Risk factors for human disease emergence

Abstract

A comprehensive literature review identifies 1415 species of infectious organism known to be pathogenic to humans, including 217 viruses and prions, 538 bacteria and rickettsia, 307 fungi, 66 protozoa and 287 helminths. Out of these, 868 (61%) are zoonotic, that is, they can be transmitted between humans and animals, and 175 pathogenic species are associated with diseases considered to be 'emerging'. We test the hypothesis that zoonotic pathogens are more likely to be associated with emerging diseases than non-emerging ones. Out of the emerging pathogens, 132 (75%) are zoonotic, and overall, zoonotic pathogens are twice as likely to be associated with emerging diseases than non-zoonotic pathogens. However, the result varies among taxa, with protozoa and viruses particularly likely to emerge, and helminths particularly unlikely to do so, irrespective of their zoonotic status. No association between transmission route and emergence was found. This study represents the first quantitative analysis identifying risk factors for human disease emergence.

Identifying host species driving transmission of schistosomiasis japonica, a multihost parasite system, in China

“…Based on the findings from our previous field and molecular epidemiological studies (10)(11)(12), the definitive host species incorporated into the transmission model This article is a PNAS Direct Submission. 1 To whom correspondence should be addressed. E-mail: james.rudge@lshtm.ac.uk.…”

“…M ost human pathogens are zoonoses (i.e., diseases that can be transmitted, directly or indirectly, from animals to humans) and often involve a multiplicity of reservoirs and vectors (1). However, most epidemiological theory of parasitic infections has been developed for the case of single host-parasite and hostvector-parasite systems.…”

Evolution and Emergence of Plant Viruses

“…Viruses are the major taxonomic group of emergent pathogens of humans, wildlife and plants, causing in all three host classes just under half of reported emergent diseases (Anderson et al, 2004;Dobson & Foufopoulos, 2001;Taylor et al, 2001). The high socio-economic impact of emergent infectious diseases has motivated research efforts to disentangle the complex causes of pathogen emergence.…”

Modelling the Effects of Mass Drug Administration on the Molecular Epidemiology of Schistosomes

“…Zoonotic reservoirs affect the transmission dynamics of a disease and can limit the extent to which a pathogen can be controlled or potentially eliminated (Taylor et al, 2001). Work on the zoonotic S. japonicum offers an example of how inter-disciplinary research with population genetics and modelling can be done successfully.…”