Where do viruses dangerous to humans come from, and how have they evolved? Scientists working with Prof. Dr. Christian Drosten, Head of the In-stitute for Virology at the Universit-tsklinikum Bonn, have made significant progress in answering this question. "We already knew from prior studies that bats and rodents play a role as carriers of paramyxoviruses," said Prof. Drosten. The many varied members of this large virus family cause, e.g., measles, mumps, pneumonias and colds. The highly dangerous Hendra and Nipah viruses cause types of encephalitis that result in death for one out of two patients. Paramyxoviruses also play a role in veterinary medicine, causing e.g., canine distemper or rinderpest.
Researchers double the number of known paramyxovirus species
With support from numerous scientific institutes in Germany and around the world, they tested a total of 9,278 animals from Europe, South America and Asia, including 86 bat and 33 rodent species. "These animals live in very large social communities with millions of individuals in some cases," reported the Bonn virologist. "Their close contact promotes mutual infection and provides for great variety in circulating viruses." Using molecular biology methods, the scientists identified which virus species are rampant in bats and rodents. According to their own estimates, they discovered more than 60 new paramyxovirus species. "That is about as many as the number that was already known," said Drosten.
Bats are the original paramyxovirus hosts
Using computational biology methods, the scientists calculated a common evolutionary tree for the new and the known viruses. They then deduced, using mathematical methods, in which host animals the viruses have most likely taken up residence during their evolutionary history. "Our analysis shows that almost all of the forebears of today's paramyxoviruses have existed in bats," explained Prof. Drosten. "Just as with influenza, where we are keeping an eye on birds as a source of new pandemic viruses, we will now have to study the bat viruses to see if they are a danger to humans." So, the current data might play a useful role in early detection and prevention of epidemics - a major new goal in virus research.
Mumps viruses have jumped to humans