The Centers for Disease Control and Prevention (CDC) today announced a third human illness from H5 avian influenza in a dairy farm worker, but unlike the earlier cases, the patient is experiencing respiratory symptoms.
In a statement, the CDC said the latest sick dairy farm worker was exposed on a different farm than Michigan's earlier case. Michigan has been hit hardest by the dairy farm outbreaks and has reported 22 outbreaks across 10 of the state's counties.
The Michigan Department of Health and Human Services (MDHHS) said the patient had worked closely with H5-infected dairy cows.
Patient has respiratory symptoms
The patient reported symptoms, including cough without fever and eye discomfort with watery discharge, to local health officials. Michigan health officials are using a text-based monitoring system for people exposed to H5N1-infected cows.
The 2.3.4.4b H5N1 clade circulating globally is known to cause a range of illnesses, from no symptoms to severe or fatal outcomes.
Natasha Bagdasarian, MD, MPH, chief medical executive at the MDHHS, said health officials have been tracking the situation closely since the virus emerged in poultry and dairy cows. "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."
Oseltamivir was given, and the patient is isolating and recovering at home. Contacts are free of symptoms so far, and no other infections have been reported in the farm's other workers.
The patient's samples were positive for H5 on a CDC test conducted at Michigan's state health department lab, and tests by the CDC yesterday confirmed the findings. Genetic sequencing of the virus that infected that patient is under way at the CDC.
"The identification of an additional case of H5 is not surprising and shows the importance of a proactive public health response," the CDC said, adding that the risk to the general public remains low.
Michigan patients weren't wearing full PPE
Bagdasarian said Michigan's first patient experienced eye symptoms after a direct splash to the eye from infected milk, and the second patient had direct exposure to a sick cow.
"Neither individual was wearing full personal protective equipment (PPE)," she said. "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."
The CDC had earlier issued interim PPE recommendations for dairy farm worker protection, and federal officials have encouraged states to provide PPE to farm workers. In new guidance, the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) yesterday issued PPE recommendations for people visiting H5N1-infected herds.
Earlier cases in the United States include a Texas dairy farm worker who had conjunctivitis in early April and an individual from Colorado who had little to no symptoms after participating in poultry-culling operations and whose illness was reported in early April.