# What virus has infected the most people (currently living) on earth? **URL:** \ **Category:** Factual Questions\ **Created:** [January 20, 2013, 5:58am UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787 "2013-01-20T05:58:44Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![GameHat](https://avatars.discourse-cdn.com/v4/letter/g/ed655f/32.png) [@GameHat](https://boards.straightdope.com/u/GameHat)\ **Post date:** [January 20, 2013, 5:58am UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/1 "2013-01-20T05:58:44Z")
Tried a simple googling, but got nowhere. There are, what, bajillions of viruses in existence? I know not all are deadly or even necessarily harmful. I’m not looking for “deadliest virus” or “killingest virus”, I’m just wondering if there’s some virus nearly every human carries, and what the most common one is. In my own case, I’m thinking whatever virus causes chicken pox - well, I had that one as a kid, I’m sure I’m still carrying it. Same with whichever herpes virus causes the basic mouth cold sores. I think I remember reading somewhere that something crazy like 60% of American adults have the cold sore HSV-1 virus. So what is the most prevalent virus? Biological only, no computer viruses, please 😉 ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 20, 2013, 6:13am UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/2 "2013-01-20T06:13:39Z")
I took a shot with “Common Cold” on wiki and came back with this " It is the most frequent infectious disease in humans with the average adult contracting two to three colds a year and the average child contracting between six and twelve. These infections have been with humanity since antiquity." So, I’d start with that. ---
**Author:** ![GameHat](https://avatars.discourse-cdn.com/v4/letter/g/ed655f/32.png) [@GameHat](https://boards.straightdope.com/u/GameHat)\ **Post date:** [January 20, 2013, 7:06am UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/3 "2013-01-20T07:06:11Z")
> [@Joey\_P](#): > > I took a shot with “Common Cold” on wiki and came back with this " It is the most frequent infectious disease in humans with the average adult contracting two to three colds a year and the average child contracting between six and twelve. These infections have been with humanity since antiquity Is that one virus, or one of many? ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [January 20, 2013, 7:06am UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/4 "2013-01-20T07:06:35Z")
I think your immune system eradicates the cold virus by the time the infection has been quelled, but I’d have to check to be sure. As for virii that actually stay with you and that you “carry”, I’d have to go with herpes simplex. ---
**Author:** ![Shakester](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shakester/32/437_2.png) [@Shakester](https://boards.straightdope.com/u/Shakester)\ **Post date:** [January 20, 2013, 7:27am UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/5 "2013-01-20T07:27:08Z")
> [@deltasigma](#): > > virii The plural of virus is viruses. > **[Plural form of words ending in -us](https://en.wikipedia.org/wiki/Plural_form_of_words_ending_in_-us#Treating_v.C4.ABrus_as_2nd_declension_masculine)** > > In English, the plural form of words ending in -us, especially those derived from Latin, often replaces -us with -i. There are many exceptions, some because the word does not derive from Latin, and others due to custom (e.g., campus, plural campuses). Conversely, some non-Latin words ending in -us and Latin words that did not have their Latin plurals with -i form their English plurals with -i, e.g., octopi is sometimes used as a plural for octopus (the standard English plural is octopuses). Mos... ---
**Author:** ![jk1245](https://avatars.discourse-cdn.com/v4/letter/j/49beb7/32.png) [@jk1245](https://boards.straightdope.com/u/jk1245)\ **Post date:** [January 20, 2013, 7:33am UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/6 "2013-01-20T07:33:52Z")
Cytomegalovirus (also known as herpesvirus 5) is estimated to have infected 40% of the worldwide population. It causes some disease, but is also largely symptomless in healthy adults. There is another virus I recall reading about that can be detected in over 90% over people throughout the world, but I can’t remember what it is. It is harmless as far as anyone knows, so no efforts to prevent or treat it. I’ll see if I can find what it is. ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [January 20, 2013, 7:37am UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/7 "2013-01-20T07:37:55Z")
> [@Shakester](#): > > The plural of virus is viruses. > > [Plural form of words ending in -us - Wikipedia](http://en.wikipedia.org/wiki/Plural_form_of_words_ending_in_-us#Treating_v.C4.ABrus_as_2nd_declension_masculine) Hmmm. Interesting. > [@](#): > > The English plural of virus is viruses.[1] In most speaking communities this is non-controversial and speakers would not attempt to use the non-standard plural in -i. However, in computer enthusiast circles in the late 20th century and early 21st, the non-standard viri form (sometimes even virii) was well-attested, generally in the context of computer viruses.[2] > > While the number of users employing these non-standard plural forms of virus was always a proportionally small percentage of the English-speaking population, the variation was notable because it coincided with the growth of the Internet, a medium on which users of viri were over-represented. As the distribution of Internet users shifted to be more representative of the population as a whole during the 2000s, the non-standard forms saw decline in usage. A tendency towards prescriptivism in the computer enthusiast community, combined with the growing awareness that viri and virii are not etymologically supported plural forms, also played a part.[citation needed] > > Nonetheless, the question of what the Latin plural of virus would have been turns out not to be straightforward, as no plural form is attested in extant Latin literature. Furthermore, its unusual status as a neuter noun ending in -us apparently not of Greek origin obscures its morphology, making guesses about how it should have been declined difficult.[citation needed] ---
**Author:** ![Minnie\_Luna](https://avatars.discourse-cdn.com/v4/letter/m/4bbf92/32.png) [@Minnie\_Luna](https://boards.straightdope.com/u/Minnie_Luna)\ **Post date:** [January 20, 2013, 5:14pm UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/8 "2013-01-20T17:14:04Z")
> [@jk1245](#): > > Cytomegalovirus (also known as herpesvirus 5) is estimated to have infected 40% of the worldwide population. It causes some disease, but is also largely symptomless in healthy adults. > > There is another virus I recall reading about that can be detected in over 90% over people throughout the world, but I can’t remember what it is. It is harmless as far as anyone knows, so no efforts to prevent or treat it. I’ll see if I can find what it is. [Epstein-Barr?](http://www.cdc.gov/ncidod/diseases/ebv.htm) It’s not necessarily harmless, but 95% of American adults test positive. ---
**Author:** ![SCAdian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scadian/32/3292_2.png) [@SCAdian](https://boards.straightdope.com/u/SCAdian)\ **Post date:** [January 20, 2013, 6:19pm UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/9 "2013-01-20T18:19:42Z")
> [@deltasigma](#): > > virii > [@Shakester](#): > > The plural of virus is viruses. I’ve never understood how people get “virii” out of “virus.” It’s obviously incorrect. ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [January 20, 2013, 7:10pm UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/10 "2013-01-20T19:10:59Z")
> [@SCAdian](#): > > It’s obviously incorrect. So it would appear. But thanks for reiterating. ---
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [January 20, 2013, 7:48pm UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/11 "2013-01-20T19:48:15Z")
There would be endogenous retroviruses that are part of the human genome, which means that every human is infected from birth and these are not thought to be universally and completely harmless. ---
**Author:** ![Darth\_Panda](https://avatars.discourse-cdn.com/v4/letter/d/ee7513/32.png) [@Darth\_Panda](https://boards.straightdope.com/u/Darth_Panda)\ **Post date:** [January 20, 2013, 8:07pm UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/12 "2013-01-20T20:07:14Z")
Fucking hipsters and their retro viruses. ---
**Author:** ![Werekoala](https://avatars.discourse-cdn.com/v4/letter/w/7993a0/32.png) [@Werekoala](https://boards.straightdope.com/u/Werekoala)\ **Post date:** [January 20, 2013, 8:39pm UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/13 "2013-01-20T20:39:22Z")
Mitochondria? ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [January 20, 2013, 9:28pm UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/14 "2013-01-20T21:28:03Z")
> [@Joey\_P](#): > > I took a shot with “Common Cold” on wiki and came back with this " It is the most frequent infectious disease in humans with the average adult contracting two to three colds a year and the average child contracting between six and twelve. These infections have been with humanity since antiquity." > > So, I’d start with that. Two or three times a year?! I have a lot of catching up to do… the latter number is even more incredulous, I don’t remember getting sick every month or two as a kid. Or, are many of those colds so mild you don’t notice them? ---
**Author:** ![Superhal](https://avatars.discourse-cdn.com/v4/letter/s/b4bc9f/32.png) [@Superhal](https://boards.straightdope.com/u/Superhal)\ **Post date:** [January 21, 2013, 1:38am UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/15 "2013-01-21T01:38:55Z")
One of the hepatitis viruses (the one that causes chicken pox) supposedly still exists in everybody who had it. There is a chickenpox vaccine now, but I would suspect before it existed the prevalence of infection would be 100%. ---
**Author:** ![Iggy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iggy/32/3364_2.png) [@Iggy](https://boards.straightdope.com/u/Iggy)\ **Post date:** [January 21, 2013, 2:26am UTC](https://boards.straightdope.com/t/what-virus-has-infected-the-most-people-currently-living-on-earth/647787/16 "2013-01-21T02:26:35Z")
> [@Werekoala](#): > > Mitochondria? Evolutionarily mitochondria were probably a bacteria, not a virus.