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PE31.1-14 | Tuberculosis and Febrile Infections — PBL Case

CLINICAL SETTING

District government hospital, Jharia coal-mining belt, Jharkhand. The paediatric ward receives referrals from three Primary Health Centres and sees a high volume of children from mining families with poor housing, inadequate sanitation, and limited immunization uptake. It is the month of October — post-monsoon peak for vector-borne and enteric fevers. The on-call intern and resident are managing a 13-bed ward with two senior doctors on-call.

Trigger 1: Day 1 Admission: Ramesh, 6 Years, 17 Days of Fever

Ramesh, a 6-year-old boy, is brought by his mother from a mining colony. She reports fever for 17 days — initially high-grade (39–40°C), associated with headache and mild abdominal pain, but now the fever seems continuous and the child is becoming increasingly lethargic. He has had no rash, no cough, no rigors, no loose stools. His appetite is poor and he has lost approximately 2 kg in the past month. The family shares one room in a mining tenement. His father had 'chest disease' 4 months ago and completed some medicines for 3 months before stopping. Ramesh's BCG scar is absent. His immunization card shows he received only two doses of OPV and Hep B at birth — no DPT, no MMR, no typhoid vaccine. On examination: wt 15 kg (SAM threshold consideration: MUAC 12.2 cm), height 108 cm, temperature 38.9°C, HR 76/min (pulse rate slower than expected for this fever), RR 24/min. No lymphadenopathy noted initially. Abdomen: soft, non-tender. Spleen tip just palpable.

DISCUSSION POINTS

  • What features of this history alert you to a serious underlying infection? What does relative bradycardia (slow pulse relative to fever height) suggest diagnostically?
  • Ramesh's father had 'chest disease' — how does this change your approach? What is the risk classification for Ramesh as a TB contact under NTEP, given his age and BCG status?
  • The family is from a mining colony. How does socioeconomic and environmental context (crowded housing, coal dust, poor sanitation) affect your differential diagnosis priority list?
  • Construct a problem list and a prioritised differential diagnosis: what are your top three diagnoses at this stage, and what single investigation would most rapidly narrow the field?
Click to reveal Trigger 2: Day 2: Investigations Return — Complexity Deepens (discuss previous trigger first!)

Trigger 2: Day 2: Investigations Return — Complexity Deepens

Initial investigations: CBC — Hb 9.4 g/dL (microcytic hypochromic), TLC 8,200/mm³ (lymphocytes 48%, neutrophils 42%), platelet count 1,40,000/mm³, ESR 92 mm/hr, CRP 3.8 mg/dL. Blood culture ordered (results pending 48 hours). Widal test: TO titre 1:160, TH titre 1:80. Peripheral blood smear: no malarial parasites seen. Chest X-ray: right hilar enlargement with a faint calcified nodule in the right mid-zone. Mantoux test done today — reading scheduled for 48–72 hours. NS1 dengue antigen: negative. The ward nurse reports that Ramesh had a seizure-like episode in the early morning and is now fully conscious. A new examination reveals posterior cervical lymphadenopathy (2 × 2 cm, firm, non-tender). The mother mentions that last week she saw him scratch his scalp vigorously and found a small blister that resolved.

DISCUSSION POINTS

  • The Widal TO titre is 1:160. Does this confirm typhoid? What are the limitations of the Widal test in an endemic setting, and what would you accept as diagnostic evidence for Salmonella typhi infection?
  • The CXR shows right hilar enlargement and a calcified focus. What is the significance of these findings in a child with TB contact history? What additional TB-specific investigations should be prioritised now?
  • Ramesh's blood picture shows lymphocytosis and elevated ESR. How do these findings combine with the CXR and contact history to raise or lower your TB probability? Apply the scoring system you know.
  • A seizure in a febrile child: discuss the differential causes in the context of this specific case. Is this a simple febrile seizure, or does the clinical context demand further evaluation (LP, imaging)?
Click to reveal Trigger 3: Day 4: Mantoux Read + Culture Result (discuss previous trigger first!)

Trigger 3: Day 4: Mantoux Read + Culture Result

Mantoux test read at 72 hours: induration 14 mm. Blood culture (48-hour result): Salmonella typhi isolated, sensitive to ceftriaxone and ciprofloxacin. Gastric aspirate has been collected on 3 consecutive mornings and sent for CBNAAT. Ramesh's fever persists (38.4°C). He has mild abdominal distension noted on examination. His mother asks why her son has two problems — 'blood infection' and 'TB test positive.' The CBNAAT result returns from the district TB lab: MTB NOT DETECTED from gastric aspirate. The team now debates: does the negative CBNAAT rule out TB completely?

DISCUSSION POINTS

  • Blood culture grows Salmonella typhi. What is the most appropriate antibiotic regimen for this child (drug, dose, route, duration)? When in the illness course should the team watch for intestinal perforation, and what are its clinical signs?
  • Mantoux 14 mm with right hilar lymphadenopathy and TB contact: does the NEGATIVE CBNAAT from gastric aspirate rule out primary TB? What is the sensitivity of CBNAAT in paucibacillary childhood TB versus adult smear-positive TB?
  • How will you manage BOTH conditions simultaneously — typhoid treatment AND TB evaluation? What communication approach would you use with the mother to explain two concurrent diagnoses?
  • Discuss the nutritional management: Ramesh is at SAM borderline (MUAC 12.2 cm). How does malnutrition affect TB risk, typhoid severity, and your treatment choices (drug absorption, immune response)?
Click to reveal Trigger 4: Day 10: Recovery, Discharge Planning, and Public Health Action (discuss previous trigger first!)

Trigger 4: Day 10: Recovery, Discharge Planning, and Public Health Action

Ramesh is improving on IV ceftriaxone (now switched to oral cefixime) with defervescence. Repeat CXR at day 8 is unchanged (persistent hilar adenopathy). The Paediatric TB committee reviews the case: Mantoux 14 mm + right hilar enlargement + TB contact (smear-positive father — confirmed by review of father's treatment card: defaulted after 3 months of Category I NTEP) = probable primary pulmonary TB. The committee initiates 2HRZE/4HRE. Ramesh's 3-year-old younger sister Meena lives in the same household and has no symptoms. The mother asks: 'Does Meena need treatment too?' Additionally, the ASHA worker reports that three other children in the colony have had fever in the past 10 days and one has a dengue-like illness.

DISCUSSION POINTS

  • The TB committee has initiated 2HRZE/4HRE for Ramesh. Calculate his weight-band FDC tablet dosing for the 17 kg category. What is the duration of each phase? Who provides supervision in NTEP's current framework?
  • Meena is 3 years old, asymptomatic, household contact of a confirmed smear-positive TB defaulter. What is NTEP's recommendation for Meena — full treatment or IPT? What drug, dose, and duration?
  • Three children in the colony have febrile illness in October (post-monsoon). What vector-borne and enteric fever surveillance actions should the health team initiate? What samples would you collect for rapid assessment?
  • Design a discharge plan for Ramesh: medications (TB + completion of oral typhoid therapy), follow-up schedule, red flags to return immediately (signs of typhoid perforation, TB deterioration), nutritional rehabilitation, and immunization catch-up (what vaccines does an incompletely immunized 6-year-old need).

Group Task Assignments

Group 1: Collaborative Task

Group 2: Collaborative Task

Group 3: Collaborative Task

Learning Issues

Research these questions and bring your findings to the discussion.

  1. [PE31.1] What are the clinical types of childhood TB (primary complex, miliary, lymph node TB, TB meningitis) and how does malnutrition modify their presentation and severity?
  2. [PE31.2] What is the diagnostic approach to childhood TB when the child cannot produce sputum? Compare Mantoux, CBNAAT, gastric aspirate, and BACTEC culture for sensitivity, specificity, and practical use in resource-limited settings.
  3. [PE31.3] Describe the NTEP 2HRZE/4HRE regimen in detail: weight-band FDC tablet dosing, phases, supervision under DOTS, management of adverse effects, and what constitutes treatment failure requiring referral.
  4. [PE31.4] What are NTEP's objectives for childhood TB? Define the roles of IPT, BCG vaccination, and contact tracing in the prevention strategy. What is the difference between a TB contact and a high-risk contact?
  5. [PE31.5] How do you elicit, document, and interpret a TB contact history in a paediatric clinic? When is Mantoux positive in an immunocompetent child (≥10 mm) vs. an immunocompromised child (≥5 mm)? Does a BCG scar affect interpretation?
  6. [PE31.8] What does CBNAAT (GeneXpert MTB/RIF) detect and what are its limitations in paucibacillary childhood TB? When would BACTEC MGIT liquid culture add diagnostic value over CBNAAT?
  7. [PE31.12] Review the natural history of enteric fever week by week. Why is blood culture the gold standard? What makes the Widal test unreliable in endemic areas? What is the management, and at which stage of illness does intestinal perforation typically occur?
  8. [PE31.9] What are the common causes of prolonged fever (>10 days) in Indian children? Outline a systematic diagnostic approach considering infective, inflammatory, and malignant causes.
  9. [PE31.14] Compare P. vivax and P. falciparum malaria: morphological features on smear, treatment (ACT vs CQ+primaquine), G6PD testing requirement, and the conditions under which IV artesunate is indicated for severe malaria.