Montana reports a variant H1N1 (H1N2v) infection, 3rd human ‘swine flu’ case of 2023

NewsDesk @bactiman63

Montana state health officials reported on a human infection with a novel influenza A virus. The patient was infected with an influenza A(H1N2) variant (A(H1N2)v) virus.

The patient was < 18 years of age at the time of infection, sought health care during the week ending August 5, 2023 (week 31), and has not been hospitalized.

An investigation by local public health officials found that prior to their illness onset the patient attended an agricultural fair. The investigation is currently ongoing.

This is the third human infection with a variant influenza A virus reported in the United States in 2023, including one infection with an H3v (Michigan) virus and two infections with H1N2v (Michigan, Montana) viruses.

When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a “variant” influenza virus. Most human infections with variant influenza viruses occur following exposure to swine, but human-to-human transmission can occur. It is important to note that in most cases, variant influenza viruses have not shown the ability to spread easily and sustainably from person to person.

Early identification and investigation of human infections with novel influenza A viruses are critical so that the risk of infection can be understood, and appropriate public health measures can be taken.