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In 2001, the World Health Assembly (WHA) passed the landmark WHA 54.19 resolution for global scale-up of mass administration of anthelmintic drugs for morbidity control of schistosomiasis and soil-transmitted helminthiasis, which affect more than 1·5 billion of the world's poorest people. Since then, more than a decade of research and experience has yielded crucial knowledge on the control and elimination of these helminthiases. However, the global strategy has remained largely unchanged since the original 2001 WHA resolution and associated WHO guidelines on preventive chemotherapy. In this Personal View, we highlight recent advances that, taken together, support a call to revise the global strategy and guidelines for preventive chemotherapy and complementary interventions against schistosomiasis and soil-transmitted helminthiasis. These advances include the development of guidance that is specific to goals of morbidity control and elimination of transmission. We quantify the result of forgoing this opportunity by computing the yearly disease burden, mortality, and lost economic productivity associated with maintaining the status quo. Without change, we estimate that the population of sub-Saharan Africa will probably lose 2·3 million disability-adjusted life-years and US$3·5 billion of economic productivity every year, which is comparable to recent acute epidemics, including the 2014 Ebola and 2015 Zika epidemics. We propose that the time is now to strengthen the global strategy to address the substantial disease burden of schistosomiasis and soil-transmitted helminthiasis.

The two geohelminths, Ascaris lumbricoides and Trichuris trichiura, infect more than a billion people worldwide but are only reported sporadically in the developed part of the world. In contrast, the closely related species A. suum and T. suis in pigs have a truly global distribution, with infected pigs found in most production systems. In areas where pigs and humans live in close proximity or where pig manure is used as fertilizer on vegetables for human consumption, there is a potential risk of cross-infections. We therefore review this relationship between Ascaris and Trichuris in the human and pig host, with special focus on recent evidence concerning the zoonotic potential of these parasites, and identify some open questions for future research.

Standley, C.J., Pointier, J.P., Issia, L., Wisnivesky-Colli, C., Stothard, J.R. (2011): Identification and characterization of Biomphalaria peregrina (Orbignyi, 1835) from Agua Escondida in northern Patagonia, Argentina. Journal of Natural History 45 (5-6): 347-356, DOI: 10.1080/00222933.2010.531153, URL: http://dx.doi.org/10.1080/00222933.2010.531153

Humans and animals have co-existed with parasites in a battle of constant adaptation to one another. It is becoming increasingly clear that extracellular vesicles (EVs) play important roles in this co-existence and pathology. This chapter reviews the current research on EVs released by protozoa, nematodes, trematodes, and cestodes with a special focus on EVs in parasite life cycles. The environmental changes experienced by the parasite during its life cycle is associated with distinct changes in EV release and content. The function of these EV seems to have a significant influence on parasite pathology and survival in the host by concomitantly modulating host immune responses and triggering parasite differentiation. The role of EVs in communication between the parasites and the host adds a new level of complexity in our understanding of parasite biology, which may be a key to further understand the complexity behind host-parasite interactions and communication. This increased understanding can, in turn, open up new avenues for vaccine, diagnostic, and therapeutic development for a wide variety of diseases such as parasite infection, cancers, and immunological disorders.

Soil-transmitted helminth (STH) infections represent a major public health problem globally, particularly among socio-economically disadvantaged populations. Detection of STH infections is often challenging, requiring a combination of diagnostic techniques to achieve acceptable sensitivity and specificity, particularly in low infection-intensity situations. The microscopy-based Kato-Katz remains the most widely used method but has low sensitivity in the detection of, for instance, Strongyloides spp. infections, among others. Antigen/antibody assays can be more sensitive but are parasite species-specific. Highly sensitive PCR methods have been developed to be multiplexed to allow multi-species detection. Novel diagnostic tests for all STH species are needed for effective monitoring, evaluation of chemotherapy programmes, and to assess the potential emergence of parasite resistance. This review discusses available diagnostic methods for the different stages of STH control programmes, which vary in sensitivity and spectrum of detection requirements, and tools to evaluate drug efficacy and resistance.

Schistosomiasis is a parasitic disease that affects over 100 million children in the world living mostly in sub-Saharan Africa. This thesis explored several aspects of the disease affecting the health of children from two African endemic countries: Kenya and Uganda. Epidemiological work revealed a worrisome association between schistosomiasis and malnutrition (both acute and chronic) as well as anaemia. A novel paediatric quality of life assessment was performed in children with the disease with a significant decrease in their psychosocial functioning. Further work went into testing and validating novel morbidity detection tools to identify sub-clinical and overt disease; firstly in Kenya the 20-meter shuttle run test performed accurately in detecting anaemia associated with schistosomiasis, secondly in Uganda, point-of-care tests (faecal occult blood and calprotectin) correlated with severity of intestinal schistosomiasis. As a disease of poverty, schistosomiasis co-exists with other pandemic diseases such as HIV and the tandem HIV-schistosomiasis has not yet been explored in children. A review on the current knowledge on the subject to help delineate the very needed research agenda is presented. The final work in the thesis is the first pharmacokinetic/pharmacodynamics study of praziquantel in children, the only drug available for the treatment of schistosomiasis. The results of this study suggest that the current recommended dose for control programmes may be too low, particularly for preschool children. Overall, this work is an important contribution to paediatric schistosomiasis and opens up future research venues that need to be explored in order to fully understand this disabling disease. This can be done through better clinical staging, affordable morbidity detection tools and optimized treatment.