Why is Zika capitalized and chikungunya and yellow fever are not?



I noticed the usage on the CDC website. I don't understand why Zika is capitalized while the other two were in lower cases.

There is no vaccine to prevent or medicine to treat chikungunya virus infection.

There is no specific treatment for yellow fever; care is based on symptoms.

Zika virus disease (Zika) is a disease caused by Zika virus that is spread to people primarily through the bite of an infected Aedes species mosquito.


Posted 2016-02-29T12:17:07.090

Reputation: 372

Related: https://ell.stackexchange.com/q/10976/

– ColleenV – 2017-09-05T18:07:34.190



"chikungunya" and "yellow" are, respectively, a common Makonde word meaning "something bending up", and a color name.

Therefore, neither is capitalized.

However, "Zika" is a proper noun, named after a forest in Africa; therefore, it's capitalized.


Posted 2016-02-29T12:17:07.090

Reputation: 573


Capitalization is stylistic choice, and people may choose to capitalize things that you don't normally see capitalized. There are a couple of guidelines that come up in a simple search, and this is one of them. There's no unilateral consensus, but there are conventions. Chicago Manual of Style is another eminent manual that is both loathed and loved at the same time.

Back to your question, just like most of the words in this sentence, words in text and descriptions shouldn't be capitalized by default. That explains the yellow fever's case.

In the other two cases, the origins of the words are helpful:

History of "Zika virus"

The virus was first isolated in April 1947 from a rhesus macaque monkey that had been placed in a cage in the Zika Forest of Uganda, near Lake Victoria, by the scientists of the Yellow Fever Research Institute. A second isolation from the mosquito A. africanus followed at the same site in January 1948. When the monkey developed a fever, researchers isolated from its serum a "filterable transmissible agent" that was named Zika virus in 1948.
emphasis mine

Thus, "Zika" is the name of a forest, and generally proper nouns, including the names of places, get capitalized.

History of "chikungunya"

The word 'chikungunya' is believed to have been derived from a description in the Makonde language, meaning "that which bends up", of the contorted posture of people affected with the severe joint pain and arthritic symptoms associated with this disease.

Often terms that enter English from foreign languages don't get capitalized. There is a related question on this on ELU.

M.A.R. ಠ_ಠ

Posted 2016-02-29T12:17:07.090

Reputation: 6 272


+1 Some other examples of often-capitalised disease names: Ebola after the river in DRC, Marburg after the German city, Lassa fever after the town in Nigeria, West Nile fever after the river/region, Alzheimer's and Asperger's after the psychiatrist who recorded the first case, etc etc. All are named after a person or place.

– user568458 – 2016-02-29T14:34:25.943

I am confused, I thought the name of each disease would be a proper noun and therefore capitalised. The first link in this answer points to a page that says "we capitalize words that are proper nouns—that is, they describe a specific thing or entity. They could be a title, a name..." and in this case the words are the names of diseases, so proper nouns? – Ian Stanway – 2016-03-02T20:29:35.160

@Ian No, the problem of that definition is that its incompleteness is misleading and confusing. Would you also call carpet, bottle, and castle proper nouns? Would you call foot, leg and arm proper nouns, since they're a name after all? I'm more inclined to think of it this way: Any noun that can reasonable be a vocative in your mind is very likely to be a proper noun. Other than that, I Can Capitalize Anything I Like, Like The Words In This Sentence. It Just Would Garner Weird Looks, like the way you're looking at me right now.

– M.A.R. ಠ_ಠ – 2016-03-02T20:35:24.517

I'm not convinced (although every reference to these diseases doesn't capitalise them). I would call all of your examples common nouns, but if you'd listed a particular castle by name it would be a proper noun. These are diseases (the common noun) and the specific name, in the same way my name is Ian, are yellow fever and the other chikungunya. I realise I'm wrong saying that because I can see the overwhelming evidence to the contrary (Wikipedia and NHS website), but nobody has explained why either they are not proper nouns or why they are not capitalised if they are proper nouns. – Ian Stanway – 2016-03-02T22:15:20.913

The best I can find is that it is because these are the vernacular names, so they are not proper nouns. If the vernacular name happens to be a proper noun it is capitalised. As I'm not sure that's correct I daren't proclaim it an answer, but if true I think it is a better explanation to the OP than this answer. – Ian Stanway – 2016-03-02T22:37:46.277

1By all means @Ian. I suspect you're on the right track. The answers here are meant to be as easily comprehensible by learners as possible. I would love to see an answer that digs a lot into this stuff, but I suspect the only correct answer when it gets to capitalization is "They (did not) capitalize because they did not." – M.A.R. ಠ_ಠ – 2016-03-03T06:20:53.037

I was really torn about whose answer to accept because I also appreciated the information you provided on stylistic choice. It gave me a more in depth understanding of capitalization. Very much appreciated @IanStanway – michele – 2016-03-03T16:36:36.117


The Zika virus is named for the Zika Forest in Uganda. Given that Zika is a proper noun, it is capitalized.


Posted 2016-02-29T12:17:07.090

Reputation: 81


Since Chikungunya and Yellow Fever are names of diseases, they are Proper Nouns, regardless of their origin. So is Zika. Hence they must be capitalized.

You can also capitalize on occasion to emphasize something, as I have in the first sentence.


Posted 2016-02-29T12:17:07.090

Reputation: 101

1You should not capitalise to emphasise something, but sadly the world's marketing people have forced this down our necks for the last couple of decades and it's becoming accepted. I agree with you on the other point, even though I'm wrong and I don't know why. – Ian Stanway – 2016-03-02T22:28:10.523

"They must be capitalized." . . . in your writing. ;) I still don't know why people are considering an answer right or wrong here, since this is all about conventions. There has never been a capitalization guide people unanimously follow. The OP wanted a convention explained, not a rule, not a law. – M.A.R. ಠ_ಠ – 2016-03-03T06:25:56.093

Well, the convention exists because of the rule, right? :-) – Chiwda – 2016-03-04T03:54:12.750