Search

Infections caused by soil-transmitted helminthias (STHs) affect over a billion people worldwide, causing anaemia and having a large social and economic impact through poor educational outcomes. They are identified in the World Health Organization (WHO) 2020 goals for neglected tropical diseases as a target for renewed effort to ameliorate their global public health burden through mass drug administration (MDA) and water and hygiene improvement. In this chapter, we review the underlying biology and epidemiology of the three causative intestinal nematode species that are mostly considered under the STH umbrella term. We review efforts to model the transmission cycle of these helminths in populations and the effects of preventative chemotherapy on their control and elimination. Recent modelling shows that the different epidemiological characteristics of the parasitic nematode species that make up the STH group can lead to quite distinct responses to any given form of MDA. When connected with models of treatment cost-effectiveness, these models are potentially a powerful tool for informing public policy. A number of shortcomings are identified; lack of critical types of data and poor understanding of diagnostic sensitivities hamper efforts to test and hence improve models., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Schistosomiasis is global in extent within developing countries, but more than 90% of the at-risk population lives in sub-Saharan Africa. In total, 261 million people are estimated to require preventive treatment. However, with increasing drug availability through donation, the World Health Organization has set a goal of increasing coverage to 75% of at-risk children in endemic countries and elimination in some regions. In this chapter, we discuss key biological and epidemiological processes involved in the schistosome transmission cycle and review the history of modelling schistosomiasis and the impact of mass drug administration, including both deterministic and stochastic approaches. In particular, we look at the potential impact of the WHO 2020 schistosomiasis treatment goals., (Copyright © 2016 Elsevier Ltd. All rights reserved.)