Sexually Transmitted Diseases/STD Origin


I don't know if this the right place to ask this question, but it has always kept me wondering. STD's are contracted when u have sex with someone who is infected, so my question is how was the first person infected to be able to infect thier partner to start the chain of stds? Just curious thanks for listening.O

Hi Ed,
STDs are yet another example of natural selection and evolution of the so called, "survival of the fit" brought down to the level of germs (bacteria, viruses, protozoa, etc.).  As everything ages and matures through life (germs, animals, plants, etc.), our basic genetic material bound together as DNA and RNA also replicates. The amino acids that comprise DNA must also be reassembled and replicated, every time there is cell growth and repair. Exposure to random variation, mutation, radiation from outer space, antibiotics, other environmental influences, etc., influences cellular growth and how these amino acids are reassembled. This is an ongoing and natural process. If one germ changes in a way to promote it's survival then it "wins out" over it's competitors, and passes on it's genetic material to it's progeny (successive generations).

Some germs, like some animals and plants have evolved to enhance their survival in the environments they exist in. Desert plants and animals do not do well in temporate climates; it's tough to keep a palm tree outside up north, or to keep tropical fish in artic waters, and so on. Many germs have adapted to their human and animal hosts as well. Over the course of many millions of generations (many bacteria may replicate once every 20 minutes, 3 generations per hour!) subtle influences promote or retard growth and subsequent replication of these germs and indeed, all cells that comprise life. These complicated processes guide whether germs live and thrive, or don't, and include how germs move around with little microscopic appendages such as cilia, or flagella, or whether they "prefer" certain types of target cells (like the genital tract), what their nutritional requirements are, etc.

When antibiotics are used, they are frequently but not always successful in killing all the "bad" germs. The few that may survive may have a tiny bit of genetic variation that allows them to survive exposure to antibiotics, and they replicate to form antibiotic resistance. And if a person's immune system isn't able to get rid of the survivors, than that host may have ill health, continued infection, or death. It's a complicated "dance" involving the germ with the host's immune system and the ambient environment.

So some germ at some point existed, changed in a way to cause illness, and then spread from one host to another. At some point, the germs may have crossed from animals to humans through unfortunate encounters-- being bitten, eating undercooked meat, rats, insects or other vermin coming in contact with people, and diseases cross from one animal to another.

Hope this addresses your question, and drives your curiosity to learn more about how natural selection guides this entire process!

Good luck!

Sexually Transmitted Diseases

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Mark P. Behar


Almost any question or concern about gay men's health issues, sexually transmitted infections, abnormal Pap smears, anal cytology (anal "Pap smears"), etc. There is no such thing as “d/d free” or “clean” (free of infection), so why do so many of us deceive ourselves into thinking that some people are indeed totally free from a potentially infectious disease, like HIV, herpes, hepatitis, syphilis, chlamydia, warts, gonorrhea, etc., just because they say so? Clinical laboratory tests are not perfect, and having a “negative” or “nonreactive” test does not mean that a person is free from infection. Perhaps at the moment the test was taken, the person was uninfected; or, perhaps, the test wasn’t sensitive enough to detect presence of the infection. There is really no way that anyone can determine that they are truly “disease free,” and there are over a hundred of infectious conditions that can be spread without your knowing anything. Rather than trying to “pre-screen” or “serosort” a potential sex-mate with deceptive questions that are impossible to know by today’s technologies, a wiser option may be to consider everyone infected with something, and either use appropriate protective measures (“safer sex”), or accept the responsibility and consequences of possibly “catching” something from someone who’s hotter than expected (pun intended!). There is much research that supports the contention that an HIV positive person reliably taking HIV medications, and having an undetectable viral load, presents a lower risk for transmission of HIV than people who may think or say they are HIV negative, but are not. Food for thought!


Family Practice PA since 1981; Volunteer Clinician for Brady East STD (BESTD) Clinic, Milwaukee, since 1977; answered STD questions submitted to their web site. Professionally lectured at national and regional Physician Assistant and Nurse Practitioner conferences, and at national gay & lesbian health conferences on topics including HIV/AIDS, herpes, hepatitis, STDs, human papilloma virus (the cause of venereal warts), abnormal Pap smears, gay and lesbian health issues, among others.

Co-Founder, Lesbian, Bisexual, & Gay Physician Assistant Caucus of the American Academy of Physician Assistants, Inc.; American Academy of Physician Assistants; Wisconsin Academy of Physician Assistants; National Co-Chair (2012-16), National Association of Black and White Men Together: A Gay, Multiracial Organization for All People (NABWMT)

Journal of the American Academy of Physician Assistants (JAPA) Q Visions, Quarterly Newsletter of the NABWMT

Bachelor's of Arts, 1972 (University of Wisconsin, Milwaukee, WI) Graduate Credits Experimental Psychology, 1972-75 (Tulane University, New Orleans, LA) Physician Assistant, Bachelor's of Science, 1981 (George Washington University, Washington, DC); Masters in Physician Assistant Studies, 2000 (University of Nebraska Medical Center, Omaha, NE)

Awards and Honors
Colposcopy Recognition Award (CRA), the American Association of Colposcopy and Cervical Pathology; Distinguished Fellow, Clinical Preceptor, American Academy of Physician Assistants; Fellow, Wisconsin Academy of Physician Assistants

Past/Present Clients
Brady East STD Clinic, Milwaukee, WI Milwaukee Health Services, Inc. (Martin Luther King Heritage Health Center), Dept. of Family Medicine and Early Intervention Program for HIV Infected Persons

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