571 eggs per g [range 372-992] vs 873 eggs per g [268-1484]); however, this difference was not statistically significant (p=0·10). Five volunteers in the intervention group developed a severe skin rash, which was associated with 40% reduction in egg counts after challenge (geometric mean 742 eggs per g [range 268-1484] vs 441 eggs per g [range 380-520] after challenge; p=0·0025) and associated with higher peak IgG1 titres.
INTERPRETATION
To our knowledge, this is the first study to describe a protective effect of short-term exposure to hookworm larvae and show an association with skin response, eosinophilic response, and IgG1. These findings could inform future hookworm vaccine development.
FUNDING
Dioraphte Foundation.
Topics: Humans; Animals; Dogs; Necator americanus; Healthy Volunteers; Netherlands; Hookworm Infections; Immunoglobulin G; Larva
PubMed: 38042152
DOI: 10.1016/S2666-5247(23)00218-5 -
International Journal of Paleopathology Mar 2024Cribra orbitalia is believed to be a skeletal indicator of chronic anaemia, scurvy, rickets or related metabolic diseases. It has been suggested that it may be used as a...
OBJECTIVE
Cribra orbitalia is believed to be a skeletal indicator of chronic anaemia, scurvy, rickets or related metabolic diseases. It has been suggested that it may be used as a proxy indicator for intestinal parasite infection, as parasites often cause anaemia today. Our aim is to investigate this association in the medieval population of Cambridge, UK.
MATERIALS
Individuals excavated from the cemeteries of the Augustinian friary and All Saints by the Castle parish church, and aged from 7 to adulthood.
METHODS
We undertook parasite analysis of the pelvic sediment and control samples of 46 burials with intact orbital roofs.
RESULTS
Human roundworm (Ascaris lumbricoides) and/or whipworm (Trichuris trichiura) were identified in the pelvic sediment of 22 individuals, and cribra orbitalia noted in 11 individuals. Barnards test showed no association between parasite infection and cribra orbitalia (p = .882).
CONCLUSION
We found no association between infection and cribra orbitalia infection in this medieval adult population, calling into question this hypothesis, at least for adults.
SIGNIFICANCE
High or low cribra orbitalia prevalence in adults should not be used to infer rates of intestinal parasite infection.
LIMITATIONS
The individuals in the study were over the age of 7, with no younger children. It is possible that only parasites which cause marked anaemia (such as hookworm, schistosomiasis or malaria) may cause cribra orbitalia, while less marked anaemia from roundworm and whipworm may not do so.
SUGGESTIONS FOR FURTHER RESEARCH
Repeating this study in younger children, when most cribra orbitalia appears to form.
Topics: Adult; Child; Humans; Orbit; Intestinal Diseases, Parasitic; Rickets; Anemia; United Kingdom
PubMed: 38039702
DOI: 10.1016/j.ijpp.2023.11.001 -
Parasitology Jan 2024Hookworm infection affects millions globally, leading to chronic conditions like malnutrition and anaemia. Among the hookworm species, stands out as a generalist,...
Hookworm infection affects millions globally, leading to chronic conditions like malnutrition and anaemia. Among the hookworm species, stands out as a generalist, capable of infecting various hosts, including humans, cats, dogs and hamsters. Surprisingly, it cannot establish in mice, despite their close phylogenetic relationship to hamsters. The present study investigated the development of in immunodeficient NSG mice to determine the contribution of the immune system to host restriction. The infections became patent on day 19 post-infection (PI) and exhibited elevated egg production which lasted for at least 160 days PI. Infective larvae reared from eggs released by infected NSG mice were infectious to hamsters and capable of reproduction, indicating that the adults in the NSG mice were producing viable offspring. In contrast, showed limited development in outbred Swiss Webster mice. Furthermore, the closely related canine hookworm was unable to infect and develop in NSG mice, indicating that different mechanisms may determine host specificity even in closely related species. This is the first report of any hookworm species completing its life cycle in a mouse and implicate the immune system in determining host specificity in .
Topics: Humans; Cricetinae; Adult; Animals; Dogs; Mice; Ancylostoma; Ancylostomatoidea; Phylogeny; Hookworm Infections; Host Specificity
PubMed: 38018393
DOI: 10.1017/S0031182023001208 -
Tropical Medicine and Health Nov 2023Helminth infections are a public health issue in countries with poor sanitation facilities. However, there little information on the epidemiological association between...
BACKGROUND
Helminth infections are a public health issue in countries with poor sanitation facilities. However, there little information on the epidemiological association between helminths in wastewater and soil samples and rates of helminth infection among farming households along the Akaki River in Addis Ababa, Ethiopia.
METHODS
A cross-sectional study was conducted between November 2021 and February 2022. A stratified random sampling technique was used to select farming households. The sample size for each district was determined by a proportionate allocation to the number of households. From wastewater-irrigated farms, 70 wastewater samples, 28 soil samples, and 86 farmers' stool samples were collected and analyzed for helminths. A questionnaire was used to gather ethnographic data, about farming households, whereas wastewater and soil sample analysis was used to generate quantitative data on helminth loads. The data were systematically analysed by developing themes, and bias evaluated using triangulation validation methodologies. Potential pathways to helminth infection were evaluated by measuring. Total number of helminth eggs in wastewater, soil samples and farmer's stools was investigated using Poisson regression.
RESULTS
In this study, 82.9% of wastewater samples, 57.1% of soil samples, and 18.6% of farmers' stool samples contained helminth eggs. The most prevalent helminth was Ascaris lumbricoides in all samples (wastewater 67%, soil 25%, and stool 10.5%), followed by hookworm (wastewater 10%, soil 21.4%, and stool 6.9%) and Trichuris trichiura eggs (wastewater 5.7%, soil 10.7%, and stool 1.2%). There was a positive association between the total number of helminth eggs in wastewater and soil samples with counts in farmers' stool. The Poisson regression coefficients for wastewater and soil were, 1.63 (95% CI = 1.34-1.92) and 1.70 (95% CI = 1.39-2.01), (p < 0.05).
CONCLUSIONS
This research has shown a clear association between the total helminth eggs in wastewater and soil samples and farmer stools along the Akaki River. Therefore, an integrated approach is essential to address the issue in this area and prevent the spread of further helminth infections.
PubMed: 37996901
DOI: 10.1186/s41182-023-00558-0 -
Acta Parasitologica Mar 2024Hookworms are blood-feeding nematodes that infect millions of people and animals worldwide. The most common species infecting dogs in Europe are representatives of the...
BACKGROUND
Hookworms are blood-feeding nematodes that infect millions of people and animals worldwide. The most common species infecting dogs in Europe are representatives of the family Ancylostomatidae, which differ in invasiology, biology and morphological features. However, the differentiation of invasions of species such as Uncinaria stenocephala and Ancylostoma caninum based on a coproscopic examination is problematic. For this reason, it is recommended to use molecular diagnostics for this purpose. The authors of the article investigated the prevalence of U. stenocephala in dogs kept in various living conditions in Slovakia and developed a two-step morphology-molecular analysis-based strategy to identify the genus and the species of eggs and larvae of the Ancylostomatidae family in dogs.
CONCLUSIONS
In our opinion, this work is very much needed as it shows how to effectively diagnose hookworm infestations. However, we do not agree with the information in the title of the article because such studies have already been carried out in Central Europe by other authors.
Topics: Animals; Dogs; Dog Diseases; Hookworm Infections; Ancylostomatoidea; Slovakia; Prevalence; Larva; DNA, Helminth; Feces
PubMed: 37991680
DOI: 10.1007/s11686-023-00737-3 -
Emerging Infectious Diseases Dec 2023Recent reports of hookworm infection in Alabama, USA, has prompted surveillance in Mississippi, given the states' similar environmental conditions. We collected stool...
Recent reports of hookworm infection in Alabama, USA, has prompted surveillance in Mississippi, given the states' similar environmental conditions. We collected stool specimens from 277 children in Rankin County, Mississippi. Kato-Katz microscopic smear, agar plate culture, and quantitative PCR indicated no soil-transmitted helminths. Nevertheless, further surveillance in other high-risk Mississippi counties is warranted.
Topics: Child; Animals; Humans; Soil; Mississippi; Feces; Prevalence; Helminths
PubMed: 37987591
DOI: 10.3201/eid2912.230709 -
PLoS Neglected Tropical Diseases Nov 2023Intestinal helminth infections are among the most common infections worldwide and have a negative impact on the health, education, nutrition and economic development of...
BACKGROUND
Intestinal helminth infections are among the most common infections worldwide and have a negative impact on the health, education, nutrition and economic development of affected populations. This study aimed to estimate the prevalence of intestinal helminthiasis, including T. solium taeniasis, using a large-scale community-based study in Chiparamba area of Chipata District in the Eastern province of Zambia.
METHODS/PRINCIPAL FINDINGS
A cross-sectional study was conducted between June 2019 and December 2022 in a rural community of 25 randomly selected villages known to be at risk for T. solium infection. Stool samples were examined for intestinal helminths using the formol-ether concentration technique and further tested for taeniasis by copro antigen-ELISA (copro Ag-ELISA). Descriptive statistical analyses were conducted, and associations between the disease prevalence of active infections and individual- and village-level variables were determined using the chi-square or Fisher's exact test. Predictors of an individual being positive for either taeniasis or other soil-transmitted helminths were determined using binary logistic regression. A total of 2762 stool samples were examined. One hundred ninety-five (7.1%) tested positive for at least one helminthic parasite on microscopy, with hookworm being the most frequent 84 (3.0%), followed by S. mansoni, 66 (2.4%). For taeniasis, 11 (0.4%) participants were positive for Taenia spp. microscopically, while 241 (8.7%) tested positive via copro Ag-ELISA. On bivariate analysis, male sex was significantly associated with the prevalence of intestinal parasites (p = 0.012) but not with that of taeniasis based on copro Ag-ELISA results. Village level differences were significant for infection with intestinal helminths as well as for taeniasis positivity on copro Ag-ELISA (p <0.001).
CONCLUSION
Intestinal helminths, including T. solium taeniasis, are prevalent in Chiparamba area of Chipata district in the eastern province of Zambia, supporting the clear need for further targeted public health interventions for surveillance and control.
Topics: Animals; Humans; Male; Zambia; Cross-Sectional Studies; Taenia solium; Taeniasis; Helminthiasis; Helminths; Prevalence; Feces
PubMed: 37983246
DOI: 10.1371/journal.pntd.0011561 -
JMIR Public Health and Surveillance Nov 2023Soil-transmitted helminths (STHs) are widely distributed throughout the world. Various factors, including the environment, socioeconomic characteristics, and access to...
BACKGROUND
Soil-transmitted helminths (STHs) are widely distributed throughout the world. Various factors, including the environment, socioeconomic characteristics, and access to water and sanitation, play an important role in the spread and persistence of these parasites within communities. They, in turn, affect the growth and development of members of the community, especially children. Studies in the northern provinces of Argentina have shown variable prevalence of STHs, but the factors associated with their presence have not been completely elucidated.
OBJECTIVE
This cross-sectional study aimed to identify the socioeconomic and environmental factors related to STH infection in indigenous villages located in Puerto Iguazú (Misiones), Argentina.
METHODS
Between 2018 and 2019, stool samples were collected from individuals ≥1 year residing in 3 villages: Mini-Marangatú, Yriapú, and Fortín Mbororé. Standard parasitological methods were used to determine STH prevalence. Standardized questionnaires were used to assess participants' habits, customs, and household characteristics, and environmental data were obtained through satellite imagery. Multilinear regression with Akaike information criterion stepwise variables was used to explore relevant associations.
RESULTS
A total of 342 individuals from the 3 villages participated in this study. The prevalence of STHs varied across villages: 89.6% (43/48), in Mini-Marangatú, 80.8% (101/125) in Yriapú, and 68.5% (115/169) in Fortín Mbororé. Notably, there was a significant difference in hookworm infection among the villages (P=.02). The analysis highlighted the significant influence of specific environmental factors on STH presence and spatial distribution, particularly in relation to hookworm infection. Vegetation patterns represented by the Vegetation Heterogeneity Index, created ad hoc for this study, emerged as a critical factor, with 2 significant predictors related to it (P=.002 and P=.004) alongside impervious surface density with a significant predictor (P<.001). The multilinear regression model yielded a high F test score (F=4.75, P<.001), indicating a strong fit (R=0.5465). Furthermore, socioeconomic factors, including walking barefoot in houses with dirt floors and overcrowding, were significantly correlated with hookworm infection intensity (P<.001 and P=.001, respectively). We also used the multilinear regression model to calculate hookworm infection intensity (F=21.15, P<.001; R=0.4971).
CONCLUSIONS
Our study underscores the complexity of STH transmission, as villages with similar living conditions and environmental characteristics displayed varied STH prevalence and spatial distribution. Specific environmental factors, such as vegetation pattern and impervious surface density, played major roles in STH presence, demonstrating the crucial relationship between environmental factors and hookworm infection distribution. Moreover, our findings emphasize the significant influence of socioeconomic factors on hookworm infection intensity. By gaining insights into this complex interplay, our research contributes to a better understanding of STH transmission characteristics, thereby informing targeted public health interventions for effective control.
Topics: Child; Humans; Cross-Sectional Studies; Argentina; Public Health; Sanitation; Hookworm Infections
PubMed: 37934580
DOI: 10.2196/41568 -
PLoS Neglected Tropical Diseases Nov 2023In Bangladesh, preventive chemotherapy targeting soil-transmitted helminth (STH) infections in school-age children has been implemented since 2008. To evaluate the...
BACKGROUND
In Bangladesh, preventive chemotherapy targeting soil-transmitted helminth (STH) infections in school-age children has been implemented since 2008. To evaluate the success of this strategy, surveys were conducted between 2017 and 2020 in 10 out of 64 districts. We estimate the geographic distribution of STH infections by species at high spatial resolution, identify risk factors, and estimate treatment needs at different population subgroups.
METHODOLOGY
Bayesian geostatistical models were fitted to prevalence data of each STH species. Climatic, environmental, and socioeconomic predictors were extracted from satellite images, open-access, model-based databases, and demographic household surveys, and used to predict the prevalence of infection over a gridded surface at 1 x 1 km spatial resolution across the country, via Bayesian kriging. These estimates were combined with gridded population data to estimate the number of required treatments for different risk groups.
PRINCIPAL FINDINGS
The population-adjusted prevalence of Ascaris lumbricoides, Trichuris trichiura, and hookworm across all ages is estimated at 9.9% (95% Bayesian credible interval: 8.0-13.0%), 4.3% (3.0-7.3%), and 0.6% (0.4-0.9%), respectively. There were 24 out of 64 districts with an estimated population-adjusted STH infection prevalence above 20%. The proportion of households with improved sanitation showed a statistically important, protective association for both, A. lumbricoides and T. trichiura prevalence. Precipitation in the driest month of the year was negatively associated with A. lumbricoides prevalence. High organic carbon concentration in the soil's fine earth fraction was related to a high hookworm prevalence. Furthermore, we estimated that 30.5 (27.2; 36.0) million dosages of anthelmintic treatments for school-age children were required per year in Bangladesh.
CONCLUSIONS/SIGNIFICANCE
For each of the STH species, the prevalence was reduced by at least 80% since treatment was scaled up more than a decade ago. The current number of deworming dosages could be reduced by up to 61% if the treatment strategy was adapted to the local prevalence.
Topics: Child; Animals; Humans; Soil; Bayes Theorem; Bangladesh; Helminthiasis; Hookworm Infections; Helminths; Ancylostomatoidea; Ascaris lumbricoides; Prevalence; Feces
PubMed: 37930980
DOI: 10.1371/journal.pntd.0011656