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MI8.{1-2,4} | Genitourinary & Sexually Transmitted Infections — PBL Case

CLINICAL SETTING

Savitri, a 24-year-old woman from a rural village near Nagpur, attends her first antenatal visit at the Primary Health Centre (PHC) at 16 weeks of pregnancy. She is accompanied by her mother-in-law. She is a homemaker with no formal education beyond Class 8. Her husband works as a migrant labourer and is currently in Pune. This is her second pregnancy; her first child (age 2) is healthy. The ANM records her weight, blood pressure, and fundal height, and sends her blood for the standard antenatal panel: haemoglobin, blood group, VDRL, HIV rapid test (ICTC), and hepatitis B surface antigen. The PHC medical officer, Dr. Priya, receives the results the following morning. Savitri's VDRL is reactive (1:8 dilution), her HIV rapid test is reactive on the first test (Determine), and her HBsAg is positive. Savitri is currently waiting in the antenatal queue.

Trigger 1: Reactive Results — What Do They Mean?

Dr. Priya calls Savitri into a private consultation room. She explains that some of the blood tests have come back abnormal and that further testing is needed. Savitri looks frightened. She says: 'I have never had any illness. My husband comes home only once every 3 months. How can this be?' Dr. Priya notes: VDRL reactive 1:8, HIV Determine reactive (single rapid test), HBsAg positive. She needs to explain each result to Savitri, decide which require immediate confirmation, and determine what her next steps are before giving Savitri a diagnosis.

DISCUSSION POINTS

  • A single reactive HIV rapid test (Determine) is NOT a confirmed HIV diagnosis. What is the NACO two-test (or three-test) algorithm for HIV confirmation in India? What is the next step before telling Savitri she is HIV-positive?
  • VDRL is a non-treponemal screening test. What are the causes of a biologically false-positive VDRL? What confirmatory test should be ordered, and how does the titre (1:8) inform urgency?
  • HBsAg positivity at the first antenatal visit — what additional HBV markers would help assess vertical transmission risk, and why does HBeAg status matter for the unborn child?
Click to reveal Trigger 2: Confirmation, Counselling, and Partner Notification (discuss previous trigger first!)

Trigger 2: Confirmation, Counselling, and Partner Notification

One week later: Savitri returns with her husband Raju, who has come back from Pune after being urgently called. Confirmatory results: TPHA positive (syphilis confirmed), HIV confirmed by NACO algorithm (two concordant rapid tests + ELISA — Savitri is HIV-positive), HBsAg positive with HBeAg also positive (high viral replication). Savitri's CD4 count is 320 cells/µL. Raju appears defensive and avoids eye contact. Both are tested: Raju is HIV-positive (CD4 410 cells/µL) and RPR reactive 1:32. Their 2-year-old child needs to be tested as well. Dr. Priya must now navigate treatment decisions, partner testing, vertical transmission prevention, and the social dynamics of the consultation.

DISCUSSION POINTS

  • Savitri has confirmed syphilis (TPHA+, RPR 1:8) in pregnancy. She has no active lesions and has never been treated — what stage of syphilis does this represent, and what is the treatment of choice in pregnancy? What are the risks to the fetus if syphilis is untreated beyond this point?
  • For HIV in pregnancy, what is the NACO PPTCT (Prevention of Parent-to-Child Transmission) protocol? When should ART be initiated in Savitri, and which regimen is recommended? What interventions at delivery and for the newborn reduce transmission?
  • Raju's RPR is reactive at 1:32 — significantly higher than Savitri's. What does this titre difference suggest about stage and timing of infection? How should partner notification and treatment be approached sensitively, given the social context and risk of domestic consequences for Savitri?
Click to reveal Trigger 3: Vertical Transmission, Newborn Management, and Community Prevention (discuss previous trigger first!)

Trigger 3: Vertical Transmission, Newborn Management, and Community Prevention

Savitri delivers at 38 weeks — a live male baby weighing 2.8 kg, APGAR 8/10. She received 3 doses of benzathine penicillin during pregnancy and has been on TDF+3TC+EFV ART from 20 weeks (viral load undetectable at delivery). The newborn's cord blood VDRL is reactive at 1:2. The baby is referred to the district hospital PICU for assessment. Meanwhile, the PHC team must address follow-up testing of the 2-year-old sibling, the community implications (10 other pregnant women from the same village attended the PHC in the past 2 months — 3 have not yet had their VDRL results), and Savitri's long-term follow-up plan.

DISCUSSION POINTS

  • The newborn has a reactive cord blood VDRL at 1:2 while Savitri's current RPR is non-reactive (following treatment). Is this reactive VDRL in the newborn indicative of congenital syphilis? What clinical and serological features would confirm versus exclude active congenital syphilis, and what is the management algorithm?
  • The 2-year-old sibling was born before Savitri's diagnosis. What is the testing strategy for this child for HIV, syphilis, and HBV? What is the window period consideration for HIV testing in a child who was breastfed?
  • At a public health level, the NACO syndromic management programme and antenatal STI screening exist to prevent exactly this scenario. What went wrong in this case (late first ANC visit, no previous STI screening, no antenatal HBV vaccination at birth for the first child)? What community-level preventive measures — including ASHA worker roles, NACO linkages, and HPV/HBV vaccination — should the PHC implement to prevent the next case?

Group Task Assignments

Group 1: Syphilis in Pregnancy — Pathogenesis, Serology, and Treatment

  • Prepare a table comparing non-treponemal tests (VDRL, RPR) and treponemal tests (TPHA, FTA-ABS) — principle, sensitivity, specificity, use for screening vs confirmation vs monitoring.
  • Describe the mechanism of vertical transmission of T. pallidum and the spectrum of congenital syphilis — early vs late manifestations. Explain why treatment of syphilis in pregnancy is urgent even in the latent stage.

Competencies: MI8.2

Group 2: HIV — Diagnosis Algorithm and PPTCT Protocol

  • Draw the NACO HIV testing algorithm (ICTC strategy I/II/III) and identify where Savitri is in the algorithm. Explain what 'discordant' results mean and how they are resolved.
  • Outline the NACO PPTCT protocol: timing of ART initiation, preferred regimen in pregnancy, mode of delivery considerations, newborn NVP prophylaxis, and infant diagnostic testing timeline (DNA PCR at 6 weeks, ELISA at 18 months).

Competencies: MI8.2

Group 3: Hepatitis B — Vertical Transmission and Newborn Prophylaxis

  • Explain the significance of HBeAg positivity in determining vertical transmission risk. What is the mechanism of perinatal HBV transmission, and why does it predominantly lead to chronic carriage rather than acute hepatitis in the newborn?
  • Describe the newborn prophylaxis protocol for HBV (vaccine + HBIG within 12 hours). What is the expected serological outcome at 9–12 months after the birth dose, and how is vaccine-induced immunity confirmed?

Competencies: MI8.2, MI8.1

Group 4: Public Health, NACO Systems, and Community Prevention

  • Map the NACO linkages relevant to this case: ICTC (testing and counselling), ART Centre (treatment), PPTCT programme, syphilis treatment at PHC level. Identify gaps that delayed diagnosis in Savitri's case.
  • Design a 3-point action plan for the PHC to improve early antenatal STI screening and prevention in this community, including ASHA worker training, birth dose HBV vaccination coverage, and partner-testing uptake.

Competencies: MI8.2

Learning Issues

Research these questions and bring your findings to the discussion.

  1. [MI8.2] What is the NACO HIV confirmation algorithm (ICTC Strategy I/II/III), and at what stage is a patient considered HIV-positive for the purpose of initiating ART and PPTCT?
  2. [MI8.2] What are the differences between VDRL and TPHA — principle, what they detect, when each is used, and how titre trends (rising vs falling) guide clinical interpretation?
  3. [MI8.2] What is the recommended treatment for syphilis in pregnancy, including dose, route, and monitoring? What is the Jarisch-Herxheimer reaction and when is it relevant in obstetric patients?
  4. [MI8.2] What is the NACO PPTCT protocol — when to start ART in pregnancy, recommended first-line regimen, and interventions to reduce perinatal HIV transmission to <2%?
  5. [MI8.2] How does HBeAg positivity in the mother alter the risk of vertical HBV transmission, and why does perinatal HBV infection result in chronic carriage in >90% of neonates?
  6. [MI8.1] How is perinatal (vertical) HBV transmission prevented — what is the newborn prophylaxis schedule and what serological markers confirm successful immunisation at 12 months?
  7. [MI8.4] What are the testing intervals and specimen types used to diagnose HIV in an exposed infant (born to an HIV-positive mother on ART) — and why is the diagnostic algorithm different from testing in adults?