A new global review reveals how quickly the influenza influenza viruses are evolving to new species, including dairy bovine, and emphasizes the urgent need for coordinated action to prevent the next pandemic.
Three influenza virus particles (H5N1/Bird flu) (rod -shaped). NOTE: The layout incorporates two thumbnails that have been renovated, repositioned and colored by NIAID. The scale has been modified. Credit Picture: CDC and NIAID
Since its discovery in 1996, the GS/GD genealogy of bird influenza viruses with H5 with hematopoiesis, including H5N1 and other H5NX subtypes, has caused widespread infections and mortality between many animal species and sporadic infections, Antarctic.
In a recent review published in the magazine Nature reviews microbiologyResearchers in the Viroscience, Erasmus MC section, the Netherlands, reviewed the current knowledge of evolution, global spread and the growing risks posed by persistent and adaptable virus.
Influenza
Influenza A viruses have caused four human pandemics and countless outbreaks between animal populations in the last century. Among them, the high -pathogenic virus of the birds of birds (HPAIV) are a significant threat because of their ability to evolve rapidly. While most bird flu viruses circulate harmlessly among the wild aquatic birds, some have been mutated into more deadly forms, especially in H5 and H7 subtypes. When these viruses have leaked to poultry, they can evolve into extremely pathogenic forms that cause serious illnesses and death.
The GS/GD genealogy of the H5 viruses, which includes the well -known H5N1 subtype (which is first determined by humans in Hong Kong in 1997) and other H5NX variants, has emerged from a complex mixture of bird viruses and has been differentiated in many generations. This genealogy has become a dominant global threat, spreads to all continents and infects a wide range of birds and mammals. In addition, despite the ongoing attempts at surveillance and control, the gaps remain in understanding the way it evolves, evolves and adapts to new hosts, including people.
The current study
The researchers carried out a comprehensive review of scientific literature, surveillance reports and genetic analysis to understand the evolution and spread of high pathogenic viruses of H5 GS/GD lines. They watched the origin of the virus back in a 1996 outburst of domestic geese in Guangdong, China and followed its genetic differentiation through world restaurants over the last 25 years.
The group examined how the virus has changed through a process known as a redesign, where genes from different influenza viruses are mixed in co-polluted hosts, creating new virus variants. They focused on fireplaces on wild birds, poultry and mammals, including tigers, marine lions, boots and dairy bovine.
The study also analyzed how the virus crosses the barriers of species. This included the review of molecular data in mutations in viral proteins, including hemosiplitine, neuralidase and polymerase ingredients, which help the virus adapt to mammalian cells. Hemositin structural characteristics were examined that affect the commitment to host receptors, as well as changes in the polymerase of viral ribonucleic acid (RNA) that enhance copying in mammals. In addition, the study explored immunoocials in different species and how the virus avoids these defenses.
In order to assess the impact on human health, the authors also examined the evidence of confirmed human infections, exposure risks and clinical symptoms, considered the role of environmental and agricultural practices to facilitate the spread of the virus and examined the current measures such as controlling measures.
Basic findings
The study said that viruses of GS/GD genealogy have been significant genetic development, allowing them to infect a wider range of species and insist on worldwide. The virus, which was originally released on poultry, has now spread to wild birds and mammals, including rare travelers in humans.
More worrying, it has recently arrived in dairy cattle in the United States, where it has spread mainly due to the movement of contaminated animals among farms. Infected milking equipment facilitates transmission within farms and causes extensive infections. The virus has now been detected on every continent, including Antarctica, marking an unprecedented expansion.
Its ability to redefine with other influenza viruses has also created multiple variations, including those with new combinations of genes that enhance mammals adaptation. This genetic mixing has also improved the virus’s ability to bind to human receptors and to resist the innate mammalian immune defense.
Since 1997, there have been over 1,000 laboratory confirmed cases of GS/GD lines in humans, with more than 500 deaths reported. However, the actual mortality rate is uncertain because of the possible inadequate reporting of mild and subclinical infections and the variability of severity between restaurants. Most infections occurred after direct contact with contaminated poultry, but recent cases in the US involved in dairy workers have proposed new transmission routes. Although no prolonged human transmission to humans has occurred, the increase in mild or detected human infections raises concerns about the potential of pandemic.
The virus also had disastrous effects on the wild, with high mortality between marine lions, seals and birds documented throughout America and Europe. Mammalian transmission to mammals, especially in farmed Mink and Sea Lion colonies, also shows that the virus can evolve to the most effective spread between mammals.
The review emphasizes that the options available for the management of wildlife restaurants are limited and may include removal of the slaughter and targeted vaccination of endangered species.
Conclusions
The continued spread and evolution of GS/GD H5 viruses, including H5N1 and other H5NX subtypes, underline the serious threat that these influenza viruses put on animals, ecosystems and human health. With the increasing proof of transmission and global distribution, this virus remains a threatening concern.
The review emphasizes the critical need for a unified “health” approach that incorporates animal, human and environmental health strategies worldwide. The review has shown that enhancing surveillance, promoting strategic vaccines, expanding the use of newest vaccine technologies, coordinating international reserves and vaccine development and integrating efforts into animals and human health are critical measures to prevent future measures.
