The Colorado Department of Public Health and Environment (CDPHE) has reported five human H5 avian influenza infections in workers who were part of the response to a recent large outbreak at a layer farm, four of which have been confirmed by the US Centers for Disease Control and Prevention (CDC).

Patients have eye, respiratory symptoms

The patients have mild illness, including conjunctivitis and common respiratory symptoms. None were hospitalized, according to statements from the CDPHE. Though officials haven’t said if the virus on the poultry farm is the same as the B3.13 genotype infecting dairy cattle, conjunctivitis has also been reported in four dairy farm workers over the past few months.