Veterinarians in Canada have discovered the first evidence that at least two highly contagious strains of avian influenza, H5N1 and H5N5, can be transmitted from infected sheep to their young through milk.
First evidence of highly contagious avian influenza being transmitted through sheep's milk
Illustrative image / Sputnik
Read more
The journal Science Advances indicates that researchers have stressed the need to take this discovery into account when combating the spread of infection on farms, after finding evidence suggesting the possible transmission of two highly contagious types of avian influenza, H5N1 and H5N5, from infected sheep to their young through milk.
The researchers said: "These viruses are evolving rapidly and spreading to new animal populations, posing a significant threat to their survival and to public health. We have found that they are able to actively replicate in the mammary glands of sheep and be transmitted through milk to their young, which is crucial when monitoring the spread of influenza and protecting domestic animals."
According to the study, this research was launched after a possible case of severe avian influenza (H5N1) was detected on a British farm, prompting a research team led by Johannes Berhein from the Canadian National Centre for Exotic Animal Diseases to conduct an in-depth study on the behavior of the virus in sheep and its transmission methods within the flock.
During the experiments, the researchers injected particles of the H5N1 and H5N5 viruses into female sheep and monitored the development of the infection. The results showed that the two viruses actively multiply in the mammary glands and accumulate in the milk, allowing them to be transmitted to lambs through lactation, in addition to the possibility of transmission within the flock through direct contact.
It was also noted that the infection was accompanied by symptoms such as mastitis, fever, and a clear immune response, indicating a direct effect of the virus on the animal's health.
The researchers concluded that highly contagious avian influenza can spread among sheep flocks not only through droplets or contact, but also through milk, which, according to their recommendations, necessitates including it in veterinary monitoring and farm safety procedures, along with strengthening prevention measures and limiting the spread of infection.
It should be noted that scientists have documented over the past four years the rapid spread of highly contagious avian influenza (H5N1 and H5N5) among large numbers of wild animals and birds in Europe and the United States.
