Dogs and Cattle Offer Clues about the Emergence of New Diseases

Researchers provide evidence on how pets and other domesticated animals offer clues on the rise of infections that can be easily transmitted between humans and animals.

The amount of parasites and pathogens a human is infected with totally depends on the duration the animals have been domesticated, claim researchers at the University of Liverpool.  They also suggest that the crucial link in the emergence of new infections is provided not by wild animals but humans' oldest companion i.e. livestock and pets like cattle and dog. 

To verify all the known cases of parasites and pathogens in domestic animals along with the duration the have been domesticated by humans, the researchers used the data from current studies and also gathered database of Liverpool ENHanCEd Infectious Diseases (EID2).

Analysis of the data revealed that, dogs that have been domesticated for 17,000 years nearly 71 parasites and pathogens were transmitted to humans and in 11,000 year relation between humans and cattle nearly 34 such infections have been accumulated.

"We don't have enough knowledge of how new diseases get from wildlife into humans. This study shows that domesticated animals can play an important role in that process and that diseases have been shared in this way for thousands of years," said Dr Marie McIntyre and epidemiologist who was a part of the study.

In order to determine those domestic animals that are located in the centre of the web of shared infections, they examined the 'centrality'.  These animals play an active role in spreading infections to other domesticated animals and this centrality is further associated with the length of time right from when domestication was initiated.

The EID2 data used was created by University researchers with an aim to provide 'big data' approach to the emerging diseases.  It carries details on the spread and emergence of pathogens globally and can be used as a cross reference with data on climate change that also influences the spread of disease.

Dr McIntyre said, "Using data in this way can help us address the major threat of new diseases and the spread of existing diseases caused by climate change. Vast amounts of research are being carried out in this field, yet it isn't easy to search or draw patterns from it. As with this research into domestic animals, a database can help by bringing huge amounts of evidence together in one place."