Influenza remains a health concern going into the new year, both in Marshall County and internationally. A mutated strain of influenza A, H3N2 subclade K, is increasing worldwide.

The CDC’s FluView website tracks national rates of flu. Iowa is classified as “moderate” while bordering states Minnesota and Missouri are listed as “very high.”

“There are routine vaccines available for both children and adults along with seasonal vaccines such as COVID and flu. A majority of our protective vaccines are given when we are children such as MMR, polio, meningitis, Dtap etc.,” said Sydney Grewell, who serves as Marshall County Public Health director. “However, there are a few that are given as we get older such as tetanus every seven to 10 years and shingles, to name a few. All vaccines should be discussed with your healthcare provider to determine what is best for you and your health.”

According to the CDC, 42% of adults and children have received a yearly flu shot. Grewell added that COVID-19 remains on the radar, as it has become a normal part of the respiratory season.

H3N2 subclade K has been reported throughout the U.S. since late November, according to the Global Initiative on Sharing All Influenza Data (GISAID) database. It’s estimated to be causing 90% of flu cases nationwide. Subclade K’s mutations are not enough of a change to be considered an entirely new kind of flu, according to reporting by the Associated Press. However, its small genetic changes make it differ from the H3N2 strain used to make the 2025-2026 U.S. flu vaccine. This change is called an antigenic drift.

“Many respiratory viruses peak in colder months due to spending more time indoors and increased gathering. Things like COVID, flu, RSV, and the common cold may be seen in clinics,” Grewell said.

She added that tips for slowing the spread of germs include: washing hands with soap and water, cleaning high touch areas, drinking plenty of water, covering your mouth when you cough or sneeze and staying home when you’re sick.

The CDC reports people should act quickly for flu treatment, particularly those who are pregnant, have asthma and other chronic lung conditions, diabetes, or heart disease. Flu antiviral drugs can be prescribed to ease symptoms and shorten duration of illness, but work best when taken within one to two days after flu symptoms start.

Additional U.S. public health concerns include whooping cough and the measles.

Grewell said whooping cough (pertussis) is a communicable disease that is required to be reported to Iowa Health and Human Services (HHS).

“Therefore in Iowa, if someone tests positive at a healthcare clinic those results are shared with HHS and local public health for follow up. We are not seeing anything out of the ordinary for this time of year regarding our pertussis rates, which are very low. In all of 2025 we only saw two cases,” she noted.

Measles is a growing concern locally and across the nation, as vaccine rates are decling. As of Dec. 30, 2025, a total of 2,065 confirmed measles cases were reported in the United States by the CDC. A rate of 92% of those patients are unvaccinated or have unknown vaccination status. The last time the U.S. saw more than 2,000 cases was in 1992.

“The Measles, Mumps and Rubella (MMR) vaccine is the best defense against measles. One dose is 93% effective while two doses is 97% effective,” she said. “We have not seen a positive measles case in Marshall County. It is a communicable disease and is required to be reported by law in the State of Iowa. If someone residing within Marshall County were to contract measles, Marshall County Public Health would work directly with Iowa Health and Human Services to address the situation.”

For more information, the CDC’s FluView may be accessed here: www.cdc.gov/fluview/surveillance/usmap.html.