An estimated 2.2 million people in the world die annually because of infectious diseases from animals. With such a high mortality rate, scientists have started to identify which specific creatures are the most likely to carry deadly illnesses and where they can be found. The result is a comprehensive map of viral hotspots in the world.
In a study featured in the journal Nature, researchers from EcoHealth Alliance in New York examined various animals that could likely serve as carriers for infectious diseases. They focused their study on viral infections from mammals since humans are particularly vulnerable to these illnesses, possibly due to the similarities in biologies.
The scientists' search centered on zoonotic diseases, which are illnesses known to spread from one species to another. They wanted to know what exactly happens when these pathogens are transmitted from animals to humans during a "spillover event."
To help them find out more, the researchers collected viral data from 754 different species of mammals. This number represents 14 percent of all known mammals in the world. These were combined with information on 585 different viruses known to infect mammals. About one third of the viruses examined have been known to infect humans as well.
The researchers also added information on various mammalian family types and where they can be found in the world. They then determined the likelihood of the mammalian viruses to infect humans using a mathematical model.
Danger Map Of Animal-To-Human Diseases
Using the comprehensive list of viruses that they have created, the researchers were able to identify mammals that pose the biggest threat in terms of animal-to-human infection.
Topping the list are bats, which have been known to transmit several diseases such as Ebola, Histoplasmosis, Hendra virus disease and Marburg hemorrhagic fever. They can also infect humans with severe acute respiratory syndrome. The research team estimates that bats could carry an additional 17 other zoonotic viruses that have yet to be identified.
Primates have also been found to be primary sources of animal-to-human diseases. Of these mammals, the ones from Africa, Central America and Southwest Asia appear to be the most likely virus carriers.
Coming in at third are rodents, which many believe helped spread the Black Death that almost wiped out the population of Europe during the mid-1300s. The study showed that rodents living in Central Africa and in North and South America are the ones most likely to infect humans.
The researchers said there are still approximately 10 more zoonotic viruses that have yet to identified in primates and rodents.
While the study helps identify potential carriers of animal-to-human diseases, it is important to note that its estimates were produced through computer modeling and contain incomplete information. The researchers hope that they would be able to add more information to their database over time so that they could refine their findings further.
Once the database is complete, the research team believes it could help determine when and where the next catastrophic pandemic could occur. This would allow fellow scientists to prevent a disease outbreak from happening, or at the very least prepare public health agencies beforehand.
