A group of international scientists have completed the first global inventory of flu strains in birds by reviewing more than 50 published studies and genetic data, providing new insight into the drivers of viral diversity and the emergence of disease that can ultimately impact human health and livelihoods.
The research, published in the journal PLOS ONE and performed as part of the USAID PREDICT project, identified over 116 avian flu strains in wild birds. This is roughly twice the number that were found in domestic birds, and more than ten times the number found in humans. Additionally, an analysis of studies that sampled more than 5,000 birds suggested some regions may have more viral diversity than others.
Avian flu outbreaks come with no warning. In 2013, an H7N9 avian flu strain caused a deadly outbreak in people in China. This surprised virologists, as the strain had never before caused disease in humans. To date, there have been more than 300 clinical cases of H7N9 with a 33 percent mortality rate. This year, another strain known to infect birds, H10N8, has caused human cases for the first time.
As was the case in the H7N9 outbreak, most direct bird-to-human spillover events (when a virus jumps from one species to another) of avian flu can be traced back to human contact with domestic poultry. Although avian flu strain diversity often originates in wild birds, it is the mixing of viruses among poultry, pigs, and people that substantially heightens the disease risk in humans.
In an effort to improve preparedness, scientists are looking to better understand and monitor the diversity of all avian flu viruses not just those known to cause disease. Completing the first global inventory of flu strains in birds is a key step in building that understanding.
"This snapshot of the world of flu virus diversity in birds is the outcome of many years of ecology and evolution, as viewed through the lens of sur
|Contact: Scott Smith|
Wildlife Conservation Society