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Respiratory

Tuberculosis

TB High-yield Verified · Sep 2026

Tuberculosis is an infectious bacterial disease caused by Mycobacterium tuberculosis that usually attacks the lungs but can also attack other parts of the body, including the kidneys, spine, and brain.

The highest-yield infectious respiratory disorder: it ties together airborne isolation, the 5/10/15 mm skin-test tiers, a four-drug regimen that only works if it is finished, and the nurse’s public-health role — reporting, contact investigation, and directly observed therapy.

What’s going wrong in the body

The normal physiology, where it fails, and why the body’s compensation backfires.

01 An airborne bacterium the body walls off but rarely kills

TB spreads person-to-person by airborne droplet nuclei that stay suspended in the air for several hours after a person with active pulmonary or laryngeal TB coughs, sneezes, talks, or sings. Transmission risk climbs with prolonged exposure in enclosed, poorly ventilated spaces — a household, a shelter dormitory, a cell block. It is not spread by touching, kissing, or sharing food; there is no fomite story here, which is exactly why the precautions are about air, not surfaces. Even after heavy household exposure, only about 20% of contacts convert their skin test, and only ~5% of those infected fall ill early.

When inhaled bacilli reach the alveoli, alveolar macrophages ingest them — and often fail to kill them. Survivors ride to the pulmonary lymph nodes and prime T cells, which recruit more T cells, B cells, monocytes, giant cells, dendritic cells, and fibroblasts into a granuloma: the immune system building a wall around bacteria it cannot destroy. The primary granuloma plus its draining hilar lymph nodes is the Ghon complex — typically a subpleural, 1.0–1.5 cm lesion with a fibroblastic rim around caseous (“cheese-like”) necrosis. When it calcifies it becomes the Ranke complex, visible on chest x-ray years later as the fingerprint of an old primary infection.

Primary infection: inhaled bacilli are walled into a granuloma. Most people enter latency; a minority progress early, and latency can reactivate whenever immunity falters.

02 Latent vs active — one bug, two completely different patients

The fork every exam question hinges on: about 90% of infected people contain the bacteria as latent TB infection (LTBI) — immunologic evidence of infection (a positive TST or IGRA) without clinical disease. They feel well, have a normal evaluation, and — the point nurses teach over and over — cannot spread TB to anyone. Latency is not perfectly dormant, though: people can cycle between true dormancy and subclinical disease, which is why “latent” still gets treated.

The lifetime risk that latent infection reactivates into active disease is roughly 5–10% in immunocompetent people (up to 15% in some sources), and about half of that risk is concentrated in the first 2 years after infection. Active disease is the mirror image of latency: symptomatic, culture-positive, and — when pulmonary or laryngeal — infectious. Both states are treated: active disease to cure it, latent infection to cancel the reactivation risk before it happens (protective efficacy of LTBI therapy runs 60–90%).

The latent-vs-active fork: same organism, opposite implications for symptoms, infectiousness, and regimen — and both get treated.

03 Reactivation: the granuloma becomes a cavity

The granuloma holds only as long as the immune system funds it. With waning immunity — HIV, TNF-α blockers, chronic steroids, transplant drugs, diabetes, dialysis, malnutrition, or simply age — the walled-off lesion can undergo caseation necrosis, erode into an airway, and form a cavity in which bacilli proliferate freely. Cavitary disease is the engine of the classic picture: erosion into airways and vessels produces the chronic productive cough and hemoptysis, and a cavity open to the airways makes the patient highly infectious. On x-ray, reactivation disease classically sits in the apical and posterior upper lobes, with cavitation in 20–45% of adult cases.

This is why most TB a US nurse admits is not a fresh exposure: about 85% of reported US cases are reactivation of latent infection, often acquired years earlier (76% of US cases occur in people born outside the US, where exposure is more common). The systemic symptoms track the biology: fever and drenching night sweats are the immune response to bacterial antigens, and the relentless weight loss — the “consumption” of the old name — reflects the systemic inflammatory and metabolic burden.

04 When containment fails completely — miliary and extrapulmonary TB

Bacilli that escape into the lymphatics and bloodstream seed distant organs. Miliary TB is lymphohematogenous dissemination that studs the lungs and other organs with millet-seed-sized (1–2 mm) tubercular foci — highest-risk in the immunocompromised (HIV with CD4 below 200 cells/mm³, immunosuppressive therapy, diabetes, chronic kidney disease, advanced age) and lethal untreated: mortality around 15–20% in children and 25–30% in adults.

Seeded organs explain the extrapulmonary syndromes: meningitis (CNS TB), osteomyelitis of the spine (Pott disease), peritonitis, renal abscess, and genitourinary TB that can cause infertility. One infection-control nuance worth knowing: only pulmonary, laryngeal, and pleural TB disease is typically transmissible — extrapulmonary TB at other sites spreads only in rare procedural circumstances, which is why the isolation decision keys on the lungs and larynx — and why the entire precautions pathway below follows directly from the airborne biology.

The isolation decision path that follows from airborne biology: precautions start on suspicion and end only with ruled-out disease or the three-negative-smears standard.

Causes & risk factors

Modifiable factors are teaching targets — the patient can act on them.

Birth in or travel to a TB-endemic country Close contact (especially household) with a person with active TB Residents & employees of congregate settings — shelters, jails/prisons, nursing homes Healthcare workers & mycobacteriology lab workers HIV infection (the strongest progression risk) Infection within the past 2 years Children under 5 & older adults Immunosuppression — transplant, TNF-α antagonists, chronic steroids (≥ 15 mg/day prednisone equivalent) modifiable Diabetes (control is the modifiable part) modifiable End-stage renal disease / dialysis · silicosis · malignancy Malnutrition (BMI < 20 or < 90% ideal body weight) modifiable Tobacco use modifiable Excessive alcohol use modifiable

Signs & symptoms

Each finding tied to the mechanism that produces it — and the triage it calls for.

Cough lasting longer than 3 weeks, usually productive Expected
Why: Cavitary disease eroding into airways keeps the cough going — the 3-week mark is the classic threshold that should trigger a TB workup in anyone with risk factors.
Hemoptysis — blood or bloody sputum late Hold & notify
Why: The cavity eroding pulmonary vessels. Any hemoptysis is a report-to-provider finding; it marks cavitary, highly infectious disease.
Massive hemoptysis, or breathing that suddenly obstructs late Report immediately
Why: Large-vessel erosion or airway obstruction — among TB’s named emergencies, alongside septic shock. Get help now.
Drenching night sweats Expected
Why: The immune response to mycobacterial antigens — the classic systemic clue that separates TB from an ordinary lingering cough.
Fever & chills, often low-grade and persistent Expected
Why: The same antigen-driven immune response; it smolders for weeks rather than spiking like a typical bacterial pneumonia.
Unintentional weight loss & anorexia Expected
Why: The systemic inflammatory and metabolic response consumes the patient — the historical name for TB was “consumption” for exactly this reason.
Fatigue & weakness Expected
Why: Weeks of inflammatory burden, poor intake, and disrupted sleep (night sweats) drain reserve — often the symptom that finally brings the patient in.
Chest pain Expected
Why: Part of the classic active-disease cluster — with a chronic cough and systemic symptoms, it should push TB up the differential rather than be read as musculoskeletal.
No symptoms at all — latent infection early Expected
Why: Primary infection and LTBI are typically silent; the only trace is a positive TST or IGRA on screening. Latent patients are not infectious.
No symptoms despite active disease (high-risk groups) early
Why: Asymptomatic active disease is well described in high-risk populations — the reason screening programs exist instead of waiting for a cough.

Diagnostics

Test In this disorder Normal
Tuberculin skin test (TST / Mantoux) 0.1 mL of 5-TU PPD given intradermally on the inner forearm — correct placement raises a 6–10 mm wheal. Read at 48–72 hours. Prior BCG vaccination can cause a lifelong false positive; testing within ~8 weeks of infection or while immunosuppressed can be falsely negative. Positive at ≥ 5 mm induration — HIV, recent close contacts, prior-TB changes on x-ray, transplant & other immunosuppressed patients · ≥ 10 mm — immigrants from high-incidence countries, residents/employees of congregate settings & healthcare facilities, injection-drug users, young children, diabetes/renal failure/silicosis/malignancy, < 90% ideal body weight · ≥ 15 mm — healthy people with no risk factors CDC cutoffs (per StatPearls) No induration (measure induration, never redness)
IGRA blood test (QuantiFERON-TB Gold Plus, T-SPOT.TB) A single blood draw with no return visit, and not affected by BCG vaccination — preferred for BCG-vaccinated patients and anyone unlikely to come back for a reading. False negatives with impaired immunity; ~4% indeterminate. Positive with TB infection — like the TST, it cannot distinguish latent from active disease —
Sputum AFB smear & culture The nurse owns collection quality: space the specimens correctly and capture the early-morning one — overnight pooling concentrates the bacilli. 3 serial specimens, collected 8–24 hours apart, at least one early-morning — smear sensitivity only 34–80%; culture is the gold standard (sensitivity 80–93%) —
NAAT (Xpert MTB/RIF) Also detects rifampin resistance (sensitivity ~96%, specificity ~98%) — an early flag for MDR-TB before cultures mature. Detects M. tuberculosis DNA — sensitivity ~70% on one specimen, ~90% across 3; specificity ~98% —
Chest x-ray A normal film does not fully exclude TB. Every positive TST/IGRA gets a symptom review + chest x-ray to rule out active disease before it can be called latent. Reactivation TB: patchy consolidation of the apical & posterior upper lobes, with cavitation in 20–45% of adults · primary TB: Ghon/Ranke complex, hilar lymphadenopathy, or effusion —

Complications

Warning: Massive hemoptysis · airway obstruction · septic shock Report immediately
Cavitary disease eroding a large vessel, obstructing an airway, or seeding the bloodstream — TB’s named emergencies.
Any hemoptysis is reported; massive hemoptysis or obstructed breathing is a rapid-response call. The patient is still on airborne precautions — responders wear fit-tested N95s even while moving fast.
Warning: Miliary (disseminated) TB Report immediately
Lymphohematogenous spread studding lungs and organs with 1–2 mm millet-seed foci — mortality 15–20% in children and 25–30% in adults if untreated.
Highest risk when immunity is lowest: HIV with CD4 < 200 cells/mm³, immunosuppressive therapy, diabetes, CKD, advanced age. A deteriorating, febrile, immunocompromised patient with known TB infection is this until proven otherwise.
Warning: Drug-resistant TB — MDR → pre-XDR → XDR Hold & notify
MDR-TB is resistance to both isoniazid and rifampin; add fluoroquinolone resistance for pre-XDR; XDR-TB (as classically defined by these sources) adds resistance to ≥ 1 second-line injectable — WHO has since revised the XDR definition.
~410,000 of 2022’s TB cases were MDR/RR-TB, and incomplete or interrupted treatment is the driver. Every adherence conversation, every DOT visit, is resistance prevention — this is the complication nursing directly prevents.
Caution: Extrapulmonary TB — meningitis, Pott disease & more Hold & notify
Seeded organs produce TB meningitis, spinal osteomyelitis (Pott), peritonitis, renal abscess, and genitourinary disease that can cause infertility.
New neuro findings, back pain with systemic symptoms, or unexplained organ dysfunction in a TB patient warrant a workup — TB is not obligated to stay in the chest.
Caution: Permanent lung damage
Untreated or late-treated disease leaves bronchiectasis, empyema, broncho-pleural fistula, and scarred, cavitated lung that never fully recovers.
The case for early case-finding: the 3-week-cough threshold and risk-group screening exist to catch disease before the damage is structural.

Medications for this condition

Why each class is prescribed here — every card links to its full pharmacology page.

Antitubercular Agents First-line
Immune / Anti-infective · isoniazid

Active drug-susceptible TB gets the 4-drug RIPE regimen — rifampin, isoniazid, pyrazinamide, ethambutol: all four for a 2-month intensive phase, then isoniazid + rifampin for a 4-month continuation (6 months minimum; extend to ~9 when there is cavitation plus a positive 2-month culture). Four drugs at once because monotherapy or truncated therapy selects resistant mutants — incomplete treatment, not bad luck, is what breeds MDR-TB. Latent infection is treated too (short rifamycin-based regimens such as 3HP, weekly isoniazid + rifapentine for 12 weeks) to cancel the reactivation risk before it happens.

Beyond medications

  • Directly observed therapy (DOT) — the CDC standard of care for TB disease: a health care worker watches each dose being taken (in person or by video), monitors for adverse effects, and offers support. Missed doses raise the risk of drug resistance, relapse, and continued transmission.
  • Nurse case management — TB-trained nurses and cultural health workers link patients into care, use incentives and enablers, monitor adverse effects, and measurably improve completion rates. The newer short regimens exist specifically to make finishing feasible.
  • Public-health reporting — suspected or confirmed TB is reportable by law to the local/state health department. Tell the patient up front: the provider is required to report.
  • Contact investigation — follows every infectious case: household contacts are highest priority, and the infectious period is counted from ≥ 3 months before symptom onset. HIPAA’s Privacy Rule explicitly permits the required information sharing with public health authorities.
  • Home isolation while infectious — stay home, cover the mouth when coughing, ventilate the space, and keep distance/mask around others. Per the 2024 NTCA community guideline, most people on effective therapy can end home-isolation restrictions after ≥ 5 days of treatment, masking indoors and avoiding crowded, poorly ventilated settings.
  • BCG vaccine context — a live attenuated M. bovis vaccine given to infants in high-incidence countries; protection wanes after early childhood and it is not routinely used in the US. Its lasting footprint is a false-positive TST for life — screen these patients with an IGRA instead.

Nursing considerations

The RN-specific layer — each action paired with the reason it matters.

Screening, assessment & monitoring
Think TB for any cough > 3 weeks — and ask the risk questions: country of birth/travel, congregate-setting residence or work, known contacts, HIV status, immunosuppressing drugs.
Why: Classic symptoms plus an exposure or progression risk factor is the case-finding pattern; 76% of US cases occur in people born outside the US, and asymptomatic disease in high-risk groups is why screening beats waiting.
Give the TST correctly: 0.1 mL of 5-TU PPD intradermally, inner forearm, bevel up — a 6–10 mm wheal proves correct placement.
Why: A dose that goes subcutaneous produces no wheal and an unreadable test — the most common administration failure.
Read the TST at 48–72 hours, measuring the widest diameter of induration — never the redness.
Why: Erythema has no diagnostic value; only the palpable raised area counts, against the patient’s risk-tiered cutoff (5/10/15 mm). Reader-to-reader variation runs up to 15%, so technique matters.
Use two-step testing to baseline serial testers such as healthcare workers.
Why: In remote infection the first TST can be falsely negative but “boosts” the waned response; the second test 1–4 weeks later shows the true positive instead of a false “conversion” next year.
After any positive TST/IGRA: symptom review + chest x-ray before anyone calls it latent.
Why: A positive test only proves infection. Treating unrecognized active disease with a 1–2-drug latent regimen is insufficient and promotes resistance.
On treatment, track liver function (baseline, then monthly surveillance) and ask about hepatitis symptoms at every encounter.
Why: The first-line drugs are hepatotoxic; anorexia, nausea, jaundice, or dark urine warrants prompt evaluation — early, it is reversible.
While the patient is infectious (airborne precautions)
Initiate airborne precautions immediately for known or suspected TB — a private airborne infection isolation room (AIIR) under negative pressure, 6–12 air exchanges/hour, door closed, air exhausted outside or HEPA-filtered.
Why: Droplet nuclei hang in the air for hours; negative pressure keeps that air from reaching the corridor. Waiting for smear results to isolate means exposing the unit in the meantime.
Everyone entering wears a fit-tested N95 respirator (filters ≥ 95% of airborne particles): hand hygiene before donning, remove by the straps, replace it if soiled or wet.
Why: A surgical mask does not seal and does not protect the wearer from airborne nuclei; fit-testing is required for all providers entering the AIIR.
Transport only when essential: the patient wears a surgical mask (not an N95), skips waiting areas, and takes an empty elevator when possible.
Why: The mask on the source captures droplet nuclei at the mouth — the patient does not need a respirator seal, the corridor needs source control.
Know the classic off-precautions criteria: TB ruled out with an alternate diagnosis, or 3 consecutive negative AFB smears 8–24 hours apart (≥ 1 early-morning) plus ~2 weeks of effective multidrug therapy with clinical improvement.
Why: This is the CDC in-facility standard (and the exam answer). The 2024 NTCA guideline separately lets most patients end home isolation after ≥ 5 days of effective treatment — community rules, not hospital ones.
Patient teaching (adherence is the cure)
Complete the entire 6-month course — even when symptoms vanish after a few weeks. Never stop or skip without the provider.
Why: Truncated therapy fails to eradicate the infection and promotes drug resistance — the direct route to MDR-TB, which is far harder to treat than the original disease.
Explain DOT as support, not surveillance: a nurse or health worker watches doses so nothing derails a curable disease.
Why: Framing DOT as partnership protects the relationship the whole 6-month course depends on — and DOT, not self-report, is what keeps a 6-month course on track.
Teach the hepatitis warning signs — anorexia, nausea, jaundice, dark urine — and to call promptly if they appear.
Why: Early recognition keeps drug-induced liver injury reversible; the monthly labs only catch what happens on lab day.
Anticipate the med quirks: pyridoxine (B6) alongside isoniazid for high-risk patients (pregnancy, HIV, diabetes, malnutrition, alcohol use, CKD, older age); rifampin turns tears, urine and sweat orange-red and interacts with many drugs, including warfarin and DOACs.
Why: A forewarned patient doesn’t quit over orange urine, and the interaction list is why every provider needs the full medication history.
While still infectious: stay home, cover coughs, ventilate rooms, and keep distance or mask around others.
Why: Household members are the highest-risk contacts; simple source control at home is what protects them until treatment takes hold.
Prepare the patient for the public-health side: the diagnosis is reported by law, and the health department will screen contacts — household first.
Why: Contact investigation finds the ~20% of household contacts who convert their skin test and treats them before the ~5–10% lifetime reactivation risk plays out. HIPAA permits this sharing.

How a real nurse thinks

The clinical-judgment loop, worked for a typical presentation — reasoning, not reference.

  1. 1
    Recognize cues

    The cues that matter: cough > 3 weeks, night sweats, weight loss, blood-streaked sputum, an apical cavitary lesion on x-ray — and two exposure risk factors (birth in an endemic country, work in a homeless shelter). The near-normal vitals are the noise: TB smolders; it rarely announces itself hemodynamically.

  2. 2
    Analyze cues

    The pattern is active cavitary pulmonary TB until proven otherwise. The cavity explains the story end to end: erosion into airways sustains the cough, erosion into vessels produces the hemoptysis — and a cavity open to the airways makes him highly infectious. Every hour he spends in shared air is an exposure event.

  3. 3
    Prioritize

    The priority is containment before workup: this patient cannot go to a semi-private room — suspected TB triggers airborne precautions immediately, before any smear result exists. Nothing else on the admission checklist outranks stopping transmission. Second priority: the blood-streaked sputum stays under watch — hemoptysis is a report finding, and massive hemoptysis would be an emergency.

  4. 4
    Generate solutions

    Place a surgical mask on the patient now; hold the transfer and get an AIIR assigned (negative pressure, 6–12 air exchanges/hour, door closed); fit-tested N95s for every person entering; notify the provider and infection control; plan the sputum series — 3 specimens, 8–24 hours apart, at least one early-morning — so therapy can start on schedule.

  5. 5
    Take action

    Mask the patient and reroute him directly to the AIIR — no waiting areas, an empty elevator if possible. Don a fit-tested N95 before entering. Collect the first sputum specimen and map out the next two. Start RIPE as ordered once specimens are secured, and remind the team the health department report is required by law — contact investigation of his household and the shelter will follow.

  6. 6
    Evaluate

    Success looks like: precautions unbroken (door closed, N95 on every entry), the sputum series collected correctly, fever and night sweats fading on therapy, weight stabilizing, and no escalation of hemoptysis. He comes off airborne precautions only with 3 consecutive negative AFB smears 8–24 hours apart plus ~2 weeks of effective therapy and clinical improvement — and any massive hemoptysis re-escalates immediately.

Scenario — you’re the nurse

Work each question before revealing the answer. Rationales explain the wrong options too.

Medical unit · 1930, admission arriving from the ED

A 34-year-old man admitted for evaluation of a 4-week productive cough, drenching night sweats, and unintentional weight loss. Born in a TB-endemic country, he moved to the US 3 years ago and works evenings at a homeless shelter. In the ED he coughed up blood-streaked sputum. Orders: sputum AFB smear & culture × 3, RIPE therapy to start once specimens are collected.

1900 vitals — T 38.1 °C · HR 96 · BP 118/74 · RR 20 · SpO₂ 95% on room air
ED chest x-ray — patchy consolidation of the right apical upper lobe with a cavitary lesion
Nurse’s note — thin, tired-appearing; productive cough with blood-streaked sputum; reports soaking the sheets at night for 3 weeks
Sputum AFB × 3 — ordered, none collected yet
Bed board — the ED has assigned a standard semi-private room; the transporter is on the way up
Q1 Select all that apply
Which admission findings support the suspicion of active pulmonary TB? Select all that apply.
  1. A. Productive cough for 4 weeks
  2. B. Blood pressure 118/74 mmHg
  3. C. Drenching night sweats and unintentional weight loss
  4. D. Blood-streaked sputum
  5. E. SpO₂ 95% on room air
  6. F. Cavitary lesion in the right apical upper lobe
Reveal answer & rationale
Answer: A, C, D, F
The classic active-TB cluster: cough > 3 weeks (A), the systemic signs of night sweats + weight loss (C), hemoptysis from cavitary vessel erosion (D), and the textbook apical cavitary lesion of reactivation disease (F). The normal blood pressure (B) and acceptable oxygen saturation (E) are exactly what TB usually looks like — a smoldering illness with unremarkable vitals — so they neither support nor exclude anything.
Q2 Multiple choice
The transporter arrives to take the patient to his assigned semi-private room. The nurse’s best action is to:
  1. A. Send the patient with the transporter and keep the privacy curtain drawn between beds
  2. B. Place a surgical mask on the patient, hold the transfer, and arrange a negative-pressure airborne infection isolation room
  3. C. Request droplet precautions: a private room with the door open and surgical masks for staff within 3 feet
  4. D. Place an N95 respirator on the patient before transport to the semi-private room
Reveal answer & rationale
Answer: B
Suspected TB triggers airborne precautions immediately — a private AIIR under negative pressure with the door closed, never a shared room (B). A curtain (A) does nothing against droplet nuclei that stay airborne for hours and would expose the roommate. Droplet precautions (C) are the wrong category entirely — TB is airborne, and an open door defeats negative pressure. The N95 belongs on the staff, not the patient; the patient wears a surgical mask for source control during transport (D confuses the two masks — a classic exam trap).
Q3 Put in order
Put the nurse’s first four actions in priority order:
  1. A. Notify the provider and infection control that airborne precautions are in place
  2. B. Place a surgical mask on the patient
  3. C. Move the patient into a negative-pressure AIIR with the door closed
  4. D. Don a fit-tested N95 respirator before further care in the room
Reveal answer & rationale
Correct order: B → C → A → D
Source control first: the surgical mask on the patient takes seconds and cuts transmission immediately, wherever he is. Next, get him out of shared air and into the AIIR, door closed. Then the notification calls — provider and infection control — which can happen from the desk once the immediate hazard is contained. The N95 is required before every room entry, but ongoing in-room care comes after containment and notification are set. Calling first (A) leaves an unmasked, cavitary patient in shared air while you’re on the phone.
Q4 Multiple choice
On hospital day 3 the patient asks, “When can I get out of this room?” The most accurate response is that in-facility airborne precautions continue until:
  1. A. “You’ve completed 24 hours of TB medication.”
  2. B. “Your cough is completely gone.”
  3. C. “You have 3 negative sputum smears collected 8–24 hours apart, plus about 2 weeks of effective treatment and clear improvement.”
  4. D. “You finish the full 6-month course of medication.”
Reveal answer & rationale
Answer: C
The classic in-facility standard is 3 consecutive negative AFB smears, 8–24 hours apart with at least one early-morning specimen, plus ~2 weeks of effective multidrug therapy and clinical improvement (C). Twenty-four hours of therapy (A) is a rule for other infections, not TB. Symptom resolution alone (B) is neither sufficient nor required — infectiousness is judged by smears and treatment response. And 6 months (D) confuses the treatment duration with the isolation duration: patients come off precautions long before the regimen ends.
Q5 Multiple choice
Six weeks later at the DOT clinic the patient says, “I feel completely fine now — I don’t see why I need four more months of pills and a nurse watching me swallow them.” The nurse’s best response teaches that:
  1. A. “Stopping now means the surviving bacteria can come back resistant to the drugs — the full course plus observed dosing is what cures you and keeps the medicines working.”
  2. B. “You can step down to just one medication now that your symptoms have resolved.”
  3. C. “Feeling well means the infection is cured, but you should finish the month’s supply you have at home.”
  4. D. “The observed dosing is required by law because TB is a reportable disease.”
Reveal answer & rationale
Answer: A
Feeling better is the drugs working, not the infection gone: truncated therapy fails to eradicate the infection and promotes drug resistance — MDR-TB is driven by incomplete treatment, which is exactly what DOT exists to prevent (A). Dropping to monotherapy (B) is the resistance-breeding move the 4-drug design guards against. “Cured at symptom resolution” (C) is false and finishing “the month’s supply” abandons the continuation phase. Reporting to the health department is the legal requirement; DOT is an adherence strategy, not a statute (D conflates the two).

Common questions

What causes tuberculosis?
Common causes and risk factors include birth in or travel to a tb-endemic country, close contact (especially household) with a person with active tb, residents & employees of congregate settings — shelters, jails/prisons, nursing homes, healthcare workers & mycobacteriology lab workers, hiv infection (the strongest progression risk), and others.
What are the early signs of tuberculosis?
Early findings include No symptoms at all — latent infection, No symptoms despite active disease (high-risk groups).
Which findings should a nurse report immediately in tuberculosis?
Report immediately: Massive hemoptysis, or breathing that suddenly obstructs, Massive hemoptysis · airway obstruction · septic shock, Miliary (disseminated) TB. These signal deterioration that needs rapid intervention.
Can latent TB spread to other people?
No. Latent TB infection means the immune system has walled the bacteria into granulomas — the person has no symptoms and cannot transmit TB. It still gets treated, because roughly 5–10% of latent infections reactivate into contagious active disease over a lifetime, and preventive therapy is 60–90% effective at stopping that.
Why does TB treatment take four drugs for six months?
M. tuberculosis mutates its way around any single drug — monotherapy or a shortened course leaves resistant survivors behind. The RIPE regimen (rifampin, isoniazid, pyrazinamide, ethambutol) attacks by multiple mechanisms at once: all four drugs for 2 months, then isoniazid + rifampin for 4 more. Incomplete treatment is the engine of MDR-TB, which is why directly observed therapy exists.
I had the BCG vaccine as a child — will my TB skin test always be positive?
It can be: BCG vaccination can cause a false-positive TST for life. The fix is the IGRA blood test (QuantiFERON-TB Gold Plus or T-SPOT.TB), which is not affected by BCG and needs only a single blood draw. A positive result on either test still gets a symptom review and chest x-ray to separate latent infection from active disease.

Sources

Reviewed by Hae Suk Lee, RN

Educational summary for nursing students. Scenarios are fictional teaching cases. Always verify against current guidelines and your institution's protocols before acting in practice. Not medical advice.

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