Malaria Transmission Biology


Book Description

The malaria parasite life cycle is complex and includes an obligatory developmental stage in its mosquito vector host. This transition from human-host to mosquito-host to human-host involves multiple developmental stages and divergent host tissues. Over the years, the research focus on the asexual stage parasites, which causes the symptoms of the disease, has transitioned towards a renewed focus on the transmission forms (or gametocytes), the only stages transmittable to the mosquito vector through ingestion of an infected blood meal. Analysis of sporozoite-liver interactions that result in the establishment of parasitic infection in the mammalian host has become an important research focus, and we now have a greater appreciation of the fascinating development of the sporozoites of the mosquito midgut wall and its travel to the salivary glands prior to inoculation into the mammalian dermis. This Research Topic embraces the full transition of the malaria parasite between its two obligatory hosts in what is termed as “malaria transmission biology”. Of note are the critical, enabling technologies and experimental systems that have been developed over the recent decade and have opened up significant new avenues for exploring the multi-stage, and multi-step processes that comprise malaria transmission biology. From uncovering that gametocyte development occurs in the bone marrow to quantifying the influence of both human host metabolism and parasite genetics on mosquito infection, it is clear that malaria transmission biology has entered an exciting era of discovery. Importantly, recent maturation of humanized liver mice and more sophisticated in vitro platforms have allowed more accurate recapitulations of the mosquito-to-skin-to-liver stages of human malaria infection. This allows both observation and study of the biological nuances of parasite vector-to-mammalian host transmission as well as interventions which can inhibit or block this stage of transmission. Paired with observations from clinical trials and the field, we can better understand exactly which parameters in which systems are most relevant for translation and biology.




Advances in Malaria Research


Book Description

Thoroughly reviews our current understanding of malarial biology Explores the subject with insights from post-genomic technologies Looks broadly at the disease, vectors of infection, and treatment and prevention strategies A timely publication with chapters written by global researchers leaders




Malaria Genome Projects, The: Promise, Progress, And Prospects


Book Description

The year 2012 marks the tenth anniversary of the announcement of the genome sequence of the human malaria parasite Plasmodium falciparum and that of its mosquito vector Anopheles. The genome sequences were a result of the Plasmodium falciparum Genome Project.This book covers in detail the biology of malaria parasites and the mosquitoes that transmit the disease, how the Genome Projects came into being, the people who created them, and the cadre of scientists who are attempting to see the promise of the Projects realized. The promise was: a more complete understanding of the genes of the parasite (and its vector) would provide a rational basis for the development of antimalarial drugs and vaccines, allow a better understanding of the regulation of the complex life cycle in the red blood and liver cells of the human, identify the genes the parasite uses to thwart the host immune response and the ways in which the parasite evades cure by drug treatments, as well as leading to more effective measures of control transmission. The hope was that cracking the genetic code of Plasmodium and Anopheles would reveal the biochemical Achilles heel of the parasite and its vector, leading to the development of novel drugs and better methods of control, and by finding the targets of protective immunity could result in the manufacture of effective vaccines.Through a historic approach, this book will allow for those new to the field, or those with insufficient background in the sciences, to have an easier entry point. Even scientists already working in the field may better appreciate how discoveries made in the past can impact the direction of future research.




From Genes to Biomarkers


Book Description

Each year, approximately 230 million malaria cases and 400,00 malaria deaths are reported worldwide. Malaria is a life-threatening disease caused by Plasmodium parasites that are transmitted from one individual to another through the bites of infected female Anopheles mosquitoes. Malaria parasites replicate asexually in the human host, and, in each replication cycle, a portion of the asexual stages develops into sexual gametocytes that permit transmission. The proportion of infections that carries gametocytes and the infectivity of gametocytes are indicators of human-to-mosquito transmission potential. In P.¬†falciparum, gametocytes appear 10,Äì14¬†days after infection, whereas in P.¬†vivax gametocytes appear simultaneously with asexual schizonts. Such difference in development not only increases the length of time that an individual is infectious, but also increases the likelihood of transmission before treatment. The conversion from asexual parasites to gametocytes is also highly variable between infections. Differences in age, host immune response, parasite genetic composition, density of red blood cells, presence of co-infecting parasite strains, and antimalarial drug use could affect gametocytes production. In P. vivax, the unique ability to produce hypnozoites, a dormant liver stage of the parasite, may allow gametocytes to be produced periodically from relapse and contribute to transmission. In this chapter, we will provide an overview of the biology of Plasmodium gametocytes, existing tools for gametocyte detection, and features of gametocyte genes. The biological insights and genetic findings are essential to¬†developing better detection biomarkers and effective strategies to reduce transmission in malaria-endemic countries.




Malaria


Book Description

Malaria is making a dramatic comeback in the world. The disease is the foremost health challenge in Africa south of the Sahara, and people traveling to malarious areas are at increased risk of malaria-related sickness and death. This book examines the prospects for bringing malaria under control, with specific recommendations for U.S. policy, directions for research and program funding, and appropriate roles for federal and international agencies and the medical and public health communities. The volume reports on the current status of malaria research, prevention, and control efforts worldwide. The authors present study results and commentary on the: Nature, clinical manifestations, diagnosis, and epidemiology of malaria. Biology of the malaria parasite and its vector. Prospects for developing malaria vaccines and improved treatments. Economic, social, and behavioral factors in malaria control.




Current Topics in Malaria


Book Description




Malaria


Book Description

Malaria is a mosquito-borne disease caused by parasitic protozoa that belong to the genus Plasmodium. This disease imposes a significant global health burden, claiming the lives of several thousand children and pregnant women each day. Increasing antimalarial drug resistance and the complexity of the Plasmodium life cycle, among other factors, have made eradication difficult. Written and edited by experts in the field, this collection from Cold Spring Harbor Perspectives in Medicine examines the biology, pathology, and epidemiology of malaria, as well as ongoing efforts to treat infections and manage their spread. Contributors discuss the Plasmodium life cycle, focusing on the molecular mechanisms by which the various parasitic stages induce clinical symptoms, interact with the immune system, and lead to further transmission of malaria. They also explore topics such as the interaction between mosquito reproduction and Plasmodium development, epigenetic regulation of malaria-associated genes, and unique features of malaria in pregnant women (e.g., parity-dependent susceptibility) and describe how an improved understanding of these phenomena may lead to novel intervention strategies. The driving forces behind antimalarial drug resistance are covered, as is progress in developing an effective vaccine and controlling mosquito populations. This volume is therefore an essential reference for all scientists, clinicians, and public health professionals interested in understanding malaria and reducing its devastating effects.




Malaria Immunology


Book Description

Despite extensive efforts to control it, malaria is still one of the most devastating infectious diseases worldwide. This book, now in its second edition, provides a broad and up-to-date overview of the rapidly expanding field of malaria immunology and its importance in the control of this disease. The first section deals with the malaria parasite and its interactions with both the vertebrate host and the mosquitoes which transmit the disease. In the second part, the mechanisms of immunity and their regulation by environmental and genetic factors are discussed. Finally, this volume contains several chapters on malaria vaccine development, describing the application of the most recent vaccine technologies as well as ongoing and planned vaccine trials. Authored by well-recognized experts, this volume not only demonstrates the rapid progress being made in the search for vaccines against malaria, but also broadens our understanding of immunity to infection in general. It is therefore highly recommended reading for all scientists and professionals in the fields of immunology, infection and vaccine development.




Saving Lives, Buying Time


Book Description

For more than 50 years, low-cost antimalarial drugs silently saved millions of lives and cured billions of debilitating infections. Today, however, these drugs no longer work against the deadliest form of malaria that exists throughout the world. Malaria deaths in sub-Saharan Africaâ€"currently just over one million per yearâ€"are rising because of increased resistance to the old, inexpensive drugs. Although effective new drugs called "artemisinins" are available, they are unaffordable for the majority of the affected population, even at a cost of one dollar per course. Saving Lives, Buying Time: Economics of Malaria Drugs in an Age of Resistance examines the history of malaria treatments, provides an overview of the current drug crisis, and offers recommendations on maximizing access to and effectiveness of antimalarial drugs. The book finds that most people in endemic countries will not have access to currently effective combination treatments, which should include an artemisinin, without financing from the global community. Without funding for effective treatment, malaria mortality could double over the next 10 to 20 years and transmission will intensify.