Current Topics Ingiardiasis

Giardiasis is still a significant infectious and parasitic disease, caused by the protozoan Giardia intestinalis. There are estimates of more than 200 million cases of giardiasis occurred in the world annually. The advance in research in giardiasis during the last century and particularly during the last decade is considerable. Nevertheless, many challenges still are ahead in order to reach a higher control of this disease. This book tried to update the significant epidemiological and clinical research in many aspects with a multinational perspective. This book with 9 chapters has been organized in 3 major sections: 1. "Overview, Epidemiology and Clinical Aspects," 2. "Biological and Diagnostic Aspects," and 3. "Treatment, Prevention and Public Health."

Giardia is a relatively simple eukaryotic microbe, causing acute and chronic diarrhea which has been used as a model to understand complex biological processes occurring in eukaryotic cells. Further, due to its parasitic lifestyle, Giardia is an excellent system for the study of the mechanisms of adaptation and cell differentiation from the perspectives of molecular and cell biology. This book presents a comprehensive review of the current state of knowledge regarding all aspects of Giardia’s biology, including epidemiology, cell and molecular biology, genetics, pathogenesis, diagnostics, and clinical treatment. It was written by internationally renowned authors, the leading researchers in the field including several chapters with techniques and resources available for the study of this microorganism. Questions that need to be addressed to fully understand the molecular mechanisms of the parasite as well as the cause of its pathology are presented. Furthermore, Giardia’s biology is compared with that of other parasites in relation to their complexity. This volume is an indispensable resource for researchers working with this parasite. It is a “must” for libraries and the bookshelves of everyone interested in the biology of parasites and early-branching eukaryotes.

Giardia and Giardiasis, Volume 106 in Advances in Parasitology series includes in the first part aspects of molecular and cellular biology of Giardia and the role of particular molecules or molecular groups in essential functions and/or trafficking in the parasite. These approaches are with the aim to explore how this parasite adapts to an ever-changing environment both within and outside of the host animal. Subsequently a comprehensive description of virulence factors secreted by Giardia, are reviewed on their cytotoxic mechanisms and roles in the pathophysiology of giardiasis, and also a description on the potential of these secreted molecules as targets for drugs is included. In the context of the immuno-pathogenesis of giardiasis a review on the data and information on innate and adaptive immunity to Giardia, is included as well as a discussion on how improved knowledge of immunity is advancing our understanding of the pathogenesis and clinical outcomes of giardiasis. The final part of this volume includes a review of the epidemiology of giardiasis in a veterinary context using molecular tools together with a discussion of the current status of the species and assemblages of Giardia, and issues surrounding the assignment of host specificity and the zoonotic potential using current molecular markers. Informs and updates on all the latest developments in the field of parasitology Includes medical studies of parasites of major influence Features reviews of more traditional areas, such as zoology, taxonomy, and life history, which help to shape current thinking and applications

This book examines the two major parasite groups that are transmitted via water or foods: the single-celled protozoa, and the helminths: cestodes (tapeworms), nematodes (round worms), and trematodes (flukes). Each chapter covers the biology, mechanisms of pathogenesis, epidemiology, treatment, and inactivation of these parasites. This important new text offers a better understanding of the biology and control of parasitic infections necessary to reduce or eliminate future outbreaks in the U.S. and elsewhere.

One of the top four contributors to the global burden of disease is diarrheal infections. Intestinal parasites are major causes of morbidity and mortality associated with diarrheal diseases in both the developed and developing world. Amebiasis is responsible for 50 million cases of invasive disease and 70,000 deaths annually in the world. Giardiasis has an estimated worldwide prevalence of 280 million cases annually. In developed countries, Giardia lamblia infects about 2% of adults and 6-8% of children. The prevalence of G. lamblia infection is generally higher in developing countries, ranging from 3% to 90%. Furthermore, giardial infections contribute substantially to the 2.5 million annual deaths from diarrheal disease. In Asia, Africa, and Latin America, about 500,000 new giardiasis cases are reported each year. Cryptosporidium accounts for 20% and 9% of diarrheal episodes in children in developing and developed countries, respectively. Infection with Cryptosporidium can be chronic and especially debilitating in immunosuppressed individuals and malnourished children. A recent study to measure disease burden, based on disability-adjusted life years (DALYs), found that cryptosporidiosis and amebiasis produce about 10.6 million DALYs. This exceeds the DALYs of any helminth infection currently being targeted by the World Health Organization for preventive chemotherapy. Because of its link with poverty, Giardia and Cryptosporidium were included in the WHO Neglected Diseases Initiative in 2004. E. histolytica, G. lamblia, and C. parvum have been listed by the National Institutes of Health (NIH) as category B priority biodefense pathogens due to low infectious dose and potential for dissemination through compromised food and water supplies in the United States. Despite the prevalence of amebiasis, giardiasis, and cryptosporidiosis there are no vaccines or prophylactic drugs. The first-line drugs for invasive amebiasis and giardiasis chemotherapy are nitroimidazoles, with the prototype, metronidazole, being the most common drug used worldwide. Metronidazole has been shown to be both mutagenic in a microbiological system and carcinogenic to rodents, and frequently causes gastrointestinal side effects. In spite of the efficacy of nitroimidazole drugs, treatment failures in giardiasis occur in up to 20% of cases. Clinical resistance of G. lamblia to metronidazole is proven and cross resistance is a concern with all commonly used antigiardial drugs. Nitazoxanide, the only FDA-approved drug for the treatment of cryptosporidiosis, is effective in the treatment of immunocompetent patients and partially effective for immunosuppressed patients. Therefore, it is critical to search for more effective drugs to treat amebiasis, giardiasis, and cryptosporidiosis. This Research Topic for Frontiers in Microbiology will explore the recent progress in drug development for parasitic diarrheal diseases. This includes an understanding of drug resistance mechanisms. We would also welcome submissions on the drug development for other diarrheal parasites. We hope that this research topic will include a comprehensive survey of various attempts by the parasitology research community to create effective drugs for these diseases.

Neglected tropical diseases (NTDs) is a diverse group of communicable diseases that prevail in tropical and subtropical conditions in 149 countries. NTDs affect more than one billion people and cost developing economies billions of dollars every year. According to the World Health Organization (WHO), NTDs mainly affect populations living in poverty, without adequate sanitation, and in close contact with infectious vectors, domestic animals, and livestock. Migration, as well as climate change and variability, are key factors in NTD prevalence. Therefore, NTDs deserve more study. Recently, viruses transmitted by vectors (arboviruses) that affect not only people living in the tropics, but also travelers and migrating populations, have been causing epidemics. Examples of these viruses include Dengue, Chikungunya, Zika, Mayaro, and encephalitis viruses. These viruses emerge and reemerge in multiple regions of the world, as occurred in the Americas recently (2013-2017) with Chikungunya and Zika. This book aims to update the significant epidemiological and clinical research of NTDs in many aspects with a multinational perspective.

New emerging diseases, new diagnostic modalities for resource-poor settings, new vaccine schedules ... all significant, recent developments in the fast-changing field of tropical medicine. Hunter’s Tropical Medicine and Emerging Infectious Diseases, 10th Edition, keeps you up to date with everything from infectious diseases and environmental issues through poisoning and toxicology, animal injuries, and nutritional and micronutrient deficiencies that result from traveling to tropical or subtropical regions. This comprehensive resource provides authoritative clinical guidance, useful statistics, and chapters covering organs, skills, and services, as well as traditional pathogen-based content. You’ll get a full understanding of how to recognize and treat these unique health issues, no matter how widespread or difficult to control. Includes important updates on malaria, leishmaniasis, tuberculosis and HIV, as well as coverage of Ebola, Zika virus, Chikungunya, and other emerging pathogens. Provides new vaccine schedules and information on implementation. Features five all-new chapters: Neglected Tropical Diseases: Public Health Control Programs and Mass Drug Administration; Health System and Health Care Delivery; Zika; Medical Entomology; and Vector Control – as well as 250 new images throughout. Presents the common characteristics and methods of transmission for each tropical disease, as well as the applicable diagnosis, treatment, control, and disease prevention techniques. Contains skills-based chapters such as dentistry, neonatal pediatrics and ICMI, and surgery in the tropics, and service-based chapters such as transfusion in resource-poor settings, microbiology, and imaging. Discusses maladies such as delusional parasitosis that are often seen in returning travelers, including those making international adoptions, transplant patients, medical tourists, and more.