Do You Capitalize Disease Names Like Coronavirus?

"Ebola" is capitalized but "coronavirus" is not. Here's why.

Mignon Fogarty
3-minute read
The Quick And Dirty

Diseases named after regions and people are capitalized; other diseases are not.


The name of the coronavirus disease that emerged in late 2019 is not capitalized because most disease names aren't unless they are named after a person or a region.

For example, influenza, diabetes, and cancer also aren't capitalized. The other official name for coronavirus disease is COVID-19, which is capitalized because it's an abbreviation for "COronaVIrus Disease-2019."

Diseases Named After Regions Are Capitalized

Diseases that are named after regions are capitalized. For example, Ebola is the name of a river in Zaire,* and it was near the Ebola River that the virus first caused disease in humans. Thus, the disease became known as the Ebola virus.

"West Nile" in "West Nile virus" is capitalized for a similar reason: It was first found in a patient in the West Nile district of northern Uganda.

Diseases named after people or regions are capitalized.

Diseases Named After People Are Capitalized

Some disease names are capitalized because they are named after the person who discovered them. For example, Alzheimer’s disease is named after a German doctor named Alois Alzheimer. Other disease names are capitalized because they’re named after a person who had the disease, such as Lou Gehrig’s disease, which is also known as amyotrophic lateral sclerosis or ALS.

'Alzheimer’s Disease' Versus 'Alzheimer Disease'?

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Apostrophes are a related topic: When people start thinking about disease names, they often wonder why some have apostrophes and some don’t, and why you sometimes see the same name written both with and without an apostrophe.

You sometimes see disease names such as Alzheimer (without the apostrophe) because there is a movement to omit the apostrophe from names based on the name of the doctor who discovered the disease. Some patient advocacy groups say that the apostrophe implies the disease belongs to the physician and that such names are inappropriate.

On the other hand, the argument that an apostrophe means the doctors own the disease is linguistically simplistic, and the sentiment isn't universal among advocacy groups. For example, the British Alzheimer’s Society makes its opinion clear. Their website reads: “Alzheimer’s is often misspelt without an apostrophe which is incorrect….”

Researchers haven’t reached a consensus about including or omitting the apostrophe — at least not one that has stuck. An article by Len Leshin (which I found through the Separated by a Common Language blog), refers to a motion made by the U.S. National Institutes of Health in 1974 that read, “The possessive form of an eponym should be discontinued, since the author neither had nor owned the disorder.”

Yet, although the apostrophe-free spelling is more common in medical literature than in general writing, the apostrophe-bearing version is still in use. Stanford ethicist Hank Greely noted in a 2011 blog post that at the time, the Alzheimer’s spelling still appeared in 15% of English medical articles. 

Most Disease Names Aren’t Capitalized

Returning to capitalization, most disease names aren’t capitalized. The names are often named based on some hallmark of the condition. Diabetes, for example, was named because of what happens to people who have the disease. They urinate a lot, so the name, based on a Greek word, means “to go through, pass through, or pass over.”

*When the Ebola virus was discovered, the country was called Zaire. Today, it is called the Democratic Republic of the Congo.


Greely, H. “Diseases and Apostrophes—A (Sort of) Poll.” The Centre for Law and the Biosciences blog at the Stanford Law School. September 2, 2011. http://blogs.law.stanford.edu/lawandbiosciences/2011/09/02/diseases-and-apostrophes-a-sort-of-poll/ (accessed August 8, 2014).

Leshin, L. “What’s in a Name?” Down Syndrome: Health Issues. 2003. http://www.ds-health.com/name.htm (accessed March 13, 2020).

Sejvar, J.J. “West Nile Virus: An Historical Overview.” The Ochsner Journal. 2003 Summer-Autumn; 5(3): 6-10. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3111838/ (accessed March 13, 2020).

“diseases.” AP Stylebook, online edition. https://www.apstylebook.com/ap_stylebook/diseases (subscription required, accessed March 13, 2020).

“diseases, procedures, and such.” Chicago Manual of Style, 17th edition, section 8.144 https://www.chicagomanualofstyle.org/book/ed17/part2/ch08/psec144.html (subscription required, accessed March 13, 2020).

"diabetes." Dictionary.com Unabridged. Random House, Inc. https://www.dictionary.com/browse/diabetes (subscription required, accessed March 13, 2020).

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About the Author

Mignon Fogarty

Mignon Fogarty is the founder of Quick and Dirty Tips and the author of seven books on language, including the New York Times bestseller "Grammar Girl's Quick and Dirty Tips for Better Writing." She is an inductee in the Podcasting Hall of Fame, and the show is a five-time winner of Best Education Podcast in the Podcast Awards. She has appeared as a guest expert on the Oprah Winfrey Show and the Today Show. Her popular LinkedIn Learning courses help people write better to communicate better.