First case of HPAI (H5) detected in Michigan resident
The Michigan Department of Health and Human Services (MDHHS) announced its first case of the influenza A (H5) virus in a Michigan farm worker who had regular exposure to livestock infected with influenza A (H5). This follows extensive public health actions over the past few months by the state of Michigan to enable farm workers to monitor their health and notify local public health officials if they develop symptoms. The farm worker reportedly had mild symptoms and has since recovered.
According to genomic analysis performed by US CDC, the identified virus belonged to HA clade 2.3.4.4b, genotype B3.13. The genome of the virus was closely related to viruses found in dairy cattle, suggesting cow-to-human transmission. The E627K mutation observed in the PB2 segment of the virus from the Texas case was not present. The genome of the virus from the Michigan case did, however, have the PB2 M631L change, which is associated with viral adaptation to mammalian hosts and has been observed in 99% of virus sequences from dairy cows but only occasionally in birds.
