Isolation of swine-like influenza A(H1N1) viruses from man in Switzerland and The Netherlands

Swine influenza A (H1N1) viruses were isolated from two people in Switzerland and one in the Netherlands in early 1986. In haemagglutination-inhibition and neuraminidase-inhibition assays, the three viruses were closely related to one another and to the A/New Jersey/8/76 strain. The Swiss patients showed only mild symptoms, whereas the Dutch patient suffered from severe pneumonia. Two of the patients had been in close contact with diseased pigs. No such contact could be established for the third patient. None of the three individuals was known to suffer from immunodeficiency. No man-to-man transmission of the virus has been detected.