Via The Lancet, an editorial: Pandemic potential of emerging influenza. It makes a factual error in the first sentence (the Canadian H5N1 case was a woman, not a man), but this is a thoughtful commentary. Excerpt:
In January this year, the first case of highly pathogenic avian influenza H5N1 was detected in the Americas when a Canadian man returning from Beijing fell ill and subsequently died. January also saw a sharp upturn in the number of cases of H7N9 avian influenza in China with 169 cases detected in 1 month, compared with 144 up to the end of last year since it was first identified in March 2013.
Another familiar virus, 2009 pandemic influenza A H1N1 has also been hitting the headlines in Egypt, where there have been over 300 cases and around 38 deaths since December, and in Mexico over 400 deaths have been associated with H1N1 this year.
Moreover, researchers have recently reported the first case of human disease caused by an H10N8 strain, which killed a 73-year-old woman in China in December last year.
Each new and emerging strain detected in association with severe disease or rapid global spread brings speculation of the next pandemic, the spectre of the 1918 influenza pandemic looming large in the consciousness of health professionals, virologists, and the public.
Anticipation of a new pandemic is added a sense of mystery by the mercurial nature of influenza viruses, which undergo continuous antigenic evolution as they pass through human populations, retreat into animal reservoirs, reassort with other viruses, and re-emerge.
With changes in surveillance and technology the detection and identification of new influenza strains causing human disease is easier than ever—the challenge now is how to judge the risk posed by each virus.