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Module 17210 lessonsRxPrep 2023 Chapter 23, reconciled with CDC chlamydia, LGV, proctitis, screening, neonatal, and 2024 doxycycline PEP guidance

Chlamydial Infections

Follow an intracellular pathogen across exposed sites, select treatment by anatomy and pregnancy, protect the newborn, recognize LGV, and close cure, retesting, partners, and HIV prevention.

01

Explain the intracellular developmental cycle and silent mucosal infection.

02

Choose exposure-specific NAAT specimens and evidence-based screening intervals.

03

Use preferred and alternative adult regimens with correct administration counseling.

04

Explain why rectal infection changes the doxycycline versus azithromycin decision.

05

Treat pregnancy and complete test of cure and reinfection follow-up.

06

Recognize and treat neonatal conjunctivitis and infant pneumonia.

07

Recognize invasive LGV and deliver a complete 21-day regimen.

08

Separate routine retesting from indication-based test of cure.

09

Manage partners, abstinence, and lawful expedited partner therapy.

10

Integrate HIV testing, PrEP, and population-specific doxy PEP guidance.

172.01

Lesson

Follow an Intracellular Pathogen Across Mucosal Sites

C. trachomatis alternates between an infectious elementary body and a replicating intracellular reticulate body. Local symptoms can be absent while tissue injury continues.

What to learn
  • Elementary body
  • Reticulate body
  • Silent infection
  • Ascending disease
  • Reinfection
Clinical pathwayFollow infection across sites
01EntryDefine the compartment

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

02ReplicationSelect the evidence

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

03InflammationDeliver the intervention

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

04SpreadSecure the next decision

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

Follow the developmental cycle

Elementary bodies enter susceptible epithelial cells, reorganize into replicating reticulate bodies, then produce new elementary bodies for release and transmission.

Expect asymptomatic disease

Urogenital and rectal infection is frequently silent. Screening is therefore a prevention intervention, not merely a response to symptoms.

Recognize reproductive injury

Untreated cervical infection can ascend and cause PID, ectopic pregnancy, infertility, and chronic pelvic pain. Some apparently uncomplicated infections already include subclinical upper-tract disease.

Do not expect durable immunity

Repeat infection is common, especially when partners remain untreated. Each repeat infection can add reproductive risk.

Quick check

0 of 1 answered
01What makes symptom-based chlamydia screening unsafe?
Answer every question to submit.
172.02

Lesson

Match Every Exposure to the Right NAAT Specimen

NAAT is the preferred diagnostic method, but its answer is limited to the site and specimen collected.

What to learn
  • Vaginal swab
  • First-catch urine
  • Rectal swab
  • Pharyngeal result
  • Screening interval
Clinical pathwayMatch exposure to specimen
01HistoryDefine the compartment

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

02SiteSelect the evidence

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

03NAATDeliver the intervention

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

04IntervalSecure the next decision

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

Choose optimal urogenital specimens

Patient-collected or clinician-collected vaginal swabs are optimal for many women. First-catch urine is preferred for many men, with urethral or meatal options when appropriate.

Test exposed extragenital sites

Use a validated rectal NAAT after rectal exposure. Routine pharyngeal chlamydia screening is not recommended, but a positive result reported by a combined assay should be treated.

Screen by age and risk

Screen sexually active women younger than 25 annually and older women with increased risk. Screen MSM at exposed sites at least annually and every 3 to 6 months when risk is increased.

Let point-of-care testing improve stewardship

Rapid NAAT can shorten time to treatment, reduce unnecessary empiric antibiotics, and improve partner treatment when available.

Quick check

0 of 1 answered
01Which approach best detects rectal chlamydia after rectal exposure?
Answer every question to submit.
172.03

Lesson

Use Doxycycline as the Cross-Site Standard

Doxycycline provides the most reliable efficacy across urogenital, rectal, and oropharyngeal infection in nonpregnant adolescents and adults.

What to learn
  • 100 mg twice daily
  • Seven days
  • Full-course dispensing
  • Esophageal safety
  • Alternatives
Clinical pathwayBuild reliable exposure
01PregnancyDefine the compartment

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

02DoxycyclineSelect the evidence

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

03AdherenceDeliver the intervention

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

04CloseSecure the next decision

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

Use the preferred regimen

Give doxycycline 100 mg orally twice daily for 7 days. A delayed-release 200 mg once-daily formulation for 7 days is an effective but more costly alternative formulation.

Counsel for absorption and injury prevention

Take with a full glass of water, remain upright, use sun protection, and separate from antacids or supplements containing polyvalent cations.

Place azithromycin correctly

Azithromycin 1 g orally once is an adherence alternative, not equal cross-site therapy. Directly observe the dose and plan post-treatment evaluation when rectal infection is possible.

Place levofloxacin correctly

Levofloxacin 500 mg orally daily for 7 days is effective but carries tendon, nerve, CNS, glycemic, QT, aortic, pregnancy, and interaction boundaries.

Quick check

0 of 1 answered
01What is preferred for uncomplicated chlamydia in a nonpregnant adult?
Answer every question to submit.
172.04

Lesson

Treat the Compartments That Can Reseed Infection

Rectal infection can coexist with urogenital disease, including in women who do not report receptive anal sex. Inadequate rectal cure can contribute to repeat urogenital infection.

What to learn
  • Rectal efficacy
  • Autoinoculation
  • Proctitis
  • Oropharyngeal detection
  • HIV PrEP
Clinical pathwayProtect every compartment
01RectumDefine the compartment

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

02EfficacySelect the evidence

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

03ReseedingDeliver the intervention

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

04PrEPSecure the next decision

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

Use the efficacy difference

A randomized rectal-chlamydia trial reported 100 percent microbiologic cure with doxycycline and 74 percent with azithromycin. This difference drives the preferred regimen.

Do not infer site from history alone

Concomitant rectal infection in women is common and does not track reliably with reported anal exposure. Persistent rectal infection can reseed the urogenital tract.

Separate uncomplicated proctitis from LGV

Bloody discharge, tenesmus, mucosal ulceration, severe pain, genital ulcers, or buboes require the LGV pathway rather than a routine 7-day course.

Treat a detected pharyngeal result

Routine screening is not recommended because prevalence and clinical significance are low, but detected infection can transmit and should be treated, with doxycycline favored when appropriate.

Quick check

0 of 1 answered
01Why can azithromycin 1 g be insufficient for a woman with cervical chlamydia?
Answer every question to submit.
172.05

Lesson

Treat Pregnancy and Prove Eradication

Pregnancy changes the preferred drug and creates a mandatory cure checkpoint because persistent maternal infection threatens both patients.

What to learn
  • Azithromycin
  • Amoxicillin alternative
  • Four-week cure test
  • Three-month retest
  • Third-trimester rescreen
Clinical pathwayTreat and prove eradication
01ScreenDefine the compartment

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

02TreatSelect the evidence

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

03Test cureDeliver the intervention

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

04RetestSecure the next decision

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

Use the recommended pregnancy regimen

Give azithromycin 1 g orally once. Observe the dose when possible and reassess when vomiting or absorption is uncertain.

Use amoxicillin as an alternative

Amoxicillin 500 mg orally three times daily for 7 days is an alternative. Persistence concerns keep it behind azithromycin.

Prove cure at the correct time

Obtain NAAT about 4 weeks after completion. Testing earlier can detect nonviable organisms. Retest again at 3 months for reinfection.

Screen across pregnancy

Screen at the first prenatal visit when younger than 25 or at increased risk, repeat in the third trimester when risk continues, and screen at delivery when prenatal testing was missed.

Quick check

0 of 1 answered
01What follow-up is required after treatment during pregnancy?
Answer every question to submit.
172.06

Lesson

Recognize Eye Disease and Afebrile Pneumonia on Time

Perinatal cervical exposure can cause conjunctivitis at 5 to 12 days or a subacute afebrile pneumonia at 1 to 3 months. Prenatal treatment is the strongest prevention.

What to learn
  • Five to twelve days
  • Systemic therapy
  • Staccato cough
  • Eosinophilia
  • Pyloric stenosis
Clinical pathwayConnect maternal and infant care
01ExposureDefine the compartment

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

02EyeSelect the evidence

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

03LungDeliver the intervention

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

04FollowSecure the next decision

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

Recognize conjunctivitis

Consider chlamydia in every infant 30 days or younger with conjunctivitis, especially with maternal infection. Collect conjunctival cells, not exudate alone, and test for gonorrhea.

Treat systemically

Give erythromycin base or ethylsuccinate 50 mg/kg/day divided four times daily for 14 days. Azithromycin 20 mg/kg daily for 3 days is a shorter alternative with limited evidence.

Recognize pneumonia

Look for staccato cough, tachypnea, hyperinflation, bilateral diffuse infiltrates, and eosinophilia in an afebrile infant aged 1 to 3 months. Collect a nasopharyngeal specimen.

Follow both efficacy and safety

Erythromycin efficacy is about 80 percent, so a second course can be necessary. Monitor infants younger than 6 weeks for infantile hypertrophic pyloric stenosis after either macrolide.

Quick check

0 of 1 answered
01Which finding most strongly suggests infant chlamydial pneumonia?
Answer every question to submit.
172.07

Lesson

Recognize Invasive Chlamydia Before It Scars

LGV serovars invade lymphatic tissue and can cause destructive proctocolitis, strictures, fistulas, genital ulcer disease, and painful inguinal buboes.

What to learn
  • Bloody proctitis
  • Tenesmus
  • Mucosal ulcer
  • Bubo
  • Twenty-one days
Clinical pathwayRecognize invasive disease
01SyndromeDefine the compartment

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

02PresumeSelect the evidence

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

03TreatDeliver the intervention

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

04ResolveSecure the next decision

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

Identify the clinical syndrome

Presume LGV with rectal chlamydia plus bloody discharge, tenesmus, mucosal ulceration, or severe proctitis, or with a genital ulcer and severe inguinal lymphadenopathy or bubo.

Use extended doxycycline

Give doxycycline 100 mg orally twice daily for 21 days. Aspiration through intact skin or drainage can be needed for fluctuant buboes.

Place alternatives carefully

Azithromycin 1 g weekly for 3 weeks or erythromycin base 500 mg four times daily for 21 days are alternatives. Consider cure testing after the less-validated azithromycin regimen.

Close the invasive pathway

Follow clinically until resolution, test HIV, gonorrhea, and syphilis, offer HIV PrEP when appropriate, and retest for chlamydia at 3 months.

Quick check

0 of 1 answered
01What regimen treats clinically compatible LGV?
Answer every question to submit.
172.08

Lesson

Separate Cure Testing From Reinfection Testing

Nonpregnant patients usually do not need routine test of cure, but every treated patient needs a reinfection plan and partner closure.

What to learn
  • No early NAAT
  • Three-month retest
  • Sixty-day partners
  • Most recent partner
  • EPT
Clinical pathwaySeparate cure from reinfection
01TimingDefine the compartment

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

02RetestSelect the evidence

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

03PartnersDeliver the intervention

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

04EPTSecure the next decision

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

Do not test too early

Avoid routine NAAT before 4 weeks. In nonpregnant patients, cure testing is reserved for questionable adherence, persistent symptoms, or suspected reinfection.

Retest at 3 months

Schedule retesting at treatment regardless of whether the patient believes partners were treated. If that is impossible, retest at the next visit within 12 months.

Manage every relevant partner

Evaluate, test, and presumptively treat partners from the preceding 60 days, plus the most recent partner even when the last contact was earlier.

Use EPT within its limits

Consider expedited partner therapy when lawful and timely evaluation is unlikely, while giving written allergy, adverse-effect, and complication warnings.

Quick check

0 of 1 answered
01When is test of cure indicated in a nonpregnant adult?
Answer every question to submit.
172.09

Lesson

Close Sex, Partners, HIV Risk, and Doxy PEP Together

The treatment course is one part of a longitudinal prevention system. Exact abstinence timing, partner completion, HIV prevention, and repeat screening prevent the next infection.

What to learn
  • Seven days
  • Partner completion
  • HIV test
  • PrEP
  • Doxy PEP
Clinical pathwayClose the prevention system
01AbstainDefine the compartment

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

02PartnersSelect the evidence

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

03HIVDeliver the intervention

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

04Doxy PEPSecure the next decision

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

Give exact abstinence instructions

Avoid sex for 7 days after single-dose azithromycin or until the 7-day doxycycline course is complete, symptoms resolve, and partners are treated.

Test linked infections

Test for gonorrhea, syphilis, and HIV. Offer HIV PrEP to appropriate HIV-negative patients, especially MSM with rectal chlamydia.

Use doxy PEP within guidance

Discuss with MSM and transgender women who had syphilis, chlamydia, or gonorrhea in the previous 12 months. Use doxycycline 200 mg within 72 hours after sex, no more than 200 mg per 24 hours.

Reassess the prevention plan

Repeat site-specific STI testing and reassess doxy PEP need every 3 to 6 months, while reviewing esophageal safety, cations, photosensitivity, adherence, and antimicrobial resistance.

Quick check

0 of 1 answered
01Which patient fits the core CDC doxy PEP recommendation?
Answer every question to submit.
172.10

Lesson

Own the Whole Pathway From Specimen to Return Visit

A complete plan names the infected and exposed sites, regimen, pregnancy status, cure checkpoint, reinfection test, partners, and prevention owner.

What to learn
  • Site
  • Host
  • Regimen
  • Timeline
  • Ownership
Clinical pathwayOwn the complete pathway
01SiteDefine the compartment

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

02HostSelect the evidence

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

03TimelineDeliver the intervention

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

04OwnerSecure the next decision

Connect intracellular biology, anatomy, treatment, follow-up, and prevention.

Name every site

Document which anatomy was exposed, which specimen was collected, which result was positive, and which complication was excluded.

Name every host modifier

Record pregnancy, age and weight for pediatric care, allergy, adherence, swallowing, interactions, HIV status, and access.

Name every timeline

Write the last dose, required test of cure when applicable, 3-month retest, partner window, and safe return to sexual activity.

Name every owner

Assign maternal-newborn communication, partner services, EPT materials, HIV PrEP, doxy PEP reassessment, and escalation for pelvic, testicular, rectal, ocular, or respiratory danger signs.

Quick check

0 of 1 answered
01Which plan is complete?
Answer every question to submit.

Module test

Check the connections.

Each attempt draws 10 questions from the complete 130 question bank.

130 questions in this module bank10 questions per attempt

Each attempt draws a fresh set and rearranges the answer choices.

References

Current clinical foundation.

Lecture material was synthesized with the following contemporary guidance. Verify local policy and current guidance before applying clinical information.

  1. CDC Chlamydial Infections
  2. CDC Lymphogranuloma Venereum
  3. CDC Proctitis, Proctocolitis, and Enteritis
  4. CDC STI Screening Recommendations
  5. CDC 2024 Doxycycline PEP Guideline
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