One Health: perspectives on ethical issues and evidence from animal experiments

Abstract

Zoonoses constitute more than 60% of all known infectious diseases and 75% of emerging infectious diseases. Their impact is not monitored, prevented and treated in an integrated way. The efficacy of therapeutic interventions for zoonotic diseases is deemed to be comparable across species with scientifically valid results originating from a range of animal experiments. Ethical obligations limit the number of animals used in experiments as well as reduce repetition of studies. The evidence based on randomized controlled trails and systematic reviews for the effectiveness of health care interventions is often inconclusive. Subjecting human volunteers to risk in the absence of scientifically valid results from animal experiments is unethical. The One Health concept is a comparative, clinical approach directed towards zoonoses which present challenges to research workers and clinicians. Optimal health for all-One Health-should be underpinned by ethically conducted research in animals or humans and the results should be complementary to both.

Bradford Hill’s criteria, emerging zoonoses, and One Health

“…The World Health Organization [10] defines emerging zoonosis as ''a zoonosis that is newly recognized or newly evolved, or that has occurred previously, but shows an increase in incidence or expansion in geographical, host or vector range". Important drivers (social, ecological, economic, epidemiological, and evolutionary) of zoonoses emergence and transmission are: (1) infectious dose; (2) the density of the host and vector population; (3) number of biological (microbial genetics, pathogenesis) and environmental characteristics (climate change, molecular ecology); (4) reassortment or recombination in multiple hosts, or pathogens that infect species that can harbor multiple closely related agents; (5) routes of transmission by more than one or by indirect contact; (6) anthropogenic practices (land use, travel, and intensified animal production systems); (7) antimicrobial use; (8) loss of biodiversity; and (9) breakdown of public health measures.…”

“…People and animals have been in close contact since the domestication of animals, which has assisted in the swapping of diseases and their spread. The shared risks between humans and animals concerning zoonoses, compels the adoption of One Health among human and animal health professionals to identify and reduce such risks [6]. By definition, One Health is a multidisciplinary concept based on a systems approach, which amalgamates the ''collaborative effort of multiple disciplines working locally, nationally, and globally to attain optimal health for people, animals and our environment" [7].…”

Abordagem Da Saúde Única Na Ocorrência De Enteroparasitas Em Humanos De Área Urbana No Norte Do Paraná

“…Para reduzir os riscos de infecção diante dessa nova interação entre humanos e animais de estimação, é fundamental que a saúde da família seja monitorada de forma única, com interação entre profissionais da área humana e animal (ASOKAN et al, 2012).…”

Disaster response under One Health in the aftermath of Nepal earthquake, 2015

“…Existing surveillance systems for zoonoses have substantial gaps, especially in developing countries like Nepal. The two general surveillance systems for early warning and preparedness: “syndromic surveillance” and “risk surveillance” should be commissioned for unbridled joint signaling for a regular rapid flow of information between veterinary and health sectors, give early warning of pathogen emergence, and focus on determinants of disease emergence [ 40 ]. Therefore, a One Health understanding is essential for the identification of opportunities at the interface of Himalayan livestock populations and the pastoralists that depend on them.…”