Tuberculosis — MCQs

10 questions

A 62-year-old man with diabetes presents with a foot ulcer and fever. X-ray shows bone destruction. Blood cultures grow Staphylococcus aureus. What is the recommended antibiotic duration?

A 26-year-old man presents with acute onset severe headache, fever, and neck stiffness. This shows lymphocytic pleocytosis with normal glucose. HSV PCR is positive. What is the most appropriate treatment?

A 22-year-old student presents with fever, headache, and a petechial rash on her legs. CSF shows: protein 2.1 g/L, glucose 1.8 mmol/L (serum 5.2), WCC 850 (90% neutrophils). What is the most likely organism?

A 37-year-old man presents with acute onset severe headache, fever, and neck stiffness. Lumbar puncture shows lymphocytic pleocytosis with normal glucose. HSV PCR is positive. What is the most appropriate treatment?

A 65-year-old man with diabetes presents with a non-healing foot ulcer for 3 months. X-ray shows osteolytic changes in the underlying bone. MRI confirms osteomyelitis. What is the most appropriate treatment duration for antibiotics?

A 58-year-old woman with diabetes presents with severe foot pain and a deep ulcer exposing bone. X-ray shows osteolytic changes. What is the most likely complication?

A 19-year-old student presents with fever, headache, and a non-blanching purpuric rash on his legs. Lumbar puncture shows: WCC 2000/μL (95% neutrophils), protein 3.2 g/L, glucose 1.0 mmol/L. Gram stain shows gram-negative diplococci. What is the most appropriate treatment?

Q10

A 35-year-old man with HIV infection (CD4 count 80 cells/mm³, viral load 125,000 copies/mL, not on antiretroviral therapy) presents with a 4-week history of headache, fever, and confusion. CT head shows basal meningeal enhancement and multiple small nodules. Lumbar puncture shows: opening pressure 32 cmH2O, CSF white cells 45/mm³ (80% lymphocytes), protein 1.2 g/L, glucose 1.9 mmol/L (serum glucose 5.4 mmol/L). India ink stain is positive. Cryptococcal antigen is positive in both CSF and serum at titres of 1:2048 and 1:1024 respectively. He is started on liposomal amphotericin B and flucytosine. Which one of the following additional interventions has been shown to improve survival in this patient?

Tuberculosis UK Medical PG Practice Questions and MCQs

Question 1: A 62-year-old man with diabetes presents with a foot ulcer and fever. X-ray shows bone destruction. Blood cultures grow Staphylococcus aureus. What is the recommended antibiotic duration?

A. 2 weeks
B. 4 weeks
C. 6 weeks
D. 8-12 weeks (Correct Answer)
E. 6 months

Explanation: ***8-12 weeks***- This prolonged duration is typically recommended for **diabetic foot osteomyelitis (DFO)**, especially when complicated by **Staphylococcus aureus bacteremia** and radiographic evidence of **bone destruction**.- The extended treatment ensures adequate eradication of bacteria from the poorly vascularized bone, which is crucial in diabetic patients prone to **recurrence**.*2 weeks*- This duration is vastly insufficient for established **osteomyelitis**, which requires prolonged therapy due to poor antibiotic penetration into bone and the potential for **biofilm** formation.- A 2-week course is generally reserved for uncomplicated **soft tissue infections** or **cellulitis**, not for deep bone infections with systemic involvement.*4 weeks*- While sometimes used for acute, uncomplicated osteomyelitis without extensive bone involvement, **4 weeks** is typically inadequate for severe cases like **DFO** with **bacteremia** and significant **bone destruction**.- In such complex scenarios, a shorter course significantly increases the risk of **treatment failure** and **relapse**.*6 weeks*- **6 weeks** is considered the standard minimum duration for acute, uncomplicated osteomyelitis, particularly after successful **surgical debridement** of infected bone.- However, for complicated DFO with **S. aureus bacteremia** and significant bone destruction, a longer course, often up to 12 weeks, is frequently necessary, especially if debridement is limited.*6 months*- This exceptionally long duration is generally reserved for very specific, highly refractory infections, such as **tuberculosis osteomyelitis**, or for chronic suppressive therapy in certain **prosthetic joint infections**.- It is typically excessive for **Staphylococcus aureus** DFO when managed with appropriate initial therapy and a standard prolonged course (8-12 weeks).

Question 2: A 26-year-old man presents with acute onset severe headache, fever, and neck stiffness. This shows lymphocytic pleocytosis with normal glucose. HSV PCR is positive. What is the most appropriate treatment?

A. IV aciclovir (Correct Answer)
B. IV ceftriaxone
C. IV ampicillin
D. Supportive care only
E. IV immunoglobulin

Explanation: ***IV aciclovir***- The positive **HSV PCR** confirms Herpes Simplex Virus encephalitis/meningitis, which requires immediate high-dose IV **aciclovir** to prevent severe neurological damage or death.- Aciclovir inhibits viral **DNA synthesis** and is the specific, life-saving antiviral treatment for HSV **meningoencephalitis**.*IV ceftriaxone*- **Ceftriaxone** is a broad-spectrum antibiotic used to cover common causes of **bacterial meningitis** (*S. pneumoniae*, *N. meningitidis*).- It is ineffective against a viral infection confirmed by a positive **HSV PCR**.*IV ampicillin*- **Ampicillin** is typically added to empiric bacterial regimens to cover **Listeria monocytogenes**, particularly in immunocompromised or older patients.- It provides no specific or therapeutic benefit against **Herpes Simplex Virus**.*Supportive care only*- HSV encephalitis is a medical emergency with high mortality and morbidity; definitive antiviral therapy is mandatory, not just **supportive care**.- While supportive care (e.g., fever management) is necessary, it cannot eradicate the highly destructive **HSV viral load** in the central nervous system.*IV immunoglobulin*- **IV immunoglobulin (IVIg)** is generally used for autoimmune, inflammatory conditions (like Guillain-Barré) or certain immunodeficiencies.- It has no proven role in the primary treatment or eradication of acute **HSV CNS infection**.

Question 3: A 22-year-old student presents with fever, headache, and a petechial rash on her legs. CSF shows: protein 2.1 g/L, glucose 1.8 mmol/L (serum 5.2), WCC 850 (90% neutrophils). What is the most likely organism?

A. Streptococcus pneumoniae
B. Neisseria meningitidis (Correct Answer)
C. Haemophilus influenzae
D. Listeria monocytogenes
E. Enterovirus

Explanation: ***Neisseria meningitidis***- The classic presentation of fever, headache, and a **petechial rash** (indicating **meningococcemia**) in a young adult is highly characteristic of *Neisseria meningitidis* infection.- The CSF profilehigh protein, **low glucose** (low CSF/serum ratio), and **high white cell count** with **predominantly neutrophils** (90%)-is consistent with acute bacterial meningitis caused by this organism.*Streptococcus pneumoniae*- While *Streptococcus pneumoniae* is a common cause of bacterial meningitis with a similar CSF profile (high protein, low glucose, neutrophilic pleocytosis), it is less typically associated with a fulminant **petechial rash**.- This organism often affects extremes of age (very young or elderly) or individuals with specific risk factors such as **pneumonia**, **otitis media**, or **CSF leaks**.*Haemophilus influenzae*- *Haemophilus influenzae* type b (HiB) was a major cause of meningitis in **unvaccinated children** before widespread vaccination, making it less common in immunocompetent young adults.- Although it can cause bacterial meningitis with similar CSF findings, the striking **petechial rash** and patient's age make *Neisseria meningitidis* a more likely diagnosis.*Listeria monocytogenes*- *Listeria monocytogenes* typically causes meningitis in specific vulnerable populations, including **neonates**, the **elderly**, pregnant women, or the **immunosuppressed**.- Given the patient is a healthy 22-year-old student, *Listeria* is a less probable cause compared to *Neisseria meningitidis*.*Enterovirus*- **Enteroviruses** cause **aseptic (viral) meningitis**, which is characterized by a different CSF profile than seen here.- Viral meningitis typically presents with **normal CSF glucose**, normal or mildly elevated protein, and a **lymphocytic pleocytosis** (lymphocyte predominance), which contradicts the 90% neutrophil count in this case.

Question 4: A 37-year-old man presents with acute onset severe headache, fever, and neck stiffness. Lumbar puncture shows lymphocytic pleocytosis with normal glucose. HSV PCR is positive. What is the most appropriate treatment?

A. IV aciclovir (Correct Answer)
B. IV ceftriaxone
C. IV ampicillin
D. Supportive care only
E. IV immunoglobulin

Explanation: ***IV aciclovir*** - The clinical presentation (acute severe headache, fever, neck stiffness) and cerebrospinal fluid (CSF) findings (**lymphocytic pleocytosis**, **normal glucose**) are highly suggestive of **viral meningoencephalitis**. - A positive **HSV PCR** in the CSF confirms **Herpes Simplex Virus (HSV) encephalitis**, a severe and potentially fatal condition that necessitates immediate high-dose intravenous **aciclovir**. *IV ceftriaxone* - Ceftriaxone is an antibiotic primarily used for **bacterial meningitis**, which typically presents with **neutrophilic pleocytosis** and **low CSF glucose**. - It is ineffective against **viral infections** like HSV, making it an inappropriate treatment for confirmed HSV encephalitis. *IV ampicillin* - Ampicillin is another antibiotic used to treat specific forms of **bacterial meningitis**, particularly covering *Listeria monocytogenes*. - It does not have antiviral activity and therefore is not an effective treatment for **HSV encephalitis**. *Supportive care only* - **HSV encephalitis** carries a high risk of mortality and significant neurological sequelae if left untreated with specific antiviral agents. - Relying solely on supportive care is insufficient and would be detrimental in a confirmed case of HSV encephalitis. *IV immunoglobulin* - Intravenous immunoglobulin (IVIG) is typically used in the management of certain **immunodeficiency syndromes** or **autoimmune disorders**. - It has no established role or efficacy in the **acute treatment** of viral encephalitis, including that caused by HSV.

Question 5: A 65-year-old man with diabetes presents with a non-healing foot ulcer for 3 months. X-ray shows osteolytic changes in the underlying bone. MRI confirms osteomyelitis. What is the most appropriate treatment duration for antibiotics?

A. 2 weeks IV
B. 4 weeks IV
C. 6 weeks IV
D. 4-6 weeks IV followed by 2-6 weeks oral
E. 12 weeks total therapy (Correct Answer)

Explanation: ***12 weeks total therapy***- Management of **diabetic foot osteomyelitis (DFO)** often requires **prolonged antibiotic therapy**, typically ranging from **6 to 12 weeks**, especially given the chronicity (3 months non-healing ulcer) and confirmed osteolytic changes.- For **DFO** where surgical debridement is incomplete or non-surgical management is chosen, a **12-week course** maximizes cure rates and prevents recurrence.*2 weeks IV*- This duration is generally too short for established **osteomyelitis**, particularly in a patient with **diabetes** and a **chronic foot ulcer**, which suggests a complex infection.- Such a short course is more appropriate for uncomplicated **soft tissue infections** or as a very brief initial therapy before transitioning to oral in specific, less severe cases, not for confirmed bone infection.*4 weeks IV*- While 4 weeks of IV antibiotics might be considered in some cases of osteomyelitis *after* complete and aggressive surgical resection of all infected bone (e.g., amputation), it is usually insufficient for severe **diabetic foot osteomyelitis** if significant infected bone remains.- This duration is not standard for definitive treatment of **DFO** when managed primarily with antibiotics or limited debridement, as the risk of relapse is high.*6 weeks IV*- A **6-week course** of IV or highly bioavailable oral antibiotics is the standard minimum for most non-diabetic cases of osteomyelitis after successful debridement.- For **diabetic foot osteomyelitis (DFO)**, 6 weeks is the typical minimum *if* extensive surgical debridement or amputation has been performed; however, for extensive or chronic cases without complete debridement, a longer course is often warranted.*4-6 weeks IV followed by 2-6 weeks oral*- This option suggests a total treatment duration of 6 to 12 weeks (4+2=6 to 6+6=12 weeks), which aligns with the overall recommended duration for **DFO**.- However, it emphasizes a prolonged initial IV course, whereas current guidelines often allow for an earlier transition to high-bioavailability *oral* antibiotics, potentially making the "12 weeks total therapy" a more encompassing and accurate statement for this complex scenario without specifying strict IV/oral proportions initially.

Question 6: A 65-year-old man with diabetes presents with a non-healing foot ulcer for 3 months. X-ray shows osteolytic changes in the underlying bone. MRI confirms osteomyelitis. What is the most appropriate treatment duration for antibiotics?

A. 2 weeks IV
B. 4 weeks IV
C. 6 weeks IV
D. 4-6 weeks IV followed by 2-6 weeks oral
E. 12 weeks total therapy (Correct Answer)

Explanation: ***12 weeks total therapy***- The treatment duration for confirmed **diabetic foot osteomyelitis (DFO)** without amputation or with residual infected bone often requires 10–12 weeks or 3 months of total antibiotic therapy (IV and/or oral) to achieve cure and prevent relapse.- Prolonged treatment is crucial because of the **poor vascular supply** in diabetic feet and the low penetration of antibiotics into the avascular, infected bone. *2 weeks IV*- This duration is insufficient for bone infection, as antibiotics require extended time to reach therapeutic concentrations within the **avascular, necrotic bone**.- **Acute uncomplicated cellulitis** or soft tissue infection might be treated in 2 weeks, but not osteomyelitis. *4 weeks IV*- A 4-week course might be considered sufficient only if the infected bone has been completely removed during **surgical debridement** (e.g., partial foot amputation), which is not guaranteed by the prompt.- This duration drastically increases the risk of **relapse** in confirmed, non-surgically cleared osteomyelitis. *6 weeks IV*- This is the standard duration for **vertebral osteomyelitis** or chronic osteomyelitis where adequate surgical debridement was achieved, often substituting for the total 12-week regimen.- However, for conservative management of **DFO**, guidelines often recommend a total of 10–12 weeks (IV and oral) to maximize bone penetration. *4-6 weeks IV followed by 2-6 weeks oral*- While this combination (totaling 6–12 weeks) is a common strategy, it is less definitive than the 12-week option and can be interpreted as potentially insufficient depending on the chosen duration (e.g., 6 weeks total is too short).- The **IDSA guidelines** often suggest at least 6 weeks following resection of infected bone, but up to 12 weeks is recommended if bone cannot be fully resected or infection is severe.

Question 7: A 37-year-old man presents with acute onset severe headache, fever, and neck stiffness. Lumbar puncture shows lymphocytic pleocytosis with normal glucose. HSV PCR is positive. What is the most appropriate treatment?

A. IV aciclovir (Correct Answer)
B. IV ceftriaxone
C. IV ampicillin
D. Supportive care only
E. IV immunoglobulin

Explanation: ***IV aciclovir*** - The clinical presentation (headache, fever, neck stiffness) combined with **lymphocytic pleocytosis** and **normal glucose** in CSF is highly suggestive of **viral meningoencephalitis**.- The definitive diagnosis of **HSV encephalitis** is confirmed by a **positive HSV PCR** in the CSF, making intravenous aciclovir the essential and life-saving antiviral treatment.*IV ceftriaxone*- **IV ceftriaxone** is a broad-spectrum antibiotic primarily used to treat **bacterial meningitis**, which typically presents with **neutrophilic pleocytosis** and **low CSF glucose**.- It has no efficacy against **viral infections** like HSV and would be inappropriate as a sole treatment given the positive HSV PCR.*IV ampicillin*- **IV ampicillin** is an antibiotic used for bacterial meningitis, particularly effective against **Listeria monocytogenes** and **Streptococcus agalactiae**, but the CSF findings and positive HSV PCR point away from bacterial etiology.- Similar to ceftriaxone, ampicillin is ineffective against **viral pathogens** and would not treat HSV encephalitis.*Supportive care only*- Given the severity and potentially devastating neurological sequelae of **HSV encephalitis**, supportive care alone is completely insufficient and would lead to significant morbidity and mortality.- **HSV encephalitis** requires urgent and specific antiviral therapy to prevent irreversible brain damage.*IV immunoglobulin*- **IV immunoglobulin (IVIG)** is typically used in conditions involving immune dysfunction, such as certain autoimmune diseases or severe infections in immunocompromised patients, but it is not a primary treatment for **acute viral encephalitis**.- While IVIG might have some immunomodulatory effects, it lacks direct antiviral activity against **HSV** and would not address the underlying viral replication causing the encephalitis.

Question 8: A 58-year-old woman with diabetes presents with severe foot pain and a deep ulcer exposing bone. X-ray shows osteolytic changes. What is the most likely complication?

A. Cellulitis
B. Osteomyelitis (Correct Answer)
C. Charcot arthropathy
D. Peripheral arterial disease
E. Deep vein thrombosis

Explanation: ***Osteomyelitis***- The combination of a **deep ulcer exposing bone** and radiologic evidence of **osteolytic changes** strongly indicates infection and destruction of the bone itself.- In patients with **diabetes**, foot ulcers often progress rapidly from soft tissue infection to bone infection due to underlying neuropathy and vascular disease.*Cellulitis*- Cellulitis is a superficial soft tissue infection characterized by erythema, swelling, and warmth, typically without **ulceration exposing bone**.- It affects the dermal and subcutaneous layers and does not cause **osteolytic changes** on X-ray.*Charcot arthropathy*- Charcot foot involves **neuropathic joint destruction** and deformity (e.g., *rocker-bottom* foot), but typically presents with little pain and diffuse bony fragmentation, rather than a localized deep, infected ulcer causing severe pain and lytic changes.- Although common in diabetes, pure Charcot arthropathy is usually sterile; the presence of a deep, draining ulcer points strongly to a progressive infection.*Peripheral arterial disease*- While PAD often contributes to ulcer formation (ischemic ulcers), these ulcers are typically **dry**, **punched-out**, and associated with diminished or absent pedal pulses.- PAD causes ischemia, but the identification of a deep ulcer exposing bone and active **osteolytic changes** points primarily toward a severe, established bone infection.*Deep vein thrombosis*- DVT involves clotting in a deep vein, presenting primarily with **unilateral swelling**, pain, and warmth in the leg (often calf or thigh).- It does not cause localized deep foot ulcers or underlying **osteolytic changes** in the bone.

Question 9: A 19-year-old student presents with fever, headache, and a non-blanching purpuric rash on his legs. Lumbar puncture shows: WCC 2000/μL (95% neutrophils), protein 3.2 g/L, glucose 1.0 mmol/L. Gram stain shows gram-negative diplococci. What is the most appropriate treatment?

A. IV benzylpenicillin
B. IV ceftriaxone (Correct Answer)
C. IV vancomycin
D. IV ampicillin
E. Oral ciprofloxacin

Explanation: ***IV ceftriaxone***- This third-generation cephalosporin is the **first-line treatment** for suspected bacterial meningitis due to its excellent penetration into the **cerebrospinal fluid (CSF)** and broad coverage of common pathogens like *Neisseria meningitidis*.- The clinical presentation (fever, purpura) and CSF findings (Gram-negative diplococci) confirm **meningococcal meningitis**, necessitating immediate, high-dose parenteral antibiotics.*IV benzylpenicillin*- While IV penicillin is effective against penicillin-sensitive *N. meningitidis*, **penicillin resistance** has been reported, making **ceftriaxone** the preferred initial empirical therapy until antimicrobial susceptibilities are known.- It may be used as targeted monotherapy if the organism is confirmed sensitive, but it is not the universally recommended initial empirical agent for severe disease.*IV vancomycin*- Vancomycin is primarily used to cover **multi-drug resistant *Streptococcus pneumoniae*** or **MRSA**, and is typically unnecessary as monotherapy for a Gram-negative infection like *N. meningitidis*.- Although often included in very broad empirical coverage, it would be insufficient alone and is usually added only if co-infection with resistant Gram-positive organisms is highly suspected.*IV ampicillin*- Ampicillin is primarily added to empirical meningitis regimens to cover **Listeria monocytogenes**, which typically causes disease in neonates, the elderly, or those who are **T-cell immunocompromised**.- It is not indicated as the primary treatment agent for meningococcal disease in an otherwise healthy young adult.*Oral ciprofloxacin*- **Oral ciprofloxacin** is used strictly for **chemoprophylaxis** of close contacts exposed to *N. meningitidis*, such as household members or roommates.- It is ineffective and inappropriate for the treatment of established, life-threatening invasive meningococcal disease, which requires high-dose intravenous therapy.

Question 10: A 35-year-old man with HIV infection (CD4 count 80 cells/mm³, viral load 125,000 copies/mL, not on antiretroviral therapy) presents with a 4-week history of headache, fever, and confusion. CT head shows basal meningeal enhancement and multiple small nodules. Lumbar puncture shows: opening pressure 32 cmH2O, CSF white cells 45/mm³ (80% lymphocytes), protein 1.2 g/L, glucose 1.9 mmol/L (serum glucose 5.4 mmol/L). India ink stain is positive. Cryptococcal antigen is positive in both CSF and serum at titres of 1:2048 and 1:1024 respectively. He is started on liposomal amphotericin B and flucytosine. Which one of the following additional interventions has been shown to improve survival in this patient?

A. Commencing antiretroviral therapy immediately alongside antifungal treatment
B. Adding adjunctive dexamethasone 0.4 mg/kg daily for 6 weeks
C. Performing daily therapeutic lumbar punctures until opening pressure normalizes (Correct Answer)
D. Adding adjunctive interferon-gamma to enhance immune response
E. Inserting a ventriculoperitoneal shunt to manage hydrocephalus

Explanation: ***Performing daily therapeutic lumbar punctures until opening pressure normalizes*** - Management of **elevated intracranial pressure** (opening pressure >25 cmH2O) is critical, as it is a major cause of mortality in **cryptococcal meningitis** associated with HIV. - Daily drainage of 20-30 mL of CSF is recommended to achieve an **opening pressure** of <20 cmH2O or a 50% reduction from baseline, which significantly **improves survival** and reduces neurological sequelae. *Commencing antiretroviral therapy immediately alongside antifungal treatment* - **Early initiation of ART** (within 2 weeks) in HIV-associated cryptococcal meningitis is associated with an increased risk of **Immune Reconstitution Inflammatory Syndrome (IRIS)** and higher mortality. - Current guidelines recommend deferring ART for **4 to 6 weeks** after the initiation of induction antifungal therapy to allow for partial clearance of the fungal load and reduce IRIS risk. *Adding adjunctive dexamethasone 0.4 mg/kg daily for 6 weeks* - Routine use of **corticosteroids** is contraindicated in cryptococcal meningitis as they have been shown to **increase mortality** and reduce fungal clearance rates in clinical trials. - Steroids also increase the risk of serious **adverse events** without providing any survival benefit in these patients. *Adding adjunctive interferon-gamma to enhance immune response* - While **interferon-gamma** may facilitate faster fungal clearance in some experimental settings, it has not been shown to provide a **survival benefit** in high-quality clinical trials for HIV-associated cryptococcal meningitis. - It is not currently recommended as part of the **standard induction therapy** for this condition. *Inserting a ventriculoperitoneal shunt to manage hydrocephalus* - **Ventriculoperitoneal (VP) shunts** are generally reserved for patients who fail to respond to repeated **therapeutic lumbar punctures** or develop persistent symptomatic hydrocephalus refractory to medical management. - Although useful for long-term pressure management, it is not the primary or first-line intervention for improving **acute survival** compared to serial lumbar punctures, which are less invasive and carry fewer immediate risks.

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