Third Avian Influenza Case Identified

Yesterday, the Michigan Department of Health and Human Services (MDHHS) announced a new case of influenza A (H5) in a Michigan farmworker, which makes it the second case in the state and third overall in the US.¹

This person worked closely with influenza A (H5) positive cows, and was employed at a different farm than the other case that was announced previously on May 22.¹

In this latest case, the individual experienced presented with more typical symptoms including respiratory issues after direct exposure to an infected cow. This differs from the first 2 US cases where the individuals’ primary symptom had been conjunctivitis.¹

In the first case in Michigan, the farmworker contract H5N1 after a direct splash of infected milk to the eye. This offers evidence into transmissibility.¹

“Neither individual was wearing full personal protective equipment (PPE). This tells us that direct exposure to infected livestock poses a risk to humans, and that PPE is an important tool in preventing spread among individuals who work on dairy and poultry farms,” Natasha Bagdasarian, MD, MPH, FIDSA, FACP, chief medical executive, for the State of Michigan, said in a statement.¹

This third infected individual is recovering and was prescribed antivirals.¹

Previous Cases
The first case in Michigan was diagnosed in a farmworker who had mild symptoms and has since recovered.² This news comes almost 2 months after the first human case of avian influenza A in the United States was reported by the Texas Department of State Health Services.² That person became infected following contact with dairy cows presumed to be infected with avian influenza. The person’s primary symptom has been conjunctivitis and is being treated with an antiviral. The person was told to isolate while in recovery.²

Michigan’s Response, Risks of Human-to-Human Transmission
"Michigan has led a swift public health response, and we have been tracking this situation closely since influenza A (H5N1) was detected in poultry and dairy herds in Michigan. Farmworkers who have been exposed to impacted animals have been asked to report even mild symptoms, and testing for the virus has been made available,” Bagdasarian said.¹

“We have not seen signs of sustained human-to-human transmission, and the current health risk to the general public remains low,” Bagdasarian stated.¹

References
1. Additional influenza A (H5) case detected in Michigan. Michigan Health and Human Services news statement. May 30, 2024. Accessed May 31, 2024.
https://www.michigan.gov/mdhhs/inside-mdhhs/newsroom/2024/05/30/h5n1-updates
2.Parkinson J. Second Case of Avian Influenza Confirmed in United States. Contagion. May 22, 2024. Accessed May 31, 2024.