Here’s a very interesting and splendidly mathematical paper: Dynamics and control of infections transmitted from person to person through the environment by Sheng Li, Joseph N. S. Eisenberg, Ian H. Spicknall and James S. Koopman published in May last year in the American Journal of Epidemiology. Here’s the Abstract:
The environment provides points for control of pathogens spread by food, water, hands, air, or fomites. These environmental transmission pathways require contact network formulations more realistically detailed than those based on social encounters or physical proximity. As a step toward improved assessment of environmental interventions, description of contact networks, and better use of environmental specimens to analyze transmission, an environmental infection transmission system model that describes the dynamics of human interaction with pathogens in the environment is presented. Its environmental parameters include the pathogen elimination rate, µ, and the rate humans pick up pathogens, ρ, and deposit them, α. The ratio, ρN/µ (N equals population size), indicates whether transmission is density dependent (low ratio), frequency dependent (high ratio), or in between. Transmission through frequently touched fomites, such as doorknobs, generates frequency-dependent patterns, while transmission through thoroughly mixed air or infrequently touched fomites generates density-dependent patterns. The environmental contamination ratio, α/γ, reflects total agent deposition per infection and outbreak probability, where γ is defined as the recovery rate. These insights provide theoretical contexts to examine the role of the environment in pathogen transmission and a framework to interpret environmental data to inform environmental interventions.
Fomites? See here.
About Me
- Duncan Mara
- University of Leeds, United Kingdom
- I'm an emeritus professor of civil engineering at the University of Leeds in England. I've been working on low-cost sanitation in developing countries since the mid-1970s, and also on low-cost wastewater treatment and reuse. I was a lecturer at the University of Nairobi, Kenya, 1970-73 and then a senior lecturer at the University of Dundee, Scotland, 1974-79 before moving to Leeds in late 1979. I was a visiting professor of sanitary engineering at the Universidade Federal da Paraiba in Campina Grande, northeast Brazil, during 1976-95, and since 1996 I have been a visiting professor of environmental engineering at the Instituto Cinara, Universidad del Valle in Cali, Colombia.