STD Testing and Sexual Health: A Clinical Guide to Types, Symptoms, and Care

STD Testing and Sexual Health: A Clinical Guide to Types, Symptoms, and Care

Quick Answer: Sexually transmitted infections (STIs) spread primarily through sexual contact and require laboratory screening for accurate detection because up to 70% to 80% of cases produce no initial symptoms. Bacterial and parasitic infections are curable with prescription antibiotics, while viral infections are managed through suppressive antivirals to prevent transmission and long-term systemic complications.

Key Takeaways:

• Many common sexually transmitted infections develop without visible signs, making routine laboratory screening essential regardless of how healthy a partner appears.
• Bacterial pathogens (such as chlamydia, gonorrhea, and syphilis) and parasites (such as trichomoniasis) can typically be cleared with targeted antibiotic or antiparasitic therapy.
• Viral pathogens, including HIV, herpes simplex virus (HSV), and hepatitis B, cannot be eliminated completely, but modern antiviral medications suppress viral activity and preserve immune function.
• Oral sex transmits multiple bacterial and viral pathogens, frequently causing throat infections that produce no symptoms and that routine genital swabs cannot detect.
• Post-exposure interventions, including HIV PEP and Doxy-PEP, can substantially lower infection risk after condomless sex if initiated within a strict 72-hour clinical window.

Sexually transmitted diseases (STDs), clinically referred to as sexually transmitted infections (STIs), are infections caused by bacteria, viruses, or parasites passed between individuals through vaginal, anal, or oral sexual activity, as well as skin-to-skin intimate contact. An infection begins when a pathogen colonizes mucosal tissue or enters the bloodstream; a clinical disease develops when that infection causes tissue damage and active physical symptoms.

---

What Are the Main STD Types and How Are They Transmitted?

Sexually transmitted diseases fall into three biological categories: bacterial infections such as chlamydia, gonorrhea, and syphilis; viral infections including human immunodeficiency virus (HIV), herpes simplex virus (HSV), human papillomavirus (HPV), and hepatitis B; and parasitic infections such as trichomoniasis. Transmission occurs primarily through direct mucosal contact during vaginal, anal, or oral sex, as well as through infected bodily fluids and non-penetrative skin-to-skin contact with infectious lesions.

Pathogens enter the body across mucosal membranes in the urethra, vagina, cervix, rectum, and pharynx (throat), or through microscopic abrasions in the skin. Understanding the specific classification of different STD types is crucial because biological characteristics dictate how the pathogen behaves, how quickly it spreads, and what medical approach is required to clear or suppress it.

Bacterial Infections

Bacterial STDs are caused by single-celled organisms that colonize mucosal surfaces and multiply if untreated:

• Chlamydia (Chlamydia trachomatis): The most frequently reported bacterial STI worldwide. It infects epithelial cells of the cervix, urethra, rectum, and throat. Transmission happens through semen, pre-seminal fluid, and vaginal fluids during penetrative intercourse, as well as via contaminated sex toys.
• Gonorrhea (Neisseria gonorrhoeae): An adaptable bacterium that thrives in warm, moist tracts of the reproductive system, throat, and rectum. It transfers readily during genital, anal, or oral intercourse.
• Syphilis (Treponema pallidum): A spirochete bacterium that enters through minor micro-abrasions in mucosal tissues or skin. Unlike chlamydia and gonorrhea, syphilis transmits through direct skin-to-skin contact with an active, infectious chancre (ulcer) during any intimate contact.

Viral Infections

Viruses are microscopic genetic agents that insert themselves into host cells to replicate, often creating persistent reservoirs in the body:

• Human Immunodeficiency Virus (HIV): Targets CD4 helper T cells in the immune system. HIV transmits through contact with blood, semen, pre-seminal fluids, rectal fluids, and vaginal fluids, but not through saliva, sweat, or casual contact.
• Herpes Simplex Virus (HSV-1 and HSV-2): Causes oral and genital herpes. Transmission occurs through direct skin-to-skin contact with viral lesions, mucosal secretions, or asymptomatic viral shedding from intact skin.
• Human Papillomavirus (HPV): The most common viral STI, comprising over 100 strains. High-risk strains (such as types 16 and 18) alter cellular DNA and can cause cervical, anal, and oropharyngeal cancers. Low-risk strains (types 6 and 11) cause genital warts. HPV passes efficiently through superficial skin-to-skin contact, meaning fluid exchange is unnecessary for transmission.
• Hepatitis B Virus (HBV): A virus attacking liver tissue. It is highly concentrated in blood and bodily fluids and transmits through sex or shared needle equipment.

Parasitic and Fungal Conditions

• Trichomoniasis (Trichomonas vaginalis): A single-celled protozoan parasite that infects the vulva, vagina, cervix, or male urethra. It transmits primarily during vaginal intercourse or vulva-to-vulva contact.
• Pubic Lice (Phthirus pubis) and Scabies (Sarcoptes scabiei): Ectoparasitic arthropods and mites that live on hair shafts and skin folds, transferring through shared bedding or prolonged physical contact.

---

Recognizing STD Symptoms: Common Warning Signs in You and Your Partner

Many sexually transmitted infections remain entirely asymptomatic for weeks or years, meaning you cannot determine whether a partner has an infection simply by looking. When noticeable symptoms do occur, they commonly include atypical genital or rectal discharge, painful urination (dysuria), genital sores, painless chancres, uncharacteristic rashes on the torso or palms, pelvic aching, and irregular vaginal bleeding.

Relying on a visual inspection of a partner before intimacy is clinically unreliable. The vast majority of people carrying chlamydia, HPV, or early-stage syphilis show no observable signs. A sexual partner can be completely honest about feeling healthy while unknowingly transmitting a pathogen.

Infection	Typical Incubation Window	Common Primary Symptoms	Asymptomatic Frequency
Chlamydia	7-21 days	Dysuria, clear or cloudy discharge, testicular pain, abnormal vaginal bleeding	Up to 70% in women; 50% in men
Gonorrhea	2-14 days	Thick yellow or green discharge, severe dysuria, scrotal swelling, rectal bleeding	~50% in women; 10%-15% in men
Syphilis	10-90 days (avg. 21 days)	Primary: single firm, painless chancre. Secondary: non-itchy palm/sole rash, fever, swollen lymph nodes	High in early latent and late latent phases
Trichomoniasis	5-28 days	Frothy greenish-yellow discharge with fishy odor, vulvar redness, dysuria, urethral itching	~70%-85% of all infected individuals
Genital Herpes (HSV)	2-12 days	Clusters of painful, fluid-filled vesicles that rupture into crusted ulcers, localized tingling, or nerve pain	~80% of carriers are unaware of infection
HIV	2-4 weeks (acute phase)	Flu-like illness: fever, night sweats, sore throat, maculopapular rash, joint pain	Followed by a clinical latency phase often lasting years

Understanding STD symptoms and treatment begins with monitoring subtle changes in your body. In women, symptoms can mimic urinary tract infections or yeast imbalances: pelvic discomfort during intercourse (dyspareunia), unusual intermenstrual spotting, or a sudden change in vaginal discharge volume, color, or odor. In men, common indicators include white, yellow, or greenish urethral discharge, burning during urination, and tenderness in the testicles or epididymis. Both sexes may experience rectal soreness, bleeding, or tenesmus (a persistent urge to pass stool) following receptive anal intercourse.

Skin manifestations require close medical evaluation. A painless ulcer on the shaft of the penis, labia, anus, or tongue is a classic marker of primary syphilis. Because it causes no pain, it often goes unnoticed and heals on its own, leading patients to assume the threat has passed. In contrast, painful, clustered blisters that tingle, sting, and break into tender sores point to an active outbreak of herpes simplex virus.

---

Can You Contract an STD from Oral Sex?

Oral sex carries a documented transmission risk for multiple pathogens, notably gonorrhea, chlamydia, syphilis, herpes simplex virus, and human papillomavirus. Performing oral sex can result in pharyngeal infections that frequently present with a sore throat or remain silent, while receiving oral sex can transfer oral pathogens directly to the genital tract.

The mucosal surface lining the pharynx and tonsils consists of non-keratinized stratified squamous epithelium, which provides an entry point for bacterial and viral organisms. When an individual performs fellatio (oral contact with a penis), cunnilingus (oral contact with a vulva), or anilingus (oral contact with an anus), infected secretions and shedding viral particles come into direct contact with the throat lining:

• Pharyngeal Gonorrhea: Neisseria gonorrhoeae colonizes the throat efficiently. Most pharyngeal infections produce zero symptoms, though some individuals experience a mild, persistent sore throat, difficulty swallowing, or swollen anterior cervical lymph nodes. Because throat infections are rarely symptomatic, they serve as a silent reservoir for community transmission.
• Pharyngeal Chlamydia: Although less common than gonorrhea in the throat, Chlamydia trachomatis can establish pharyngeal colonization, which rarely causes noticeable pain but can be passed to future partners' genitals.
• Herpes Simplex Virus: HSV-1, classically associated with oral cold sores, is a frequent cause of first-episode genital herpes, transmitted when a partner performs oral sex while carrying oral HSV-1 (even without an active cold sore). Conversely, genital HSV-2 can occasionally establish oral colonization.
• Syphilis: Primary syphilitic chancres can develop directly on the lips, mucosal borders of the mouth, tongue, or posterior pharyngeal wall following oral intercourse with an infected partner.
• Human Papillomavirus (HPV): High-risk strains transmitted to the throat can integrate into mucosal DNA, creating a long-term risk factor for oropharyngeal squamous cell carcinoma (throat and tonsillar cancer).

---

STD Testing Methods: Swabs, Urine Samples, and Full Blood Panels

Comprehensive STD testing uses targeted diagnostic methods matched to each pathogen: urine tests and mucosal swabs detect bacterial infections like chlamydia and gonorrhea via nucleic acid amplification, while blood panels screen for antibodies or antigens related to HIV, syphilis, and hepatitis B. Full panel testing evaluates the patient for the most common infections simultaneously and accounts for diagnostic window periods to ensure accurate readings.

Diagnostic Sample	Target Pathogens Evaluated	Clinical Considerations
First-catch urine	Genital chlamydia, gonorrhea, trichomoniasis	Patient must avoid urinating for at least 1 hour before collection
Mucosal swabs	Pharyngeal and rectal chlamydia and gonorrhea; active HSV lesions	Site-specific collection based on anatomy and sexual exposure
Blood sample (serology)	HIV (Ag/Ab combo), syphilis (RPR/treponemal), hepatitis B and C	Evaluates systemic infection and immune response across diagnostic window periods

No single diagnostic test checks for every sexually transmitted infection from one sample. Accurate laboratory screening requires pairing the correct biological specimen with the suspected pathogen and respecting each infection's diagnostic window period, the time between initial exposure and the point when a test can reliably detect the organism or immune response.

Nucleic Acid Amplification Tests (NAAT)

NAAT is the gold standard for identifying chlamydia, gonorrhea, and trichomoniasis. This molecular technique amplifies microscopic segments of bacterial or protozoan DNA or RNA:

• First-catch urine: Detects organisms in the urethra. Patients must not urinate for at least 1 hour before collection to avoid flushing bacteria out of the urethral canal.
• Site-specific mucosal swabs: Essential for individuals who engage in receptive oral or anal intercourse. A routine urine test does not detect pharyngeal or rectal gonorrhea and chlamydia. Self-collected or clinician-collected vaginal swabs represent the most sensitive testing approach for women.

Serological and Blood-Based Panels

Serology evaluates the body's immune reaction or detects specific pathogen antigens in blood samples:

• HIV 4th-Generation Antigen/Antibody Combo: Detects both HIV-1/2 antibodies and the p24 viral capsid protein. It can identify acute infection as early as 18 days, with a diagnostic window of up to 45 days post-exposure via venipuncture.
• Syphilis Serology: Employs a two-tier approach using non-treponemal tests (such as RPR or VDRL) to measure current disease activity alongside treponemal tests (such as FTA-ABS or TP-PA) to confirm specific antibodies against Treponema pallidum.
• Hepatitis B Surface Antigen (HBsAg): Identifies an active, transmissible hepatitis B infection.
• Herpes Type-Specific IgG Serology: Differentiates past exposure to HSV-1 versus HSV-2, though routine blood testing is generally reserved for confirming ambiguous lesion swabs rather than screening asymptomatic individuals.

An STD full panel testing protocol typically bundles these tests together, drawing blood for systemic viral and treponemal agents while gathering urine and anatomically relevant swabs for mucosal bacterial pathogens. Depending on the setting, clinical providers also offer rapid testing for STD markers, such as point-of-care fingerstick tests for HIV and syphilis, or rapid antigen swabs, which can provide preliminary results within 15 to 30 minutes. Non-reactive rapid tests taken too early in the window period require confirmatory laboratory testing.

The out-of-pocket STD screening cost varies depending on clinical setting and insurance coverage. Comprehensive laboratory panels without insurance generally range from $100 to $300 at commercial outpatient laboratories, while public sexual health clinics often provide testing on a sliding-scale basis determined by income.

---

When to See a Doctor and Which Specialist to Consult for STD Care

Patients should seek medical evaluation within days of unprotected contact with a new partner, immediately if unexplained genital or urinary symptoms appear, or whenever an existing partner reports an infection. Primary care physicians, gynecologists, urologists, infectious disease specialists, and dedicated sexual health clinics all routinely evaluate, diagnose, and treat sexually transmitted infections.

Do not wait for severe symptoms before seeking medical advice. Clinical timelines depend on the nature of your exposure:

• Immediate (Within 72 Hours): If you experienced condom failure or non-consensual contact with a partner of unknown or positive HIV status, go to an emergency room, urgent care center, or sexual health clinic immediately to evaluate eligibility for post-exposure prophylaxis.
• Symptomatic (Within 24-48 Hours): If you develop genital lesions, sores, atypical discharge, intense burning during urination, or sudden lower abdominal pain, schedule an examination promptly.
• Asymptomatic Post-Exposure: If you feel completely well after an encounter with a new or casual partner, wait approximately 10 to 14 days before taking NAAT swabs or urine tests to minimize false-negative results, followed by repeat viral blood screening at 45 to 90 days.

When selecting doctors for STD testing, consider which clinical environment best fits your circumstances:

• Primary Care Physicians (Family Medicine, Internal Medicine): Ideal for integrating routine, confidential sexual health evaluations into annual checkups.
• Gynecologists (OB-GYN): Best suited for women experiencing abnormal pelvic pain, atypical vaginal bleeding, or cervical changes linked to HPV.
• Urologists: Specialize in male reproductive anatomy and evaluate complex urethral discharge, chronic epididymal swelling, or unresolved urinary obstruction.
• Infectious Disease Specialists: Handle antibiotic-resistant gonorrhea, complicated syphilis involving neurological systems, and ongoing antiretroviral management for HIV.
• Dedicated Public Sexual Health Clinics: Provide low-cost, walk-in, highly specialized care with confidential services and rapid on-site laboratory capabilities.

---

STI Treatment and Cures: Antibiotics, Antivirals, and Recovery Timelines

Bacterial and parasitic infections such as chlamydia, gonorrhea, syphilis, and trichomoniasis are curable with targeted antibiotic or antiparasitic regimens that typically span from a single dose to 14 days of therapy. Viral infections such as HIV, HSV, and hepatitis B cannot be cleared completely from the body, but they are managed with suppressive antiviral medications that lower viral loads, control outbreaks, and reduce transmission risk.

Prescription medications for STIs target the specific pathogen involved. Self-treating with leftover antibiotics from past illnesses or relying on non-prescription remedies is ineffective and risks complications such as antimicrobial resistance.

Infection Category	Pathogen	Standard Clinical Treatment
Curable (bacterial / parasitic)	Chlamydia	Doxycycline (100 mg orally twice daily for 7 days)
	Gonorrhea	Ceftriaxone (500 mg single intramuscular injection)
	Syphilis	Benzathine penicillin G (intramuscular injection based on stage)
	Trichomoniasis	Metronidazole or tinidazole (oral course)
Manageable (viral suppression)	HIV	Antiretroviral therapy (ART; suppresses viral load)
	Genital herpes (HSV)	Valacyclovir or acyclovir (episodic or daily suppressive therapy)
	Hepatitis B	Tenofovir or entecavir (long-term suppressive therapy to protect liver)

Standard chlamydia STI treatment requires a structured oral antibiotic regimen, typically doxycycline taken twice daily for 7 full days, which achieves cure rates above 95% when taken as directed. Alternative options, such as single-dose azithromycin, are reserved for situations where adherence is a concern or pregnancy prevents tetracycline use. Gonorrhea requires a single high-dose intramuscular injection of ceftriaxone to counter emerging drug-resistant strains. Syphilis requires long-acting benzathine penicillin G, administered intramuscularly in doses determined by whether the disease is in the primary, secondary, or late latent stage.

Effective STI treatment also requires strict behavioral precautions:

1. Complete all medication: Finish every prescribed dose, even if discharge or discomfort disappears within 48 hours. Stopping early allows surviving bacteria to multiply and develop resistance.
2. Abstain from all sexual contact: Refrain from vaginal, anal, and oral sex for at least 7 full days after finishing a multi-day antibiotic regimen, or for 7 days following a single-dose injection.
3. Notify and treat all partners: Any sexual partner from the preceding 60 days should receive diagnostic testing and concurrent treatment to prevent reinfection.
4. Schedule a test-of-cure: Patients treated for pharyngeal gonorrhea, pregnant individuals, and those with persistent symptoms should complete follow-up testing approximately 14 to 28 days post-treatment.

For chronic viral infections, modern medicine provides safe, highly effective suppression. Individuals living with HIV who take daily Antiretroviral Therapy (ART) and maintain an undetectable viral load in their blood do not transmit the virus sexually to others, a clinical standard known as Undetectable = Untransmittable (U=U). For genital herpes, daily suppressive doses of valacyclovir reduce symptomatic recurrence rates by 70% to 80% and decrease asymptomatic viral shedding, helping reduce transmission risk to uninfected partners.

---

Risks of Untreated STDs: Long-Term Damage and Potentially Fatal Complications

Untreated bacterial infections can migrate into the upper reproductive tract, causing pelvic inflammatory disease, fallopian scarring, chronic pelvic pain, ectopic pregnancy, and tubal factor infertility in women, or epididymitis in men. Unchecked syphilis progresses over years to tertiary stages that damage the cardiovascular and central nervous systems, while untreated HIV advances to AIDS, both carrying fatal risks without medical intervention.

Leaving an STD untreated because symptoms have faded or never appeared is dangerous. While the body's immune response may temporarily quiet active surface signs, the underlying pathogen continues to cause progressive tissue damage.

Reproductive and Structural Complications

In women, untreated chlamydial or gonococcal organisms ascend past the cervix into the uterus, fallopian tubes, and ovaries, triggering Pelvic Inflammatory Disease (PID). PID leads to tubal scarring, which multiplies the lifetime risk of ectopic pregnancy, a life-threatening condition where a fertilized egg implants outside the uterus, and can cause permanent infertility.

In men, untreated urethral pathogens migrate upward into the vas deferens and epididymis, causing acute epididymo-orchitis. This condition causes intense testicular swelling, severe scrotal pain, and potential long-term impairment of sperm motility and counts.

Systemic and Neurological Damage

• Tertiary Syphilis: Without penicillin treatment, Treponema pallidum can remain dormant for 10 to 30 years before attacking vital organs. Neurosyphilis damages brain and spinal cord tissue, causing sensory ataxia, progressive dementia, and vision loss. Cardiovascular syphilis weakens the muscular walls of the aorta, causing aortic aneurysms that can rupture.
• Advanced HIV Disease (AIDS): HIV steadily depletes CD4 T cells over years. Without antiretroviral therapy, the immune system eventually collapses, leaving the body vulnerable to opportunistic infections (such as Pneumocystis pneumonia and toxoplasmosis) and aggressive malignancies like Kaposi sarcoma.
• Oncogenesis from High-Risk HPV: Persistent infections with oncogenic HPV strains alter normal cellular reproduction. Over 10 to 20 years, untreated cervical dysplasia can progress to invasive cervical cancer. HPV also causes significant proportions of anal, penile, vulvar, and throat cancers.
• Cirrhosis and Liver Failure from Hepatitis B: Chronic, unmanaged HBV inflammation leads to progressive liver fibrosis, end-stage cirrhosis, and hepatocellular carcinoma (primary liver cancer).

---

Emergency Protection After Unprotected Sex: PEP, Doxy-PEP, and Immediate Actions

Following potential exposure during condomless sex, emergency medical countermeasures can substantially reduce infection risk if initiated promptly: HIV post-exposure prophylaxis (PEP) must start within 72 hours and continue for 28 days, while doxycycline post-exposure prophylaxis (Doxy-PEP) involves taking an oral antibiotic within 72 hours to prevent bacterial STIs such as syphilis and chlamydia under qualified clinical guidance.

When an unexpected sexual exposure occurs, taking the correct steps within the first few hours and days significantly reduces overall health risks.

Clinical Timeframe	Recommended Action	Underlying Medical Rationale
Immediately post-exposure	Gentle external hygiene	Clean external skin with mild soap and water; avoid internal douching or scrubbing
Within 72 hours	HIV PEP clinical evaluation	Initiate a 28-day triple-drug antiretroviral regimen if exposure warrants
Within 72 hours	Doxy-PEP medical consultation	Evaluate eligibility for a single 200 mg dose of doxycycline to prevent bacterial STIs
Within 120 hours	Emergency contraception	Assess pregnancy risk and administer oral emergency pills or place a copper IUD
14 to 90 days	Structured laboratory follow-up	Complete window-period swabs, urine tests, and viral serology panels

1. Immediate Hygiene Steps

Right after condomless sex, gently clean external genital areas with mild soap and warm water, and urinate to help flush microbes from the urethral canal. Avoid internal douching, aggressive scrubbing, or applying alcohol, hydrogen peroxide, or harsh disinfectants. These irritate fragile mucosal surfaces, causing micro-abrasions that make it easier for viral and bacterial pathogens to enter the body.

2. HIV Post-Exposure Prophylaxis (PEP)

PEP is a 28-day course of antiretroviral medication prescribed to prevent HIV after high-risk exposure (such as condom breakage with a partner living with untreated HIV, or sexual assault).

• The 72-Hour Rule: PEP must be started as soon as possible, ideally within 24 hours and no later than 72 hours after exposure. Beyond 72 hours, HIV establishes permanent cellular reservoirs, rendering PEP ineffective.
• Adherence: Patients must complete the full 28-day regimen without missing doses, followed by confirmatory antibody testing at 4 to 12 weeks.

3. Doxycycline Post-Exposure Prophylaxis (Doxy-PEP)

Doxy-PEP is an evidence-supported strategy for individuals at elevated risk of bacterial infections (specifically men who have sex with men and transgender women with a history of bacterial STIs).

• It involves taking a single 200 mg dose of oral doxycycline, ideally within 24 hours and no later than 72 hours following condomless sex.
• Clinical trials report that Doxy-PEP reduces the incidence of chlamydia and syphilis by more than 70% to 80%, though its efficacy against gonorrhea is lower due to existing antimicrobial resistance patterns. It should always be taken under a physician's guidance.

4. Emergency Contraception and Hepatitis B Immunization

If exposure involves potential pregnancy risk, take emergency contraception (such as oral levonorgestrel or ulipristal acetate, or have a copper IUD placed) within 72 to 120 hours. For patients unvaccinated against hepatitis B who experience exposure, an immediate dose of the hepatitis B vaccine paired with Hepatitis B Immune Globulin (HBIG) provides passive-active post-exposure protection.

---

Frequently Asked Questions

Does urgent care do STD testing?

Yes, most urgent care clinics provide on-site STD testing, including rapid blood panels for HIV and syphilis, diagnostic urinalysis, and mucosal swabs for chlamydia and gonorrhea. These facilities can initiate immediate empiric antibiotic therapy, perform clinical examinations for painful sores, and prescribe 28-day emergency HIV PEP regimens within the 72-hour window.

What is the average STD screening cost without insurance?

A complete out-of-pocket screening panel typically ranges from $100 to $300 at commercial walk-in laboratories and urgent care clinics, depending on the number of pathogens evaluated. Individual rapid fingerstick tests or urine screens generally cost between $40 and $90, while non-profit sexual health organizations and municipal clinics often offer comprehensive panels on a sliding-scale basis determined by income.

How long after possible exposure should I get an STD test?

Testing should follow pathogen-specific timelines to avoid false-negative readings during diagnostic window periods. Swabs and urine tests for chlamydia and gonorrhea achieve high accuracy 1 to 2 weeks post-exposure, whereas modern 4th-generation HIV blood tests detect antigens and antibodies between 18 and 45 days. Testing for syphilis and hepatitis B should be conducted at 4 to 6 weeks, with an optional confirmatory screen at 90 days.

Can you get reinfected with an STD after completing treatment?

Yes, clearing a bacterial or parasitic infection such as chlamydia, gonorrhea, or trichomoniasis does not produce protective immunity, meaning you can be reinfected immediately if re-exposed. Reinfection frequently occurs when partners are not treated concurrently or when sexual activity resumes before finishing the full treatment course. Clinical guidelines recommend a re-test 3 months after treatment to confirm that reinfection has not occurred.