Influenza A(H1N2)v case reported in Brazil

Over the past 14 years we've seen over 460 human infections with swine variant viruses in the United States, with the H3N2v strain the most common, followed by H1N2v, and H1N1v. Although these infections are still relatively uncommon, all known human influenza pandemics have come from H1, H2, or H3 viruses.

According to a World Health Organization (WHO) report, a human infection with Influenza A(H1N2) variant virus or A(H1N2)v has been reported in an individual in Brazil.

The patient is a 22-year-old female, with no comorbidities, worked in a swine slaughterhouse in Ibiporã Municipality, Paraná State, and developed an influenza-like illness on 12 April 2020.

The patient initially sought medical care on 14 April and a respiratory specimen was obtained on 16 April as part of routine surveillance activities. The patient was treated with oseltamivir, was not hospitalized and has recovered.

On 26 June 2020, local authorities started a retrospective and prospective investigation in the slaughterhouse in Ibiporã Municipality and other municipalities where the slaughterhouse workers live. According to the preliminary epidemiological investigation, a second individual who also worked at the slaughterhouse developed respiratory symptoms during the same timeframe as the confirmed case, but no sample was collected from this person. No other suspected cases amongst contacts of the confirmed case have been identified.

To date, 26 cases of influenza A(H1N2)v have been reported to WHO since 2005, including two from Brazil. Most of the cases have presented with mild illness and there has been no evidence of person-to-person transmission.