Helminthes and Diseases

PLOS Neglected Tropical Diseases, 2012

A disproportionate burden of helminthiases in human populations occurs in marginalised, low-income, and resource-constrained regions of the world, with over 1 billion people in developing areas of sub-Saharan Africa, Asia, and the Americas infected with one or more helminth species. The morbidity caused by such infections imposes a substantial burden of disease, contributing to a vicious circle of infection, poverty, decreased productivity, and inadequate socioeconomic development. Furthermore, helminth infection accentuates the morbidity of malaria and HIV/AIDS, and impairs vaccine efficacy. Polyparasitism is the norm in these populations, and infections tend to be persistent. Hence, there is a great need to reduce morbidity caused by helminth infections. However, major deficiencies exist in diagnostics and interventions, including vector control, drugs, and vaccines. Overcoming these deficiencies is hampered by major gaps in knowledge of helminth biology and transmission dynamics, platforms from which to help develop such tools. The Disease Reference Group on Helminths Infections (DRG4), established in 2009 by the Special Programme for Research and Training in Tropical Diseases (TDR), was given the mandate to review helminthiases research and identify research priorities and gaps. In this review, we provide an overview of the forces driving the persistence of helminthiases as a public health problem despite the many control initiatives that have been put in place; identify the main obstacles that impede progress towards their control and elimination; and discuss recent advances, opportunities, and challenges for the understanding of the biology, epidemiology, and control of these infections. The helminth infections that will be discussed include: onchocerciasis, lymphatic filariasis, soil-transmitted helminthiases, schistosomiasis, food-borne trematodiases, and taeniasis/cysticercosis.

Advances in Experimental Medicine and Biology, 2014

The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.

International Journal for Parasitology, 2006

Pathogens frequently use vectors to facilitate transmission between hosts and, for vertebrate hosts, the vectors are typically ectoparasitic arthropods. However, other parasites that are intimately associated with their hosts may also be ideal candidate vectors; namely the parasitic helminths. Here, we present empirical evidence that helminth vectoring of pathogens occurs in a range of vertebrate systems by a variety of helminth taxa. Using a novel theoretical framework we explore the dynamics of helminth vectoring and determine which host-helminth-pathogen characteristics may favour the evolution of helminth vectoring. We use two theoretical models: the first is a population dynamic model amalgamated from standard macro-and microparasite models, which serves as a framework for investigation of within-host interactions between co-infecting pathogens and helminths. The second is an evolutionary model, which we use to predict the ecological conditions under which we would expect helminth vectoring to evolve. We show that, like arthropod vectors, helminth vectors increase pathogen fitness. However, unlike arthropod vectors, helminth vectoring increases the pathogenic impact on the host and may allow the evolution of high pathogen virulence. We show that concomitant infection of a host with a helminth and pathogen are not necessarily independent of one another, due to helminth vectoring of microparasites, with profound consequences for pathogen persistence and the impact of disease on the host population. q

Society for the Study of Human Biology, 2008

American Journal of Biomedical Sciences, 2018

Parasite is an organism living in, with, or on another organism in parasitism. Parasites are creatures that invade a host, attach themselves externally and internally (to tissues and organs), and rob the host of nutrients. Symptoms may occur immediately or take up to 20 years for symptoms to manifest. Why in some cases it could be asymptomatic. The presentation of signs and symptoms in some food and take anthelmintic at least one time diseases may involve with helminthic infection. If you are sick with unknown cause, helmenthic infection should be concern. Protection from helminthic infection by eating cooked.

Springer eBooks, 2018

Helminth infections are one of the most common infections of mankind. The nematode and trematode parasites cause almost ten million disability-adjusted life years (DALYs) worldwide. The worm burden and the resulting morbidities are largely restricted to the children and those mainly belonging to poor countries. Although preventive chemotherapy is the most common method of treatment, it is associated with high-intensity recurrent infections. Therefore, the preventive strategies such as water, sanitation and health education along with chemotherapy are required to completely eliminate the soil-transmitted helminth (STH) infections. The frequent use of anthelmintic drugs because of reinfections results in their diminished efficacy leading to drug resistance. Therefore, mass drug administration is not an effective measure to combat STH infections. In such cases, vaccine too proves ineffective because these parasites often evade or modify the immune responses. Therefore, the approach now is to control the disease by reducing the worm burden below threshold level. Keywords Disease burden • Epidemiology • Helminths • Neglected tropical diseases • Soil-transmitted helminths • Vaccination 8.1 Introduction Water is a vital resource to life on the planet Earth. Early civilizations sprang fast mainly in the fertile flood plains along the banks of the rivers (Keddy 2000). According to US Geological Survey, freshwater habitats including lakes, rivers, swamps, etc. constitute about 0.3% of the total water of the world. Due to an increasing demand and pressures, these habitats have been overexploited and degraded. This was largely because of the lack of understanding of their nature and dynamics. Water quality is nowadays a major issue with drinking water sources in developing world getting scarcer as well as contaminated, thus impacting the health, economic

Immunology, 2009

JURNAL Al-AZHAR INDONESIA SERI SAINS DAN TEKNOLOGI

In Indonesia, the prevalence of helminthiasis is still high, especially in children. The frequency is 60-70% in populations at risk. The lack of use of family latrines causes soil contamination with feces around the yard. There are still few articles that review the morphology of worms that cause infectious diseases in Indonesia. Whereas knowledge of morphology is important to understand the life cycle of worms that play a role in disease transmission in humans and mammals. This article aims to discuss the latest findings regarding the morphology of worms that cause infectious diseases in humans. It can be concluded that at the adult stage, worms can be sexed. Usually, the female type has a relatively larger size than the male. On the head (anterior) there are 3 lips that have sensor papillae, one on the mediodorsal and 2 on the ventrolateral. Between the 3 lips there is a bucal cavity which is triangular in shape and functions as a mouth.Keywords - Morphology, Helminth, Infectious ...

Immunological Reviews, 2004

We extend particular thanks to Maria Yazdanbakhsh (Leiden University) for interactive discussions and concepts, and generous help with material for figures. Summary: Immune regulation by parasites is a global concept that includes suppression, diversion, and conversion of the host immune response to the benefit of the pathogen. While many microparasites escape immune attack by antigenic variation or sequestration in specialized niches, helminths appear to thrive in exposed extracellular locations, such as the lymphatics, bloodstream, or gastrointestinal tract. We review here the multiple layers of immunoregulation that have now been discovered in helminth infection and discuss both the cellular and the molecular interactions involved. Key events among the host cell population are dominance of the T-helper 2 cell (Th2) phenotype and the selective loss of effector activity, against a background of regulatory T cells, alternatively activated macrophages, and Th2-inducing dendritic cells. Increasingly, there is evidence of important effects on other innate cell types, particularly mast cells and eosinophils. The sum effect of these changes to host reactivity is to create an anti-inflammatory environment, which is most favorable to parasite survival. We hypothesize therefore that parasites have evolved specific molecular strategies to induce this conducive landscape, and we review the foremost candidate immunomodulators released by helminths, including cytokine homologs, protease inhibitors, and an intriguing set of novel products implicated in immune suppression.

Trends in Parasitology, 2012

Knowledge of pattern and process in helminth population biology is mostly based on the endemic equilibrium state that characterises infections before control. Current large-scale intervention programmes aim at controlling/eliminating helminth infection, transmission and morbidity. As a result, age-infection profiles will be modified; immune responses will be affected; underlying parasite distributions may become more aggregated; density-dependent regulatory processes will relax; and the contribution to transmission and morbidity of different host population groups will shift. There is an urgent need to understand how the paradigm that has guided parasite population biology research is changing under chemotherapy-based control programmes for this research to continue supporting parasite control efforts effectively.