Giuseppe
Emeritus
Eurosurveillance - To baptise a virus and its disease (edited)
Eurosurveillance, Volume 14, Issue 21, 28 May 2009
Editorials
To baptise a virus and its disease
Editorial team 1
1. European Centre for Disease Prevention and Control, Stockholm, Sweden
Citation style for this article: Editorial team. To baptise a virus and its disease. Euro Surveill. 2009;14(21)
ii=19225. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19225
Date of submission: 28 May 2009
The currently circulating new novel Mexican North American Californian swine-like influenza A(H1N1) virus of swine origin has been named and renamed more than once since its recognition a month ago [1]. It is time to agree on names for the virus, and for the disease it causes.
When it comes to individual isolates, the issue seems to be straightforward. According to established convention, an A(H1N1) isolate obtained from a patient in California in 2009 could be called influenza A/California/4/2009(H1N1)swl. This name indicates the species (influenza virus), the type (A) and the subtype (H1N1), and details the origin of the isolate in question, in the case of our example, an isolate with laboratory number 4, obtained from a patient in California in 2009. The abbreviation swl, for swine influenza-like, also referred to as swine lineage, is added to the name to indicate that parts of this virus are genetically related to influenza A(H1N1) viruses circulating in pigs [2].
When it comes to a more general naming of the virus and the disease it causes, however, a consensus is harder to reach. The virus and disease have been called ?swine flu?, a name that worried the pig faming industry, and ?Mexican flu?, a name that threatened the Mexican tourism industry and ?new? or ?novel influenza A(H1N1)?, a name not chosen to last. Most simply, but unspecifically it is called, ?influenza A(H1N1)? which is what currently appears on WHO?s website. The name of the virus will have to become more specific quite quickly as there are already the circulating A(H1N1) seasonal viruses which are quite different from the new virus [3]. With the Southern Hemisphere influenza season nearly upon us there will be two ?A(H1N1)? viruses co-circulating. Different names will be essential in this respect.
Among the later suggestions for the name of the virus are ?influenza A(H1N1)swl? and ?A(H1N1)-SL? ? both stand for swine-like, as well as ?A(H1N1)-SOIV? ? for swine origin influenza virus and ?A(H1N1)-SO? ? swine origin [2,4]. On balance the term SL or swl seems more neutral and simply descriptive. It might be debatable how appropriate the denomination ?swine-like? is, as the virus also contains genes from human and bird as well as from swine influenza viruses. However, this denomination is already widely used in the isolate names [2].
Also the question how to call the disease this virus causes is not an easy one. The term ?swine flu? has been used so extensively in the media that it will be difficult to get rid of it. Swine flu however, is not desirable, neither medically or scientifically as this is now a human influenza, transmitting efficiently from one person to another. The vast majority of those infected will receive it from other humans not from pigs. Even if the disease pattern currently mirrors seasonal influenza simply calling it ?influenza? is also not optimal, as there are emerging indications that are distinct. Furthermore, there are implications that health professionals and the general public need to understand, when a human is infected with new influenza A(H1N1) rather than the seasonal influenza A(H1N1) [5-7]. Even if the virus fits the three criteria of a pandemic strain: infecting humans, making them ill and transmitting efficiently from human to human, a pandemic remains yet to be declared so we cannot call it 2009 pandemic influenza.
References
1. United States Centers for Disease Control and Prevention (CDC). Swine influenza A (H1N1) infection in two children--Southern California, March-April 2009. MMWR Morb Mortal Wkly Rep. 2009;58(15):400-2. Available from: www.cdc.gov/mmwr/preview/mmwrhtml/mm5815a5.htm
2. Garten RJ, Davis CD, Russell CA, Shu B, Lindstrom S, Balish A et al. Antigenic and Genetic Characteristics of Swine-Origin 2009 A(H1N1) Influenza Viruses Circulating in Humans. Science Express. Published Online May 22, 2009. Science DOI: 10.1126/science.1176225. Available from: www.sciencemag.org/cgi/content/abstract/1176225v1
3. European Centre for Disease Prevention and Control. Seasonal influenza European Status. Available from: http://ecdc.europa.eu/en/health_content/episu/090522_EISS.aspx
4. Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team. Emergence of a Novel Swine-Origin Influenza A (H1N1) Virus in Humans. N Engl J Med. Published online on May 7, 2009, and updated on May 22, 2009. N Engl J Med 2009;360. 10.1056/NEJMoa0903810. Available from: http://content.nejm.org/cgi/content/full/NEJMoa0903810?resourcetype=HWCIT
5. United States Centers for Disease Control and Prevention (CDC). Novel Influenza A (H1N1) Virus Infections -Worldwide, May 6, 2009. MMWR Morb Mortal Wkly Rep. 2009;58(17):453-8. Available from: www.cdc.gov/mmwr/preview/mmwrhtml/mm5817a1.htm
6. United States Centers for Disease Control and Prevention (CDC). Hospitalized Patients with Novel Influenza A (H1N1) Virus Infection - California, April--May, 2009. MMWR Morb Mortal Wkly Rep. 2009;58(19):536-41. Available from: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5819a6.htm
7. European Centre for Disease Prevention and Control. Scientific Advances Influenza A(H1N1). Available from: www.ecdc.europa.eu/en/health_content/sciadv/090524_sciadv.aspx
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<cite cite="http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19225">Eurosurveillance - View Article</cite>Editorials
To baptise a virus and its disease
Editorial team 1
1. European Centre for Disease Prevention and Control, Stockholm, Sweden
Citation style for this article: Editorial team. To baptise a virus and its disease. Euro Surveill. 2009;14(21)
ii=19225. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19225Date of submission: 28 May 2009
The currently circulating new novel Mexican North American Californian swine-like influenza A(H1N1) virus of swine origin has been named and renamed more than once since its recognition a month ago [1]. It is time to agree on names for the virus, and for the disease it causes.
When it comes to individual isolates, the issue seems to be straightforward. According to established convention, an A(H1N1) isolate obtained from a patient in California in 2009 could be called influenza A/California/4/2009(H1N1)swl. This name indicates the species (influenza virus), the type (A) and the subtype (H1N1), and details the origin of the isolate in question, in the case of our example, an isolate with laboratory number 4, obtained from a patient in California in 2009. The abbreviation swl, for swine influenza-like, also referred to as swine lineage, is added to the name to indicate that parts of this virus are genetically related to influenza A(H1N1) viruses circulating in pigs [2].
When it comes to a more general naming of the virus and the disease it causes, however, a consensus is harder to reach. The virus and disease have been called ?swine flu?, a name that worried the pig faming industry, and ?Mexican flu?, a name that threatened the Mexican tourism industry and ?new? or ?novel influenza A(H1N1)?, a name not chosen to last. Most simply, but unspecifically it is called, ?influenza A(H1N1)? which is what currently appears on WHO?s website. The name of the virus will have to become more specific quite quickly as there are already the circulating A(H1N1) seasonal viruses which are quite different from the new virus [3]. With the Southern Hemisphere influenza season nearly upon us there will be two ?A(H1N1)? viruses co-circulating. Different names will be essential in this respect.
Among the later suggestions for the name of the virus are ?influenza A(H1N1)swl? and ?A(H1N1)-SL? ? both stand for swine-like, as well as ?A(H1N1)-SOIV? ? for swine origin influenza virus and ?A(H1N1)-SO? ? swine origin [2,4]. On balance the term SL or swl seems more neutral and simply descriptive. It might be debatable how appropriate the denomination ?swine-like? is, as the virus also contains genes from human and bird as well as from swine influenza viruses. However, this denomination is already widely used in the isolate names [2].
Also the question how to call the disease this virus causes is not an easy one. The term ?swine flu? has been used so extensively in the media that it will be difficult to get rid of it. Swine flu however, is not desirable, neither medically or scientifically as this is now a human influenza, transmitting efficiently from one person to another. The vast majority of those infected will receive it from other humans not from pigs. Even if the disease pattern currently mirrors seasonal influenza simply calling it ?influenza? is also not optimal, as there are emerging indications that are distinct. Furthermore, there are implications that health professionals and the general public need to understand, when a human is infected with new influenza A(H1N1) rather than the seasonal influenza A(H1N1) [5-7]. Even if the virus fits the three criteria of a pandemic strain: infecting humans, making them ill and transmitting efficiently from human to human, a pandemic remains yet to be declared so we cannot call it 2009 pandemic influenza.
References
1. United States Centers for Disease Control and Prevention (CDC). Swine influenza A (H1N1) infection in two children--Southern California, March-April 2009. MMWR Morb Mortal Wkly Rep. 2009;58(15):400-2. Available from: www.cdc.gov/mmwr/preview/mmwrhtml/mm5815a5.htm
2. Garten RJ, Davis CD, Russell CA, Shu B, Lindstrom S, Balish A et al. Antigenic and Genetic Characteristics of Swine-Origin 2009 A(H1N1) Influenza Viruses Circulating in Humans. Science Express. Published Online May 22, 2009. Science DOI: 10.1126/science.1176225. Available from: www.sciencemag.org/cgi/content/abstract/1176225v1
3. European Centre for Disease Prevention and Control. Seasonal influenza European Status. Available from: http://ecdc.europa.eu/en/health_content/episu/090522_EISS.aspx
4. Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team. Emergence of a Novel Swine-Origin Influenza A (H1N1) Virus in Humans. N Engl J Med. Published online on May 7, 2009, and updated on May 22, 2009. N Engl J Med 2009;360. 10.1056/NEJMoa0903810. Available from: http://content.nejm.org/cgi/content/full/NEJMoa0903810?resourcetype=HWCIT
5. United States Centers for Disease Control and Prevention (CDC). Novel Influenza A (H1N1) Virus Infections -Worldwide, May 6, 2009. MMWR Morb Mortal Wkly Rep. 2009;58(17):453-8. Available from: www.cdc.gov/mmwr/preview/mmwrhtml/mm5817a1.htm
6. United States Centers for Disease Control and Prevention (CDC). Hospitalized Patients with Novel Influenza A (H1N1) Virus Infection - California, April--May, 2009. MMWR Morb Mortal Wkly Rep. 2009;58(19):536-41. Available from: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5819a6.htm
7. European Centre for Disease Prevention and Control. Scientific Advances Influenza A(H1N1). Available from: www.ecdc.europa.eu/en/health_content/sciadv/090524_sciadv.aspx
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