Chlamydia Contact Tracing

Clinical Scenario

Leah White, 25, calls about possible STI exposure. Her partner of 2 years has tested positive for chlamydia and disclosed this to her. They had unprotected sex approximately 3 weeks ago. Leah is asymptomatic. She is on the combined oral contraceptive pill. She is shocked, upset, and questioning whether her partner has been unfaithful — the positive result raises trust issues in their relationship.

What This Case Tests

Initiating epidemiological treatment without waiting for test results; arranging a comprehensive STI screen including HIV; explaining the window periods for different STIs; addressing the relationship and trust implications sensitively; providing accurate information about chlamydia transmission, treatment, and complications.

Common Mistakes Trainees Make

The three most common mistakes are: waiting for Leah's test results before treating (epidemiological treatment should be started immediately given confirmed partner contact — 50-70% of contacts are positive), not arranging a full STI screen (if the partner has chlamydia, there may be other undiagnosed infections), and focusing exclusively on the clinical management without acknowledging the relationship crisis — Leah is dealing with a potential betrayal alongside a health concern.

The Consultation Challenge

Leah is dealing with two simultaneous crises: a potential STI and a potential relationship betrayal. Both need addressing, but in the right order. Start with the clinical priority (treatment and screening), then create space for the emotional dimension.

Establish the facts quickly. Her partner has tested positive for chlamydia. They had unprotected intercourse 3 weeks ago. She is asymptomatic — but 70-80% of women with chlamydia are asymptomatic, so this does not exclude infection.

Explain epidemiological treatment. Given confirmed contact with a positive partner, the probability of Leah being infected is 50-70%. BASHH (British Association for Sexual Health and HIV) guidelines recommend treating contacts without waiting for results. First-line treatment is doxycycline 100mg twice daily for 7 days (97% cure rate). Explain the practical aspects: take with food, avoid dairy within an hour either side, use sun protection, and avoid sex until both partners have completed treatment.

Arrange a full STI screen. Chlamydia exposure raises the possibility of other co-infections. Test for: chlamydia and gonorrhoea (urine or swab), HIV (baseline, repeat at 4 and 12 weeks due to window period), syphilis (blood test, window period up to 12 weeks), and hepatitis B if indicated. Explain the window periods clearly — a negative HIV or syphilis test today does not exclude infection from 3 weeks ago.

Now address the relationship dimension. Leah is likely wondering whether her partner has been unfaithful. You are not a couples counsellor, but you can acknowledge the emotional impact: "I can see this has been a shock, and I understand you might be questioning things in your relationship. I'm not in a position to comment on what's happened between you and your partner, but I want to make sure you're looked after medically and that you know there's support available if you need to talk to someone."

It is worth noting that chlamydia can be dormant for months or even years — a positive test in her partner does not necessarily indicate recent infidelity. This information may be clinically relevant to share if Leah raises the question directly.

Time check: Spend the first 3 minutes establishing the clinical history and exposure details. By minute 5, initiate epidemiological treatment and explain doxycycline. Arrange the full STI screen between minutes 6-8. Address the emotional and relationship dimension between minutes 9-11. Use the final minute for follow-up arrangements and safety netting.

How Examiners Mark This Case

Data Gathering and Diagnosis: Examiners assess whether you establish the exposure details (timing, type of contact, partner's test result), take a sexual history (other partners, previous STIs, contraception), screen for symptoms (even though Leah is asymptomatic, ask about discharge, dysuria, pelvic pain, intermenstrual bleeding), and arrange appropriate testing with awareness of window periods. A trainee who does not ask about other sexual partners (relevant for contact tracing) will miss an important dimension.

Clinical Management and Medical Complexity: Examiners expect epidemiological treatment initiated at this consultation without waiting for results. They look for correct antibiotic choice (doxycycline 100mg BD for 7 days first-line), practical prescribing advice, a comprehensive STI screen including HIV and syphilis with window period counselling, and advice on abstinence until both partners complete treatment. Knowledge of when to retest (test of cure not routinely recommended for chlamydia unless pregnant, but rescreen at 3 months for reinfection) demonstrates depth.

Relating to Others: Examiners assess whether you address the emotional impact of the diagnosis on the relationship, whether you maintain a non-judgmental tone throughout (no assumptions about who has been unfaithful), and whether you provide information about chlamydia dormancy that may be relevant to the relationship question. The consultation should feel supportive and practical, not clinical and transactional.

Example Opening

Strong opening: "Hello Leah, thank you for calling. I understand your partner has tested positive for chlamydia and you've been in contact. I want to reassure you that this is really common, very treatable, and I'm going to make sure you're looked after. Can I ask you a few questions so we can get you started on the right treatment today?"

When addressing the relationship: "I can see this has been upsetting, and I understand there might be questions about your relationship that this raises. I'm not in a position to comment on that, but I can tell you that chlamydia can sometimes be dormant for a long time without causing symptoms — so a positive test now doesn't necessarily tell you when someone was exposed. If you'd like to talk to someone about how you're feeling, I can point you in the right direction."

Avoid: "Do you think your partner has been cheating?" (Inappropriately intrusive and not your role).

How This Appears in the SCA

STI contact tracing tests your knowledge of epidemiological treatment, screening protocols, and your ability to manage a sensitive consultation with both clinical and emotional dimensions. Examiners assess whether you treat promptly without waiting for results, screen comprehensively, and handle the relationship implications with appropriate sensitivity.

Key Statistic

Chlamydia is the most common bacterial STI in the UK, with approximately 200,000 diagnoses annually. It is asymptomatic in 70-80% of women and 50% of men. Untreated chlamydia can cause pelvic inflammatory disease, ectopic pregnancy, and tubal infertility. Doxycycline 100mg BD for 7 days has a 97% cure rate.

Relevant Guidelines

• BASHH guideline on management of Chlamydia trachomatis genital tract infection
• NICE PH3: Sexually transmitted infections and under-18 conceptions — prevention
• BASHH partner notification guidelines.

Frequently Asked Questions

Why should I treat Leah before her test results come back?

This is epidemiological treatment — treating a contact of a confirmed case based on the high probability of infection (50-70% of sexual contacts of chlamydia-positive individuals are infected). BASHH guidelines recommend treating contacts without waiting for results because: the probability of infection is high, early treatment prevents complications and onward transmission, and waiting for results creates a window where transmission can continue. This is not empirical guesswork — it is evidence-based contact management.

What is the first-line treatment for chlamydia?

Doxycycline 100mg twice daily for 7 days (97% cure rate). This has replaced azithromycin 1g stat as first-line following updated BASHH guidelines, as doxycycline has superior cure rates particularly for rectal and pharyngeal infection. Practical advice: take with food to reduce nausea, avoid dairy products within an hour either side (reduces absorption), use sun protection (photosensitivity), and avoid intercourse until both partners have completed treatment and symptoms have resolved.

What STIs should I screen for alongside chlamydia?

A comprehensive screen includes: chlamydia and gonorrhoea (urine NAAT or swab — accurate at 2+ weeks post-exposure), HIV (blood test — baseline and repeat at 4 and 12 weeks for window period), syphilis (blood test — window period up to 12 weeks), and hepatitis B if risk factors are present. Explain the window periods clearly — a negative HIV test today does not exclude recent infection, and repeat testing is essential.

Can chlamydia be dormant and what does this mean for the relationship?

Yes — chlamydia can remain dormant and asymptomatic for months or even years. This means a positive test does not necessarily indicate recent sexual exposure. If Leah asks directly about infidelity, you can share this clinical fact without taking sides: "Chlamydia can sit quietly without symptoms for a very long time, so a positive test now doesn't tell us exactly when the infection was acquired." This provides useful information without making judgments about the relationship.

What are the complications of untreated chlamydia in women?

Untreated chlamydia can cause pelvic inflammatory disease (PID), which can lead to chronic pelvic pain, ectopic pregnancy, and tubal infertility. Complications typically develop over months to years, not weeks — so Leah's 3-week exposure is unlikely to have caused complications yet, which is reassuring. However, this underscores the importance of prompt treatment. Screening and treating early prevents these serious long-term consequences.