When the Blue Marble Health concept challenges our current understanding of One Health

Abstract

We address the issue of reconciling the hygienist and dilutionist (H&D) perspectives for a global understanding of health as envisioned in the One Health framework. Rich and poor countries share pockets of poverty on the outskirts of urban centres, known as 'infectious bubbles', which remain high-risk areas for disease emergence due to a common failure of both the H&D perspectives. People living in these IBs are exposed to infectious microbes on a daily basis due to inadequate hygiene infrastructure, while at the same time lacking a heathy nature to act as a buffer through a dilution effect. The Blue Marble Health approach shows that the burden of neglected diseases has also been neglected in rich countries. We argue for a single health framework that incorporates a mixed model of H&D views and addresses the issue of IB in the distribution and endemicity of emerging infectious diseases in large developed cities.

Keywords: Dilution effect; Global Health; Neglected diseases; Poverty; Urban health.

Fig. 1

Current understanding of both the hygiene and dilution effect on the risk of emerging infectious diseases along an urban to pristine gradient, means that the dilution effect is the greatest in pristine natural ecosystem where biodiversity of competent and non-competent hosts is high while hygiene is the strongest in cities where people have access to clean water, clean food, an efficient cold chain, access to medicine and hospitals. The emerging infectious risk is thus relatively weak in pristine environments as there are few human and the biodiversity is high and in cities where the nature is mostly absent and people have access to high hygiene life style. Low emerging infectious disease risk is indicated in green; Mid emerging infectious disease risk is indicated in yellow. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

A: Blue Marble Health concept. The Blue Marble areas are areas of economic deprivation on the outskirts of towns and cities. Neglected diseases have become endemic in these « poverty pockets » [13,14] B: Infectious bubbles correspond to areas where the dilution effect is weak, because nature in these areas is highly degraded, although still present, and where poor populations with already degraded health have limited access to hygiene (clean water, cold food chain, sewage, etc.). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 3

Impact of the hygiene and dilution effect on disease risk in different environments along a rural to urban gradient. The infectious bubbles are the areas where both the hygiene and dilution effects are weakest, resulting in a higher risk of emerging infectious disease. Green: low infectious risk; Yellow: mid infectious risk; red: high infectious risk. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)