Infectious Diseases

Infectious Diseases Indian Medical PG Question 1: The web-based IT system for case-based surveillance under National Tuberculosis Elimination Programme (NTEP, formerly RNTCP) is

• A. NIKSHAY (Correct Answer)
• B. E-TB Tracker
• C. SURAKSHA
• D. SAFETY-NET

Infectious Diseases Explanation: ***NIKSHAY*** - **NIKSHAY** is the official web-based IT system used by the National Tuberculosis Elimination Programme (NTEP, formerly RNTCP) in India for **case-based surveillance** and monitoring of TB cases. - Launched in 2012, it facilitates **real-time data entry**, tracking of patient outcomes, drug logistics management, and program monitoring, significantly improving the efficiency of TB control efforts. - It enables **notification of all TB cases**, both from public and private sectors, ensuring comprehensive surveillance. *E-TB Tracker* - **E-TB Tracker** is not the designated IT system for TB surveillance under NTEP in India. - This term may refer to other electronic tracking systems used in different contexts, but NIKSHAY remains the official platform for India's TB programme. *SURAKSHA* - **SURAKSHA** means safety or protection in Hindi and is not associated with any specific web-based IT system for TB surveillance under NTEP. - This is not a recognized TB surveillance platform in the Indian context. *SAFETY-NET* - **SAFETY-NET** is a generic term referring to social protection programs or health support systems. - There is no specific NTEP initiative for TB surveillance identified by this name.

Infectious Diseases Indian Medical PG Question 2: A 15-year-old boy presented with fever and chills for 3 days. On examination, he was found to have delayed skin pinch time and dry oral mucosa. Identify the pathogen involved based on the provided peripheral blood smear image.

• A. Babesia
• B. Plasmodium vivax (Correct Answer)
• C. Plasmodium falciparum
• D. Salmonella typhi

Infectious Diseases Explanation: ***Plasmodium vivax*** - The image shows **enlarged red blood cells** infected with various stages of *Plasmodium vivax*, including trophozoites and schizonts displaying **ameboid forms**. - The presence of **Schüffner's dots**, though not distinctly visible in this specific resolution, is characteristic of *P. vivax* infection. - *P. vivax* preferentially infects **reticulocytes** and young red blood cells, leading to the characteristic RBC enlargement. *Babesia* - *Babesia* infection typically presents with **ring forms** in red blood cells that lack pigment and often form **tetrads** (Maltese cross appearance), which are not seen here. - While it can cause fever and chills, the morphology of the parasites in the image is inconsistent with *Babesia*. *Plasmodium falciparum* - *P. falciparum* characteristically presents with **multiple small ring forms** in a single red blood cell and **crescent-shaped gametocytes**. - It infects red blood cells of all ages, does not typically enlarge the red blood cells, and early trophozoites (*ring forms*) are the most common stage seen in peripheral blood, which differs from the image. *Salmonella typhi* - *Salmonella typhi* is a bacterium that causes **typhoid fever** and is a systemic infection. - It does not infect red blood cells or present with intraerythrocytic parasites on a peripheral blood smear; diagnosis is typically made by **blood culture**.

Infectious Diseases Indian Medical PG Question 3: A man with chills, fever, and headache is thought to have "atypical" pneumonia. History reveals that he raises chickens, and that approximately 2 weeks ago he lost a large number of them to an undiagnosed disease. Which of the following is the most likely diagnosis of this man's condition?

• A. Leptospirosis
• B. Relapsing fever
• C. Anthrax
• D. Ornithosis (Correct Answer)

Infectious Diseases Explanation: ***Ornithosis*** - The patient's symptoms of **chills, fever, headache, and atypical pneumonia**, combined with a history of **raising chickens** that recently died from an undiagnosed disease, are highly suggestive of ornithosis (also known as **psittacosis** or **parrot fever**). [2], [3] - This zoonotic infection is caused by **Chlamydophila psittaci** and is transmitted to humans through inhalation of contaminated aerosols from infected birds (poultry, parrots, pigeons). [2] *Leptospirosis* - **Leptospirosis** is typically associated with exposure to **contaminated water or soil** with animal urine, not direct contact with sick poultry. - While it can cause fever and headache, it often presents with **jaundice, renal failure, and hemorrhagic manifestations**, which are not mentioned here. *Relapsing fever* - **Relapsing fever** is characterized by **recurrent episodes of fever** separated by afebrile periods, caused by **Borrelia** species transmitted by lice or ticks. - The clinical presentation does not align with the typical course or epidemiological link to sick chickens. *Anthrax* - **Inhalational anthrax** can cause severe respiratory symptoms and fever but is primarily associated with exposure to **Bacillus anthracis spores**, often from infected livestock (cattle, sheep) or bioweapon exposure. [1] - The rapid death of a large number of chickens and the patient's "atypical pneumonia" do not fit the typical presentation or common transmission routes of anthrax. [1]

Infectious Diseases Indian Medical PG Question 4: Match List-I with List-II and select the correct answer using the code given below the Lists:

• A. A→4 B→3 C→2 D→1 (Correct Answer)
• B. A→1 B→3 C→2 D→4
• C. A→1 B→2 C→3 D→4
• D. A→4 B→2 C→3 D→1

Infectious Diseases Explanation: ***A→4 B→3 C→2 D→1*** - A **symposium** (A) is characterized by a "discussion among the speakers" (4), where experts present different aspects of a topic, followed by interaction. - A **panel discussion** (B) involves a "series of speeches on a selected subject" (3) by panel members in front of an audience, often with interaction moderated by a chairperson. - A **workshop** (C) typically focuses on "arriving at a plan of action to solve the problem" (2) through practical, hands-on activities and collaborative problem-solving. - **Role-play** (D) is a technique where a "situation is dramatized" (1) by participants acting out roles to understand different perspectives or practice new skills. *A→1 B→3 C→2 D→4* - This option incorrectly matches "Symposium" with "Situation is dramatized" and "Role-play" with "Discussion among the speakers". - Role-play is about dramatizing a situation, while a symposium involves discussion among speakers. *A→1 B→2 C→3 D→4* - This option misaligns multiple matches, particularly with "Symposium" (A) and "Workshop" (C). - A workshop is about action plans, and a symposium is about discussions among speakers, not the other way around. *A→4 B→2 C→3 D→1* - This option incorrectly matches "Panel discussion" with "Arriving at a plan of action to solve the problem" and "Workshop" with "Series of speeches on a selected subject". - Workshops focus on action plans, and panel discussions involve a series of speeches.

Infectious Diseases Indian Medical PG Question 5: A patient with advanced HIV presents with cryptococcal meningitis. Which CSF finding is most characteristic?

• A. High opening pressure (Correct Answer)
• B. High protein
• C. Low glucose
• D. Neutrophilic pleocytosis

Infectious Diseases Explanation: ***High opening pressure*** - **Elevated intracranial pressure** is a hallmark of cryptococcal meningitis, often due to the **fungal burden** and associated inflammatory response, leading to impaired CSF outflow [1]. - This symptom is crucial for both diagnosis and management, as persistently high pressure can cause **neurological damage** and vision loss. *High protein* - While CSF protein can be mildly elevated in cryptococcal meningitis, it is **not the most characteristic finding** compared to the dramatic increase seen in bacterial meningitis [1]. - Protein levels typically increase with inflammation and breakdown of the **blood-brain barrier**, but less significantly than other findings in cryptococcal infection. *Low glucose* - **Low CSF glucose** (hypoglycorrhachia) is more typical of **bacterial meningitis** due to bacterial consumption of glucose. - In cryptococcal meningitis, glucose levels can be normal or mildly decreased, but **not as consistently low** as in bacterial infections. *Neutrophilic pleocytosis* - **Neutrophilic pleocytosis** (predominance of neutrophils) is a classic finding in **acute bacterial meningitis** [1]. - Cryptococcal meningitis typically presents with a **lymphocytic or mixed pleocytosis**, not neutrophilic, reflecting a more chronic or fungal inflammatory response.

Infectious Diseases Indian Medical PG Question 6: A 25-year-old woman presents with a sudden onset of high fever, chills, and rigors. Blood cultures are pending. What is the next appropriate step in her management?

• A. Administer broad-spectrum antibiotics (Correct Answer)
• B. Wait for blood culture results
• C. Start antipyretic therapy only
• D. Order a CT scan

Infectious Diseases Explanation: ***Administer broad-spectrum antibiotics*** - The patient presents with classic signs of **sepsis** (high fever, chills, rigors), which is a medical emergency requiring prompt intervention [2]. - **Early administration of broad-spectrum antibiotics** is crucial to improve outcomes and reduce mortality in suspected sepsis, even before culture results are available [1]. *Wait for blood culture results* - Delaying antibiotic treatment in a patient with suspected sepsis can lead to rapid clinical deterioration and increased mortality [1]. - While blood cultures are essential to guide definitive therapy, initial empiric broad-spectrum antibiotics should not be withheld [3]. *Start antipyretic therapy only* - Antipyretics only address the symptom of fever and do not treat the underlying infection causing the fever and chills. - This approach would leave the potentially life-threatening infection untreated, leading to worsening patient condition. *Order a CT scan* - A CT scan is not the immediate priority in a patient presenting with acute signs of systemic infection and suspected sepsis. - While it may be useful later to identify a source of infection, controlling the infection with antibiotics is the most urgent step.

Infectious Diseases Indian Medical PG Question 7: Which of the following is a primary cause of decreased glucose levels in CSF?

• A. TB meningitis
• B. Fungal meningitis
• C. Viral meningitis
• D. Bacterial meningitis (Correct Answer)

Infectious Diseases Explanation: ***Bacterial meningitis*** - **Bacteria** actively consume glucose for their rapid metabolic needs and proliferation within the cerebrospinal fluid (CSF). - The inflammatory process in bacterial meningitis also increases the **metabolism of glucose** by host cells and leukocytes in the CSF [1]. *TB meningitis* - While TB meningitis can cause decreased CSF glucose, the reduction is usually **less severe and slower** in onset compared to bacterial meningitis. - The causative agent, *Mycobacterium tuberculosis*, has a **slower metabolic rate** and growth compared to typical bacterial pathogens. *Fungal meningitis* - Fungi can consume glucose from the CSF, leading to decreased levels, but this is generally **less pronounced** and develops more chronically than in acute bacterial infections. - Fungal infections in the CSF are often **insidious** and progress slowly, leading to a more gradual consumption of glucose. *Viral meningitis* - In viral meningitis, **CSF glucose levels are typically normal**, or only slightly decreased [1], [2]. - Viruses are intracellular parasites and do not consume glucose from the CSF in the same way that bacteria or fungi do [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 708-711. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1274-1275.

Infectious Diseases Indian Medical PG Question 8: What does the term 'pathology' specifically refer to in medical science?

• A. The examination of bodily functions
• B. The details of disease processes
• C. The explanation of disease mechanisms
• D. The study of diseases and their effects on the body (Correct Answer)

Infectious Diseases Explanation: ***Work*** - **Pathology** focuses on the **study of disease processes** [1,2], which encompasses how diseases affect the body's function and behavior. - It refers to the **work** carried out by scientists and clinicians in understanding the **mechanisms** and effects of diseases [1]. *Details* - While pathology does involve details, it specifically investigates **disease processes** rather than just presenting details [2]. - The term does not simply mean parts or pieces, but rather the comprehensive examination of **functional impairments** due to disease. *Explains* - Although pathology seeks to explain disease mechanisms, the term more accurately describes the **field of study** rather than the act of explaining itself [1]. - It encompasses methodologies and principles, rather than merely serving as an explanation of conditions. *Function* - The term "function" generally refers to the normal activities of an organism, while pathology studies **dysfunction** inherent in disease. - It highlights **what goes wrong** rather than focusing solely on functional attributes in health [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 22-23. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Cellular Responses to Stress and Toxic Insults: Adaptation, Injury, and Death, p. 43.

Infectious Diseases Indian Medical PG Question 9: Necrotizing granulomatous inguinal lymphadenopathy is caused by which of the following?

• A. Syphilis (Correct Answer)
• B. Granuloma inguinale
• C. Sarcoidosis
• D. All of the above

Infectious Diseases Explanation: **Explanation:** The correct answer is **Syphilis (Option A)**. In the primary and secondary stages of Syphilis (caused by *Treponema pallidum*), the regional lymph nodes (inguinal) typically show non-specific lymphadenitis. However, in some cases, particularly in the tertiary stage or as a specific immune response, syphilis can present with **necrotizing granulomatous inflammation**. Histologically, these are characterized by "gummas"—central zones of coagulative necrosis surrounded by mononuclear cells, plasma cells (a hallmark of syphilis), and fibroblasts [2]. The presence of obliterative endarteritis in the surrounding vessels is a key diagnostic clue [1]. **Why other options are incorrect:** * **Granuloma Inguinale (Donovanosis):** Caused by *Klebsiella granulomatis*, this condition is characterized by chronic spreading ulcerations. Histologically, it shows **pseudoepitheliomatous hyperplasia** and the presence of **Donovan bodies** (intracytoplasmic inclusions in macrophages) rather than necrotizing granulomas. * **Sarcoidosis:** While sarcoidosis is a classic granulomatous disease, it characteristically produces **non-caseating (non-necrotizing)** granulomas. Furthermore, it rarely presents as isolated inguinal lymphadenopathy; it more commonly involves hilar lymph nodes and the lungs. **High-Yield Clinical Pearls for NEET-PG:** * **Plasma cell infiltration** is the histological "signature" of syphilitic lesions [2]. * **Lymphogranuloma Venereum (LGV):** Often confused with this topic, LGV (caused by *Chlamydia trachomatis* L1-L3) causes "Stellate abscesses" within the lymph nodes [3]. * **Cat-scratch disease** also causes necrotizing granulomas in lymph nodes, but these are typically axillary or cervical and show a characteristic "stellate" (star-shaped) necrotic center. * **Silver stains (Warthin-Starry)** are used to visualize the spirochetes in syphilitic tissues [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 388-389. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 386-388. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 504-505.

Infectious Diseases Indian Medical PG Question 10: What is the mechanism of acute rheumatic fever?

• A. Cross-reactivity with endogenous antigen (Correct Answer)
• B. Innocent bystander effect
• C. Due to toxin secretion by streptococci
• D. Release of pyrogenic cytokines

Infectious Diseases Explanation: ### Explanation **Correct Answer: A. Cross-reactivity with endogenous antigen** The pathogenesis of Acute Rheumatic Fever (ARF) is based on the concept of **Molecular Mimicry** (Type II Hypersensitivity). Following an infection with **Group A Beta-Hemolytic Streptococci (GABHS)**, the body produces antibodies against the streptococcal **M-protein** [1]. Because the M-protein shares structural homology with human molecules, these antibodies "cross-react" with endogenous antigens [2]. Specifically, they target **cardiac myosin**, sarcolemmal membrane proteins, and valvular glycoproteins, leading to the characteristic inflammatory lesions (Aschoff bodies) in the heart [1]. **Analysis of Incorrect Options:** * **B. Innocent bystander effect:** This refers to tissue damage where healthy cells are destroyed during an immune response against a nearby pathogen (often seen in Type III hypersensitivity or viral infections). ARF is a direct autoimmune attack due to structural similarity, not collateral damage. * **C. Due to toxin secretion:** While streptococci produce toxins (like Streptolysin O or Erythrogenic toxin), these cause direct tissue damage (e.g., Scarlet Fever or Toxic Shock Syndrome) rather than the delayed, immune-mediated multi-system inflammation seen in ARF. * **D. Release of pyrogenic cytokines:** While cytokines mediate the resulting fever and inflammation, they are the *mediators* of the response, not the primary *mechanism* of disease initiation. **High-Yield Clinical Pearls for NEET-PG:** * **Latent Period:** ARF typically occurs 2–3 weeks after streptococcal pharyngitis (never after skin infections like impetigo). * **Jones Criteria:** Diagnosis is clinical, requiring 2 Major or 1 Major + 2 Minor criteria plus evidence of preceding GABHS infection. * **Pathognomonic Feature:** **Aschoff bodies** (granulomatous foci) containing **Anitschkow cells** ("caterpillar cells" with condensed chromatin) [1]. * **Most Common Valve Involved:** Mitral valve (Mitral Regurgitation in acute phase; Mitral Stenosis in chronic phase). **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 566. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 65-66.

Infectious Diseases Flashcard 1 of 10

Question: According to Ridley's logarithmic scale for bacterial index, _____ rating is >1000 bacilli, on average, in each oil-immersion field

Answer: 6+

Infectious Diseases Flashcard 2 of 10

Question: Dissemination of _____ from the lungs is most likely to occur in the skin and bones

Answer: Blastomycosis

Infectious Diseases Flashcard 3 of 10

Question: According to Ridley's logarithmic scale for bacterial index, _____ rating is 100-1000 bacilli, on average, in each oil-immersion field

Answer: 5+

Infectious Diseases Flashcard 4 of 10

Question: In certain infections like _____ bacteria the cellular infiltrate is dominated by continuously recruited neutrophils for several days

Answer: Pseudomonas

Infectious Diseases Flashcard 5 of 10

Question: Paths of Progression after Primary Mycobacteria tuberculosis infection: _____ infection aka miliary tuberculosis

Answer: disseminated/systemic

Infectious Diseases Flashcard 6 of 10

Question: Malakoplakia is seen in chronic bacterial infection, mostly by _____

Answer: Escherichia coli

Infectious Diseases Flashcard 7 of 10

Question: Invasion of microbes is seen in the stage of _____ of ASOM

Answer: pre suppuration

Infectious Diseases Flashcard 8 of 10

Question: _____ is a Rickettsial disease that presents with monocytes with morulae in their cytoplasm.

Answer: Ehrlichiosis

Infectious Diseases Flashcard 9 of 10

Question: 764efae429d34dfaaf5c4ff129c5640b-ao-1

Answer: samples for CBNAAT

Extra Information: 

Infectious Diseases Flashcard 10 of 10

Question: 9b73b326df1f48018198c53149c5274e-ao-2

Answer: sputum grading for TB under microscope

Extra Information: