A research study released in the CDC journal Emerging Infectious Diseases explains the recognition of an extremely pathogenic bird influenza An infection in a domestic cat that lived near a duck farm contaminated by a carefully associated infection in France in December 2022.
Background
A case of extremely pathogenic bird influenza A (H5N1) clade 2.3.4.4b virus infection in a domestic cat was verified by the bird influenza National Reference Laboratory of the Agency for Food, Environmental and Occupational Health & Safety in France on December 27, 2022.
The cat lived beside a duck farm, in which a comparable infection was found in more than 8,000 ducks in December 2022. The cat at first experienced a degeneration in basic health condition, consisting of passiveness and moderate hyperthermia, followed by serious neurologic and breathing signs.
The cat went through caring euthanasia on December 24, 2022. Laboratory screening of breathing and anal samples of the cat verified extremely pathogenic bird influenza A (H5N1) clade 2.3.4.4b viral infection.
Study observations
Scientists compared the total viral series separated from the cat with other carefully associated viral series distributing in France throughout the exact same duration, consisting of those separated from the duck farm.
Phylogenetic analyses showed that the cat-isolated infection came from the duck-isolated virus-like genotype. This viral genotype has actually primarily flowed in France and Europe given that September 2022.
The cat-isolated infection varied from the duck-isolated infection by just 2 anomalies, consisting of an E627K anomaly in polymerase basic protein 2 and E26G anomaly in nonstructural protein 2.
The E627K anomaly is accountable for influenza infection adjustment to mammalian hosts. The E26G anomaly, on the other hand, may have a function in viral adjustment to temperature level modifications.
Among 90 openly available series of extremely pathogenic bird influenza A (H5N1) clade 2.3.4.4b infections found in mammals, 20 had the E627K anomaly, showing a quick choice of this anomaly in mammalian hosts.
A sharp increase in mammalian cases of extremely pathogenic bird influenza A (H5N1) clade 2.3.4.4b infections has actually been observed given that winter season 2021-22.
A greater frequency of extremely pathogenic bird influenza H5 infection infections in wild and domestic birds and an increased interaction in between contaminated birds and mammals may be accountable for this increase.
Another factor might be increased security of bird influenza in wildlife, resulting in more detection of infection in mammals. In addition, a greater capability of presently distributing infections to contaminate mammalian hosts may be accountable for the increase in mammalian cases.
In mammals, extremely pathogenic bird influenza A (H5N1) virus infection is generally connected with medical discussion (neurologic signs) or death.
Although inter-mammal transmission of this infection is an unusual occasion, enormous infections in seal nests in the United States and a mink farm in Spain in 2022 have actually been reported. In the present research study, nevertheless, no inter-mammal infection transmission was found.
Study significance
The research study explained a case of extremely pathogenic bird influenza A (H5N1) clade 2.3.4.4b infection in a domestic cat in December 2022. Sporadic infections by extremely pathogenic bird influenza A (H5N1) clades one and 2.2 have actually been found in cats given that 2004.
As discussed by researchers, close interactions in between domestic cats and human beings and quick choice of anomalies might trigger an infection with the capacity for inter-human viral transmission. This might be a prospective public health risk.
Given the research study findings, researchers advise increased security of symptomatic domestic predators near to contaminated birds. This is required to recognize inter-mammal transmission occasions and avoid human transmission quickly.
In addition, staff members in bird farms ought to be supplied with suitable protective equipment and barrier procedures to prevent direct viral transmission from contaminated birds.
