Talk:Virus classification

Hantaviruses

What about Hantaviruses? -- Emperorbma 21:17, 31 Dec 2003 (UTC)

Nevermind, they are up where they should be now... -- Emperorbma 21:57, 31 Dec 2003 (UTC)

Orf, a parapox virus

This stub article is orphaned: orf - is there a home for it? Ancheta Wis 00:13, 20 Mar 2004 (UTC)

Potexvirus and Pomovirus genera misplaced

Wilke reverted a ViralQuest removal of Potexvirus from the dsDNA viruses, Family Polyomaviridae section. I am reversing that edit (and removing Genus Pomovirus) because these two genera are postive-strand ssRNA virus groups (not dsDNA). Genus Potexvirus is a member of the Family Flexiviridae and the Genus Pomovirus is an unassigned (+)ssRNA virus member. See said listings already in previous Virus Classification edits. See also: ICTV Genus Potexvirus ICTV Genus Pomovirus ICTV Family Polyomaviridae and ICTV Taxonomy Browser (Viruses) Thanks for allowing this edit. --ViralQuest 23:40, Nov 26, 2004 (UTC)

Virus taxonomy

• Shouldn't Viruses appear at the WikiSpecies wiki?

  http://sn2000.taxonomy.nl/Main/Classification/..%5CDetails%5C71304.htm

  http://www.laureestan.unige.it/progr/botanica.html

  http://sn2000.taxonomy.nl/Main/Classification/..%5CDetails%5C71303.htm

  http://wiki.tatet.ru/pt/Biologia.html

  http://www.bioproject.info/particular_biology/superkingdom_viruses.html

  pt:Acytota

132.205.15.43 04:57, 16 Dec 2004 (UTC)

Possibly, although that's something for them to worry about. However, viruses are an odd case because they don't appear in the normal classification of living things. Kingdom Virus is rare, and Aphanobionta and Acyota are very obscure. More subtly, though, they shouldn't appear in the normal classification of living things because they don't form a phylogenetic hierarchy, and probably don't even have a single origin. So I'm not sure what we should do with them, but I'd say casually giving them a kingdom, domain, or empire isn't the solution. Josh

• Though we wouldn't casually be giving them a kingdom/domain/empire. People already do that. A rankless taxobox would work as well, as anything above order is controversial, and they are all viruses, and the taxoboxes are nice to have on the virus pages. 132.205.15.43 05:38, 16 Dec 2004 (UTC)

A few people do that, but it is not very common, and I have not seen it done alongside three domains. As for the taxoboxes, I've moved my suggestion to Wikipedia talk:WikiProject Tree of Life. Josh

• WikiSpecies seems to have a start: WikiSpecies:Virus 132.205.15.43 04:28, 24 Dec 2004 (UTC)

WikiProject?

Is there a WikiProject for viruses? 132.205.15.43 04:43, 24 Dec 2004 (UTC)

• Wikipedia:WikiProject Viruses has been tagged as inactive. 132.205.94.174 23:13, 24 July 2005 (UTC)

Virus family numbers?

Do the numbers in the "Virus Family" column of the DNA Viruses and RNA Viruses tables mean anything, or are they just kind of there? (E.g. is Parvoviridae always DNA virus family number 3, by some authoritative source?) I'd suggest removing them if they're not meaningful, or explaining and citing a source if they are meaningful. -Agyle 03:22, 20 September 2007 (UTC)

Abbreviation ICVCN

The abbreviation ICVCN (with piped link to this article) appears in the article Biology in the paragraph shown below, but does not appear here in this article.

The dominant classification system is called Linnaean taxonomy, which includes ranks and binomial nomenclature. How organisms are named is governed by international agreements such as the International Code of Botanical Nomenclature (ICBN), the International Code of Zoological Nomenclature (ICZN), and the International Code of Nomenclature of Bacteria (ICNB). A fourth Draft BioCode was published in 1997 in an attempt to standardize naming in these three areas, but it has yet to be formally adopted. The Virus International Code of Virus Classification and Nomenclature (ICVCN) remains outside the BioCode.

Could this please be added in proper context so that people redirected here will find some material in context to satisfy them. AshLin 04:29, 28 September 2007 (UTC)

I am fairly sure ICVCN refers to the ICTV's classification system, although I can't find a good, clearcut reliable statement relating the two. It seems like the code is informally referred to as "the ICTV code," "the ICTV database," and is formally cited as "The Seventh Report of the ICTV" or something, and that ICVCN is used rarely (perhaps more commonly around 1998-2000). Examples of dual usage this abstract, and this website. I'm hesitant to add info to either article clarifying this without an unambiguous citation. -Agyle 18:29, 28 September 2007 (UTC)

Sorted as of now (only 16 years late!!) Tony 1212 (talk) 05:38, 6 January 2024 (UTC)

(@ Agyle) For a "good, clearcut reliable statement relating the ICVCN and ICTV taxonomy" see the paragraph 8.1 of the ICTV Statutes. Another relation: The Comment to the paragraph 1.2 of ICVCN refers to the Master Species List, which is also basis for the current ICTV Taxonomy. (ICVCN incl. the binomial nomenclature for the virus species is strictly applied for new taxon names.) --Petr Karel (talk) 09:31, 8 January 2024 (UTC)

Since the Code is now called "The International Code of Virus Classification and Nomenclature (ICVCN), March 2021 edition" on its own website and as now cited in the article, I believe that satisfies the requirement to explain the acronym :) Tony 1212 (talk) 17:06, 8 January 2024 (UTC)

Retroviridae in RNA virus table

It appears that the table under the RNA viruses heading is meant to list RNA viruses, but the Retroviridae are considered group VI in the Baltimore classification (whereas only groups III, IV, and V are listed as strictly RNA viruses here on this page). Should the Retroviridae be removed from the RNA virus table? Should the table include the Baltimore classifications?Scray (talk) 04:53, 11 April 2008 (UTC)

Here's a relevant link to ICTV that shows the reverse-transcribing viruses clearly distinct from the RNA virusesScray (talk) 11:11, 11 April 2008 (UTC)

• I don't really understand your question, but retroviruses eg HIV are RNA viruses. During replication they have a DNA intermediary, (pro-viral DNA), but they are RNA viruses nonetheless. GrahamColm^Talk 15:27, 11 April 2008 (UTC)

I checked out Scray's edit when it was made. He appears to be correct - see See Also link at bottom of page. In Baltimore's classification retroviruses belong to Group VI, and therefore don't belong in a list of taxa in Groups III-V. Lavateraguy (talk) 15:44, 11 April 2008 (UTC)

@Scray Below is a reformulated excerpt suitable for inclusion in an English Wikipedia article:

---

== Viral Replication and Classification==

Viruses are unique infectious agents composed of genetic material—either DNA or RNA—encased in a protein coat. Unlike cellular organisms, viruses lack the metabolic machinery required for independent replication. Instead, they rely entirely on the host cell’s resources and energy to propagate. In cellular organisms, the central dogma of molecular biology describes the normal flow of genetic information: DNA in the nucleus is transcribed into messenger RNA (mRNA), which is then translated by ribosomes in the cytoplasm to form proteins.

Upon infection, a virus commandeers the host cell’s ribosomes to synthesize its own proteins and replicate its genetic material. Since ribosomal protein synthesis depends on the presence of mRNA, viruses must provide a mechanism to generate viral mRNA within the infected cell. Different viral families have evolved various strategies to achieve this, a feature that forms the basis for one method of virus classification known as the Baltimore system.

The Baltimore classification categorizes viruses according to their type of nucleic acid and the strategy used to produce mRNA. This system is often represented by a shorthand notation, for example, [s|d] s [D|R] NA, where “s” and “d” denote single-stranded and double-stranded forms, respectively, and “D” and “R” indicate DNA or RNA. For instance, double-stranded DNA (dsDNA) viruses typically rely on the host’s nuclear transcription machinery to produce viral mRNA. Because these viruses must enter the cell nucleus, there exists a potential for interaction with or interference in the host cell’s own DNA; however, since only a limited subset of cells in a multicellular organism are usually infected, the overall systemic impact on host genomic integrity is generally minimal.

---

This overview explains how viral replication takes advantage of host cell processes and how the nuances of messenger RNA production contribute to one of the primary systems for classifying viruses—the Baltimore classification. The interplay between viral replication strategies and host cellular functions continues to be a critical area of study in virology, influencing everything from our understanding of viral evolution to the development of antiviral therapies. Dominic3203 (talk) 02:00, 17 April 2025 (UTC)

Positive/negative sense?

Could someone put a definition of what positive or negative sense RNA/DNA is?72.46.10.212 (talk) 21:14, 1 August 2008 (UTC)

I added a link to the sense article in the "Baltimore Classification" sectionPhantombantam (talk) 21:22, 1 August 2008 (UTC)

DNA viruses - summary table

What is the basis for the 'virus family' classification in the table in this section?

There are seven 'families' which is confusing since they echo the seven groups under Baltimore. At least it's confusing to me as a non-taxonomist... For instance it sort of suggests the Hepadnaviridae/HBV ('family 6') are in Group VI. ICTV isn't very helpful (Hepadnaviridae are an unassigned family) but i've not come across this system before so i'd like to know more about it (although it seems coherent enough.) If it's just a listing of recognised families, would it be helpful to list their baltimore groups s well, to make it clear where they fit in the overall ICTV scheme? ditto the equivalent table under RNA viruses section.

Can anyone enlighten me / give a reference for this system? I don't have Virus Taxonomy to hand... Cheers... Comrade jo (talk) 12:43, 10 August 2008 (UTC)

Table confusion

The tables in the "Baltimore Classification" system appear to be from a different taxonomy. I was very confused when I found the "Hepatitis B" entry in what appeared to be the "Group II" table.

I attempted to unscrew this mess by adding a column to each table giving the Baltimore group, but if the tables are in fact from some othre taxonomy, they should be removed fromt h eBaltimore section and added to a new "comparison of classificatins" section. -Arch dude (talk) 13:52, 9 September 2008 (UTC)

"But"

This issue has been fixed. The following discussion has been closed. Please do not modify it.

What does the word "but" refer to in the class VI description? --rmhermen

Shouldn't be there. Fixed now, I think, will also fix in Virus (Biology). Someone else

Any rulebooks....and the identifier of the document...???

• http://www.ictvdb.rothamsted.ac.uk/ICTVWeb/rules.html

--222.67.205.32 (talk) 10:59, 6 February 2010 (UTC)

• This is an old document from 1996 based on the International Committee on Taxonomy of Viruses (ICTV) guidelines. Their current (2010) website is here . Graham Colm ^Talk 11:44, 6 February 2010 (UTC)

"Which are not yet definitively classified as living or non-living"

I'm changing this at least until I see a source. Viruses are non-living particles with some life-like chemical characteristics, but still pretty definitively non-living. The Mysterious El Willstro (talk) 20:01, 1 June 2012 (UTC)

RT

Reverse Transcriptase is feature of Group VI as well. Unfortunately RT is present in many cells in the body and it not specific to "retroviruses" — Preceding unsigned comment added by 2601:7:8500:982:E014:6DFA:5BEE:729C (talk) 01:49, 27 October 2014 (UTC)

Minor change?

Under "ICTV classification" it says: "Herpesvirales contain large eukaryotic dsDNA viruses." Wouldn't it be better to say: "Herpesvirales includes" (with an "s") "large dsDNA viruses which have eukaryotic hosts." - or something? -lifeform (talk) 03:59, 13 March 2016 (UTC)

Prions are not viruses

Prions are not viruses at all, as we have known for many years. I therefore propose the deletion of the prion paragraph. --Gfpaleorna (talk) 10:32, 13 August 2017 (UTC)

Agreed! Mvolz (talk) 13:56, 4 January 2021 (UTC)

But it never said they were viruses, but rather "Subviral agents", ie. beneath the complexity of viruses. If you read the ICTV 9th Report (2011) Subviral Agents (2011) it does list prions as being subviral agents. --Jules (Mrjulesd) 22:07, 4 January 2021 (UTC)

Subviral agents are not viruses. Graham Beards (talk) 23:26, 4 January 2021 (UTC)

In that case why not remove the whole "subviral" section? Viroids aren't normally considered to be viruses either. Jules (Mrjulesd) 00:23, 5 January 2021 (UTC)

Article omits discussion of the whole topic ??

So, how are viruses classified in the sense of organizing them into the ICTV hierarchy (realm, kingdom, phylum, and so on)? The article appears to say nothing at all on this subject. The Baltimore system is separate, and the LHT system appears to be an alternate system. — Preceding unsigned comment added by 2603:9000:AC08:A600:F9A2:D64C:B3D4:6FBF (talk) 00:36, 10 June 2020 (UTC)

Strains versus variants, strain and variant classification

I'd like to see a section on this! Mvolz (talk) 13:55, 4 January 2021 (UTC)

Note: Classification of virus taxa below the rank of species is not ruled by The International Code of Virus Classification and Nomenclature:

"Par. 3.3: The ICTV is not responsible for classification and nomenclature of virus taxa below the rank of species. The classification and naming of serotypes, genotypes, strains, variants and isolates of virus species is the responsibility of acknowledged international specialist groups.

Comment: A variety of subspecific grouping may be identified within the members of a single virus species. These may be described as viruses with alternative names (e.g. blackeye cowpea mosaic virus and peanut stripe virus, which are both classified in the species Bean common mosaic virus, genus Potyvirus, family Potyviridae), or as serotypes, genotypes, clades, strains, variants, isolates etc. Naming of such entities is not the responsibility of the ICTV but of international specialty groups. It is the responsibility of ICTV Study Groups to consider how these entities may best be classified into species."

I don't know any of the "acknowledged international specialist groups" for this topic; maybe some info could be found on a web site from the list of Virology Departments and Institutes or Virology Societies. --Petr Karel (talk) 08:42, 8 January 2021 (UTC)

I've done a little more research on this - Yeah, ICTV doesn't do naming of strains. However, they do have working groups that decide on naming /conventions/. The Coronaviridate Study Group of the ICTV did name SARS-CoV-2... Gorbalenya, Alexander E.; Baker, Susan C.; Baric, Ralph S.; de Groot, Raoul J.; Drosten, Christian; Gulyaeva, Anastasia A.; Haagmans, Bart L.; Lauber, Chris; Leontovich, Andrey M.; Neuman, Benjamin W.; Penzar, Dmitry (2020-04). "The species Severe acute respiratory syndrome-related coronavirus : classifying 2019-nCoV and naming it SARS-CoV-2". Nature Microbiology. 5 (4): 536–544. doi:10.1038/s41564-020-0695-z. ISSN 2058-5276. {{cite journal}}: Check date values in: |date= (help) Mvolz (talk) 12:37, 9 January 2021 (UTC)

Strains are the same as variants and they are not classified. They just have a designation. Influenza virus variants are a good example;

Diagram of influenza nomenclature

Graham Beards (talk) 14:27, 8 January 2021 (UTC)

My understanding now is that strains and variants are different. Generally a strain is biologically different in some way - so, different phenotype. Variant refers instead to genotype. (This is picked up from this paper: Kuhn, Jens H.; Bao, Yiming; Bavari, Sina; Becker, Stephan; Bradfute, Steven; Brister, J. Rodney; Bukreyev, Alexander A.; Chandran, Kartik; Davey, Robert A.; Dolnik, Olga; Dye, John M. (2013). "Virus nomenclature below the species level: a standardized nomenclature for natural variants of viruses assigned to the family Filoviridae". Archives of Virology. 158 (1): 301–311. doi:10.1007/s00705-012-1454-0. ISSN 0304-8608. PMC 3535543. PMID 23001720. ~ Mvolz (talk) 12:35, 9 January 2021 (UTC)

What? "... about which species concept."

There's a template now that says, "This article is missing information about which species concept."

I sincerely have no idea what that means. IAmNitpicking (talk) 12:07, 8 August 2022 (UTC)

Since the species concept *is* covered in the article, I have removed this template... I too had no idea to what it was referring. Tony 1212 (talk) 05:40, 6 January 2024 (UTC)

issues with the image

The main image on this page is a graph of different ranks in Virus classification similar to an image on the main page for Taxonomy but it seems to have a problem, it show "life" as the first rank, I am not all that knowledgeably about viruses so correct me if I'm wrong but I'm pretty sure that viruses as not typically considered to be alive because they do not have cells so I think life should not be the first rank, instead something like "virus" or "non-cellular life" would work better there. the image in question is an SVG with some more advanced features like the ability to render it in other languages so I don't think I can edit it without breaking it and no one seem be looking at the talk page of the image itself so I thought this would be a good place to raise concern about this image as this seems like quite the glaring issue PharaohCrab speak𓀁 works𓀨 15:13, 19 February 2026 (UTC)

Updates to article?

The page states "As of 2022, the ICTV taxonomy listed 11,273 named virus species (including some classed as satellite viruses and others as viroids) in 2,818 genera, 264 families, 72 orders, 40 classes, 17 phyla, 9 kingdoms and 6 realms."

When I click on the source cited the numbers of taxonomic orders has since been changed and it now states that there are: 7 realms, 11 kingdoms, 22 phyla, 4 subphyla, 49 classes, 93 orders, 12 suborders, 368 families, 213 subfamilies, 3768 genera, 86 subgenera, 16213 species. Is it ok if I update the article by changing the numbers to reflect this change? If so should I write as of 2024 (when the current taxonomy was released) or as of 2026 (when I checked it last)?

In addition it states " In 2021, the ICTV changed the International Code of Virus Classification and Nomenclature (ICVCN) to mandate a binomial format (genus|| ||species) for naming new viral species similar to that used for cellular organisms; the names of species coined prior to 2021 are gradually being converted to the new format, a process planned for completion by the end of 2023." Does anyone know if this has been completed? Lucas Comac (talk) 12:56, 21 February 2026 (UTC)

• Yes, it is OK to apply the updated reference to ICTV official web pages with virus taxonomy (we do not need to wait to the reviewed publication in a printed journal, as this for the 2024 release. BTW, the 2025 release will be published soon, the numbers will change again.
• When citing the second reference, "... the species rank, with a current total of 16,213 species, almost all of which possess binomial names".

Petr Karel (talk) 07:26, 23 February 2026 (UTC)

I have updated the article. Petr Karel (talk) 11:19, 24 February 2026 (UTC)

Thank you. Lucas Comac (talk) 12:22, 24 February 2026 (UTC)