Sexually Transmitted Infections

Context

What are STIs?

Sexually transmitted infections (STIs)–also referred to as sexually transmitted diseases (STDs)–are viral or bacterial infections that are transmitted through sexual activity. This can include oral vaginal or anal sex and, in some cases, close physical contact. They are extremely common, preventable, and treatable. Some are also curable.

Why is it important to get tested for STIs?

We screen for these infections because they sometimes don’t present with symptoms and, if not detected early, they can lead to serious complications, such as pelvic inflammatory disease, chronic pelvic pain, infertility, and cervical cancer.

While discussing these topics can be sensitive, it’s essential to be honest when answering questions pertaining to sexual practices and history so that your provider can, without judgement, adequately assess risk and order the most appropriate testing.

What’s the difference between an STI and an STD? Is there one?

Generally, these terms are used interchangeably among healthcare providers and researchers. In recent years, the medical community has leaned more toward the use of STI (sexually transmitted infection) rather than use of STD (sexually transmitted disease). This is because the word “disease” implies something that has clear and distinct symptoms, and it’s entirely possible to have an infection without symptoms, as is often the case with STIs.

What are the most common STIs?

• By far the most common STI is human papillomavirus (HPV), the virus that causes genital warts and cervical cancer. Some researchers estimate that HPV is likely to be contracted by 80% of the population by the age of 45, and CDC data from 2013-2014 estimated that 42% of men and 40% of women had HPV. That said, these numbers are likely to be declining due to the availability of the HPV vaccine.

• Trichomoniasis is an extremely common parasitic STI with an estimated 3.7 million cases.

• Gonorrhea and chlamydia are both bacterial. They are often mentioned together because the same tests are used to detect both, and people are sometimes diagnosed with them at the same time. There were 555,608 cases of gonorrhea in 2017. 1.7 million cases of chlamydia were reported for 2017, a 22% rise since 2013.

• Herpes simplex virus (HSV-1 and HSV-2) is the virus that causes genital and oral herpes, which both lead to small blisters around the genitals or mouth. Estimates by the CDC indicate that approximately 776,000 people are newly infected with genital herpes yearly. In the United States, it’s estimated that approximately 56% of people between the ages of 14-49 have evidence of HSV-1 and 16% of people between the ages of 14-49 have HSV-2. While HSV-1 is more commonly associated with cold sores and HSV-2 is most often associated with genital herpes, it’s possible to transmit either strain of the virus to the oral or genital area through oral sex.

• There were 101,567 new cases of syphilis, which is bacterial, diagnosed in 2017.

• There were 39,782 new reported cases of human immunodeficiency virus (HIV) for 2017.  At the end of 2016, it was estimated that over 1 million people were living with HIV in the United States.

• Other infections that are not considered to be STIs, but can be associated with sexual or close physical contact are bacterial vaginosis, mulloscum contagiosum (a viral infection causing papules on the skin), and scabies (a skin mite that burrows under the skin). Some of the less common STIs include pubic lice, chancroid, lymphogranuloma venereum, and mycoplasma. While not usually categorized as STIs, hepatitis B and hepatitis C, both bloodborne viruses, can be transmitted by sexual activity.

Symptoms

Do all STIs have symptoms?

STIs may have no symptoms at all or very mild ones, which can be mistaken for other issues, such as urinary tract infections (UTIs). Undiagnosed STIs can lead to complications such as pelvic inflammatory disease (PID) in women and damage to the reproductive system in both sexes. Absence of symptoms is one of the reasons why screening is important depending on your risk.

What are the symptoms of the most common STIs?  

As mentioned previously, many STIs present with mild or no symptoms at all. It’s important to remember that the type of sexual activity influences where the disease is transmitted, so oral sex may result in having symptoms such as a sore throat, while anal sex may result in pain, itching, and discharge or bleeding from the anus. Gender anatomical differences cause symptom variability also.

• Human papillomavirus (HPV) has many different strains, some of which are associated with actual warts in the anal or genital area, while others cause changes to the cells in the tissue, most often the cervix in women. While the strains causing warts can be obvious to see due to the formation of cauliflower-like wart growth on the skin, the strains that cause precancerous cellular changes are most often diagnosed by a pap smear.

• Trichomoniasis does not have symptoms approximately 70% of the time. Women may experience irritation, itching, and burning in the genital area, as well as painful urination and increased discharge, which may have an unpleasant or fishy odor to it. Men may have urethral discharge, as well as irritation or burning with urination or ejaculation.

• In general, if symptoms occur in gonorrhea or chlamydia, they may include burning and discharge with urination. Women may experience bleeding in-between periods, while men can have urethral discomfort, or, in cases of deeper infection, pain or swelling in the testicles or prostate.

• A first-time herpes (HSV) infection usually presents with a painful outbreak of multiple small blisters called vesicles. During this first outbreak, systemic symptoms, such as fever and swollen lymph nodes, are more common. Subsequent outbreaks tend to be less dramatic, with one or more painful lesions preceded by an itchy or tingling sensation at the blister eruption site.

• Syphilis has distinct infection stages, each of which has characteristic clinical features. The primary stage sometimes goes unnoticed and is marked by the presence of a painless ulcer known as a chancre. This typically occurs wherever the site of the infection was, so it can be in the genital area, anus, rectum, or mouth.

The secondary stage of syphilis is associated with more systemic flu-like symptoms (fever, malaise, swollen lymph nodes) and a rash. Though the rash can vary, one that includes the palms of the hands and soles of the feet is highly suspicious for syphilis in an at-risk person.

After this, if not previously treated with antibiotic injections, the infection goes into a latent phase where there are no symptoms at all. Tertiary syphilis, typically occurring 10-30 years following infection, can cause very serious medical conditions throughout the body, including the heart, blood vessels, brain, and nervous system. Symptoms of neurosyphilis and ocular syphilis include severe headaches, weakness, difficulty with coordination, dementia, and blindness. This phase of the disease is very concerning and can lead to death.

• Human immunodeficiency virus (HIV) has different stages. A newly infected person may experience a flu-like illness two-to-four weeks after exposure. Symptoms may include fever, muscle aches, fatigue, sore throat, swollen lymph nodes, rash, and gastrointestinal disturbances. It’s important to note that not all patients have these symptoms, or they can be mild enough to go unnoticed.

In the second stage of HIV, the virus is dormant. This asymptomatic stage can last for years, sometimes a decade or more for patients who are not taking medications. When left untreated, HIV can evolve into acquired immunodeficiency syndrome (AIDS).

Because AIDS compromises the immune response, a person may experience unique infections from pathogens that typically do not cause illness in most individuals. Patients not receiving treatment may survive for about three years once the infection has progressed to AIDS.

How soon do STI symptoms typically appear?

The answer varies widely by both STI and person.

• Genital warts (caused by HPV) is variable in its presentation due to the number of different strains of the virus. Some strains are more likely to cause actual warts in the genitals (though sometimes these are internal and may not be noticeable), where other strains may cause unnoticeable changes at the cellular level of the cervix, anal tissue, or throat. Typically the incubation period is up to 90 days.

• Trichomoniasis vaginalis (sometimes called “trich”) may be detected one-to-four weeks after exposure. It is most often spread through penis-to-vagina or vagina-to-penis contact, though vagina-to-vagina transmission is also possible.

• Gonorrhea and chlamydia may present with mild symptoms or, more commonly in women, no symptoms at all. The incubation period for gonorrhea can range from 2-30 days, while the incubation period for chlamydia can last from 14-21 days.

• Herpes (HSV) can be extremely variable in its presentation, which may range from a mild localized rash to a severe outbreak with systemic symptoms such as fever, body aches, and swollen lymph nodes around four days after exposure. Because symptoms can be so variable, some people may not know that they are carrying the virus, or may not realize it until years later.

• The incubation period for syphilis is 10-90 days, though it’s important to note that because the initial lesion is painless, it sometimes goes unnoticed.

• Another STI that may have mild or no symptoms at all is human immunodeficiency virus (HIV). When present, symptoms usually arise two-to-four weeks following exposure. There have, however, been cases where symptoms appear as long as ten months after exposure.

Can STI symptoms come and go?

Absolutely. In some STIs, such as herpes, the typical cycle of infection is one in which outbreaks occur, then go away for a period of time. Other STIs, like syphilis, change in their presentation over time.

An initial presentation of syphilis would include a painless ulcer that often goes unnoticed followed by a rash, swollen lymph nodes, and a fever weeks-to-months later, which will spontaneously resolve even without treatment (though the disease will continue to progress).

Can any STIs be self-diagnosed?

It’s difficult to self-diagnose most STIs because symptoms can be so variable and are often non-existent. While you may have an idea of a diagnosis based on what a particular lesion might look like, it’s best to confirm with a medical professional who can advise you regarding any testing and treatment options that might be necessary. As an example, while genital warts have a fairly typical appearance, they may be mistaken for other small non-contagious growths, such as skin tags.

If you are concerned about a possible exposure, symptoms, or would simply like screening, you can reach out to Galileo for assistance with testing or diagnosis. Our clinicians have seen many variations of most STIs and are well versed in current screening and treatment recommendations.

Testing

Who should be tested for STIs?

We use testing in two different ways, for screening and for diagnosis.

Screening refers to testing in the absence of symptoms. It allows us to detect infections before symptoms manifest. Anyone who is sexually active and potentially exposed to STIs should be screened with some regularity.

A slightly different testing scenario is for diagnosis when STI symptoms are present. The aim there is to identify the cause of said symptoms.

Risk factors such as age, lifestyle, sexual practices, and possible symptoms determine which specific tests are used. For example, a person in a monogamous relationship who always uses protection would require “low-risk” testing, whereas someone who engages in oral and anal sex with multiple partners and does not use condoms would require more frequent “high-risk” testing.

Low-risk testing might include a urine sample for gonorrhea and chlamydia along with an HIV test, whereas high-risk testing in this example might add gonorrhea and chlamydia of the throat and rectum (depending on practices) HIV, syphilis, and possibly hepatitis.

It’s important to note that while the community of gay, bisexual, and other men who have sex with men (MSM) is extremely broad, this population as a whole is more highly affected by STIs. Therefore, more intensive screening is generally recommended.

Pregnant women are screened for STIs because transmission from mother to baby (“vertical transmission”) poses unique risks to infants that can have detrimental impacts on their development.

What infections are typically tested for (and how)?

People are typically screened for particular STIs based on their specific risk factors.

• All girls and women younger than age 26 who have sex, women older than 26 who have more than one partner and do not use condoms, and men of any age based on risk factors and symptoms may be tested for gonorrhea and chlamydia. This can be a urine test, or throat or anal swab, depending on the area of exposure.

• Herpes (HSV) is usually only tested for in the setting of a first infection (meaning that the test is for diagnosis rather than screening). The fluid from intact blisters can be swabbed and tested for the virus.

• Syphilis screening is a blood test, and appears as “RPR” on a lab report. Because there are other (non-syphilis) causes for elevated RPR results, positive results are followed with treponemal testing, which is specific to syphilis.

• All men and women, including teens, may be tested for human immunodeficiency syndrome (HIV). This is a usually a blood test, though other detection methods are available.

• All men, and women who are at higher risk for STIs and are having sex with more than one partner or who do not have a stable partner may be tested for hepatitis B (HBV) or hepatitis C (HCV). These are blood tests. Those who are immunized against hepatitis B do not require testing.

What is not tested for?

Human papillomavirus (HPV) strains can be clinically silent, meaning they are detectable without actually causing warts, a situation that does not necessitate treatment. Often, our immune systems will fight these HPV infections successfully without medical intervention, similar to the way our bodies fight cold viruses.    

Testing for herpes (HSV) is a complicated topic. The CDC and other educational organizations advise against screening for herpes infections. As mentioned above, confirming an initial herpes infection from a blistering rash is valuable for diagnosis clarification. Herpes blood testing, especially when no symptoms are present, can produce misleading results. The extremely high community prevalence of exposure to HSV-1, the strain that usually causes cold sores, contributes to the difficulty interpreting these results.

There are some situations when a provider might order a blood test looking at herpes antibodies, but this doesn’t tell us how long the infection has been present or when the infection was passed on. If, however, someone has active symptoms, such as lesions, or is involved with a partner who is known to have herpes, testing may be useful. The online Herpes Handbook is a valuable source for finding answers to any Herpes question.

How soon after exposure would a test give a reliable result?

STIs vary in their incubation periods, and tests also have different processing times.

Gonorrhea can take two-to-four days to test positive following exposure, while chlamydia may come back positive between 24 hours and five days after infection.

Early blood tests may not show syphilis. That said, if it is a suspected diagnosis, treatment should be given immediately, before test results come back. A negative result in a situation of high clinical suspicion warrants repeat testing after two-to-four weeks.

Depending on the type of test used, human immunodeficiency virus (HIV) can be detected anywhere between ten and 90 days after exposure.

What do the test results mean?

For some STIs, such as gonorrhea or chlamydia, results are a straightforward positive (meaning the infection is present) or negative (meaning there is no infection). In other cases, such as human immunodeficiency virus (HIV) or syphilis, an initial positive result means that more testing needs to be done in order to confirm the results.

Is more testing better?

The adage “better safe than sorry” applies here. The main risk of testing is probably financial cost, while the costs of missed diagnoses are more profound and include increased transmission and evolution to a later stage disease or complications. The best way to moderate these extremes is for individuals to be educated on their particular risks.

People who have unprotected sex with multiple partners, for example, would benefit from frequent testing. Those taking HIV pre-exposure prophylaxis need to be tested every three months to ensure it’s safe for them to keep taking the medication. If they have contracted HIV while on this medication, issues of resistance can develop.

For people who are low-risk, testing can be determined on a case-by-case basis. Entering into a new sexual relationship is often a time to get tested, as that confidence can strengthen transparency in a relationship.

What are some of the latest developments in technologies and science around STIs?

While not necessarily the newest developments, two of the most impactful ones in recent years have been pre-exposure prophylaxis (PrEP) for HIV and vaccinations for HPV. Additionally, there is promising work being done in the development of an HIV vaccine.

Other new developments include better access to testing for HIV and other STIs with home test kits available by mail order or at the pharmacy. Many STI testing can also be ordered with a virtual consultation–something that Galileo is happy to assist with.

Treatment

How are the most common STIs treated?

• There is no curative treatment for human papillomavirus (HPV), only symptom management. If the virus manifests in the form of warts, topical wart treatment or cryotherapy (freezing the warts off) can be utilized, though the warts will often resolve themselves. If the virus is causing changes to the cells in the cervix or anus, management is aimed at preventing the abnormal cells from turning into cancer cells. Regular pap smears and follow-up based on those results is extremely important.

• Gonorrhea is typically treated with an injectable antibiotic along with a dose of oral antibiotics, while chlamydia treatment usually involves oral antibiotics. Unfortunately, we are increasingly seeing antibiotic resistance to gonorrhea and have limited options available.

• Trichomoniasis is treated with a one-time dose of an oral medication.

• Herpes (HSV), while not curable, is treatable with antiviral medications that can shorten the duration and severity of the outbreaks. These medications can be taken at first recognition of outbreak symptoms, a strategy called episodic therapy. If someone is getting very frequent outbreaks, it can be used daily to reduce their number. This is known as suppressive therapy.

• Early syphilis can be treated with an injection of antibiotics (penicillin, unless the patient is allergic). Late syphilis requires additional doses of penicillin. Treatment as early as possible prevents progression to later stages of syphilis, which can be severe.

• Antiretroviral medications available for the treatment of human immunodeficiency virus (HIV) have been very successful at prolonging life and allowing patients to live normally and healthily for many years. Full-scope care of a person with HIV includes other considerations that are dependent on the immune status of the individual.

Do most STIs resolve with treatment?

There is no curative treatment for viral STIs, such as human immunodeficiency virus (HIV) and herpes (HSV). Treatments are aimed at symptoms support.

In the case of HSV, the virus is always going to be present in the body and will sometimes flare up in the form of an outbreak. While there is medication available that can shorten the duration and intensity of the outbreak, it does not “cure” the virus. For people who have frequent outbreaks, daily dosing of this medication is an option to reduce the frequency of outbreaks.

Antiretroviral therapy (ART) in HIV-infected individuals can reduce viral load and help ensure good health for many years. It is not, however, typically a cure.

STIs with a bacterial or protozoan etiology are treatable, though this becomes more intensive and difficult in some infections at later stages. For example, if a case of gonorrhea goes untreated and turns into pelvic inflammatory disease (PID), it becomes more complicated to address, requiring longer and more intensive courses of antibiotics.

Can any STIs resolve without treatment?

Bacterial STIs may resolve without treatment. However, because they can lead to complications when left untreated, it’s generally best to treat them.

Human papillomavirus (HPV) is an interesting example of a viral STI for which there is no treatment, but that typically resolves itself eventually. Women who test positive for HPV on a pap smear most often eventually revert to negative as the body’s immune system fights the virus.

Are there long-term risks of any untreated STIs?

Long-term risks of untreated gonorrhea or chlamydia include pelvic inflammatory disease (PID) in women.

Some strains of human papillomavirus (HPV) can lead to cancers (vulva, cervix, anus, penis, and head-and-neck cancers). It’s important for women to have regular pap smears in order to screen for cervical cancers. There are some populations that are also at risk for anal cancer and should therefore be screened with anal pap smears.

Long-term, severe health problems and death can result when syphilis and human immunodeficiency virus (HIV) are untreated. Syphilis can lead to problems throughout the body, including the cardiovascular and nervous systems. The development of neurosyphilis can cause a variety of problems, including strokes, meningitis, dementia, and personality changes. If not treated, some HIV patients will eventually develop AIDS, which results in a whole host of opportunistic infections, as the immune system is severely compromised.

How do you find out if an STI has cleared?

Genital warts will typically shrink and disappear and require no formal testing, though sometimes a trained eye is helpful for reassurance.

Test-of-cure for gonorrhea in patients who received the standard treatment is not usually necessary.

Following an infection with chlamydia, re-testing is recommended after three months. This isn’t so much to see whether the antibiotics were effective, but rather to ensure you haven’t been re-infected. Test-of-cure, or checking effectiveness of antibiotics, is reserved for certain circumstances because antibiotic regimens typically work very well.

Herpes lesions will clear up and do not require follow-up testing.

Syphilis requires lab monitoring to assess resolution.

Prevention

What are the best ways to prevent STIs if you’re sexually active?

Obviously, the only way to completely avoid becoming infected with an STI is to abstain from vaginal, anal, and oral sexual intercourse altogether. However, efforts to reduce STI transmission through this approach have not been successful and can be unrealistic for most people.

Latex condoms can help to reduce the risk of contracting STIs when they are used correctly, consistently, and with every oral, vaginal, or anal contact. Reducing the number of partners; engaging in mutually monogamous relationships; and receiving vaccinations against human papillomavirus (HPV), hepatitis B, and hepatitis A are all strategies that can reduce risk.

Pre-exposure prophylaxis (PrEP) has been effective in reducing the likelihood of contracting human immunodeficiency virus (HIV) when used by people who participate in high-risk activities, including those who are negative for HIV but in a relationship with someone who is positive.

Another important strategy is post-exposure prophylaxis (PEP), which can be used by people with a high-risk exposure. This may include non-sexual exposures, such as needle sticks. Victims of sexual assault may also benefit from post-exposure prophylaxis for HIV.

How effective are contraceptives?

While most contraceptives are very effective when it comes to preventing pregnancy, latex male condoms are the only ones that offer protection from STIs. The use of spermicides in addition to condoms may offer extra protection from certain infections.

Related Topics

What are the best ways to prevent an STI?

What is a parasitic STI?

What is a bacterial STI?

What is a viral STI?

What’s the difference between an STI and an STD?

Useful Links

A broad overview of sexually transmitted infections (World Health Organization)

A useful guide to the HPV vaccine (Mayo Clinic)

The Herpes Handbook (Westover Heights)

A comprehensive list of STD resources (Centers for Disease Control and Prevention)

Latest news updates on pre-exposure prophylaxis (World Health Organisation)

A helpful guide to pre-exposure prophylaxis (Planned Parenthood)

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