Sexually transmitted infection screening (GYN): Clinical sciences

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Introduction0:00–0:35

Sexually transmitted infections, or STIs, are infections that are transmitted through sexual contact. The goal of screening for STIs is to diagnose and treat infections, and provide education, which then prevents further transmission.
While some STIs cause symptoms such as lesions or cervical discharge, many are asymptomatic. STI screening is encouraged for all patients, and specifically in special populations such as pregnant patients, where some STIs, like syphilis, can cause congenital disease.When a patient presents for STI screening, begin with a focused history and physical exam.

Screening and assessment0:35–1:38

Start by reviewing your patient’s age, pregnancy status, and HIV status. Ask your patient if they have had a known exposure to an STI.
If yes, inquire about the timing of sexual exposure, review previous screenings or treatment results, and ask if they’re experiencing symptoms.
On a physical exam, look for cervical discharge or genital lesions which may prompt additional screening. Also keep in mind that STI screening can be completed at a specific STI screening visit or as part of a preventative visit, like a well-patient care exam.
STI screening can also be completed without a physical exam by patient-collected swabs, and lab tests such as blood and urine tests; however, this is only appropriate for asymptomatic patients.Okay, let’s start by talking about which infections are screened for and how that screening is completed.

Infections1:38–6:20

Chlamydia, caused by Chlamydia trachomatis, is the most frequently reported bacterial STI with the highest prevalence in patients who are under 25 years of age.
Gonorrhea, caused by Neisseria gonorrhoeae is the second most frequently reported bacterial STI. Testing for both is completed through a nucleic acid amplification test or NAAT.
If a provider obtains a sample for testing, a specimen collection swab is used to obtain the sample from the patient’s cervix.
If the patient collects their own sample, either a vaginal swab or first catch urine specimen can be used. Positive results are reported to the CDC.On the other hand, Trichomoniasis, caused by Trichomonas vaginalis, is not a reportable disease.
That being said, it has a higher prevalence rate than gonorrhea or chlamydia, and is known to increase the risk of acquiring HIV.
Testing is done by a NAAT test using a cervical or vaginal swab, or a first catch urine sample. NAAT is preferred for its increased specificity and sensitivity, but screening can also be completed via wet mount microscopy with visualization of motile trichomonads, which confirms the diagnosis.
When it comes to HIV, screening is typically completed by using an antigen/antibody test for HIV 1 and 2. Positive test results are reportable to the CDC.Next, screening for syphilis, which is caused by Treponema pallidum, is usually completed by a 2-step process.
A non-treponemal test is obtained first, either a Venereal Disease Research Laboratory, or VDRL; or Rapid Plasma Reagin, or RPR.
This is followed by a treponemal test, such as the T. pallidum passive particle agglutination, or TP-PA test.
A positive test is reportable to the CDC. Now, hepatitis B screening has traditionally been done by checking for hepatitis B surface antigen or HBsAg.
However, the CDC now recommends the triple panel test. This panel is composed of HBsAg; antibody to hepatitis B surface antigen, or anti-HBs; and total antibody to hepatitis B core antigen, or total anti-HBc.
This test is recommended because there can be a window during an acute infection when the HBsAg and anti-HB are both negative.
During this window, the only test that can accurately detect an acute infection is the total anti-HBc. Positive results are reported to the CDC.
Additionally, there’s a hepatitis B vaccine that should be offered to those at risk who have not been previously infected or vaccinated.
Keep in mind that the vaccine will not clear the virus any faster, but that there’s also no risk to vaccinating someone who is already infected.Moving on, hepatitis C screening is simple and is done by checking for HCV antibodies.
Positive results are reported to the CDC.Now, screening for human papillomavirus, or HPV, looks for high-risk types of the human papilloma virus, and is usually co-tested along with routine cervical cancer screenings, as indicated based on age and previous screening.
Also, the HPV vaccine is recommended for all patients ages 11 to 26. For patients aged 27 to 45, vaccination can be considered using shared-decision making.
Finally, screening for herpes simplex virus, or HSV, is only indicated when a patient has a suspicious genital lesion. These lesions are initially painful and vesicular, and are followed by ulceration.
A prodromal period of tingling or itching may precede their appearance. HSV testing is done by obtaining a swab of fluid from the ulcer, which is analyzed by polymerase chain reaction, or PCR for both HSV 1 and 2.
While traditionally HSV 1 was thought to only cause oral herpes or cold sores and HSV 2 only caused genital outbreaks, evidence shows that either strain of the virus can cause an outbreak in either area.
Additionally, all patients who have suspicious lesions should also have serology testing for type-specific antibodies to HSV 1 and 2.

Non-pregnant patients6:20–8:37

Now let's break down screening recommendations into patient categories, and talk about non-pregnant patients without HIV.
Often when a patient presents for STI screening, they may ask to have “everything” done which can mean different things to different patients.
As such, it's always a good idea to review all options and recommendations and then proceed through shared-decision making.
For non-pregnant patients without HIV, gonorrhea and chlamydia screening should be done annually for sexually active patients who are less than 25 years old, and for sexually active individuals 25 years of age or older who are at increased risk for infection.
Here is a clinical pearl! Individuals who are at increased risk for infection include biological females who have a new sex partner or have multiple sex partners; and those with a history of transactional sex, incarceration, drug misuse or abuse, or a prior STI.Moving on, trichomoniasis screening should be considered for those who are receiving care in high-prevalence settings, such as STI clinics and correctional facilities, as well as for asymptomatic patients at high risk for infection.
HIV screening is recommended for all biological females aged 13 to 64 years old as an opt-out modality, meaning they will be tested for HIV unless they specifically decline the screening.
As far as syphilis screening goes, patients who are asymptomatic but at increased risk for infection should be screened.
Next, hepatitis B screening is indicated for those at increased risk for infection; and remember to encourage vaccination if not previously completed.
Hepatitis C screening is recommended for anyone over age 18, except in settings where the hepatitis C infection positivity is < 0.1%.>
HPV screening is co-tested along with cervical cancer screenings, based on routine guidelines; and vaccination should be offered.
Finally, HSV screening is indicated if there is a suspicious genital lesion. Okay, now let’s discuss STI screening for pregnant patients.

Pregnant8:37–10:34

This is a little more straightforward as it is performed via an opt-out panel at your patient's first prenatal visit. The panel includes: gonorrhea and chlamydia if they’re under 25 years, or older than 25 years if they’re at increased risk for infection; HIV; syphilis; hepatitis B; and hepatitis C.
Other screenings include HPV and cervical cancer screening, which are completed based on routine guidelines, as well as HSV if your patient has a suspicious genital lesion.
Here’s a clinical pearl: If your pregnant patient tested positive for chlamydia, a test-of-cure is indicated 3 to 4 weeks after treatment and then again within 3 months.
If positive for gonorrhea, repeat testing is indicated within 3 months, or sooner if reinfection is suspected. And here’s another clinical pearl to keep in mind!
If your patient declines HIV screening at their prenatal visit, rapid HIV testing can be performed at delivery, unless the patient declines.
Okay, if your patient is high-risk for infection, additional screening is recommended. Chlamydia and gonorrhea should be tested again in the third trimester.
HIV should also be tested again in the third trimester, ideally before 36 weeks of gestation; and repeat testing for hepatitis B and hepatitis C should be done at 28 weeks.
Syphilis should also be checked again at 28 weeks and again at delivery to help prevent congenital syphilis. Likewise, if your patient is positive for hepatitis B, remember that timely, age-appropriate HBV vaccination and hepatitis B immune globulin should be administered to their newborns.

HIV Positive10:34–11:10

Let’s finish by discussing screening for HIV-positive patients. Screening for STIs is indicated at the first evaluation following their HIV diagnosis and includes gonorrhea and chlamydia, trichomoniasis, syphilis, hepatitis B, and C.
Screening for gonorrhea and chlamydia, trichomoniasis, and syphilis are then repeated at least annually. HPV and cervical cancer screening is based on routine guidelines for individuals with HIV.
Herpes serology testing may also be considered in this population.Alright, as a quick recap… STI screening checks for infections that can cause sexually transmitted diseases.

Review11:10–11:43

The goal is to diagnose and treat infections, and provide education, which then prevents further transmission. STIs include gonorrhea and chlamydia, trichomoniasis, HIV, syphilis, hepatitis B and C, HPV as part of cervical cancer screenings, and HSV.
Screening recommendations depend on your patient’s age, as well as pregnancy and HIV status.
Sexually transmitted infection screening (GYN) | Osmosis