What is the diagnosis and treatment for a patient with comprehensive STI screening results?

Comprehensive STI Screening Panel Interpretation

This laboratory order represents a complete sexually transmitted infection (STI) screening panel designed to detect the most common and serious STIs: HIV, acute hepatitis B, chlamydia, gonorrhea, and syphilis. 1

Individual Test Components

HIV 1/2 Antigen/Antibody (Fourth Generation)

• Fourth-generation HIV testing combines detection of both HIV antibodies and p24 antigen, allowing earlier detection of infection (typically 2-4 weeks post-exposure versus 3-6 weeks for antibody-only tests) 2
• This test should be performed for all sexually active persons aged 13-64 years seeking STI evaluation 1
• The "with reflex" component means that if the initial screening test is positive, confirmatory testing will automatically be performed 2

Hepatitis Panel, Acute with Reflex to Confirmation

• Screens for acute hepatitis B infection (hepatitis B surface antigen) and typically includes hepatitis A and C markers 1
• The Centers for Disease Control and Prevention recommends hepatitis B screening for all pregnant women at first prenatal visit 1
• Hepatitis C screening is particularly important for persons who inject drugs, even if only once 1
• Acute hepatitis testing is critical because early detection allows for appropriate management and prevention of transmission 2

Chlamydia/N. Gonorrhoeae RNA, TMA, Urogenital

• Nucleic acid amplification test (NAAT) using transcription-mediated amplification (TMA) for both chlamydia and gonorrhea from urogenital sites 2
• NAATs are the gold standard due to superior sensitivity and ability to use non-invasive specimens 1
• For women, vaginal swab is the preferred specimen; for men, first-void urine or urethral swab 1, 3
• Testing simultaneously for both pathogens is optimal for detection of the most common treatable STIs 2

Chlamydia/N. Gonorrhoeae RNA, TMA, Throat

• Oropharyngeal testing is essential for detecting pharyngeal infections, which are frequently asymptomatic 2
• This is particularly critical for men who have sex with men (MSM) who report receptive oral intercourse 3, 4
• Pharyngeal gonorrhea is often missed if only urogenital testing is performed 1
• The Centers for Disease Control and Prevention recommends three-site testing (urogenital, rectal, and pharyngeal) for MSM based on reported sexual practices 3

RPR (Rapid Plasma Reagin) with Reflex Titer and T. pallidum Antibody

• Reverse syphilis screening algorithm that starts with a treponemal-specific test (T. pallidum antibody via immunoassay), followed by nontreponemal testing (RPR) to confirm active disease 2
• Most laboratories now use this reverse algorithm: treponemal test first (EIA/chemiluminescence immunoassay) followed by RPR to confirm 2
• If the treponemal test is positive, the RPR titer will be automatically performed to quantify disease activity and guide treatment 2
• Syphilis screening is recommended annually for all sexually active HIV-infected persons and high-risk individuals 1, 4

Clinical Context and Indications

Who Should Receive This Panel

• All sexually active women under 25 years should receive annual screening for chlamydia, gonorrhea, HIV, and syphilis 1
• Men who have sex with men (MSM) require comprehensive three-site testing every 3-6 months if they have multiple or anonymous partners, methamphetamine use, or sex in conjunction with drug use 1, 3
• HIV-infected individuals with high-risk behaviors should be tested every 3-6 months regardless of previous negative results 1, 4
• All pregnant women should be screened for hepatitis B, HIV, and syphilis at first prenatal visit 1
• Persons with new or multiple sex partners, inconsistent condom use, or a partner with STI warrant this comprehensive screening 1

Critical Pitfall to Avoid

The absence of rectal testing in this panel is a significant gap for MSM or anyone reporting receptive anal intercourse. 3 Rectal infections with chlamydia and gonorrhea are frequently asymptomatic and will be missed without specific rectal swab testing 2, 3. High-risk individuals, especially MSM, should have extragenital sites evaluated (rectal and oropharyngeal) for gonorrhea and chlamydia 2.

Post-Testing Management

If Results Are Positive

• Sexual partners within 60 days preceding symptom onset (or testing for asymptomatic patients) should be evaluated and treated 3
• Mandatory 3-month retesting is required for all patients treated for chlamydia or gonorrhea due to high reinfection rates of 25-40% 1
• Patients should abstain from sexual activity until they and their partners complete treatment and are asymptomatic 3
• Partner notification can be performed by the patient, healthcare provider, or public health officials 1

Reporting Requirements

Syphilis, gonorrhea, chlamydia, and HIV are reportable in most states, and clinicians should be familiar with local STD reporting requirements 1. This is a public health mandate, not optional 2.