An article published in the journal “Nature” describes the discovery of 1,445 new RNA viruses, or retroviruses, including some previously unknown families. A team from the University of Sydney and the Chinese Centre for Disease Control and Prevention in Beijing focused on invertebrates to discover the viruses that infect them. The use of new technologies allowed to extend the knowledge of virus families but also of for ways to determine what cause human diseases.

Invertebrates, animals such as insects, spiders, worms and others, make up most of the living species on Earth and many of them live in our homes. So far our knowledge of the potential risks of contracting diseases due to viruses passed by them were limited but this new research conducted on 220 species of invertebrates belonging to 9 different phyla could really change this situation a lot.

The researchers used an approach called metagenomics used because it allows not to lose the microbial diversity, unlike the cultivation in laboratory. It’s based on the collection of samples at a certain site where microorganisms’ growth is stimulated and not on their growth in laboratory.

According to this research, human beings live surrounded by viruses and many of them are carried around by invertebrates. The good news is that they generally don’t easily transfer to humans. Some types of infections transmitted by mosquitoes are well known but luckily they are exceptions. However, according to this research diseases such as influenza are derived from viruses present in invertebrates that move to mammals, including humans.

In essence, it’s possible that invertebrates are the real hosts for many types of viruses and that this kind of parasitism existed since the birth of the first invertebrates. According to the researchers retroviruses might exist in all species of cellular life. Nevertheless, so far studies on invertebrates were scarce, with the result that this research led to the discovery of a diversity greater than that existing in the current classification schemes.

The statements and conclusions of the researchers are really strong and promise to rewrite virology textbooks. Lately research on microorganisms increased thanks to the advances in genetic techniques: in this case, the scientists focused on viruses, their colleagues sometimes focused on other types of microbes such as in the research published a few weeks ago. The advances in this field are really fast!