Most common route of infection in pasteurella cellulitis -
In evaluation of a case of immotile nasal cilia, which of the following investigations should prove useful?
Saddle nose deformity is seen in?
Which of the following statements regarding Pertussis is INCORRECT?
What is the most common form of leptospirosis?
Macular sparing is associated with lesions in:
What is the primary cause of Common Variable Immunodeficiency (CVID)?
ABO non- secretors are more prone to ?
Buboes form is which stage of LGV?
What is the PRIMARY evidence-based intervention for preventing catheter-associated urinary tract infections (CAUTIs)?
NEET-PG 2015 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 41: Most common route of infection in pasteurella cellulitis -
- A. Animal bites or scratches (Correct Answer)
- B. Aerosols or dust
- C. Contaminated tissue
- D. Human to human
Explanation: ***Animal bites or scratches*** - *Pasteurella multocida* is a common commensal bacterium in the oral flora of **cats and dogs**. - **Animal bites or scratches** are the primary mode of transmission for *Pasteurella* infections, particularly cellulitis, due to direct inoculation. *Aerosols or dust* - Transmission via **aerosols or dust** is rare for *Pasteurella* infections, which typically require direct contact or inoculation. - While other bacteria can spread this way, *Pasteurella* cellulitis is not commonly acquired through airborne routes. *Contaminated tissue* - While possible in some contexts, **contaminated tissue** is not the most common route of infection for *Pasteurella* cellulitis. - Direct inoculation from an **animal's oral flora** is far more frequent than contact with contaminated environmental tissues. *Human to human* - *Pasteurella* infections are generally **not transmissible from human to human**. - The organism is primarily associated with animals and their bites or scratches.
Question 42: In evaluation of a case of immotile nasal cilia, which of the following investigations should prove useful?
- A. Rhinogram
- B. Sweat sodium levels
- C. Nitric oxide test (Correct Answer)
- D. Xray nasal and paranasal sinuses
Explanation: Nitric oxide test - A low nasal nitric oxide (nNO) concentration is a key diagnostic criterion for Primary Ciliary Dyskinesia (PCD), a genetic disorder characterized by immotile or dyskinetic cilia [1]. - Nasal NO is significantly reduced in PCD patients due to impaired ciliary function, making this test highly useful for screening. *Rhinogram* - A rhinogram is a radiographic imaging technique primarily used to visualize the nasal cavity and paranasal sinuses, often to detect structural abnormalities or foreign bodies. - It does not directly assess ciliary function or provide information about ciliary motility. *Sweat sodium levels* - Elevated sweat chloride or sodium levels are the diagnostic hallmark of cystic fibrosis, a genetic condition primarily affecting mucus production. - While cystic fibrosis can cause respiratory symptoms, it does not directly lead to immotile nasal cilia in the same manner as PCD. *Xray nasal and paranasal sinuses* - An X-ray of the nasal and paranasal sinuses can reveal structural issues, such as sinus opacification or polyps, which may accompany ciliary dysfunction. - However, it does not provide direct information about the motility or structural integrity of the cilia themselves.
Question 43: Saddle nose deformity is seen in?
- A. Primary Syphilis
- B. Secondary Syphilis
- C. Tertiary Syphilis (Correct Answer)
- D. Lupus Vulgaris
Explanation: ***Tertiary Syphilis*** - **Saddle nose deformity** is a characteristic late manifestation of **tertiary syphilis** due to destructive lesions (gummas) affecting the nasal cartilage and bone [1], [2]. - It results from the **collapse of the nasal bridge**, leading to a flattened appearance [2]. *Primary Syphilis* - Characterized by a **chancre**, a painless ulcer, usually at the site of infection [1]. - This stage does not involve destructive lesions of the nose. *Secondary Syphilis* - Presents with a **widespread rash**, lymphadenopathy, and mucous patches [1]. - While systemic, it typically does not cause structural damage like saddle nose deformity. *Lupus Vulgaris* - This is a **cutaneous form of tuberculosis**, characterized by chronic, destructive skin lesions. - While it can cause facial disfigurement, saddle nose deformity is not a typical feature of lupus vulgaris.
Question 44: Which of the following statements regarding Pertussis is INCORRECT?
- A. The drug of choice is Erythromycin.
- B. Cerebellar ataxia is a known complication. (Correct Answer)
- C. Some infections may be subclinical.
- D. The most infective stage is the catarrhal stage.
Explanation: ***Cerebellar ataxia is a known complication.*** - **Cerebellar ataxia** is not a typical or known complication of pertussis. Complications usually involve the respiratory, neurological (e.g., seizures, encephalopathy due to hypoxia), and nutritional systems due to severe coughing. - While neurological complications can occur, **ataxia** specifically is not frequently sighted in the context of pertussis. *Some infections may be subclinical.* - Some individuals, especially those partially immunized or older, can experience **subclinical or atypical infections** with pertussis, often presenting as a mild cough. - This characteristic makes it difficult to control the spread of the disease as infected individuals may not be recognized. *The most infective stage is the catarrhal stage.* - The **catarrhal stage**, characterized by non-specific cold-like symptoms, is the most contagious phase because bacterial shedding is highest. - During this stage, symptoms are mild and often indistinguishable from a common cold, leading to widespread transmission before diagnosis. *The drug of choice is Erythromycin.* - **Erythromycin**, or other macrolides like azithromycin or clarithromycin, are the drugs of choice for treating pertussis. - These antibiotics are most effective when administered early in the **catarrhal stage** to reduce disease severity and prevent transmission.
Question 45: What is the most common form of leptospirosis?
- A. Icteric form
- B. Hepatorenal form
- C. Anicteric form (Correct Answer)
- D. Weil's disease
Explanation: ***Anicteric form*** - The **anicteric form** accounts for about 90% of all leptospirosis cases, presenting with milder, flu-like symptoms without jaundice. - Patients typically experience **fever, headache, myalgia**, and conjunctival suffusion during the initial septicemic phase [1], followed by an immune phase that can involve meningitis or uveitis [1]. *Icteric form* - The **icteric form** (Weil's disease) is a severe manifestation, characterized by jaundice, renal failure, and hemorrhage, occurring in a minority of cases (5-10%). - Although more severe and often life-threatening, it is **less common** than the anicteric presentation [1]. *Hepatorenal form* - This term describes the severe complications of leptospirosis, including **liver and kidney dysfunction**, specifically associated with Weil's disease. - While a critical aspect of severe leptospirosis, it is a description of the organ involvement rather than a distinct common form of the disease. *Weil's disease* - **Weil's disease** is the most severe and potentially fatal form of leptospirosis, characterized by **jaundice, renal failure, hemorrhage, and myocarditis**. - It is a severe subset of the icteric form, making it a very serious but **uncommon variant** of the overall disease.
Question 46: Macular sparing is associated with lesions in:
- A. Lesions in the optic nerve
- B. Lesions in the lateral geniculate body
- C. Lesions in the occipital cortex (Correct Answer)
- D. Lesions in the optic chiasma
Explanation: ***Lesions in the occipital cortex*** - **Macular sparing** occurs when the central visual field (macula) is preserved despite damage to the occipital cortex, often due to its dual blood supply from the **middle cerebral artery** and the **posterior cerebral artery**. [2] - This phenomenon typically results from a **vascular lesion** in the occipital lobe, leading to a **homonymous hemianopia** with a distinct sparing of the foveal region. [2], [3] *Lesions in the optic nerve* - Lesions in the optic nerve cause **monocular vision loss** or central scotomas, rather than the homonymous visual field defects associated with macular sparing. [2] - Damage here affects the visual pathway **before** the optic chiasm, impacting the entire visual input from one eye. [2] *Lesions in the lateral geniculate body* - Lesions in the **lateral geniculate body (LGB)** produce **contralateral homonymous hemianopia** or quadrantanopia, but typically **do not exhibit macular sparing** as consistently as cortical lesions. - The LGB processes visual information from both eyes before relaying it to the visual cortex. [1] *Lesions in the optic chiasma* - Lesions in the **optic chiasma** classically cause **bitemporal hemianopia**, affecting the temporal visual fields of both eyes. [2] - This type of visual field defect is distinct from the homonymous defects seen with macular sparing, as it results from damage to the **crossing nasal fibers**. [2]
Question 47: What is the primary cause of Common Variable Immunodeficiency (CVID)?
- A. Defective B cell function
- B. Absent B cells
- C. Reduced number of B cells
- D. Defective B cell differentiation (Correct Answer)
Explanation: ***Defective B cell differentiation*** - CVID is characterized primarily by a failure of **B cells** to differentiate into **plasma cells**, which are responsible for producing antibodies [1]. - This defective differentiation leads to **hypogammaglobulinemia**, or low levels of immunoglobulins [1]. *Absent B cells* - Complete absence of B cells is characteristic of severe combined immunodeficiency (SCID) or X-linked agammaglobulinemia (XLA), not CVID [1]. - In CVID, B cells are typically present, but they are dysfunctional. *Reduced number of B cells* - While some patients with CVID may have reduced B cell numbers, this is not the primary or defining defect. - The key issue is the inability of existing B cells to mature and produce antibodies effectively. *Defective B cell function* - While B cell function is indeed defective in CVID, the root cause of this malfunction is specifically the **failure of differentiation** into mature plasma cells. - The B cells are unable to perform their primary function of antibody production due to this arrest in their development.
Question 48: ABO non- secretors are more prone to ?
- A. Increased risk of infections (Correct Answer)
- B. Autoimmune diseases
- C. Cardiovascular diseases
- D. Cancer
Explanation: Increased risk of infections - Non-secretors of ABO antigens exhibit an increased susceptibility to a variety of infections, particularly bacterial and viral pathogens. - This is thought to be due to the absence of ABO antigens in secretions, which typically act as decoy receptors to prevent pathogen adhesion to host cells. Autoimmune diseases - While some associations between ABO blood groups and autoimmune diseases exist, non-secretor status is not consistently linked to a higher overall risk of autoimmune conditions. Cardiovascular diseases - ABO blood groups have been associated with cardiovascular risk, with non-O blood types generally having a slightly higher risk of certain cardiovascular events. - However, secretor status (the ability to secrete ABO antigens into bodily fluids) itself is not a prominent independent risk factor for cardiovascular diseases. Cancer - There are some documented associations between specific ABO blood types and certain types of cancer (e.g., non-O blood types with pancreatic cancer), but this is distinct from secretor status. - Being an ABO non-secretor is not a primary, broadly recognized risk factor for developing cancer.
Question 49: Buboes form is which stage of LGV?
- A. Secondary (Correct Answer)
- B. Tertiary
- C. Latent
- D. Primary
Explanation: ***Secondary*** - Buboes, which are swollen, painful lymph nodes, are a hallmark of the **secondary stage** of **Lymphogranuloma Venereum (LGV)** [1]. - This stage typically develops weeks after the initial infection, following the unnoticed or transient primary lesion. *Primary* - The primary stage of LGV is characterized by a **small, painless papule or ulcer** at the site of inoculation, which often goes unnoticed. - **Buboes are not formed** during this initial, often asymptomatic, phase. *Tertiary* - The tertiary stage of LGV involves **chronic inflammation** and **tissue destruction**, leading to complications like **genital elephantiasis**, rectal strictures, and fistulas. - While there is chronic lymphedema, the acute, painful buboes are characteristic of the secondary stage, not this late, destructive phase. *Latent* - The concept of a latent stage is not typically used to describe the progression of LGV in the same way as other infections like syphilis. - LGV progresses through distinct symptomatic primary, secondary, and potentially tertiary stages without a prolonged asymptomatic latency period between symptom presentations.
Question 50: What is the PRIMARY evidence-based intervention for preventing catheter-associated urinary tract infections (CAUTIs)?
- A. Use of face mask during catheter insertion
- B. Prophylactic antibiotics are effective
- C. Early catheter removal when clinically appropriate
- D. Closed drainage technique to minimize bacterial entry (Correct Answer)
Explanation: ***Closed drainage technique to minimize bacterial entry*** - Maintaining a **closed drainage system** prevents the entry of bacteria into the urinary tract, which is a primary cause of CAUTIs. - This technique involves ensuring the connection between the catheter and the drainage bag remains sealed at all times, minimizing **environmental contamination**. *Prophylactic antibiotics are effective* - **Prophylactic antibiotics** are generally not recommended for routine CAUTI prevention due to concerns about **antibiotic resistance** and limited evidence of effectiveness [1]. - Their use is typically reserved for specific high-risk procedures or patient populations. *Use of face mask during catheter insertion* - While maintaining **asepsis** during catheter insertion is crucial, the use of a face mask specifically addresses **respiratory droplet transmission**, which is not the primary route of bacterial entry into the urinary system during catheterization. - **Sterile gloves** and a **sterile field** are more directly relevant for preventing contamination during insertion [1]. *Early catheter removal when clinically appropriate* - While **early catheter removal** is a critical strategy for CAUTI prevention by reducing dwell time, the question asks for the *primary* evidence-based intervention [1]. A **closed drainage system** directly addresses the mechanism of bacterial entry while the catheter is in place. - Reducing catheter duration minimizes risk, but the closed system ensures safety during the necessary period of catheterization.