STD: sexually transmitted disease — a term used since the mid-1970s for an infectious disease that is usually transmitted during oral sex, anal sex or other intimate contacts with the genitals. It is generally thought that the change from venereal disease (VD) to STD was intended to decrease the stigma associated with the antiquated term VD.
STI: sexually transmitted infection — a term introduced in the 1990s for a sexually transmitted infection that is asymptomatic (has no symptoms) and that may or may not develop into a disease with observable symptoms. This term was considered to be more accurate because some infections never turn into a disease whether they are treated or not. The term ‘infection’ was also thought to be less stigmatizing than the term ‘disease.’
An infection arises when an organism that has the potential to cause disease invades the body. An infection is declared a disease only when it causes damage to the body that is characteristic of the specific organism. Someone could be infected with a microbe, say polio or tuberculosis, and never have any symptoms. They are infected but are not diseased. Others infected by the same microbe can have all the symptoms of, and die from, the same infection — they have the disease.
This is where it gets confusing. Some STIs remain STIs, some STIs can turn into STDs, and sometimes it’s hard to know which is which.
Due to this confusion, a new term was proposed by a linguist and medical editor, Janet Byron Anderson, in the 2016 article entitled, “STD (sexually transmitted disease) or STI (sexually transmitted infection): Should we choose?”[i] Dr. Anderson makes several arguments in support of new terminology, some of which I’ve summarized here, with additional commentary:
1. The terms STD and STI are being used interchangeably, the difference between them is minor and confusing, and people, outside as well as inside the medical professions, don’t know which one is “right.”
2. If an STI remains asymptomatic by definition, does it change to an STD when the symptoms show up? Would HIV be the STI and AIDS be the STD? Do you have an STI if your herpes blood test is positive but an STD after an initial outbreak? Technically, the terms should not be used interchangeably, but the difference between them is not well delineated and is, therefore, confusing.
3. When we speak about STDs or STIs in general, should we always say “STDs and STIs” or write STD/I in order to be accurate and inclusive? That’s a mouthful, to use an indelicate term in this situation, and does away with the benefits of using acronyms in the first place. Saying “STD slash I” is ridiculous and reading STI/D can be annoying, as illustrated in this paragraph.
4. Another issue raised by Dr. Anderson is that the words ‘transmitted’ and ‘transmissible’ are significantly different. Transmitted suggests a past event, while transmissible describes a potential event. To call an STD/I ‘transmitted’ is to have diagnosed it in a person; to call an STD/I ‘transmissible’ is to identify it as an agent to protect oneself from. These two scenarios require different approaches: the former patient needs a treatment plan, the latter needs a condom. Words are important in medicine.
5. The Zika virus disease is primarily a vector- (mosquito) borne infectious disease. It can also be transmitted sexually. It is a sexually transmissible infectious disease, a STID. Many STI/Ds can have non-sexual transmission via clothing (crabs), intravenous drug use (HIV, hepatitis B), tattooing (hepatitis B), blood transfusions (HIV, HBV), birth (syphilis, gonorrhea, etc.), or dear old Aunt Ethel’s kisses (herpes-1) to name a few.
6. Ms. Anderson states, the term STID “captures more comprehensively the pathogenesis of the sexual illnesses, from the initial presence of the infective agent to the potential transfer of the agent to a susceptible human host, culminating in [an infectious process and] a possible disease.” I agree with the linguist’s carefully parsed conclusion.
7. She also concedes that “the monosyllabic STID is easy to read and say,” while allowing that “its full name is a bit of a mouthful, even for a linguist!” However, medical terminology is full of acronyms that simplify complex terms to facilitate communication as in BP, EKG, MRI, TB, DNR (do not resuscitate), NKDA (no known drug allergies), ADHD, etc.
I’m not sure that society is ready to adopt a new term when we are still struggling with the old ones but I do know that there is confusion about whether or when to say STD or STI and which one is more correct.
We are currently in the middle of a pandemic — an STI/D epidemic. As we learned from COVID-19, the best way to fight a pandemic is to widely spread accurate information about the infectious nature of the pathogen and the steps that need to be taken to protect ourselves and each other from contracting it. In the case of STIs and STDs, people hesitate when they speak, deciding in their heads which term to use, which one is right. Stumbling over terminology makes communication more difficult. This most basic distraction does not help us deal with an epidemic.
If I had to name them today, I’d call them STIDs.
[i] Anderson, JB. STD (sexually transmitted disease) or STI (sexually transmitted infection): Should we choose?” American Sexual Health Association. 2016. Available by clicking here.
Excerpt from my upcoming book, My Life in STDs.