Are all viruses "pathogenic"? wrong!
The new crown virus is raging around the world, causing many people to talk about the discoloration of the virus. Are all viruses intended to be "pathogenic"? actually not. In fact, there are many viruses that, despite infecting humans, coexist with humans for a long time and usually do not cause disease.
In recent years, the rapid development of genomics has enabled researchers to detect many viruses that are present on the human body and in the body. These viruses are collectively referred to as the "human virus group".
Recent genomic studies of human samples have found dozens of unrecognized viruses in our intestines, lungs, skin, and blood. Among them, some may be the root cause of some unknown diseases, but some are just a "harmless existence" most of the time.
Occasional pathogenicity is a typical feature of the human virus family. For example, herpes virus infects adults is a common phenomenon and they can live "asymptomatically" in cells of the immune system for long periods of time. However, at the end of the host's life, or after immunity is suppressed, these latent herpes viruses become active, inducing many diseases such as cold sores, meningitis, lymphoma, or Kaposi's sarcoma.
In addition, large numbers of new viruses can often be detected in respiratory and fecal samples from healthy people, especially children, including an increasing number of astroviruses, parvoviruses, picornaviruses, and others in human health and disease. Unknown virus.
This information indicates that even in good health, the human body is chronically infected with multiple viruses and often temporarily infected with other viruses. Therefore, the idea that every human virus causes disease is giving way to a more complex biological reality. Understanding how these newly discovered viruses affect humans can help "classify them": determine what should be prevented and treated, and what can be ignored or even co-exist with them.
Human infection with the virus at an early age may help the normal development of the immune system and provide protection against future viral infections. At the same time, the immune system can be trained to prevent allergies due to overreaction.
Some symbiotic viruses can also provide protection for the human body against other pathogenic viruses. It is reported that a virus belonging to the same family as hepatitis C virus, Zika virus and dengue virus can actually reduce the symptoms of HIV infection.
Another potential benefit of resident viruses is their preference for rapidly dividing cells. Researchers have observed that while the virus is infected, some spontaneous cancers have subsided-suggesting that the virus may preferentially infect cancer cells. To this end, the biomedical community has begun to develop oncolytic virus therapies against human tumors. Whether virus infection and cancer cell ablation is a common natural phenomenon is still an interesting research topic.
The long evolutionary history of symbiosis with a large number of bacteria and viruses has pushed humans to adapt to many viral infections-from the cellular level (domestication of retroviral genes, overreaction of the immune system) to the cultural level (adjusting lifestyle habits to reduce The burden of infectious diseases), and the survival strategy of "coexisting with viruses" is everywhere.
With the continuous improvement of sequencing technology and computing platforms, coupled with the researcher's generation of a more complete human virus genome catalog, the ability to detect viral infections will be faster and more sensitive. Based on stronger detection and analysis capabilities of blood droplets, respiratory tract or stool samples, public health workers can quickly learn about emerging viruses and better control the outbreak of infectious diseases. Rapid identification of known viral pathogens can reduce unnecessary antibiotic use.
Genomics methods will also enable epidemiological studies to make more accurate predictions about which viruses are associated with which diseases in different geographic areas. This information will determine which viruses will cause the greatest disease burden, and help develop the most effective vaccines to reduce virus transmission.
Plans are under way to sequence all viruses that infect mammals and predict which ones are most likely to spread to humans. Human viruses may also be more pathogenic through mutation or recombination with animal viruses.
In addition, better understanding of the causes of some viruses and continuous testing of virus strains in healthy and diseased populations, especially those that interact between humans and animals, can be the next major virus outbreak. Prevalence provides early warning signals. (Guan Yue)