HPAI virus zoonotic mutation found in the brains of wild carnivores
A new study on wild carnivore species infected with HPAI virus subtype H5N1 during the 2021-2022 outbreak in the Netherlands discovered the zoonotic mutation PB2-E627K in 8 of 11 cases. The fact that this mutation was not found in any wild bird sequences during the 2021-2022 Dutch epizootic suggests that it appears quickly after mammalian infection. The mutation E627K is most likely an adaptation to the lower body temperature in mammalian upper respiratory tract compared to avian species. The presence of the mammalian adaptation marker E627K in many carnivore viruses suggests that this virus can quickly adapt to replication in mammals.
Most of the animals were submitted for testing because they displayed neurological symptoms.
The HPAI H5N1 virus was detected by PCR and/or immunohistochemistry in 11 animals in this study, and it was primarily present in brain tissue, frequently associated with (meningo) encephalitis in the cerebrum. In contrast, the virus was only rarely found in the respiratory and intestinal tracts, and the associated lesions were minor. According to the findings of this study, brain samples should be included in wildlife surveillance programs for the accurate detection of the HPAI H5N1 virus in mammals.
