In a follow-up to a report earlier this month, the Centers for Disease Control and Prevention (CDC) reports an additional four human infections with novel influenza A viruses were reported by two states–California (2) and Ohio (2).

Image/Chun-San via pixabay
Image/Chun-San via pixabay

All four persons were infected with influenza A(H1N2) variant (A(H1N2)v) viruses and became ill with respiratory symptoms in early August 2018.

These patients were children < 18 years of age, were not hospitalized, and all are recovering or have fully recovered from their illness.

Three patients reported exposure to swine at an agricultural fair during the week preceding illness onset. One patient reported no contact with swine and no attendance at an agricultural fair in the week preceding illness. It is possible that limited human-to-human transmission occurred. No ongoing human-to-human transmission has been identified.

A total of 13 variant virus infections have been reported to CDC during 2018. One of these was with an influenza A(H3N2) variant (A(H3N2)v) virus–Indiana (1), and 12 have been with A(H1N2)v viruses (California [6], Michigan [3], and Ohio [3]).