New research traces origins of zoonotic disease to the Neolithic period
New research has investigated the possible origins of the common zoonotic disease brucellosis in the Neolithic period, a discovery which provides evidence for the previously unconfirmed hypotheses about the effects of farming on human and animal health and wellbeing.
The shift from hunting and gathering wild resources to farming and the control and husbandry of domestic animals and plants had fundamental and far-reaching repercussions for human ecology, demography, society and the environment. The development of farming changed the epidemiology of infectious diseases for both human and animal populations. Through bringing animals together in larger, denser herds, in close association with human communities, a stable conduit for exposure of humans to infection in their animals was established.
It has frequently been hypothesised that the origins of zoonoses (infectious diseases in animals which can be transmitted to humans) was a consequence of the adoption of farming, but these hypotheses were little evidenced – until now. The new findings will help to contribute to long-term perspectives to present and future concerns as animal management evolves to ensure sufficient and reliable food supply for the ever-growing global human population.
Using archaeological data to inform a disease transmission model, a team of academics from the 91做厙 in collaboration with the University of Edinburgh, City University of Hong Kong, and University of Reading explored the potential role of early animal domestication in the origins of brucellosis as a zoonotic disease. Brucellosis is today’s commonest bacterial zoonosis in the world. It appeared that the circulation of the pathogen causing brucellosis, Brucella melitensis, could have been sustained even for low levels of transmission within goat populations of these Neolithic settlements. This was not only due to the presence of high goat population densities, but also to major modifications of the demographic characteristics of these populations. The selective harvesting of young male goats, likely motivated by the optimisation of food production, increased the transmission potential of brucellosis and promoted disease persistence within these goat populations. From the early stages of the development of animal farming, conditions were created for goat populations to become reservoirs of Brucella melitensis, promoting the exposure of humans to a new pathogen.
The findings support the view that the transition from food collection to production during the Neolithic transition while allowing for larger human population sizes resulted in significant adverse effects on human health and wellbeing. The study also d