Interactions between landscape changes and host communities can regulateEchinococcus multilocularistransmission

Abstract

An area close to the Qinghai-Tibet plateau region and subject to intensive deforestation contains a large focus of human alveolar echinococcosis while sporadic human cases occur in the Doubs region of eastern France. The current review analyses and compares epidemiological and ecological results obtained in both regions. Analysis of rodent species assemblages within quantified rural landscapes in central China and eastern France shows a significant association between host species for the pathogenic helminth Echinococcus multilocularis, with prevalences of human alveolar echinococcosis and with land area under shrubland or grassland. This suggests that at the regional scale landscape can affect human disease distribution through interaction with small mammal communities and their population dynamics. Lidicker's ROMPA hypothesis helps to explain this association and provides a novel explanation of how landscape changes may result in increased risk of a rodent-borne zoonotic disease.

Infection of foxes byEchinococcocus multilocularisin urban and suburban areas of Nancy, France: influence of feeding habits and environment

“…), several environmental and behavioural variables influenced distribution and parasite dynamics Giraudoux et al, 2003;Miterpakova et al, 2006). In Europe, at the regional level, it has been shown that transmission to the definitive host requires focal rodent species like M. arvalis and A. terrestris (Delattre et al, 1988).…”

Fox faeces and vole distribution on a local range: ecological data in a parasitological perspective forEchinococcus multilocularis

“…Comparative studies in Europe have shown that E. multilocularis prevalence in foxes was dependent on landscape composition. Indeed, higher prevalence was recorded in landscapes favouring intermediate host population outbreaks (Pesson & Carbiener, 1989;Raoul et al, 2001b;Staubach et al, 2001;Giraudoux et al, 2003). Modifications in the population dynamics and in the spatio-temporal overlap of species involved in parasitic transmission can modulate zoonotic risk (Patz et al, 2004).…”

Multidisciplinary studies, systems approaches and parasite eco-epidemiology: something old, something new

“…Adding an explicit reference to the nested hierarchy of spatial scales at which various processes occur (c) makes the conceptual model much more complex, although temporal dimension is not represented. After Giraudoux et al (2003Giraudoux et al ( , 2006. a b c big forthcoming challenges is likely to be how to better link concepts and methods emerging from the fields of ecology, population dynamics and epidemiological studies in parasite transmission (Kitron, 1998;Holdenrieder et al, 2004;Ostfeld et al, 2005).…”

“…For instance, population dynamics of small mammal populations (thus their density variations over time) not only respond to the availability of suitable habitats to a focal species, but also to the ratio of its optimal habitat to the total land area and by the effects of neighbouring sub-optimal habitats (Lidicker, 2000). This can impact tranmission processes in systems where various small mammal communities in contrasted landscapes are key-reservoirs for parasites such as Echinococcus multilocularis (Giraudoux et al, 2003). Furthermore, to upscale results obtained on the limited areas where human population and animal community data can actually be collected to larger areas across scales is still an open challenge.…”

“…Finally, systems approaches of anthropozoonoses transmission should also incorporate the variability of human behaviour. For instance, studies on E. multilocularis in China have identified landscape patterns and ecological processes that may be conducive to more intensive transmission and human exposure (Giraudoux et al, 2003;Danson et al, 2006). However, the large variability (0-15 %) of human alveolar echinococcosis among villages in areas of high endemicity remained unexplained and may well be due to undisclosed behavioural differences between villages.…”