Disease ecology, health and the environment: a framework to account for ecological and socio-economic drivers in the control of neglected tropical diseases

Abstract

Reducing the burden of neglected tropical diseases (NTDs) is one of the key strategic targets advanced by the Sustainable Development Goals. Despite the unprecedented effort deployed for NTD elimination in the past decade, their control, mainly through drug administration, remains particularly challenging: persistent poverty and repeated exposure to pathogens embedded in the environment limit the efficacy of strategies focused exclusively on human treatment or medical care. Here, we present a simple modelling framework to illustrate the relative role of ecological and socio-economic drivers of environmentally transmitted parasites and pathogens. Through the analysis of system dynamics, we show that periodic drug treatments that lead to the elimination of directly transmitted diseases may fail to do so in the case of human pathogens with an environmental reservoir. Control of environmentally transmitted diseases can be more effective when human treatment is complemented with interventions targeting the environmental reservoir of the pathogen. We present mechanisms through which the environment can influence the dynamics of poverty via disease feedbacks. For illustration, we present the case studies of Buruli ulcer and schistosomiasis, two devastating waterborne NTDs for which control is particularly challenging.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'.

Emerging human infectious diseases and the links to global food production

“…High prevalence of infectious diseases among populations that rely heavily on subsistence, labour-intensive agriculture can reduce agricultural productivity, degrade human capital, undermine economic growth and generate conditions that systematically reinforce poverty 48 . Poverty, in turn, increases disease transmission as the lack of access to clean water and preventive care often associated with the lifestyle of the poor make them continuously exposed to parasites and pathogens embedded in the environment 142 . Malnutrition, a common consequence of poverty, may weaken immune response and increase susceptibility to disease.…”

Conservation, biodiversity and infectious disease: scientific evidence and policy implications

“…Garchitorena et al [30] present a modelling framework to consider how different transmission pathways involving social and environmental transmission, along with socio-economic drivers, rstb.royalsocietypublishing.org Phil. Trans.…”

Rainfall and other meteorological factors as drivers of urban transmission of leptospirosis

“…Approximately one billion people worldwide reside in slums and this population continues to grow [1]. In those overcrowded environments with inadequate infrastructure, the burden of environmentally-transmitted infections -such as helminths, bacterial diarrheal diseases, leptospirosis among others -is growing and causes more than half a million deaths and 57 million more than half a million deaths and 57 million Disability Adjusted Life-Years annually [2][3][4][5][6]. For these environmentally driven diseases, meteorological factors have a complex interaction with the underlying inadequate sanitation and poor environment influencing the transmission dynamics.…”