Serious & Notifiable Infections — MCQs
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A 6-year-old boy presents to the emergency department with a 5-hour history of fever, headache, vomiting, and drowsiness. On examination, he has a temperature of 39.2°C, Glasgow Coma Scale score of 13/15, neck stiffness, and a non-blanching purpuric rash on his trunk and lower limbs. Which of the following is the correct sequence of immediate management steps in the first 30 minutes?
A 31-year-old woman from Pakistan presents with a 5-week history of headache, low-grade fever, and progressive confusion. On examination, she has photophobia, neck stiffness, and bilateral papilloedema. Lumbar puncture shows opening pressure 32 cmH₂O, CSF protein 2.8 g/L, glucose 1.2 mmol/L (plasma glucose 6.5 mmol/L), white cell count 450 cells/μL (80% lymphocytes). A CT head shows basal meningeal enhancement and hydrocephalus. What is the most important additional investigation to guide long-term management?
A 46-year-old woman with smear-positive pulmonary tuberculosis has been receiving rifampicin, isoniazid, pyrazinamide, and ethambutol for 8 weeks. She is clinically improving with resolution of symptoms. Repeat sputum samples at 8 weeks remain smear-positive for acid-fast bacilli. Culture from initial samples has now grown Mycobacterium tuberculosis fully sensitive to all first-line drugs. What is the most appropriate next step in management?
A 23-year-old man with no significant past medical history presents with fever, severe headache, and neck stiffness. Lumbar puncture shows: opening pressure 24 cmH2O, white cells 1250 cells/mm³ (95% neutrophils), protein 1.5 g/L, glucose 2.5 mmol/L (plasma 5.2 mmol/L). Gram stain shows Gram-negative diplococci. Blood and CSF cultures are sent. He is started on intravenous ceftriaxone. After 24 hours of treatment, he becomes increasingly drowsy and confused. Repeat CT head shows cerebral oedema. What is the most likely cause of his clinical deterioration?
A 31-year-old healthcare worker is identified as a contact of a patient with smear-positive pulmonary tuberculosis. She had documented BCG vaccination as a child. She is asymptomatic and has no past history of TB. Her Mantoux test shows 18 mm induration. Chest X-ray is normal. Interferon-gamma release assay (IGRA) is positive. She is currently 8 weeks pregnant. What is the most appropriate management?
A 7-year-old boy who recently emigrated from India is diagnosed with tuberculous meningitis. MRI brain shows basal exudates and communicating hydrocephalus. Lumbar puncture shows: opening pressure 28 cmH2O, white cells 250 cells/mm³ (80% lymphocytes), protein 2.5 g/L, glucose 1.5 mmol/L (plasma 5.0 mmol/L). He is started on rifampicin, isoniazid, pyrazinamide, and ethambutol along with adjunctive therapy. What is the recommended duration of treatment for this patient?
A 53-year-old man is diagnosed with drug-sensitive pulmonary tuberculosis and starts rifampicin, isoniazid, pyrazinamide, and ethambutol. He takes warfarin for atrial fibrillation and has been stable on 5 mg daily with INR consistently 2.0-3.0. Three days after starting TB treatment, his INR is 1.2. What is the most appropriate management of his anticoagulation?
A 16-year-old girl presents to the emergency department with a 6-hour history of severe headache, fever, vomiting, and photophobia. She is drowsy but responds to voice. Her flatmates mention she had cold symptoms a few days ago. On examination: temperature 38.9°C, heart rate 125/min, blood pressure 100/65 mmHg, GCS 13/15, positive neck stiffness, no rash, no focal neurological signs. CT head is normal. What is the most appropriate next step in management?
A 29-year-old pregnant woman at 20 weeks gestation is diagnosed with active pulmonary tuberculosis. Sputum microscopy is positive for acid-fast bacilli, and GeneXpert MTB/RIF confirms rifampicin-sensitive Mycobacterium tuberculosis. She is otherwise well with normal liver function. What is the most appropriate anti-tuberculosis treatment regimen for this patient?
A 67-year-old man with type 2 diabetes mellitus presents with a 4-day history of fever, confusion, and photophobia. CT head shows no mass lesion or raised intracranial pressure. Lumbar puncture reveals: white cells 1850 cells/mm³ (92% neutrophils), protein 2.8 g/L, glucose 1.2 mmol/L (plasma 8.5 mmol/L). Blood cultures and CSF Gram stain show Gram-positive diplococci. He has documented severe penicillin allergy (anaphylaxis). What is the most appropriate antimicrobial therapy?
Serious & Notifiable Infections UK Medical PG Practice Questions and MCQs
Question 131: A 6-year-old boy presents to the emergency department with a 5-hour history of fever, headache, vomiting, and drowsiness. On examination, he has a temperature of 39.2°C, Glasgow Coma Scale score of 13/15, neck stiffness, and a non-blanching purpuric rash on his trunk and lower limbs. Which of the following is the correct sequence of immediate management steps in the first 30 minutes?
- A. Blood cultures, lumbar puncture, intravenous ceftriaxone, intravenous fluids
- B. Intravenous ceftriaxone, blood cultures, intravenous fluids, CT head before lumbar puncture (Correct Answer)
- C. Intravenous ceftriaxone, blood cultures, intravenous fluids, lumbar puncture
- D. Blood cultures, CT head, lumbar puncture, intravenous ceftriaxone
- E. Intravenous benzylpenicillin, immediate lumbar puncture, blood cultures, intravenous fluids
Explanation: ***Intravenous ceftriaxone, blood cultures, intravenous fluids, CT head before lumbar puncture*** - In a child with suspected **meningococcal sepsis** and features of severe infection (fever, drowsiness, neck stiffness, non-blanching purpuric rash), immediate administration of **intravenous ceftriaxone** is paramount to improve clinical outcomes and prevent rapid deterioration. - The patient's **drowsiness (GCS 13/15)** suggests possible **raised intracranial pressure (ICP)**, making a **CT head** mandatory before a **lumbar puncture** to rule out brain herniation risk. Blood cultures and IV fluids are concurrent essential steps. *Blood cultures, lumbar puncture, intravenous ceftriaxone, intravenous fluids* - Delaying the administration of **intravenous antibiotics** (ceftriaxone) to perform investigations like blood cultures and lumbar puncture is highly dangerous and increases mortality in suspected bacterial meningitis. - A **lumbar puncture** should not be the second step when there are clinical signs of **intracranial hypertension** (drowsiness) or widespread meningococcemia, as it poses a significant risk of **herniation**. *Intravenous ceftriaxone, blood cultures, intravenous fluids, lumbar puncture* - While starting with **intravenous ceftriaxone** is correct, directly proceeding to a **lumbar puncture** without prior imaging is unsafe given the patient's **drowsiness (GCS 13/15)**. - A **CT head** is required to assess for **raised ICP** or cerebral mass lesions before a lumbar puncture in patients with altered mental status or focal neurological signs, to prevent **brain herniation**. *Blood cultures, CT head, lumbar puncture, intravenous ceftriaxone* - This sequence is incorrect because it critically delays the administration of **intravenous ceftriaxone**, placing it as the last step. - In suspected bacterial meningitis or sepsis, **empirical antibiotics** should be administered as an absolute priority, and diagnostic steps should never cause a delay in this life-saving intervention. *Intravenous benzylpenicillin, immediate lumbar puncture, blood cultures, intravenous fluids* - While **benzylpenicillin** is used, **ceftriaxone** is the preferred **empirical broad-spectrum antibiotic** in the hospital setting for suspected bacterial meningitis due to its wider coverage. - An **immediate lumbar puncture** is strongly contraindicated due to the patient's **drowsiness** (indicating potential raised ICP) and the presence of a **non-blanching purpuric rash**, which can indicate **coagulopathy** or a severe disseminated infection with high herniation risk.
Question 132: A 31-year-old woman from Pakistan presents with a 5-week history of headache, low-grade fever, and progressive confusion. On examination, she has photophobia, neck stiffness, and bilateral papilloedema. Lumbar puncture shows opening pressure 32 cmH₂O, CSF protein 2.8 g/L, glucose 1.2 mmol/L (plasma glucose 6.5 mmol/L), white cell count 450 cells/μL (80% lymphocytes). A CT head shows basal meningeal enhancement and hydrocephalus. What is the most important additional investigation to guide long-term management?
- A. HIV serology (Correct Answer)
- B. Serum cryptococcal antigen
- C. CSF India ink staining
- D. CSF tuberculosis culture and molecular testing
- E. MRI brain with gadolinium contrast
Explanation: ***HIV serology*** - In a patient with highly suspected **tuberculous meningitis (TBM)**, identifying **HIV coinfection** is crucial as it significantly complicates clinical management, particularly regarding drug-drug interactions with **rifampicin** and the timing of antiretroviral therapy (ART). - **HIV status** is the most important factor in determining the long-term prognosis, the need for adjunctive steroids, and the management of complications like **Immune Reconstitution Inflammatory Syndrome (IRIS)**. *Serum cryptococcal antigen* - This test is primarily for **Cryptococcal meningitis**, which can occur in immunocompromised individuals but often presents with a less dramatic rise in **CSF protein** and less prominent **basal enhancement** compared to TBM. - While important in differential diagnosis, the patient's clinical and CSF profile strongly points towards TBM, making HIV status a more critical determinant for long-term management. *CSF India ink staining* - This technique is used to visualize the capsule of **Cryptococcus neoformans** but has lower sensitivity than antigen testing for diagnosing cryptococcal meningitis. - It is not relevant for the diagnosis or long-term management of TBM, which is strongly suggested by the clinical presentation and imaging findings. *CSF tuberculosis culture and molecular testing* - While **NAAT (e.g., GeneXpert)** and traditional culture are essential for **confirming the diagnosis** of TBM and assessing drug resistance, they are part of the initial diagnostic workup, not an *additional* investigation to guide long-term systemic management once TBM is highly suspected. - These tests confirm the pathogen, but HIV status guides the overall treatment strategy for the patient's underlying immune state. *MRI brain with gadolinium contrast* - MRI with contrast offers superior anatomical detail compared to CT, better visualizing subtle meningeal inflammation, **tuberculomas**, or infarcts associated with TBM. - Although it provides valuable diagnostic and prognostic information regarding CNS complications, it does not provide the systemic information needed to structure the **long-term drug regimen** and overall management strategy in the same way HIV status does.
Question 133: A 46-year-old woman with smear-positive pulmonary tuberculosis has been receiving rifampicin, isoniazid, pyrazinamide, and ethambutol for 8 weeks. She is clinically improving with resolution of symptoms. Repeat sputum samples at 8 weeks remain smear-positive for acid-fast bacilli. Culture from initial samples has now grown Mycobacterium tuberculosis fully sensitive to all first-line drugs. What is the most appropriate next step in management?
- A. Continue current four-drug regimen for a further 4 weeks before reassessing
- B. Switch to second-line therapy as this represents treatment failure
- C. Stop pyrazinamide and ethambutol, continue rifampicin and isoniazid for 4 months (Correct Answer)
- D. Add a fluoroquinolone to the current regimen
- E. Repeat drug sensitivity testing as resistance may have developed
Explanation: ***Stop pyrazinamide and ethambutol, continue rifampicin and isoniazid for 4 months***- Standard treatment for **drug-sensitive pulmonary tuberculosis** consists of an 8-week intensive phase (rifampicin, isoniazid, pyrazinamide, ethambutol) followed by a **continuation phase** of 4 months with rifampicin and isoniazid, which the patient is now entering.- Despite persistent smear positivity at 8 weeks, the patient is **clinically improving**, and the initial isolate was **fully sensitive** to first-line drugs, suggesting that the remaining acid-fast bacilli are likely non-viable or slowly clearing.*Continue current four-drug regimen for a further 4 weeks before reassessing*- Extending the **intensive phase** beyond 8 weeks is not typically indicated for patients with **drug-sensitive TB** who are clinically improving.- Prolonged use of **pyrazinamide** and **ethambutol** increases the risk of side effects, such as hepatotoxicity and optic neuritis, without clear additional benefit in sensitive cases.*Switch to second-line therapy as this represents treatment failure*- **Treatment failure** in TB is generally defined by persistent culture positivity or clinical deterioration after a more prolonged period of adequate treatment (e.g., 4 months) or by confirmed drug resistance.- Given the patient's **clinical improvement** and the documented **drug sensitivity**, switching to second-line drugs is premature and inappropriate.*Add a fluoroquinolone to the current regimen*- Adding a single drug to an existing regimen, especially if the regimen is not fully effective, is poor practice as it can rapidly lead to the development of **drug resistance** to the newly added agent.- There is no indication for adding a **fluoroquinolone** at this stage, as the patient has drug-sensitive TB and is clinically improving.*Repeat drug sensitivity testing as resistance may have developed*- While **acquired drug resistance** is a concern in TB treatment, it is usually suspected in cases of **clinical deterioration** or persistent culture positivity (not just smear positivity) after several months of treatment.- Given the clinical improvement and initial full sensitivity, repeating **drug sensitivity testing** is not the immediate next step, but rather transitioning to the continuation phase.
Question 134: A 23-year-old man with no significant past medical history presents with fever, severe headache, and neck stiffness. Lumbar puncture shows: opening pressure 24 cmH2O, white cells 1250 cells/mm³ (95% neutrophils), protein 1.5 g/L, glucose 2.5 mmol/L (plasma 5.2 mmol/L). Gram stain shows Gram-negative diplococci. Blood and CSF cultures are sent. He is started on intravenous ceftriaxone. After 24 hours of treatment, he becomes increasingly drowsy and confused. Repeat CT head shows cerebral oedema. What is the most likely cause of his clinical deterioration?
- A. Development of subdural empyema
- B. Inappropriate antibiotic choice
- C. Cerebral venous sinus thrombosis
- D. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) (Correct Answer)
- E. Rifampicin resistance requiring treatment modification
Explanation: ***Syndrome of inappropriate antidiuretic hormone secretion (SIADH)*** - **SIADH** is a common complication of **bacterial meningitis**, occurring due to excessive **ADH release** triggered by meningeal inflammation, leading to **dilutional hyponatremia**. - This hyponatremia exacerbates pre-existing **cerebral oedema**, worsening the patient's neurological status and causing symptoms like **drowsiness** and **confusion**. *Development of subdural empyema* - **Subdural empyema** typically manifests with focal **neurological deficits**, persistent fever, and potentially seizures, often requiring surgical drainage. - A **repeat CT head** would usually reveal a well-defined purulent collection, not generalized **cerebral oedema**. *Inappropriate antibiotic choice* - **Ceftriaxone** is a highly effective first-line antibiotic for **meningitis** caused by **Gram-negative diplococci** (e.g., *Neisseria meningitidis*). - The initial clinical and CSF findings strongly suggest appropriate treatment, and deterioration is more likely due to **complications of meningitis** itself rather than antibiotic failure. *Cerebral venous sinus thrombosis* - **Cerebral venous sinus thrombosis** is a rare but severe complication of meningitis that can cause **raised intracranial pressure**, focal neurological deficits, and **venous infarcts**. - While it can lead to oedema, it is less common than **SIADH** and typically presents with specific imaging findings such as the **delta sign** or absent flow in a sinus. *Rifampicin resistance requiring treatment modification* - **Rifampicin** is primarily used for **post-exposure prophylaxis** of close contacts of patients with **meningococcal meningitis**, not for the treatment of active infection. - Resistance of *Neisseria meningitidis* to **third-generation cephalosporins** like ceftriaxone is extremely rare and not the most probable cause of clinical deterioration in this scenario.
Question 135: A 31-year-old healthcare worker is identified as a contact of a patient with smear-positive pulmonary tuberculosis. She had documented BCG vaccination as a child. She is asymptomatic and has no past history of TB. Her Mantoux test shows 18 mm induration. Chest X-ray is normal. Interferon-gamma release assay (IGRA) is positive. She is currently 8 weeks pregnant. What is the most appropriate management?
- A. Start isoniazid prophylaxis immediately for 3 months
- B. Start isoniazid prophylaxis immediately for 6 months with pyridoxine
- C. Defer treatment for latent TB infection until after delivery (Correct Answer)
- D. Start rifampicin and isoniazid for 3 months immediately
- E. Observe without treatment and repeat chest X-ray in 6 months
Explanation: ***Defer treatment for latent TB infection until after delivery*** - In immunocompetent pregnant women with **latent tuberculosis infection (LTBI)**, treatment is typically postponed until after delivery to minimize the risk of **drug-induced hepatotoxicity** and fetal exposure. - The risk of progression to **active TB** during pregnancy is low compared to the potential adverse effects of treatment on the mother and fetus in a non-high-risk patient. *Start isoniazid prophylaxis immediately for 3 months* - A 3-month **isoniazid** course is not a standard standalone regimen for LTBI and lacks the necessary **pyridoxine** supplementation for a pregnant patient. - Immediate initiation is unnecessary as she lacks high-risk factors like **HIV infection** or recent known conversion within a high-risk setting. *Start isoniazid prophylaxis immediately for 6 months with pyridoxine* - While 6 months of **isoniazid with pyridoxine** is a valid regimen for LTBI, it is reserved for pregnant patients at high risk of rapid progression to active disease. - For this asymptomatic healthcare worker with a normal **chest X-ray**, the risks of immediate treatment generally outweigh the benefits until the postpartum period. *Start rifampicin and isoniazid for 3 months immediately* - Combination therapy with **rifampicin and isoniazid** is an alternative for LTBI, but immediate use in pregnancy is limited to patients with high risk of **disease progression**. - Standard guidelines favor waiting until after delivery to avoid exposing the fetus to multiple drugs and the mother to cumulative **liver toxicity**. *Observe without treatment and repeat chest X-ray in 6 months* - Observation alone is insufficient because positive **IGRA** and TST (18mm) confirm **latent TB infection**, which requires treatment eventually. - Simple observation fails to address the approximately 10% lifetime risk of progression to **active tuberculosis**, which is highest in the first two years after exposure.
Question 136: A 7-year-old boy who recently emigrated from India is diagnosed with tuberculous meningitis. MRI brain shows basal exudates and communicating hydrocephalus. Lumbar puncture shows: opening pressure 28 cmH2O, white cells 250 cells/mm³ (80% lymphocytes), protein 2.5 g/L, glucose 1.5 mmol/L (plasma 5.0 mmol/L). He is started on rifampicin, isoniazid, pyrazinamide, and ethambutol along with adjunctive therapy. What is the recommended duration of treatment for this patient?
- A. 6 months
- B. 9 months
- C. 12 months (Correct Answer)
- D. 18 months
- E. 24 months
Explanation: ***12 months*** - **Tuberculous meningitis** requires a prolonged treatment course of **12 months** (2 months intensive phase, 10 months continuation phase) because of the high risk of relapse and poor **CNS drug penetration**.- International guidelines (WHO/NICE) recommend this duration to ensure eradication of the bacilli and to prevent **neurological sequelae** in complex cases involving basal exudates and hydrocephalus.*6 months*- This is the standard duration for **uncomplicated pulmonary tuberculosis**, which is insufficient for central nervous system involvement.- Shorter courses are associated with significantly higher rates of **treatment failure** and recurrence in meningitis cases.*9 months*- While sometimes used for **bone and joint tuberculosis** or intensive pulmonary cases, it does not meet the standard of care for **CNS tuberculosis**.- Clinical outcomes for meningitis are superior with the extended **10-month continuation phase** (totaling 12 months).*18 months*- This extended duration is typically reserved for cases of **multidrug-resistant TB (MDR-TB)** rather than drug-sensitive strains.- Standard quadruple therapy for sensitive TB does not require such a long course unless there is **delayed clinical response** or resistance.*24 months*- This duration is generally utilized for **extensively drug-resistant TB (XDR-TB)** or extremely complex, non-responsive intracranial tuberculomas.- It is not indicated for the initial management of a standard pediatric case of **tuberculous meningitis**.
Question 137: A 53-year-old man is diagnosed with drug-sensitive pulmonary tuberculosis and starts rifampicin, isoniazid, pyrazinamide, and ethambutol. He takes warfarin for atrial fibrillation and has been stable on 5 mg daily with INR consistently 2.0-3.0. Three days after starting TB treatment, his INR is 1.2. What is the most appropriate management of his anticoagulation?
- A. Continue warfarin at the same dose and recheck INR in 2 weeks
- B. Increase warfarin dose incrementally and monitor INR closely until therapeutic range achieved (Correct Answer)
- C. Switch to a direct oral anticoagulant (DOAC) such as apixaban
- D. Stop warfarin and start subcutaneous low molecular weight heparin
- E. Add aspirin 75 mg daily to warfarin and continue same dose
Explanation: ***Increase warfarin dose incrementally and monitor INR closely until therapeutic range achieved*** - **Rifampicin** is a potent inducer of **cytochrome P450 (CYP2C9)** enzymes, which significantly increases the metabolism of **warfarin**, leading to a subtherapeutic **INR**. - An **INR** of 1.2 is below the therapeutic range (2.0-3.0) for atrial fibrillation, necessitating an **incremental increase in warfarin dose** and close **INR monitoring** to restore effective anticoagulation. *Continue warfarin at the same dose and recheck INR in 2 weeks* - The current **INR** of 1.2 indicates a significant and rapid drug-drug interaction, leaving the patient **subtherapeutic** and at high risk for **thromboembolic events**. - Delaying dose adjustment for two weeks would prolong this period of inadequate anticoagulation, which is clinically unsafe for a patient with **atrial fibrillation**. *Switch to a direct oral anticoagulant (DOAC) such as apixaban* - **Rifampicin** is also a strong inducer of **P-glycoprotein (P-gp)** and **CYP3A4**, which metabolize most **DOACs** (including apixaban), leading to significantly reduced **DOAC concentrations**. - This interaction would render the **DOAC** ineffective, leaving the patient unprotected from **stroke**, and unlike warfarin, DOAC levels are not routinely monitored to guide dose adjustments in this setting. *Stop warfarin and start subcutaneous low molecular weight heparin* - While **low molecular weight heparin (LMWH)** is effective and its anticoagulation is not affected by **rifampicin**, it is generally impractical for the long-term (6-month) duration of **tuberculosis treatment** due to the need for daily injections. - **LMWH** is typically reserved for acute anticoagulation, bridging therapy, or when oral anticoagulation is contraindicated or ineffective, which is not the primary issue here. *Add aspirin 75 mg daily to warfarin and continue same dose* - Adding **aspirin** to an already subtherapeutic **warfarin** regimen would increase the **bleeding risk** without correcting the underlying problem of inadequate **INR** for **atrial fibrillation**. - Antiplatelet therapy with **aspirin** is not a substitute for therapeutic anticoagulation with a vitamin K antagonist in the management of **atrial fibrillation**.
Question 138: A 16-year-old girl presents to the emergency department with a 6-hour history of severe headache, fever, vomiting, and photophobia. She is drowsy but responds to voice. Her flatmates mention she had cold symptoms a few days ago. On examination: temperature 38.9°C, heart rate 125/min, blood pressure 100/65 mmHg, GCS 13/15, positive neck stiffness, no rash, no focal neurological signs. CT head is normal. What is the most appropriate next step in management?
- A. Perform lumbar puncture immediately before starting antibiotics
- B. Administer intravenous ceftriaxone and dexamethasone, then perform lumbar puncture (Correct Answer)
- C. Administer intravenous aciclovir only and perform lumbar puncture
- D. Start oral antibiotics and discharge with safety netting advice
- E. Arrange urgent MRI brain before any treatment
Explanation: ***Administer intravenous ceftriaxone and dexamethasone, then perform lumbar puncture*** - In suspected **bacterial meningitis**, immediate administration of **intravenous antibiotics** is crucial and should not be delayed by diagnostic procedures once contraindications like raised intracranial pressure are ruled out by a normal CT head and absence of focal neurological signs. - **Dexamethasone** is given concurrently with or just before the first dose of antibiotics to reduce inflammation and the risk of **neurological complications** such as hearing loss. *Perform lumbar puncture immediately before starting antibiotics* - While a **lumbar puncture** is essential for definitive diagnosis and identifying the causative organism, delaying antibiotic treatment in a patient with a **GCS of 13**, fever, neck stiffness, and signs of sepsis could lead to increased morbidity and mortality. - **Blood cultures** should be drawn, but **empiric antibiotics** must be started within the 'golden hour' for suspected bacterial meningitis. *Administer intravenous aciclovir only and perform lumbar puncture* - **Aciclovir** is an antiviral agent primarily used for **herpes simplex encephalitis**. While viral meningitis can present similarly, the rapid progression, high fever, and significant meningeal signs warrant broad-spectrum bacterial coverage as the priority. - Relying solely on aciclovir without bacterial coverage in a patient with suspected bacterial meningitis could be fatal, as bacterial meningitis is a medical emergency requiring prompt and aggressive antibiotic therapy. *Start oral antibiotics and discharge with safety netting advice* - This patient presents with severe symptoms including **drowsiness** (GCS 13), **photophobia**, **neck stiffness**, and signs of **systemic inflammatory response** (fever, tachycardia, hypotension), indicating a severe infection requiring urgent inpatient management. - **Oral antibiotics** are insufficient to treat severe infections like meningitis due to poor penetration into the **cerebrospinal fluid** and inadequate systemic levels. *Arrange urgent MRI brain before any treatment* - An **urgent CT head** has already been performed and is normal, effectively ruling out mass lesions, hydrocephalus, or significant cerebral edema that would contraindicate an immediate lumbar puncture or necessitate delayed treatment. - Waiting for an **MRI brain** would cause a critical delay in administering life-saving antibiotics for suspected bacterial meningitis, which is a time-sensitive emergency.
Question 139: A 29-year-old pregnant woman at 20 weeks gestation is diagnosed with active pulmonary tuberculosis. Sputum microscopy is positive for acid-fast bacilli, and GeneXpert MTB/RIF confirms rifampicin-sensitive Mycobacterium tuberculosis. She is otherwise well with normal liver function. What is the most appropriate anti-tuberculosis treatment regimen for this patient?
- A. Rifampicin, isoniazid, and ethambutol for 2 months, then rifampicin and isoniazid for 4 months (Correct Answer)
- B. Delay treatment until after delivery
- C. Rifampicin, isoniazid, pyrazinamide, and ethambutol for 2 months, then rifampicin and isoniazid for 4 months
- D. Rifampicin and isoniazid for 9 months
- E. Isoniazid and ethambutol for 18 months
Explanation: ***Rifampicin, isoniazid, and ethambutol for 2 months, then rifampicin and isoniazid for 4 months*** - This regimen is the standard recommended treatment for **active pulmonary tuberculosis** in **pregnant women** with drug-sensitive TB, especially in regions where pyrazinamide is typically avoided due to limited safety data. - **Ethambutol** is included in the intensive phase to ensure adequate coverage and prevent resistance. **Pyridoxine (Vitamin B6)** supplementation is crucial to prevent **isoniazid-induced peripheral neuropathy**. *Delay treatment until after delivery* - **Delaying treatment** for active pulmonary tuberculosis in pregnancy poses significant risks, including disease progression in the mother, increased maternal and fetal morbidity, and potential for **congenital tuberculosis** in the neonate. - The benefits of treating active TB far outweigh the risks associated with **anti-TB medications** during pregnancy. Prompt treatment is crucial to protect both mother and child. *Rifampicin, isoniazid, pyrazinamide, and ethambutol for 2 months, then rifampicin and isoniazid for 4 months* - While this is the standard initial regimen for **non-pregnant adults** with drug-sensitive TB, **pyrazinamide** is generally **avoided during pregnancy** in some guidelines due to insufficient data on its **teratogenicity**, despite some international bodies considering it safe. - Choosing a regimen without pyrazinamide in pregnancy, but including ethambutol, is a common cautious approach to reduce theoretical fetal risks, especially when rifampicin sensitivity is confirmed. *Rifampicin and isoniazid for 9 months* - A **two-drug regimen** for the entire duration is generally considered **inadequate** for treating active pulmonary tuberculosis, as it increases the risk of **treatment failure** and the development of **drug resistance**. - An intensive phase with at least **three drugs** (including ethambutol in this case, due to pregnancy considerations) is essential to rapidly reduce the bacterial load and prevent resistance. *Isoniazid and ethambutol for 18 months* - This regimen **omits rifampicin**, a critically important and potent **bactericidal drug** that significantly shortens the duration of TB treatment. Without rifampicin, treatment effectiveness is severely compromised. - An 18-month duration is excessively long for **rifampicin-sensitive TB** and is typically reserved for more complex cases, such as **multidrug-resistant TB (MDR-TB)**, which is not indicated here.
Question 140: A 67-year-old man with type 2 diabetes mellitus presents with a 4-day history of fever, confusion, and photophobia. CT head shows no mass lesion or raised intracranial pressure. Lumbar puncture reveals: white cells 1850 cells/mm³ (92% neutrophils), protein 2.8 g/L, glucose 1.2 mmol/L (plasma 8.5 mmol/L). Blood cultures and CSF Gram stain show Gram-positive diplococci. He has documented severe penicillin allergy (anaphylaxis). What is the most appropriate antimicrobial therapy?
- A. Intravenous ceftriaxone and dexamethasone
- B. Intravenous vancomycin, rifampicin, and dexamethasone (Correct Answer)
- C. Intravenous meropenem and dexamethasone
- D. Intravenous chloramphenicol and dexamethasone
- E. Intravenous ciprofloxacin and dexamethasone
Explanation: ***Intravenous vancomycin, rifampicin, and dexamethasone*** - Given the patient's documented **anaphylaxis** to penicillin, beta-lactam antibiotics like cephalosporins and carbapenems are contraindicated due to the risk of **cross-reactivity**. - **Vancomycin** provides coverage for **Gram-positive diplococci** (*Streptococcus pneumoniae*), and **rifampicin** is added to enhance CSF penetration and provide synergistic activity, especially important with variable vancomycin CSF levels and potential resistance. **Dexamethasone** is standard adjunctive therapy. *Intravenous ceftriaxone and dexamethasone* - **Ceftriaxone** is a third-generation cephalosporin, which is a beta-lactam antibiotic and carries a significant risk of **cross-reactivity** in patients with severe penicillin allergy (anaphylaxis). - While it is a standard first-line treatment for bacterial meningitis, it must be avoided in this patient to prevent a potentially fatal **allergic reaction**. *Intravenous meropenem and dexamethasone* - **Meropenem** is a carbapenem, another class of beta-lactam antibiotics, which also carries a risk of **cross-reactivity** with penicillin, particularly in cases of anaphylaxis. - Therefore, it is not a safe or appropriate alternative for treating bacterial meningitis in a patient with a documented severe penicillin allergy. *Intravenous chloramphenicol and dexamethasone* - Although **chloramphenicol** has good **CSF penetration** and activity against *S. pneumoniae*, its use is largely limited due to severe adverse effects, notably **bone marrow suppression** (aplastic anemia). - It is generally reserved for situations where other safer and equally effective options are unavailable, which is not the case here with vancomycin/rifampicin. *Intravenous ciprofloxacin and dexamethasone* - **Ciprofloxacin**, a fluoroquinolone, generally has **suboptimal bactericidal activity** against *Streptococcus pneumoniae* in the context of meningitis. - It is not considered a reliable first-line agent for pneumococcal meningitis due to concerns about achieving adequate **CSF concentrations** and its efficacy against high bacterial loads.
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