Scientists use AI to predict diseases carriers
With so many animals and unpleasant bacteria and viruses in the world, working out which ones might infect humans is a difficult job.
One such disease is the plague, known during the Middle Ages as the Black Death. So devastating were its effects that it killed one-third of Europe’s population in just eight years between 1346 and 1353. It was caused by a bacteria carried by fleas, which in turn lived on black rats. Such diseases, which can transfer from animals to humans, are known as zoonosises. Ebola fever, as well as swine and bird flu, are examples of these.
Now Barbara Han and her colleagues from the Cary Institute of Ecosystem Studies in New York have developed a form of AI, called machine learning, to search for species that could carry diseases. This technique allows computers to analyze large sets of data and identify patterns that would be too much for the human mind. Dr. Han and her team published their findings in the Proceedings of the National Academy of Sciences.
Previous research had revealed that of the more than 217 of the 2,200 species of rodent carry pathogens, including viruses and bacteria, and protozoa and worms. Seventy-nine of these carry more than one.
Dr. Han used 86 criteria to characterize rodent species, such their speed of reproduction, and type of habitat and physiology. Researchers then did the same with rodent-born bugs and fed all the data into computer programs to predict if a particular rodent species is likely to harbor something that can cause disease in humans.
The computers predicted known disease-carrying rodents with 90 percent accuracy. The software also concluded that such species tend to have short lives and gestation periods, large litters, and reach sexual maturity early, the Economist reported. They were also discovered to live near large human populations and in areas with few other rodent species. In addition, such species tend to be far ranging.
Species with short lifespans and which breed rapidly tend to devote fewer resources to fighting off diseases. Their evolutionary strategy is to deal with illnesses by outbreeding them.
The scientists then asked the computer to look at species not known to carry human pathogens, but which could have this capability. Some 150 of were found. Another 50 already known to carry at least one human disease, were found to be capable of carrying other pathogens as well.
Dr. Han stressed that the results are statistical rather than definitive, and predictions could not be made with certainty that a particular species was carrying a disease transferable to humans.
The researchers also found a number of hotspots around the world likely to harbor disease-carrying rodents. Central Asia, in what is now Kazakhstan and northern China, was one such area, as were the states of Kansas and Nebraska in the American prairie region.