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PLoS Neglected Tropical Diseases Jan 2022We previously demonstrated that serology holds promise as an alternative diagnostic tool to copromicroscopy to monitor and evaluate deworming programs targeting...
BACKGROUND
We previously demonstrated that serology holds promise as an alternative diagnostic tool to copromicroscopy to monitor and evaluate deworming programs targeting soil-transmitted helminths (STHs). Here we explored the dynamics of anti-Ascaris antibodies (Ab) and evaluated the Ab-isotype of choice to assess the longitudinal exposure to Ascaris in Ethiopian school children.
METHODOLOGY
Between October 2018 and February 2020, stool and blood samples were collected every four months from school children (4 to 6 years of age). Stool samples were analyzed by duplicate Kato-Katz to assess the presence and intensity of any STH infection. Plasma Ab-responses against the total extract of Ascaris suum lung third stage larvae were measured through in-house Ab-ELISA's for seven different Ab-isotypes.
PRINCIPAL FINDINGS
At baseline, 42.4% of the 66 children were excreting eggs of any STH, Trichuris (37.9%) being the most prevalent. The cumulative prevalence (proportion of children tested that positive at least once over the entire study period) was 56.1% for Trichuris and 31.8% for Ascaris. For Ascaris, re-infections were frequently observed, whereas for Trichuris, children often remained excreting eggs following drug administration. When measuring anti-Ascaris Ab-levels, the cumulative seroprevalence was generally higher (IgG4: 60.6%; IgG1: 50.0%; IgE: 36.4%). The individual anti-Ascaris IgG4 levels at baseline were positively associated with the fecal egg counts averaged over the study period, the rate of egg-appearance and the number of positive test results. There was no apparent cross-reactivity between the anti-Ascaris IgG4 Ab-ELISA and Trichuris.
CONCLUSIONS/SIGNIFICANCE
We demonstrate that the children are exposed to STH before the age of four and that the exposure to Ascaris is underestimated when measured with copromicroscopy. Compared to other Ab-isotypes, IgG4 is the Ab-isotype of choice to measure Ascaris exposure in STH endemic settings. Finally, the results also highlight that measuring anti-Ascaris IgG4 levels holds promise as a tool to identify individuals at higher risk for continued exposure to this STH.
Topics: Animals; Antibodies, Helminth; Ascariasis; Ascaris lumbricoides; Child; Child, Preschool; Ethiopia; Feces; Female; Humans; Immunoglobulin G; Male; Mass Screening; Schools; Soil
PubMed: 35041666
DOI: 10.1371/journal.pntd.0010131 -
International Archives of Allergy and... 2022Epidemiological studies have indicated that anti-Ascaris IgE enhances asthma and allergies under specific conditions although the association between them is still...
BACKGROUND
Epidemiological studies have indicated that anti-Ascaris IgE enhances asthma and allergies under specific conditions although the association between them is still controversial. The association of anti-Ascaris IgE with increased asthma symptoms among children from a general population with a mild to moderate Ascaris infection prevalence was investigated.
METHODS
A total of 126 children aged 5 years with wheezing during the previous year and 110 children who did not have wheezing were selected randomly from the rural service area of the International Centre for Diarrhoeal Disease Research, Bangladesh. Serum levels of total, anti-Ascaris, anti-Dermatophagoides pteronyssinus, and anti-cockroach IgEs were tested, and their risks for wheezing were analyzed. The wheezing children were then classified by hierarchical cluster analysis to investigate the contribution of anti-Ascaris IgE to wheezing.
RESULTS
The anti-Ascaris IgE levels in wheezing and never-wheezing children were 1.07 and 0.65 UA/mL, and it contributed to 11% of wheezing in children. Anti-Ascaris IgE was significantly associated with wheezing (odds ratio [OR] per loge increment: 1.37 [95% CI: 1.01-1.87], p = 0.046). The ORs, which were adjusted for sex, parental asthma, pneumonia history, helminth infections, Haemophilus influenzae type B combination vaccination, antibiotic use during infancy, and total and specific IgE levels, increased even when only children with more specific symptoms of asthma were included in the analysis. Namely, the ORs for wheezing with sleep disturbance, four or more attacks, and wheezing with speech difficulties during the previous 1 year were OR = 1.44/loge increment [95% CI: 1.01-2.07], OR = 1.90/loge increment [95% CI: 1.11-3.25], and OR = 1.78/loge increment [95% CI: 1.01-3.14], respectively.
CONCLUSIONS
The anti-Ascaris IgE levels in wheezing and never-wheezing children in the current study significantly decreased concurrently with Ascaris infection prevalence compared with their corresponding values in 2001. The contribution of anti-Ascaris IgE to wheezing also dropped from 26% in 2001 to 11% in the current study. Despite significant decreases in the levels and the seroprevalence and its contribution to wheezing, anti-Ascaris IgE remained significantly associated with increased risk of wheezing. Anti-Ascaris IgE significantly increased the risk of wheezing in a general population with a mild to moderate Ascaris infection prevalence, suggesting robustness as a risk factor and a possible dose-response relationship.
Topics: Animals; Ascariasis; Ascaris; Asthma; Bangladesh; Child, Preschool; Humans; Immunoglobulin E; Prevalence; Respiratory Sounds; Risk Factors; Seroepidemiologic Studies
PubMed: 35100597
DOI: 10.1159/000521717 -
Bulletin of Mathematical Biology Apr 2016The Anderson-May model of human parasite infections and specifically that for the intestinal worm Ascaris lumbricoides is reconsidered, with a view to deriving the...
The Anderson-May model of human parasite infections and specifically that for the intestinal worm Ascaris lumbricoides is reconsidered, with a view to deriving the observed characteristic negative binomial distribution which is frequently found in human communities. The means to obtaining this result lies in reformulating the continuous Anderson-May model as a stochastic process involving two essential populations, the density of mature worms in the gut, and the density of mature eggs in the environment. The resulting partial differential equation for the generating function of the joint probability distribution of eggs and worms can be partially solved in the appropriate limit where the worm lifetime is much greater than that of the mature eggs in the environment. Allowing for a mean field nonlinearity, and for egg immigration from neighbouring communities, a negative binomial worm distribution can be predicted, whose parameters are determined by those in the continuous Anderson-May model; this result assumes no variability in predisposition to the infection.
Topics: Animals; Ascariasis; Ascaris lumbricoides; Binomial Distribution; Digestive System; Humans; Mathematical Concepts; Models, Biological; Nonlinear Dynamics; Parasite Egg Count; Stochastic Processes
PubMed: 27066982
DOI: 10.1007/s11538-016-0164-2 -
Parasites & Vectors Dec 2023The synanthropic house fly (Musca domestica) can potentially contribute to the mechanical spread of eggs of Taenia and Ascaris spp. in the environment and between hosts....
BACKGROUND
The synanthropic house fly (Musca domestica) can potentially contribute to the mechanical spread of eggs of Taenia and Ascaris spp. in the environment and between hosts. However, the absence of validated protocols to recover eggs hampers an in-depth analysis of the house fly's role in parasite egg transmission.
METHODS
The gastrointestinal tract and exoskeleton of euthanized house flies were spiked with Taenia saginata eggs. The performance of several recovery protocols, in terms of both the recovery rate and ease-of-use, was (microscopically) evaluated and compared. These protocols employed steps such as washing, maceration, filtration, flotation and both passive and centrifugal sedimentation. The final validated protocols were subsequently evaluated for the recovery of Ascaris suum eggs.
RESULTS
The final protocol validated for the recovery of T. saginata eggs from the house fly's gastrointestinal tract involved homogenization in phosphate-buffered saline and centrifugation at 2000 g for 2 min, yielding a recovery rate of 79.7%. This protocol required 6.5 min to perform (which included 1.5 min of hands-on time) and removed large debris particles that could hinder the differentiation of eggs from debris. Similarly, the final protocol validated for the recovery of T. saginata eggs from the fly's exoskeleton involved washing by vortexing for 2 min in Tween 80 (0.05%), 15 min of passive sedimentation and centrifugation at 2000 g for 2 min, yielding a recovery rate of 77.4%. This protocol required 20.5 min to perform (which included 3.5 min of hands-on time) and successfully removed debris. The same protocols yielded recovery rates of 74.2% and 91.5% for the recovery of A. suum eggs from the fly's gastrointestinal tract and exoskeleton, respectively.
CONCLUSIONS
Effective, simple and easy-to-use protocols were developed and validated for the recovery of T. saginata and A. suum eggs from the house fly's gastrointestinal tract and exoskeleton. These protocols can be applied to investigate the importance of flies as parasite egg transmitters in laboratory and field settings.
Topics: Animals; Taenia saginata; Ascaris suum; Exoskeleton Device; Ovum; Houseflies; Gastrointestinal Tract; Parasite Egg Count
PubMed: 38110985
DOI: 10.1186/s13071-023-06077-5 -
Biomedicine & Pharmacotherapy =... Nov 2023Toosendanin (TSN), extracted from Melia. toosendan Sieb.et Zucc. and Melia. azedarach L., has been developed into an ascaris repellent in China. However, with the... (Review)
Review
Toosendanin (TSN), extracted from Melia. toosendan Sieb.et Zucc. and Melia. azedarach L., has been developed into an ascaris repellent in China. However, with the improvement of public health protection, the incidence of ascariasis has been reduced considerably, resulting in limited medical application of TSN. Therefore, it is questionable whether this old ascaris repellent can develop into a drug candidate. Modern studies have shown that TSN has strong pharmacological activities, including anti-tumor, anti-botulinum, anti-viral and anti-parasitic potentials. It also can regulate fat formation and improve inflammation. These researches indicate that TSN has great potential to be developed into a corresponding medical product. In order to better development and application of TSN, the availability, pharmacodynamics, pharmacokinetics and toxicology of TSN are summarized systematically. In addition, this review discusses shortcomings in the current researches and provides useful suggestions about how TSN developed into a drug candidate. Therefore, this paper illustrates the possibility of developing TSN as a medical product, aimed to provide directions for the clinical application and further research of TSN.
Topics: Animals; Humans; Ascaris; Drugs, Chinese Herbal; Neoplasms; China
PubMed: 37738795
DOI: 10.1016/j.biopha.2023.115541 -
PLoS Pathogens Nov 2021Human ascariasis is the most prevalent but neglected tropical disease in the world, affecting approximately 450 million people. The initial phase of Ascaris infection is...
Human ascariasis is the most prevalent but neglected tropical disease in the world, affecting approximately 450 million people. The initial phase of Ascaris infection is marked by larval migration from the host's organs, causing mechanical injuries followed by an intense local inflammatory response, which is characterized mainly by neutrophil and eosinophil infiltration, especially in the lungs. During the pulmonary phase, the lesions induced by larval migration and excessive immune responses contribute to tissue remodeling marked by fibrosis and lung dysfunction. In this study, we investigated the relationship between SIgA levels and eosinophils. We found that TLR2 and TLR4 signaling induces eosinophils and promotes SIgA production during Ascaris suum infection. Therefore, control of parasite burden during the pulmonary phase of ascariasis involves eosinophil influx and subsequent promotion of SIgA levels. In addition, we also demonstrate that eosinophils also participate in the process of tissue remodeling after lung injury caused by larval migration, contributing to pulmonary fibrosis and dysfunction in re-infected mice. In conclusion, we postulate that eosinophils play a central role in mediating host innate and humoral immune responses by controlling parasite burden, tissue inflammation, and remodeling during Ascaris suum infection. Furthermore, we suggest that the use of probiotics can induce eosinophilia and SIgA production and contribute to controlling parasite burden and morbidity of helminthic diseases with pulmonary cycles.
Topics: Animals; Ascariasis; Ascaris suum; Eosinophils; Female; Immunoglobulin A, Secretory; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Pneumonia; Toll-Like Receptor 2; Toll-Like Receptor 4
PubMed: 34784389
DOI: 10.1371/journal.ppat.1010067 -
Scientific Reports Mar 2022Soil-transmitted helminthiasis (STHs) and undernutrition are common health problems in developing countries. Several reports showed that STH and undernutrition are often...
Soil-transmitted helminthiasis (STHs) and undernutrition are common health problems in developing countries. Several reports showed that STH and undernutrition are often associated. The main aim of this study was to determine the association of STH and undernutrition among schoolchildren in Mettu town, Southwest Ethiopia. A cross-sectional study design was employed. To collect socio-demographic data, semi-structured questionnaire and physical observation were used. Kato-Katz technique and Anthropometric measurements were also considered to see STH infection and determine the nutritional statuses of the study participants respectively. Then, the data generated from the study was managed using Chi-square test and logistic regression analysis to determine the association of demographic variables with infections of helminthes and assess the risk factors for nutritional status of the study participants respectively. As a result, among the 392 study schoolchildren, 331 (84.4%) children were positive for different species of STH and undernutrition accounted 32.6%. Ascaris lumbricoides (39.0%), Trichuris trichiura (32.9%) and hookworm (28.1%) are the predominant STH identified from the study participants. Age, maternal educational and occupation status, and fingernail status of children were found significantly associated (p < 0.05) with the risk of getting STH. Bivariate logistic regression analysis showed that, age (AOR 2.18, 95% CI 1.53, 6.59), maternal illiteracy (AOR 0.13, 95% CI 0.91, 0.34) and maternal occupation (AOR 1.67, 95% CI 1.08, 5.91) were major co-founding factors for the prevalence of STH among study participants. In addition, children with T. trichiura infection were more likely (P < 0.01) to suffer from undernutrition (AOR 0.52, 95% CI 0.31, 0.83). Thus, the findings revealed the high prevalence of STH and it has significant association with undernutrition among school age children in the study area. Anti-helminthic mass drug administration and maternal health education should be anticipated to curve the tragedy.
Topics: Animals; Ascaris lumbricoides; Child; Cross-Sectional Studies; Ethiopia; Feces; Helminthiasis; Humans; Malnutrition; Prevalence; Soil
PubMed: 35256678
DOI: 10.1038/s41598-022-07669-4 -
Bio-protocol May 2017Preparing nuclei is necessary in a variety of experimental paradigms to study nuclear processes. In this protocol, we describe a method for rapid preparation of large...
Preparing nuclei is necessary in a variety of experimental paradigms to study nuclear processes. In this protocol, we describe a method for rapid preparation of large number of relatively pure nuclei from embryos or tissues that are ready to be used for further experiments such as chromatin isolation and ChIP-seq, nuclear RNA analyses, or preparation of nuclear extracts (Kang , 2016; Wang , 2016).
PubMed: 29082294
DOI: 10.21769/BioProtoc.2262 -
Parasites & Vectors Dec 2015Intestinal helminths do not cause severe diseases in general, however, when combined with other diseases such as immunodeficiency diseases, there would be massive...
Prevalence and risk factors of Ascaris lumbricoides (Linnaeus, 1758), Trichuris trichiura (Linnaeus, 1771) and HBV infections in Southwestern China: a community-based cross sectional study.
BACKGROUND
Intestinal helminths do not cause severe diseases in general, however, when combined with other diseases such as immunodeficiency diseases, there would be massive complications. Infections with Hepatitis B Virus (HBV) may lead to immunological disturbances and defects of cellular immunity and there is a need of clarification whether HBV infections are associated with infections with intestinal helminths.
METHODS
A community-based cross sectional study was conducted in Tezi town, Puge County of the Liangshan Prefecture, southwestern China from October 23rd to November 3rd, 2014. Four hundred and thirty eight people (median age = 37 years, IQR = 22-49) were enrolled in this study. Modified Kato-Katz thick smear was used to detect intestinal helminths. HBV DNA was quantified to confirm HBV infection.
RESULTS
Among the 438 participants, 9.1%, 13.5% and 30.6% were infected with HBV, A. lumbricoides (L., 1758) and T. trichiura (L., 1771), respectively; 7.1% (30/438) were infected with both A. lumbricoides and T. trichiura and 2.3% (10/438) were co-infected with HBV and A. lumbricoides. The multivariate logistic regression analysis showed that age (21-30 years versus >50 years: OR = 6.66, 95% CI = 2.15-20.68), drug abuse (OR = 6.96, 95% CI = 1.11-43.90), A. lumbricoides infection (OR = 3.60, 95% CI = 1.48-8.75), fertilization with faeces after disposal (OR = 0.15, 95% CI = 0.04-0.47) and working on a farm (OR = 4.59, 95% CI = 1.44-14.63) were significantly associated with HBV infection. Having toilets at home was negatively related to A. lumbricoides infection (OR = 0.52, 95% CI = 0.27-0.98) and T. trichiura infection (OR = 0.48, 95% CI = 0.28-0.80).
CONCLUSIONS
Ascaris lumbricoides was independently associated with HBV infection, and faeces might be the medium of HBV transmission. Improving hygiene conditions and habits are essential to reduce the risks of A. lumbricoides and T. trichiura infections.
Topics: Animals; Ascariasis; Ascaris lumbricoides; China; Cross-Sectional Studies; DNA, Viral; Hepatitis B; Hepatitis B virus; Humans; Prevalence; Risk Factors; Trichuriasis; Trichuris
PubMed: 26704345
DOI: 10.1186/s13071-015-1279-2 -
PLoS Neglected Tropical Diseases Apr 2022It remains largely unknown where and how infections with soil-transmitted helminths (STHs; Ascaris, Trichuris, Necator and Ancylostoma) occur. We therefore aimed to...
BACKGROUND
It remains largely unknown where and how infections with soil-transmitted helminths (STHs; Ascaris, Trichuris, Necator and Ancylostoma) occur. We therefore aimed to identify possible sources of infection by assessing the environmental contamination in an STH-endemic area.
METHODS
We first performed a series of laboratory experiments designed to optimize a soil straining-flotation method to detect and quantify Ascaris and Trichuris eggs in soil, and to validate the diagnostic performance of the optimized method when followed by microscopy and qPCR. In a second phase, we applied this method to assess the level of STH contamination in 399 environmental samples collected from 10 school compounds, 50 households and 9 open markets in Jimma Town (Ethiopia). Subsequently, we explored associations between the environmental contamination and both the corresponding STH epidemiology at the level of the schools and the household characteristics. Finally, we assessed the knowledge, attitude and practice (KAP) towards STHs in school children.
PRINCIPAL FINDINGS
Our soil straining-flotation method has an analytical sensitivity of 50 eggs per 100 grams of soil and egg recovery rate of 36.0% (Ascaris) and 8.0% (Trichuris). The analysis of field samples with both microscopy and qPCR revealed the presence of 8 different helminth species of medical importance, including but not limited to the human STHs. There was a significant association between the environmental contamination and prevalence of any STH infections at the school level only. The KAP indicated a lack of knowledge and awareness of STHs.
CONCLUSIONS/SIGNIFICANCE
Our optimized straining-flotation method has a moderate diagnostic performance and revealed that life stages of helminths are ubiquitous in the environment, which might be due to the poor sanitary facilities at both the schools and the households, and a poor level of KAP towards STHs. Further research is required to gain more insights into the contribution of these life stages to transmission.
Topics: Animals; Ascaris; Ascaris lumbricoides; Child; Ethiopia; Feces; Helminthiasis; Helminths; Humans; Prevalence; Soil; Trichuris
PubMed: 35377880
DOI: 10.1371/journal.pntd.0010307