Research shows that a single mutation in the H5N1 virus that recently infected cows is enough to increase its potential for human-to-human transmission and the risk of becoming a pandemic.
Moreover, by exchanging genes with other human influenza viruses, it could acquire pandemic potential almost instantly. These observations highlight the importance of monitoring the evolution of the virus.
The bird flu epidemic that has hit dairy farms in the United States is causing increasing concern. Although the virus initially infected only poultry and seabirds, it has begun to spread to cattle and pets since March. Over the past week, the virus has been detected in 675 cow herds in 15 US states. It has also caused fatal infections in many other mammals that have come into contact with infected birds.
To date, there have been no cases of human-to-human transmission of the virus. Human cases identified in recent months have been linked to contact with contaminated environments or animals. However, health authorities are concerned about the virus’s ability to spread more efficiently among people. Last October, the virus was first detected in pigs, which are excellent incubators for the virus, indicating that it quickly mutates and expands its range of potential hosts.