Talk:Virus/Archive 1

Classification

user:Azhyd added this taxobox (Note: taxobox removed by Serephine in article cleanup, discussion has value however.). It's not that the classification given is wrong, per se, but that it's a set of convenient groups rather than a phylogenetic classification. In fact, many (most?) authors think that viruses have multiple origins, making a phylogenetic classification impossible. As a result, there is no preferred way to classify viruses, and they are usually left out of the tree of life (they usually aren't assigned a kingdom, domain, or the like). As a result, I think we should be very careful about whether we want to treat viruses in this manner. Maybe the issue should be raised at Wikipedia:WikiProject Tree of Life? Josh 02:03, 12 Aug 2004 (UTC)

I just noted that there was some movement on Tree of Life while I wasn't looking: Wikipedia_talk:WikiProject_Tree_of_Life#Viruses again. They have come up with rudimentary taxoboxes for viruses. 132.205.15.43 04:37, 24 Dec 2004 (UTC)

Algae and protists are polyphyletic too, yet protists have their own kingdom in the five-kingdom system. Viruses may turn out to be much more diverse in their origins than protists, but treating viruses as "a set of convenient groups" is surely just as valid as the hodge-podge grouping of the kingdom Protista? -- Serephine ♠ talk - 16:30, 15 June 2006 (UTC)

Removed paragraph on retroviruses and reverse transcription

I removed this paragraph:

One family of animal viruses, the retroviruses, contains RNA genomes but synthesize a DNA copy of their genome in infected cells. Hence, they interact with cells to provide an excellent example of how viruses can play an important role as models for biological research. Studies of these viruses are what first demonstrated the synthesis of DNA from RNA templates, a fundamental mode for transferring genetic material that occurs in both eukaryotes and prokaryotes.

This is misleading, if not outright wrong. First, the second sentence doesn't make much sense, but even worse it describes reverse-transcription as "a fundamental mode for transferring genetic material". I'm sorry if I'm forgetting about something, but I am pretty sure that reverse transcription is only used by parasitic elements (retroviruses and retrotransposons), so it is NOT a fundamental mode for transferring genetic material. This sentence may be technically correct, but it sounds like retrotranscription is a fundamental part of the cell. It is not. AdamRetchless 03:42, 5 Apr 2005 (UTC)

I'm not sure that complete removal of this paragraph is warranted. What about the small RNA templates used during the gap-filling betwen lagging strand Okazaki fragments? This is a fundamentally important use of RNA templates to produce DNA. There are other good examples of this, including the RNA templates used by telomerase to repair telomeres in linear DNA. I would prefer the paragraph be restated rather than removed entirely. DrNixon 02:43, 13 January 2006 (UTC) 02:43, 13 January 2006 (UTC)

I agree with DrNixon. In addition to the examples he gave reverse transcription is important for many processes of molecular evolution including horizontal gene transfer, processed pseudogenes, and gene duplication. It may not be directly fundamental to an organism but it is a contributing factor to genome evolution, even if only creating filler between exons (i.e. junk DNA which may or may not prove to have a function.) The other thing is that retrotransposons are very common in the genome, in humans it is 41%(13% of genome are LINEs that have the reverse transcriptase gene) and reverse transcriptase is one of the most common genes.( International Human Genome Sequencing Consortium, (2001) Initial sequencing and analysis of the human genome NATURE , VOL. 409 pp 860 921.) That alone makes it influential on a cell.

Maybe a better way to state the paragraph would be:

One family of viruses, the retroviruses, contains RNA genomes but synthesize a DNA copy of their genome in infected cells. These, along with other retroelements, demonstrate a variation on the central dogma of biology, called reverse transcription, and is an influential method of molecular evolution that occurs in both eukaryotes and prokaryotes.

--TimothyDOConnor 03:20, 6 August 2006 (UTC)

The TimothyDOConnor version sounds good to me. --JWSchmidt 03:27, 6 August 2006 (UTC)

Lifeform debate, evolution and the mimivirus

Copied from Talk:Mimivirus:

xyz1323: How can a "Mimivirus" live? It's a living organism, like any other virii. Did you sleep through biology class or something? -Alex 12.220.157.93 06:43, 26 December 2005 (UTC)

It's my understanding (from a strictly layman perspective) that there is still some debate as to whether viruses are living entities or merely shards of living entities, and not themselves alive. It depends on how you define "living organism." A common definition is that an organism is "a living thing that has (or can develop) the ability to act or function independently." The key word is "independently"; most viruses cannot perform these functions without preying on a cell. The mimivirus blurs the distinction between a virus and a bacterium (for example by sythesizing proteins), so some consider the mimivirus to be a life form even if they consider simpler viruses to be nonliving.

I'm more interested in thetheory hypothesis that an ancestor of the mimivirus (or a similar large DNA virus) was also an ancestor of the cell nucleus. This would mean that at least two organelles in each (eucaryotic) cell were once seperate entities (most believe that mitochondria and chloroplasts evolved from purple bacteria), which implies that the eucaryotic cell is actually a cell colony. This would mean that many "single-celled" organisms actually aren't! archola 00:48, 9 February 2006 (UTC)

The above was copied from Talk:Mimivirus. Any comments? archola 01:01, 9 February 2006 (UTC)

Personally, and as a biomedical student, I'm in the "viruses aren't alive" camp - but we always had it stressed to us that viruses are a grey area when it comes to living/non-living. Until an accepted decision by the majority of the scientific communnity is reached I think we should indicate that there is much debate over this issue. As for mimivirus, like chlamydia and rickettsia we're found another organism(?) which is able to walk that fine border between living and non-living. Like Archola has mentioned, it's all about your definition of life -- Serephine / talk - 05:05, 9 June 2006 (UTC)

As a Medical Doctor working in the field of virology, I would like to make it clear that viruses are NOT living organisms as defined by the definition of "living organisms". -absolutecaliber

It does really depend on your definition of life. As far as I know the only definite property of a virus is reliance on host protein synthesis - no viral genome encodes ribosomes. Otherwise, more complicated viruses (eg. pox viruses) can do all sorts of things. I wont go into detail here, but I'm sure if you name a cellular biochemical process, there's a virus somewhere that has its own version of it, optimised for its replication. As a molecular and cellular biology student, I think black-and-white alive/not alive distinctions are overly simplistic. As far as viruses go, my way to view them is to consider them not as a separate entities, but rather a complement to the standard cell and cellular genome, just as most biologists look at transposons and plasmids. Peter Znamenskiy 22:16, 15 June 2006 (UTC)

Can someone try and research what the purpose of a virus is to nature and what role it plays in keeping a nateral balance?

Well who says they have one!? of course population control comes to mind. But all life strives to survive, and viruses do too! they don't nessicarily need a purpose. Adenosine | Talk 21:00, 31 July 2006 (UTC)

Some of our capacity for genetic change is due to the fact that we have virus infections. Some viruses can move genetic instructions between species or cause mutations in existing genes. It might be that if organisms become too good at defending themselves from viruses then they can become less able to change and evolve, resulting in a long-term reduction in their capacity to adapt to environmental changes. However, many people feel that viruses "just happen" and have no real "purpose". There are indications from the genome projects that a large fraction of human genetic change can be associated with past exposure to various infectious agents. This would mean that a large part of "the natural balance" involves viruses and bacteria. I'm not sure if anyone has a good feel for the relative importance of viruses compared to bacteria. --JWSchmidt 21:57, 31 July 2006 (UTC)

Imaging breakthrough

http://www.sciencedaily.com/releases/2006/02/060213101846.htm There have been breakthroughs in imaging virus. Detailed image like the one in this link would be very appropriate.

virus reassembly

Can information be added to the virus wiki about virus reassembly? I feel the article lacks some details about viruses which are kinda creepy and fascinating. Jendenuvaden 04:28, 17 February 2006 (UTC)

How's the new information? I can add further detail but it gets rather technical beyond what I've put there -- Serephine / talk - 05:09, 9 June 2006 (UTC)

Taxoboxes

Shouldn't there be a taxobox on this page? IT appears as a heirarchy on WikiSpecies, and there are taxoboxes for viruses... Vvvvvvvvvvv 23:27, 2 June 2006 (UTC)

We now have a brank spanking new taxobox, though I'm not sure how to integrate the "Groups" into it. I just started from Order and listed any families in them. Info from virus classification -- Serephine / talk - 06:41, 9 June 2006 (UTC)

I'd argue there shouldn't be a taxobox, because viruses aren't treated as a taxon in most systems. It also doesn't work very well, when the placement section is meaningless and the subdivision section is necessarily very incomplete. Josh

Although the use of a taxobox here isn't the same as the one for say, animals, I think it does a lot of good for giving some of the basic points about viral classification. It shows that viruses are yet unranked in the domain of life, how the system of classification is still "evolving" (10 points for the cheesy pun) and that many viruses are yet to be classified. It will obviously be added to as more are classified. If the discipline of Microbiology includes viruses under its wing then I'm sure we can accomodate a taxobox here for the time being ☺ That isn't to say that it will become unwieldy in the future, but we will hopefully have a better classification scheme by then -- Serephine ♠ talk - 16:09, 15 June 2006 (UTC)

I'm not worried about it becoming unwieldy, just inappropriate. Taxa of viruses deserve taxoboxes, but the viruses as a whole are not usually treated as a taxon. There is a good reason for this: taxa are usually phylogenetic, but viruses may not share a common origin with each other or anything else. As such, instead of being unplaced in any domain, they might be unplaceable in domains. On these points, I think a taxobox is somewhat misleading. Wouldn't it be better to just discuss it in the article, and let virus classification give the groups in detail? Josh

I was following WikiProject:Tree of Life's creation of a viral taxobox as an example, I assumed that they'd be the reigning authority on taxobox use here. Please also note my comments further above about polyphyletic kingdoms such as Protista as well. Taxonomy and classification isn't an exact science, so there is lots of room to argue both sides here ☺ -- Serephine ♠ talk - 16:35, 15 June 2006 (UTC)

Viruses
Virus classification
Group:	I-VII
Groups
I: dsDNA viruses II: ssDNA viruses III: dsRNA viruses IV: (+)ssRNA viruses V: (-)ssRNA viruses VI: ssRNA-RT viruses VII: dsDNA-RT viruses

Protista is a paraphyletic group, not polyphyletic, and many biologists accept them as a taxon. The viruses aren't really like that, although many of their subgroups are taxa and so deserve taxoboxes. If we need to have something here, I'd suggest something less taxon- and more group-oriented, maybe like the thing at right. Personally, though, I feel it would be better to have the text discuss the matter of organizing viruses, which is not as straightforward as for many other groups. Josh

I was always told Protista was polyphyletic (as recently as a couple of weeks ago in a microbiology lecture) - Google would suggest there is there is some confusion over it, it would seem. In any case, I like your proposed taxobox ☺ -- Serephine ♠ talk - 17:00, 15 June 2006 (UTC)

Life

I think the point added about Mules that backs up why people are arguing about it doesn't only not belong on this page, but the point is moot since the Mule's cells theirself reproduce. I think this should be removed, and just state that there is an arguement over the definition. Gelsamel 01:26, 4 June 2006 (UTC)

I agreed, it did nothing for the argument. It has been removed and the lifeform debate re-structured -- Serephine / talk - 05:26, 9 June 2006 (UTC)

It probably doesn't add much to the argument, but you should recognize that something's cells can be alive without it being alive. Josh

An interesting point, but can you correlate that in a meaningful way to viruses? You are speaking only of a temporary phenomena, and viruses certainly aren't multicellular organisms, so I fail to see a meaningful connection -- Serephine ♠ talk - 16:11, 15 June 2006 (UTC)

Mimivirus

I removed the statement from ==Size==

Despite being enveloped by a viral capsid, they have also acquired lipids, a carbohydrate driven metabolism and, most notably, their own functioning proteins

as I could not find any literature supporting this. On the contrary, the ITCV database states that no lipids are present [1]. "Their own functioning proteins" needs clarification too, other viruses can come ready-packed with their own proteins - viral envelope peplomers anyone? I think I'll be paying a visit to the mimivirus article to make sure its not wading in assumptions -- Serephine ♠ talk - 03:36, 16 June 2006 (UTC)

Epidemics

I removed part of the statement (in bold):

The damage done by this disease may have significantly aided European attempts to displace or conquer the native population, in many cases, intentionally.

as it was unsubstantiated. If appropriate citations can be added, the author should consider reinstating it -- Serephine ♠ talk - 11:06, 21 June 2006 (UTC)

Plural form of Virus as viruses?? or virii?

Well, had a small argument with a fellow virologist about the technical term. I think it's viruses, but my colleague insists the whole world got it wrong. Hm. I think he's pulling my pants, but I don't see any references in Wiki to substantiate the validity of statement herein about the plural form.

Shushinla 14:41, 4 August 2006 (UTC)

I think you are correct. According to m-w.com (merriam webster online) the plural of virus is viruses. In reality language is relative, if your friend goes on to be a famous virologist maybe he will change the norm and every one will copy him but until then its viruses.TimothyDOConnor 03:29, 6 August 2006 (UTC)

While the correct latin plural form might be 'viri', 'viruses' seems to be the one I have heard far more often even in biology classes, so it may be standard english usage by now. 129.89.68.218 22:19, 9 November 2006 (UTC)

There is a creeping tendency to drop correct Latin plurals in favour of English 'corruptions'; cf 'referendums' vs 'referenda', 'caucuses' vs 'cauca' and so on. I don't think this is necessarily something to be concerned about as it is just a simple evolution of language. tablet_eraser 10:20, 1 March 2007 (UTC)

I happen to know a decent amount of Latin- yes, the "correct" plural form is "virii". In the plural, Latin words ending in 'a' become 'ae', those in 'us' become 'i', and those ending in 'um' become 'a'. Hence antennae, radii, and media. According to my Latin textbook, however, some of the words borrowed from Latin have evolved in English, being given false plural or singular forms. After a while the false forms became standard English, so both the correct and false forms are correct in English. So it can be "Virii" or "Viruses"- but only as long as the original root was Latin and not Spanish. --CommKing 20:01, 20 April 2007 (UTC)

I've only ever heard people using the word "viruses" - if the whole world insists on a word, then this word becomes correct. TimVickers 20:03, 20 April 2007 (UTC)

This whole debate is pointless. Just look it up in the dictionary! --Itub 06:22, 21 April 2007 (UTC)

Which one?--Read-write-services 02:31, 23 April 2007 (UTC)

"Virii" is plain wrong, there never was such a form. See hypercorrection and Plural of virus. --Guinnog 02:54, 23 April 2007 (UTC)

Guinnog, I agree in terms of usage on Wikipedia, but my statement is relevant to the etymology of the term. "Virii" is technically correct, but since languages evolve, false plurals and singulars can be correct too. Since only "Viruses" is in common use, then in English the only correct plural is "Viruses". "Virii" is merely the correct Latin form. Since this isn't the Latin wikipedia, we should only use the English false plural. --CommKing 23:50, 9 May 2007 (UTC)

"'Virii' is technically correct" How do you figure? Why are there two i's at the end of the word? That is not "technically correct" Latin. Who taught you Latin? 142.150.48.209 17:10, 22 June 2007 (UTC)

Vandalism

A cursory reading of the article shows several blatent examples of vandalism. Can someone familiar with this subject please take a look at it and verify the veracity of the information here? --69.143.69.249 06:48, 25 November 2006 (UTC)

Virus, life, taxonomy

Dear friends and enemies I just want to make two or three comments, which you may or may not already be aware of. First about life: I think there are two different concepts, which is relevant. The usual definition of life is, that a live thing must be able to metabolise and to reproduce. As a virus isnt able to do this on its own, it is not alive. Thats a definition. You may choose another definition, but if you accept this definition, there is no need to discus anything. The other concept is darwinian evolution. Vira (acceptet neo-latin plural of virus; viri would be plural of latin vir which means man) is definitely does undergo darwinian evolution. No doubt. If you should define life as something that undergoes darwinian evolution, then vira is alive. Again no discussion is needed, if you accept this definition. But I think it would be sensible to use both concepts and only use the word life about the first. The next point is, that vira realy isnt a clade, isnt monophyletic, isnt one biological grouping. As far as biology knows, they are completely unrelated. At the very least RNA-virus and DNA-virus cant be very closely related. They should probably be placed in different domains. Some vira is probably reduced bacteria. Other vira may have other origins, and probably have. I know, that you are looking for references. One of my sources is Lynn Margulis’ books. Not that she has written much about vira. I hope my comments will be a help. Terkild Marker, København, Danmark. 80.199.162.30 17:24, 3 March 2007 (UTC)

Plaque Forming Units?

I see that Influenza Test Kits ( http://www.craigmedical.com/media/InfluenzaAB_techs.pdf ) are certified to detect a concentration of viral particles measured in Plaque Forming Units but there's no Wikipedia article on them. Virus has a picture of a viral plaque assay and mentions:The number of plaques can be counted and the number of virions estimated from it but more detail of this process would be appreciated! Zirconscot 02:39, 5 March 2007 (UTC)

For now, you might try looking here for a little more background info on PFUs. -- MarcoTolo 02:45, 5 March 2007 (UTC)

Dead virus

How long can a single virus exist? Does it die or decay? Does it feed on something? —The preceding unsigned comment was added by Quertbarbie62 (talk • contribs) 09:34, 18 March 2007 (UTC).

Interesting question. To the best of my knowledge, a virus particle could technically last forever, if kept in the right conditions. It is only a protein and/or lipid husk containing nucleic acid, therefore as long as the particle remained intact and whole, and no constituents degenerated due to environmental effects I see no reason why a virus would not be viable (i.e. able to cause infection). That isn't to say that it won't decay - plenty of environmental agents can do that - UV radiation, detergents, oxidising agents, enzymes etc, rendering the virus useless and unviable.

However, viruses do not "feed" - they have no mouths or even cellular components requiring food as they use any energy they need to replicate whilst inside a living cell host. When outside a living cell they are not doing anything, just hanging around, being an inanimate object devoid of life. -- Serephine ♠ talk - 13:33, 18 March 2007 (UTC)

The maximum would probably be defined by the stability of their genome. In the DNA article the stability of DNA is discussed and sources cited that say it has a maximum lifespan about a million years in solution. However, dried viruses in the cold and dark could last a lot longer than that. TimVickers 15:34, 18 March 2007 (UTC)

Tell me about it, lol, I've had one of the worst ones of my life recently, I've endured diarreaho, blurred vision, pins and needles, an extra- sensitive scalp, as well as temporary memory loss, I thought I had a haemmorage, but my Doctor said it wasn't life threatening, just terribly annoying (it went on for 6 1/2 weeks, thankfully it's dying off now). Anyway the purpose of sharing this with you is, shouldn't we be including more on how viruses are often mistaken, particularly by non- medical professionals, for more serious conditions?

82.26.25.238 13:03, 26 April 2007 (UTC)

Viruses can be lyophylised (freeze dried) I recently recovered live virus from stocks prepared over thirty years ago! —Preceding unsigned comment added by GrahamColm (talk • contribs) 18:26, 21 October 2007 (UTC)

This is the talk page for discussing improvements to the Virus article. This is not a forum for general discussion about the article's subject. Petershank (talk) 19:18, 28 December 2007 (UTC)

• Yes, of course, but please note that this "discussion" ended over two months ago.--GrahamColm^Talk 19:40, 28 December 2007 (UTC)

Vitamin C

Anyone here ever heard of ascorbic acid inhibiting viral reproduction? [2] [3] [4] [5] [6] [7]

MCTs

I heard that certain MCTs (such as lauric acid / "monolaurin") are effective against lipid coated viruses. Does anyone know if this is true? Any references for that? —The preceding unsigned comment was added by 12.196.85.227 (talk) 19:07, 16 May 2007 (UTC).

UD technology removes viruses from water

"What is unique about our technology is its ability to remove viruses--the smallest of the pathogens--from water supplies," Pei Chiu, an associate professor in UD's[8] Department of Civil and Environmental Engineering, said. [9] Brian Pearson 02:46, 28 May 2007 (UTC)

Reasons for removal of text

A contributor {user:http://en.wikipedia.org/wiki/Special:Contributions/IstvanWolf} removed a section of text, I am struggling to understand why they did this-is there something I'm missing? I reverted it thinking it was vandalism? It would be appreciated if the contributors explain their actions before doing so. Any ideas? --Read-write-services 05:08, 19 June 2007 (UTC)

New philosophy section

- I hope it's OK. - Does anyone know more about Keith Ansell Pearson's Viroid Life? Seems pretty relevant, but I don't know enough to summarize it.

Virus

--Daonb 21:41, 22 June 2007 (UTC) "It has been argued extensively whether viruses are living organisms. Most virologists consider them non-living, as they do not meet all the criteria of the generally accepted definition of life. They do not respond to changes in the environment, which is a trait among living organisms."

Could be they're ghosts?

user:jjalexand Quote from the article: "Therapy is difficult for viral diseases as antibiotics have no effect..." My response: I think Antivirals are also counted as a form of Antibiotic, so this wording might benefit from adjustment/reconsideration/qualification/explanation/definition.

From the article: "It has been argued extensively whether viruses are living organisms" My response: I think the argument about what is a living organism is easily settled in that quite clearly the basic requirement for life is IMPERFECT REPRODUCTION. Obviously there can be no life without reproduction, and obviously there can be no evolution without IMPERFECT reproduction. Surely any 'organism' that exibits imperfect reproduction in an 'environmental band' will have the ability to evolve, and thus conforms with our general concept of life. Therefore the requirement of IMPERFECT REPRODUCTION is apparently both _necessary_and_sufficient_. Also, I don't like the wording of the above sentence, it might read better as "It is frequently argued that viruses are not living organisms". And the concepts are vague, and there are no references for this point of view, let alone a 'both-sides' balance to such references.

I would like anyone else who is confident of their biological expertise to adjust the article to fix these difficulties.

An evolutionary biologist like Richard Dawkins would say that the unit of life is the gene and that cells, organs and bodies are nothing but vehicles used by genes to get into the future 'gene-pool' (does this ring a bell?). Living things have genes and so have viruses, therefore they must be alive. The fact that viral genes use a host's reproductive machinery to get through into the next generation of genes does not make their reproduction imperfect. It is perfectly perfect, or there would be no viruses. As to the response to the environment, viruses respond to antiviral drugs by evolving resistance, hence they do respond to their kind of environment. Therefore they must be alive. The real question is: are prions alive? Although I have a background in evolutionary biology, I am no virologist, hence I cannot be arrogant enough to put these views on this page. Perhaps a virologist will. —Preceding unsigned comment added by Pietrocoen (talk • contribs) 23:55, August 24, 2007 (UTC)

Question

Um, I can't remember where, but I read somewhere that viruses usually don't kill the organisms they infect because they have to feed off the organism. Is that true? --76.5.169.237 15:33, 8 August 2007 (UTC)

No, if a virus can spread before its host dies then it has no "interest" in whether or not the host survives the infection process. Tim Vickers 15:41, 8 August 2007 (UTC)

'Laser Blasts Viruses in Blood'

Building on the idea that vibration wrecks a virus’ outer shell, the scientists found that their low-power laser selectively destroys viruses and spares normal human cells around them, while stronger beams kill almost everything. [10] Brian Pearson 02:42, 5 September 2007 (UTC)

Latest Edit

I think it's important to stress the diversity of viruses so I have included more examples and added a gallery. Most of the new images in the text and gallery are from my own collection. This is not vanity - it is so hard to find free images these days that Wiki editors will accept. I have also put the word sex in the article knowing that it will encourage many more readers (and hopefully, contributors). I hope no-one minds, but I have removed the computer generated cartoon of pretend viruses from the article. I felt it lowered the high standard of the article as I originally read it. There's a few other edits that you can check by comparing the versions of course.

GrahamColm 18:04, 13 October 2007 (UTC)

Latest Edit

I have nominated Virus for FA status. Please comment. GrahamColm 20:59, 22 October 2007 (UTC)

Lifeform or not?

Viruses, are they a lifeform? They do not grow, feed, or reproduce. But, people say, they do reproduce! Well, think about it this way:
A robot takes over a factory, becomes the manager, and orders the factory to make more robots like itself.
Doesn't a virus do the same thing? It invades a cell, takes over, and forces the cell to make copies of itself. Manishearth 13:32, 23 October 2007 (UTC)

That was interesting. Think about this: • How does the robot recognise the factory? • How does the robot know that the factory is capable of making other robots? • How does the robot get into the factory? • How does the robot stop the factory from making its usual products? • How does the robot instruct the factory to make other robots? • How does the robot maintain quality control and reject faulty robots? • How do the new robots get out of the factory?

And think about this:

What would you do to stop the robot taking over your factory? user:GrahamColm GrahamColm 16:48, 23 October 2007 (UTC)

A review of the lead

I see that this is at FAC, where some comments have been made about the text. I've had a look at the lead, which is a most important section.

• A virus (from the Latin noun virus, meaning toxin or poison) is a sub-microscopic particle (ranging in size from about 15–600 nm)[1] that can infect the cells of a biological organism.

The word "noun" is redundant. The size range in parenthesis is distracting in the lead sentence. I'd argue that "sub-microscopic" is sufficient detail for the lead. The final portion of this sentence is weak.

• Viruses can replicate themselves only by infecting a host cell. They therefore cannot reproduce on their own.

The second sentence is redundant. Most definitions I've read also emphasis the lack of independent metabolism (growth).

• At the most basic level, viruses consist of genetic material contained within a protective protein coat called a capsid.

Drop the "At the most basic level". This is the lead, so the description will be basic and any exceptions would be covered by the body text. I think there is room to mention RNA/DNA here. There's also room to briefly note their varied morphology (shape).

• They infect a wide variety of organisms: both eukaryotes (animals, plants, protists, and fungi) and prokaryotes (bacteria and archaea). A virus that infects bacteria is known as a bacteriophage, often shortened to phage.

I'm no expert but didn't you just list all life forms that contain cells, and if so, it would be simpler to say so.

• The study of viruses is known as virology and people who study viruses are known as virologists.

This is largely self-evident and could be removed from the lead. Simply using the word "virologist" will be enough for the reader to know that this is the correct term.

• Viruses cause several serious human diseases, such as AIDS, influenza and rabies.

This is also such common knowledge that it isn't really worth mentioning in the lead. The important thing is that most infections lead to disease (rather than being beneficial or benign).

• Therapy is difficult for viral diseases as antibiotics have no effect on viruses and the antiviral drugs currently available are designed to help deal with serious infections such as HIV; herpes viruses, ( which are best known for causing cold sores and genital herpes, but can also cause a life-threatening encephalitis); the hepatitis B and C viruses, which can cause liver cancer; and influenza A and B viruses. Compared to antibiotics, antiviral drugs are expensive.[2] The best way to prevent viral diseases is with a vaccine, which produces immunity.

You haven't convinced me why "therapy is difficult". It is certainly worth mentioning that antibiotics have no effect. I'm not sure a list of diseases that have antivirals is appropriate for the lead. BTW: why should antivirals be expensive? Is this just a patent thing or are they really hard to make? The last sentence is vital.

• It has been argued extensively whether viruses are living organisms.

Avoid "it has been argued".

• Most "plant" virologists, and those who study bacteriophages consider them non-living as they do not meet all the criteria of the generally accepted definition of life. For example, unlike most organisms as defined, viruses do not consist of cells, generally regarded as the fundamental unit of life. Whereas most "animal" virologists consider them as living because they have genes and evolve by natural selection.[3][4]

Could be shortened. I think the animal/plant virologist split is unnecessary here and a distraction. The reader will only wonder why the split opinion should focus round the host specificity of the virus?

Here's an alternative, shorter lead. It isn't perfect and I'm no expert so I'd rather someone else approve it and insert what they like. I think it covers all the above that needs to be covered but there is room to add more. For example, some idea of the impact of viral infection on humans, animals and plants. What proportion of disease is caused by them? Note: appropriate wikilinks are missing and need to be added.

A virus (from the Latin virus, meaning toxin or poison) is a sub-microscopic infectious agent that is unable to grow or reproduce outside of a host cell. Each viral particle, or virion, consists of genetic material, DNA or RNA, contained within a protective protein coat called a capsid. Their shape varies from simple helical and icosahedral (round) forms to more complex structures with tails or an envelope. Viruses may infect all cellular forms of life. They are commonly separated into animal, plant and bacterial virus subgroups (the later are known as bacteriophages or, simply, phages). Virologists are split over whether viruses are truly living organisms. While they do not consist of cells, which are generally regarded as the fundamental units of life, they do have genes and evolve by natural selection.

Viral infection usually results in disease and, in plant or animal hosts, an immune response. Often, the virus is eliminated by the immune system and supportive therapy is all that is required. In comparison with antibiotics (which have no effect on viruses) antiviral drugs are generally more specific, less effective and more expensive. For serious diseases, the best solution is prevention through vaccination, which can produce lifelong immunity.

Colin°^Talk 11:01, 2 November 2007 (UTC)

• Thanks for this User:GrahamColm

Moving on

• I have done pretty much all I can with this article and I am now moving on to do a major edit of Rotavirus. User:GrahamColm —Preceding comment was added at 19:51, 2 November 2007 (UTC)

Viruses and Chronic Prostatitis

Could someone please help on the prostatitis page? Could someone please summarise the medical literature from MEDLINE and elsewhere on "chronic prostatitis and viruses"? - thank you. Wikipedia says, "Wikipedia works by building consensus..... The primary method of determining consensus is discussion...." ReasonableLogicalMan 21:22, 2 November 2007 (UTC)

This is an interesting subject. As far as I recall Herpes simplex virus and Cytomegalovirus are suspected culprits, (at least in the immunocompromised). I will do a PubMed search in the morning and summarise it for the article. (I think Wikipedia works best by cooperation.) User:GrahamColm

Genome size -- Daltons or Kilobases / Megabases?

The article states that viral genomes weigh upwards of 1000000 Daltons, but shouldn't the more standard way of stating genome size be as a measure of number of base pairs? —Preceding unsigned comment added by 24.84.62.242 (talk) 21:15, 30 December 2007 (UTC)

• Yes, base pairs is better. A very wide range mind. I will address this valid point. Thanks.--GrahamColm^Talk 21:25, 30 December 2007 (UTC)