Altered Offspring Immunity in Maternal Parasitic Infections.

Maternal infection during pregnancy is known to alter the development and function of offspring's immune system, leading to inappropriate immune responses to common childhood infections and immunizations. Although this is an expanding field, maternal parasitic infections remain understudied. Millions of women of reproductive age are currently at risk for parasitic infection, whereas many pregnant, chronically infected women are excluded from mass drug administration due partially to a lack of resources, as well as fear of unknown adverse fetal developmental outcomes. In areas endemic for multiple parasitic infections, such as sub-Saharan Africa, there are increased rates of morbidity and mortality for various infections during early childhood in comparison with nonendemic areas. Despite evidence supporting similar immunomodulatory effects between various parasite species, there is no clear mechanistic understanding of how maternal infection reprograms offspring immunity. This brief review will compare the effects of selected maternal parasitic infections on offspring immunity.

Water sources aggregate parasites with increasing effects in more arid conditions.

Shifts in landscape heterogeneity and climate can influence animal movement in ways that profoundly alter disease transmission. Water sources that are foci of animal activity have great potential to promote disease transmission, but it is unknown how this varies across a range of hosts and climatic contexts. For fecal-oral parasites, water resources can aggregate many different hosts in small areas, concentrate infectious material, and function as disease hotspots. This may be exacerbated where water is scarce and for species requiring frequent water access. Working in an East African savanna, we show via experimental and observational methods that water sources increase the density of wild and domestic herbivore feces and thus, the concentration of fecal-oral parasites in the environment, by up to two orders of magnitude. We show that this effect is amplified in drier areas and drier periods, creating dynamic and heterogeneous disease landscapes across space and time. We also show that herbivore grazing behaviors that expose them to fecal-oral parasites often increase at water sources relative to background sites, increasing potential parasite transmission at these hotspots. Critically, this effect varies by herbivore species, with strongest effects for two animals of concern for conservation and development: elephants and cattle.

Advances and Discoveries in Myxozoan Genomics.

Myxozoans are highly diverse and globally distributed cnidarian endoparasites in freshwater and marine habitats. They have adopted a heteroxenous life cycle, including invertebrate and fish hosts, and have been associated with diseases in aquaculture and wild fish stocks. Despite their importance, genomic resources of myxozoans have proven difficult to obtain due to their miniaturized and derived genome character and close associations with fish tissues. The first 'omic' datasets have now become the main resource for a better understanding of host-parasite interactions, virulence, and diversity, but also the evolutionary history of myxozoans. In this review, we discuss recent genomic advances in the field and outline outstanding questions to be answered with continuous and improved efforts of generating myxozoan genomic data.

Fast-lived Hosts and Zoonotic Risk.

Because most emerging human pathogens originate in mammals, many studies aim to identify host traits that determine the risk of sourcing zoonotic outbreaks. Studies regularly assert that 'fast-lived' mammal species exhibiting greater fecundity and shorter lifespans tend to host more zoonoses; however, the causes of this association remain poorly understood and they cover a range of immune and nonimmune mechanisms. We discuss these drivers in the context of evolutionary ecology and wildlife-human interactions. Ultimately, differentiating these mechanisms will require linking interspecific variation in life history with immunity, pathogen diversity, transmissibility, and zoonotic risk, and critical data gaps currently limit our ability to do so. We highlight sampling and analytical frameworks to address this gap and to better inform zoonotic reservoir prediction.

How to choose the best control strategy? Mathematical models as a tool for pre-intervention evaluation on a macroparasitic disease.

During the last century, emerging diseases have increased in number, posing a severe threat for human health. Zoonoses, in particular, represent the 60% of emerging diseases, and are a big challenge for public health due to the complexity of their dynamics. Mathematical models, by allowing an a priori analysis of dynamic systems and the simulation of different scenarios at once, may represent an efficient tool for the determination of factors and phenomena involved in zoonotic infection cycles, but are often underexploited in public health. In this context, we developed a deterministic mathematical model to compare the efficacy of different intervention strategies aimed at reducing environmental contamination by macroparasites, using raccoons (Procyon lotor) and their zoonotic parasite Bayilsascaris procyonis as a model system. The three intervention strategies simulated are raccoon depopulation, anthelmintic treatment of raccoons and faeces removal. Our results show that all these strategies are able to eliminate the parasite egg population from the environment, but they are effective only above specific threshold coverages. Host removal and anthelmintic treatment showed the fastest results in eliminating the egg population, but anthelmintic treatment requires a higher effort to reach an effective result compared to host removal. Our simulations show that mathematical models can help to shed light on the dynamics of communicable infectious diseases, and give specific guidelines to contain B. procyonis environmental contamination in native, as well as in new, areas of parasite emergence. In particular, the present study highlights that identifying in advance the appropriate treatment coverage is fundamental to achieve the desired results, allowing for the implementation of cost- and time-effective intervention strategies.

The spreading of parasites by human migratory activities.

The global spread of parasites is unquestionably linked with human activities. Migration in all its different forms played a major role in the introduction of parasites into new areas. In ancient times, mass migrations were the main causes for the spread of parasites while in the recent past and present, emigration, immigration, displacement, external and internal migration, and labor migration were the reasons for the dispersal of parasites. With the advent of seagoing ships, long-distance trading became another important mode of spreading parasites. This review summarizes the spread of parasites using notable examples. In addition, the different hypotheses explaining the arrival of Plasmodium vivax and soil-transmitted helminths in pre-Columbian America are also discussed.

Contamination of coins and banknotes as sources of transmission of parasitic pathogens: a pilot study from Iran.

OBJECTIVE: This study was conducted to determine the presence, type, and rate of parasitic contamination in Iranian currencies. STUDY DESIGN: This was a cross-sectional study. METHODS: Coins and banknotes of different denominations were randomly collected from sellers and markets in Tabriz, Northwest of Iran, for examining parasitic contamination. RESULTS: Entamoeba coli and Giardia intestinalis were the most identified species of parasites in this study. Other parasites detected were Cryptosporidium parvum, Ascaris lumbricoides, Entamoeba histolytica, Fasciola hepatica, and Toxocara cati. A high rate of parasitic contamination was found in banknotes compared with coins, and a statistically significant association was found between parasitic contamination and the apparent condition of the currencies. The notes of lower denominations showed the highest contamination rates. The highest parasitic contamination was found in coins and banknotes obtained from public toilet services, butchers, and beggars. CONCLUSIONS: The findings emphasize the role of circulating coins and banknotes in the risk of pathogenic parasite transmission.

Risk factors and prevalence of enteroparasitic diseases in shellfish pickers from a lake area in the Northeast of Brazil / Fatores de risco e prevalência de enteroparasitoses em marisqueiras de uma região lagunar no Nordeste do Brasil

INTRODUCTION: Intestinal parasitosis are a public health problem worldwide. There are several risk factors and a high association with some specific labor activities. OBJECTIVE: The present study assessed the risk factors and prevalence of enteroparasitic diseases in shellfish pickers from one district of Maceió, Alagoas state, Brazil. METHODS: Crosssectional study of 41 female shellfish pickers including parasitological tests in fecal samples and a questionnaire with objective and subjective questions. Sand samples from their working environment were also analyzed. RESULTS: At least one species of parasite was found in 19.51% of the fecal samples. Pathogenic species of Giardia lamblia, Trichuris trichiura, Schistosoma mansoni, Ascaris lumbricoides, Enterobius vermicularis, from the Ancylostomatidae family, and non-pathogenic species of Entamoeba coli were found. Polyparasitism was diagnosed in 37.5% of the positive samples. A total of 57.14% of sand samples contained hookworm larvae. Regarding the risk factor, low educational level was statistically associated to the presence of parasites (p<0.05). CONCLUSION: Greater investment in basic education is needed to increase the knowledge about preventive measures against parasitic diseases and the promotion food-handling courses in order to change existing inadequate habits in the community. Basic sanitation is also essential in preventing environmental contamination.

INTRODUÇÃO: As parasitoses intestinais representam um problema de saúde pública mundial. Estão associados inúmeros fatores de risco, bem como atividades laborais específicas. OBJETIVO: O presente estudo avaliou os fatores de risco e a prevalência de enteroparasitoses em marisqueiras de um bairro da cidade de Maceió, Alagoas, Brasil. MÉTODOS: Procedeu-se um estudo de corte transversal, sendo 41 marisqueiras avaliadas mediante exame parasitológico de fezes e questionário contendo questões discursivas e de múltipla escolha. Foram analisadas também amostras de areia do ambiente de trabalho das mesmas. RESULTADOS: A positividade para pelo menos uma espécie de parasito nas fezes foi de 19,51%. Foram encontradas as espécies patogênicas Giardia lamblia, Trichuris trichiura, Schistosoma mansoni, Ascaris lumbricoides, Enterobius vermicularis e da família Ancylostomatidae, e a espécie não patogênica, Entamoeba coli. Poliparasitismo foi diagnosticado em 37,5% dos exames positivos. Um total de 57,14% das amostras de areia continha larvas de ancilostomatídeos. Em relação aos fatores de risco, a baixa escolaridade foi estatisticamente associada à presença de parasitas (p<0,05). CONCLUSÃO: É necessário maior investimento na educação básica para aprimorar o conhecimento das formas de prevenção das parasitoses e a promoção de cursos de boas práticas de manipulação de alimentos, a fim de modificar hábitos errôneos já incorporados na comunidade. O saneamento básico também é fundamental para evitar contaminação ambiental.

Zoonotic Parasites of Reptiles: A Crawling Threat.

Reptiles are reservoirs of a wide range of pathogens, including many protozoa, helminths, pentastomids, and arthropod parasitic species, some of which may be of public health concern. In this review we discuss the zoonotic risks associated with human-reptile interactions. Increased urbanization and introduction of exotic species of reptile may act as drivers for the transmission of zoonotic parasites through the environment. In addition, being a part of human diet, reptiles can be a source of life-threatening parasitoses, such as pentastomiasis or sparganosis. Finally, reptiles kept as pets may represent a risk to owners given the possibility of parasites transmitted by direct contact or fecal contamination. Awareness of reptile-borne zoonotic parasitoses is important to advocate control, prevention, and surveillance of these neglected diseases.

Detection methods and prevalence of transmission stages of Toxoplasma gondii, Giardia duodenalis and Cryptosporidium spp. in fresh vegetables: a review.

One of the ways of human parasitic infection is the accidental ingestion of vegetables contaminated with parasites, which represents a major human health hazard. This non-exhaustive review aims to evaluate studies carried out on five types of vegetables (lettuce, parsley, coriander, carrot and radish) since 2000, particularly the methods used for recovery, concentration, detection and identification of protozoan parasites such as Toxoplasma gondii, Giardia duodenalis and Cryptosporidium spp., and the results of each work. Various studies have determined the presence of pathogenic parasites in fresh vegetables with different rates; this variation in rate depends particularly on the detection method used which is related to each parasite and each vegetable type. The variation in parasitic prevalence in food could be due to different factors such as the geographical location, the size of analysed samples and the methods used for parasite detection.

A preliminary report on the awareness and knowledge of seafood-borne parasitic diseases among medical doctors in Australia.

Despite the increasing popularity of seafood in Australia and various reports of infection with transmissible parasites in Australian edible aquatic animals such as fish, the number of reported cases of human infections in the country is low. This raised the question that Australian medical doctors may not be fully aware of the presence of these parasites in Australia, which in turn can lead to misdiagnosis of infections. This also may lead to an underestimation of the risk seafood-borne parasites may pose to public health. This preliminary study was conducted to determine the awareness and level of knowledge among Australian medical practitioners in New South Wales, the most populated and multicultural state in Australia, about seafood-borne parasitic diseases. Medical doctors, both general practitioners and gastroenterologists, were surveyed through an anonymous questionnaire (n = 376). Although the response rate was low at 11%, participants represented a diverse group in terms of gender, age, nationality and expertise. Despite several publications on occurrence of zoonotic parasites in Australian fish and other edible aquatic animals, and also in humans in the country, all respondents said no seafood-borne parasite had been reported as being seen within Australian or overseas practice. Although, due to low response rate, we are unable to confidently comment on the level of awareness, the findings of this study clearly suggest that further research is needed to investigate the extent of unawareness among Australian medical doctors about these highly important parasites and understanding the underlying issues in medical education that lead to the unawareness.

A Host-Parasite System with Multiple Parasite Strains and Superinfection Revisited: The Global Dynamics.

In this paper, we revisit a host-parasite system with multiple parasite strains and superinfection proposed by Nowak and May (Proc R Soc Lond B 255(1342):81-89, 1994), and study its global dynamics when we relax the two strict conditions assumed therein. As for system with two parasite strains, we derive that the basic reproduction number [Formula: see text] is the threshold condition for parasite extinction and the invasion reproduction number [Formula: see text] is the subthreshold condition for coexistence of two parasite strains. As for system with three parasite strains, we are surprised to discover the global stability of parasite-free and coexistence equilibrium, which is distinct from the previous result. Furthermore, for system with n strains, we obtain the global asymptotical stability of the parasite-free equilibrium, conjecture a general result on the global stability of coexistence equilibrium and provide two numerical examples to testify our conjecture.

Priorities in research on foodborne parasites indicated by short-term scientific missions as part of COST Action a European Network for Foodborne Parasites (Euro-FBP).

The European Cooperation in Science and Technology (COST) is a funding organization for the creation of research networks. These networks support collaboration and networking among scientists across Europe and thereby give impetus to research advancements and innovation. One of the most important mechanisms of COST actions are the short-term scientific missions (STSM), which are a funding mechanism that enables scientists, particularly those earlier in their careers, to visit an institution or laboratory in another COST Member state in order to learn techniques that will enhance their skills and improve the scientific knowledge of their institution. The European Network for Foodborne Parasites (Euro-FBP; FA1408) was a COST Action that ended in early 2019, which brought together different experts with knowledge and interest on a broad spectrum of different foodborne parasites of relevance in Europe. In the course of the Euro-FBP COST Action, 32 such STSM occurred. This article provides a short overview of the short-term scientific missions that were approved during this action, as well as the relation of these actions to several relevant socio-economic parameters. The subjects of these STSM, the majority of which were concerned with detection techniques, probably reflect the priorities for research skills on foodborne parasites in Europe.

Parasites and Parasitology in this SARS-CoV-2, COVID-19 World: An American Society of Parasitologists Presidential Address.

The novel coronavirus disease 2019 (COVID-19) is one of the worst global health crises of this generation. The core of this pandemic is the rapid transmissibility of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, its high morbidity and mortality, and the presence of infectious asymptomatic carriers. As a result, COVID-19 has dominated this year's headlines and commanded significant research attention. As we consider SARS-CoV-2 and the COVID-19 pandemic, it is essential that scientists, governments, the media, and the general population also come to grips with the everyday cost of parasitic diseases. Plasmodium (malaria), schistosomes, filarial worms, hookworms, Ascaris, whipworms, and other protozoan and metazoan parasites take a tremendous toll on local communities. Yet, because most of these diseases are no longer endemic to developed countries, their research and intervention are not funded at levels that are proportional to their global morbidity and mortality. The scientific and public health communities must indeed vigorously fight SARS-CoV-2 and COVID-19, but while doing so and beyond, it will be essential to demonstrate steadfast resolve toward understanding and combating the parasitic diseases that for centuries have haunted humankind.

Risk-based surveillance for meat-borne parasites.

There is a plethora of meat-borne hazards - including parasites - for which there may be a need for surveillance. However, veterinary services worldwide need to decide how to use their scarce resources and prioritise among the perceived hazards. Moreover, to remain competitive, food business operators - irrespective of whether they are farmers or abattoir operators - are preoccupied with maintaining a profit and minimizing costs. Still, customers and trade partners expect that meat products placed on the market are safe to consume and should not bear any risks of causing disease. Risk-based surveillance systems may offer a solution to this challenge by applying risk analysis principles; first to set priorities, and secondly to allocate resources effectively and efficiently. The latter is done through a focus on the cost-effectiveness ratio in sampling and prioritisation. Risk-based surveillance was originally introduced into veterinary public health in 2006. Since then, experience has been gathered, and the methodology has been further developed. Guidelines and tools have been developed, which can be used to set up appropriate surveillance programmes. In this paper, the basic principles are described, and by use of a surveillance design tool called SURVTOOLS (https://survtools.org/), examples are given covering three meat-borne parasites for which risk-based surveillance is 1) either in place in the European Union (EU) (Trichinella spp.), 2) to be officially implemented in December 2019 (Taenia saginata) or 3) only carried out by one abattoir company in the EU as there is no official EU requirement (Toxoplasma gondii). Moreover, advantages, requirements and limitations of risk-based surveillance for meat-borne parasites are discussed.

How globalization and climate change could affect foodborne parasites.

Foodborne parasites, most of which are zoonotic, represent an important human health hazard. These pathogens which include both protozoa (e.g., Cryptosporidium spp., Cyclospora cayetanensis, Toxoplasma gondii) and helminths (e.g., liver and intestinal flukes, Fasciola spp., Paragonimus spp., Echinococcus spp., Taenia spp., Angiostrongylus spp., Anisakis spp., Ascaris spp., Capillaria spp., Toxocara spp., Trichinella spp., Trichostrongylus spp.), have accompanied the human species since its origin and their spread has often increased due to their behavior. Since both domesticated and wild animals play an important role as reservoirs of these pathogens the increase/decrease of their biomasses, migration, and passive introduction by humans can change their epidemiological patterns. It follows that globalization and climate change will have a tremendous impact on these pathogens modifying their epidemiological patterns and ecosystems due to the changes of biotic and abiotic parameters. The consequences of these changes on foodborne parasites cannot be foreseen as a whole due to their complexity, but it is important that biologists, epidemiologists, physicians and veterinarians evaluate/address the problem within a one health approach. This opinion, based on the author's experience of over 40 years in the parasitology field, takes into consideration the direct and indirect effects on the transmission of foodborne parasites to humans.

Zoonotic parasites of dromedary camels: so important, so ignored.

With a global population of about 35 million in 47 countries, dromedary camels play a crucial role in the economy of many marginal, desert areas of the world where they survive under harsh conditions. Nonetheless, there is scarce knowledge regarding camels' parasite fauna which can reduce their milk and meat productions. In addition, only scattered information is available about zoonotic parasites transmitted to humans via contamination (e.g. Cryptosporidium spp., Giardia duodenalis, Balantidium coli, Blastocystis spp. and Enterocytozoon bieneusi), as foodborne infections (e.g. Toxoplasma gondii, Trichinella spp. and Linguatula serrata) or by arthropod vectors (Trypanosoma spp.). Herein, we draw attention of the scientific community and health policy-making organizations to the role camels play in the epidemiology of parasitic zoonotic diseases also in the view of an increase in their farming in desert areas worldwide.

Current Status of Parasite Infections in Indonesia: A Literature Review.

Indonesia and South Korea have become inseparable in various respects since the 2 countries established diplomatic relation in 1973. Indonesia is a tropical region that stretches across the equator, comprised of 5 main islands (Java, Kalimantan, Sumatra, Sulawesi, and Papua) and 4 archipelagoes (Riau, Bangka Belitung, Nusa Tenggara, and Maluku). As most population of Eastern Indonesia (Sulawesi, Papua and Nusa Tenggara & Maluku) live in poor areas, it is expected that there will be many parasites. Nevertheless, little is known about the status of parasites in Indonesia. This study examines the prevalences of malaria and lymphatic filaria, which are prevalent in Indonesia, as well as those of soil-transmitted-helminths (STH). As a result, the Plasmodium falciparum and P. vivax case loads are almost equal. The current prevalence of P. vivax is uniformly low (<5%) in all age groups and annual parasite incidence (API) showed decreasing tendency as 0.84 per 1,000 population in 2016. However, more than 65 million people still live in malaria epidemic regions. Lymphatic filariasis remains an important public health problem and 236 cities were classified as endemic areas in 514 cities/districts in 2017. It is difficult to ascertain the current prevalence rate of STH in Indonesia, although West Sumba and Southwest Sumba in East Nusa Tenggara reported prevalence rate of more than 20%. The study also considers the (sero) prevalences of other parasites identified in Indonesia. This report should be useful not only to parasitologists but also to travelers and people with business in Indonesia.

Vector-borne disease and climate change adaptation in African dryland social-ecological systems.

BACKGROUND: Drylands, which are among the biosphere's most naturally limiting and environmentally variable ecosystems, constitute three-quarters of the African continent. As a result, environmental sustainability and human development along with vector-borne disease (VBD) control historically have been especially challenging in Africa, particularly in the sub-Saharan and Sahelian drylands. Here, the VBD burden, food insecurity, environmental degradation, and social vulnerability are particularly severe. Changing climate can exacerbate the legion of environmental health threats in Africa, the social dimensions of which are now part of the international development agenda. Accordingly, the need to better understand the dynamics and complex coupling of populations and environments as exemplified by drylands is increasingly recognized as critical to the design of more sustainable interventions. MAIN BODY: This scoping review examines the challenge of vector-borne disease control in drylands with a focus on Africa, and the dramatic, ongoing environmental and social changes taking place. Dryland societies persisted and even flourished in the past despite changing climates, extreme and unpredictable weather, and marginal conditions for agriculture. Yet intrusive forces largely out of the control of traditional dryland societies, along with the negative impacts of globalization, have contributed to the erosion of dryland's cultural and natural resources. This has led to the loss of resilience underlying the adaptive capacity formerly widely exhibited among dryland societies. A growing body of evidence from studies of environmental and natural resource management demonstrates how, in light of dryland system's inherent complexity, these factors and top-down interventions can impede sustainable development and vector-borne disease control. Strengthening adaptive capacity through community-based, participatory methods that build on local knowledge and are tailored to local ecological conditions, hold the best promise of reversing current trends. CONCLUSIONS: A significant opportunity exists to simultaneously address the increasing threat of vector-borne diseases and climate change through methods aimed at strengthening adaptive capacity. The integrative framework and methods based on social-ecological systems and resilience theory offers a novel set of tools that allow multiple threats and sources of vulnerability to be addressed in combination. Integration of recent advances in vector borne disease ecology and wider deployment of these tools could help reverse the negative social and environmental trends currently seen in African drylands.