Cows infected by bird flu in Minnesota, but human threat very low

Measles remains on the watch list, COVID-19’s presence is low

A measles vaccine is prepared
Measles— known to be very infectious among humans, but also having a highly effective vaccine — was detected among more Minnesotans in May.
Fiona Goodall | Getty Images 2019

The bird flu outbreak continues to gain steam nationwide, with over 17 million chickens, turkeys and ducks impacted across 26 states to date so far this year. While this rapid spread is concerning, the threat to human health is very low.

So far this year there are four known cases of human infection in the nation. Three worked closely with infected dairy cows and the other with infected poultry. Two reported eye infections, one had respiratory symptoms and another had fatigue. 

As reported by the University of Minnesota’s Center for Infectious Disease Research and Policy, “The World Health Organization (WHO) has confirmed that a 59-year-old Mexican man with no known exposure to infected animals has died after being infected with the H5N2 subtype of avian flu.” H5N2 is different from the H5N1 subtype that is widely circulating in the U.S. 

Health officials are monitoring the spread of bird flu extremely carefully, since it has now done something relatively rare: leaping from birds to infecting domestic goat and cow herds.  

Back in March, the Minnesota Animal Board of Health detected “the first known U.S. avian influenza infection in domestic ruminants” — in that case a small herd of young goats in Stevens County. On June 6, MPR News reported that the first case of avian flu in a Minnesota dairy herd had been identified in Benton County. Since that time two additional infected cattle herds have been reported, one in Lincoln County and another in Sibley County. This Thursday, Animal Board of Health announced that dairy cows headed to a Minnesota county fair this summer will need a negative test for the H5N1 virus.  

The Centers for Disease Control and Prevention states that human risks to the bird flu are very low, but that those working closely with infected or potentially infected animals “should wear appropriate and recommended personal protective equipment” and that everyone should avoid sick or dead animals as well as animal feces, animal bedding and unpasteurized or “raw” milk.  

Measles: Three new cases in May, but none since

Another disease — known to be very infectious among humans, but also having a highly effective vaccine — was detected among more Minnesotans in May. Late last month the Minnesota Department of Health reported three confirmed cases of measles among siblings residing in Anoka County and treated at Hennepin Healthcare.  

No additional cases have been reported since, but this does bring Minnesota’s yearly total of the rare disease to six this year following three cases reported earlier. Nationally, 17 more confirmed cases were reported by the CDC in May, bringing the national yearly total to 151 — already the highest annual total since 2019, when nearly 1,300 cases were reported nationwide. 

COVID-19: The bad but mostly good news

The bad news is, according to the Minnesota Department of Health’s most recent data, another 52 Minnesotans were admitted to the hospital with COVID-19 during the week ending May 25 and another five Minnesotans lost their lives at least in part due to COVID-19 during the week ending May 11.  

The good news is the numbers of COVID-19 hospitalizations and deaths in Minnesota are now nearly at their lowest since COVID arrived here in early 2020, rivaling the all-time low points in COVID activity reported by the department last summer. 

The latest data of COVID-19 detected in samples from wastewater treatment plants throughout the state shows that, as of June 5, the statewide level remains essentially unchanged from the prior week. In the Twin Cities metro, levels remained relatively unchanged, with a one-week increase of less than one percent, but other areas of the state saw increases or decreases. 

The study’s North West (53 percent), North East (29 percent) and South West (15.7 percent) regions all saw moderate increases, while the Central (-13.3 percent), South East (-13.2 percent) and South Central (-4.7 percent) regions all saw minimal decreases. 

We also routinely look at four-week changes to check on longer-term trends. Here we need to talk about the 1,000 lb. elephant in the room: The North West region, which saw the largest one-week increase, also shows a four-week increase of over 1,000 percent. 

That is a very large increase, but context is important when interpreting this data. The percentage change appears very large only because four weeks ago levels there were extremely low. In fact, the four-week period begins with the North West region’s lowest recorded COVID wastewater levels since tracking started. And while the four-week increase is notably large, the latest level is roughly at what the region was recording last fall, and well below a relatively high peak recorded in December. The two latest data points from the region suggest a leveling off, but we will keep our eyes on the data.    

The statewide level increased almost 50 percent compared to one month earlier, and the Twin Cities Metro level increased 75 percent. Well worth watching, but even so, overall levels remain very low when looked at over time.