A 48-year-old Swiss male farm worker tested positive for swine influenza A(H1N1)v virus, the World Health Organization (WHO) reports.


On Dec. 20, 2017, he presented with mild acute respiratory symptoms 8 days before a nasal swab was collected. The virus isolated from this human case was partially sequenced and was closely related to the European avian-like swine influenza A(H1N1) viruses circulating in swine in Europe.

Samples from the swine at the farm where the case worked also tested positive for influenza A viruses, and are currently under characterization. No additional human cases related to this event were reported.

Human cases infected with swine influenza viruses have been detected in Switzerland in 2003, 2009, 2010, 2011 and 2016. Swine influenza A(H1N1) viruses are endemic in pig populations and circulate among swine in many regions of the world.

When an influenza virus that normally circulates in swine is detected in a person, it is called a variant influenza virus and is labeled with a ‘v’.

Influenza: What is the H and what is the N?

Influenza viruses such as H1N1(v) and other related variants are not unusual in swine and can be directly transmitted from swine to people and from people to swine.

When humans are in close proximity to live swine, such as in barns and livestock exhibits at fairs, movement of these viruses can occur back and forth between humans and animals.

The illnesses resulting from H1N1(v) infection are similar to seasonal influenza. Symptoms include fever, muscle aches, decreased energy, coughing, runny nose, and sore throat.