Infectious Diseases — MCQs

Infectious Diseases Indian Medical PG Practice Questions and MCQs

Question 251: Abdominal TB can occur through all of the following EXCEPT

A. Direct spread from mesenteric lymph nodes
B. Feco - oral route
C. Direct contact with infected animal (Correct Answer)
D. Hematogenous spread

Explanation: ***Direct contact with infected animal*** - While animal products like **unpasteurized milk** can transmit *Mycobacterium bovis* to humans, direct contact with an infected animal is not a primary mode of transmission for **abdominal TB**. - **Abdominal TB** is usually caused by *Mycobacterium tuberculosis* which is primarily a human pathogen, not typically transmitted through direct contact with animals. *Direct spread from mesenteric lymph nodes* - **Mesenteric lymph nodes** are often involved in abdominal TB, and the infection can directly spread from these nodes to adjacent abdominal organs. - This is a common mechanism for localized propagation within the abdominal cavity. *Feco - oral route* - The **ingestion of contaminated food or milk** (from infected cattle) containing *Mycobacterium bovis* or swallowing of **infected sputum** (from pulmonary TB) containing *Mycobacterium tuberculosis* are common ways the bacteria can reach the gastrointestinal tract. - This leads to primary intestinal infection or reactivation of previously ingested bacteria. *Hematogenous spread* - **Hematogenous dissemination** from a primary pulmonary or other mycobacterial focus is a significant mode of transmission for abdominal TB. - Bacteria can travel through the bloodstream and seed distant abdominal organs, including the **peritoneum**, **intestines**, or **mesenteric lymph nodes**.

Question 252: Which of the following indicators can help determine whether the health system is effective at identifying leprosy cases early in the community?

A. Proportion of newly diagnosed patients with grade 2 disability (Correct Answer)
B. Annual new case detection rate per lac
C. Treatment initiation rate
D. Treatment completion rate

Explanation: ***Proportion of newly diagnosed patients with grade 2 disability*** - A **high proportion of newly diagnosed patients with grade 2 disability** indicates late detection of leprosy, suggesting shortcomings in the health system's ability to identify cases early. - Grade 2 disability in leprosy signifies **visible and irreversible damage** to eyes, hands, or feet, which would likely have been prevented with earlier diagnosis and treatment. *Annual new case detection rate per lac* - The **annual new case detection rate** reflects the number of new cases identified but does not directly indicate the timeliness of detection or the effectiveness of early case-finding efforts. - A high new case detection rate could be due to intensive active case-finding campaigns, but without knowing the disability status at diagnosis, it doesn't confirm early detection by the routine health system. *Treatment initiation rate* - The **treatment initiation rate** measures the percentage of diagnosed patients who start treatment, which is crucial for disease control but does not reflect how early cases are identified. - A high initiation rate indicates good patient adherence to treatment protocols after diagnosis, but not the efficiency of the health system in finding cases before they develop advanced disability. *Treatment completion rate* - The **treatment completion rate** indicates the effectiveness of the treatment program and patient adherence, which is vital for preventing drug resistance and relapse. - This metric does not provide information about when the diagnosis was made in the disease progression or the health system's ability to identify cases early.

Question 253: Which of the following is the true statement regarding measures to prevent typhoid transmission in the community?

A. Typhoid vaccine administration is the best method of preventing transmission.
B. Person-to-person transmission is the primary mode of spread.
C. Drug resistance in typhoid is not as big a problem as in TB.
D. Hygiene practice and clean sanitation control are more important than the typhoid vaccine. (Correct Answer)

Explanation: ***Hygiene practice and clean sanitation control is more important than the typhoid vaccine.*** - **Improved sanitation**, safe water supplies, and adequate hygiene practices are fundamental in controlling the spread of **typhoid fever**, as the disease is primarily transmitted through the **oral-fecal route**. - While vaccines are an important tool, they offer only partial protection and must be combined with **robust public health infrastructure** and **sanitation measures** for effective prevention. *Typhoid vaccine administration is the best method of preventing transmission.* - Typhoid vaccines offer protection, but their effectiveness is not 100%, and they typically require **booster doses** - **Vaccination campaigns** are most effective when implemented alongside improvements in **water and sanitation infrastructure**, as vaccines alone cannot fully prevent transmission in areas with poor hygiene. *Person-to-person transmission is the primary mode of spread.* - While person-to-person transmission can occur, especially in settings with poor hygiene, the primary mode of spread for typhoid is through the **ingestion of food or water contaminated** with the feces of an infected person or carrier. - This emphasizes the crucial role of **water and food safety** rather than just focusing on direct person-to-person contact. *Drug resistance in typhoid is not as big a problem as in TB.* - **Antimicrobial resistance (AMR)** in typhoid fever, particularly to fluoroquinolones and extended-spectrum beta-lactamase (ESBL) producing strains, is a **significant and growing global health concern**, complicating treatment. - While TB also faces serious drug resistance issues, the escalating problem of **extensively drug-resistant (XDR)** and **multi-drug resistant (MDR)** typhoid strains makes it a substantial threat, impacting treatment options and increasing morbidity and mortality.

Question 254: As per the National Tuberculosis Elimination Program (NTEP), HIV TB prevalence of what percentage would deem a district a high priority district?

A. >15 %
B. >20 %
C. >10 % (Correct Answer)
D. >12 %

Explanation: ***>10%*** - As per the **National Tuberculosis Elimination Program (NTEP)** guidelines, a district is categorized as a **high-priority district** for HIV-TB co-infection if the prevalence of HIV among TB patients is **greater than 10%**. - This threshold helps in identifying regions that require enhanced focus and resources for **integrated HIV and TB care** and prevention strategies. - This is the specific cut-off defined by NTEP for prioritizing districts for targeted interventions. *>15%* - While 15% would also indicate a high prevalence, the specific threshold set by NTEP for deeming a district high priority is **>10%**, not >15%. - Districts with prevalence between 10% and 15% would already be classified as high priority at the >10% threshold. *>20%* - A prevalence of >20% would certainly indicate a severe problem, but the **NTEP's definition** for a high-priority district is specifically **>10%**. - Using a higher threshold like 20% would delay interventions in districts that already face significant challenges with HIV-TB co-infection. *>12%* - The NTEP guidelines use a specific cut-off of **>10%** for defining high-priority districts for HIV-TB co-infection. - While 12% exceeds the 10% threshold, it is not the defining threshold mentioned in the official guidelines for this classification.

Question 255: In all the following places, hand rub can be used according to standard hand hygiene protocol, except...

A. If the hands are visibly soiled (Correct Answer)
B. While moving from a contaminated site to a clean site during patient care
C. During direct patient contact
D. Before donning gloves

Explanation: ***If the hands are visibly soiled*** - **Hand rub (alcohol-based hand rub)** is ineffective at removing gross contamination and organic matter from visibly soiled hands. - In such cases, **hand washing with soap and water** is mandatory to physically remove dirt, debris, and microorganisms. *While moving from a contaminated site to a clean site during patient care* - **Hand rub** is appropriate in this scenario to prevent the transfer of microorganisms from a potentially contaminated body site or object to another, cleaner area of the patient. - This is part of the "5 Moments for Hand Hygiene" to ensure **patient safety** and prevent **cross-contamination**. *During direct patient contact* - **Hand rub** can be used before and after direct patient contact if hands are not visibly soiled, as it provides rapid and effective decontamination. - This practice is crucial for minimizing the transmission of **healthcare-associated infections**. *Before donning gloves* - **Hand rub** should be performed before donning gloves, especially when performing procedures that involve contact with mucous membranes, non-intact skin, or sterile sites. - This ensures that hands are clean underneath the gloves, providing an additional layer of **infection prevention**.

Question 256: Match the following: Column A: a. Syphilis b. Chickenpox c. COVID-19 d. Hepatitis A Column B: 1. 6 Days 2. 90 Days 3. 16 Days 4. 28 Days

A. a-2, b-3, c-1, d-4 (Correct Answer)
B. a-3, b-4, c-2, d-1
C. a-1, b-4, c-2, d-3
D. a-3, b-4, c-1, d-2

Explanation: ***a-2, b-3, c-1, d-4*** - **Syphilis**: 90 days represents the **maximum incubation period** for *Treponema pallidum* (range 10-90 days, typical 21 days). While not the most common presentation time, it remains medically accurate and is the only viable match among available options. - **Chickenpox**: 16 days falls within the typical incubation period for **varicella-zoster virus** (range 10-21 days, commonly 14-16 days). - **COVID-19**: 6 days is consistent with the **median incubation period** for SARS-CoV-2 (range 2-14 days, mean 5-6 days). - **Hepatitis A**: 28 days represents the **typical incubation period** for HAV (range 15-50 days, average 28-30 days). *a-3, b-4, c-2, d-1* - Incorrectly assigns **Syphilis** 16 days (below the 10-90 day range's typical value), **COVID-19** 90 days (far exceeding the 2-14 day range), and **Hepatitis A** only 6 days (well below the minimum 15-day period). *a-1, b-4, c-2, d-3* - Incorrectly matches **Syphilis** with 6 days (insufficient for *T. pallidum* to produce primary chancre), **Chickenpox** with 28 days (exceeds the typical VZV range), and **Hepatitis A** with 16 days (below typical range). *a-3, b-4, c-1, d-2* - Incorrectly assigns **Syphilis** 16 days, **Chickenpox** 28 days (exceeding typical range), and **Hepatitis A** 90 days (inconsistent with acute HAV infection pattern).

Question 257: A person is bitten by a dog. The dog and the person are fully immunized. There is a small abrasion mark on the site of bite. What would you advise to the person?

A. Amoxiclav
B. Metronidazole
C. Ciprofloxacin
D. Observation (Correct Answer)

Explanation: ***Observation*** - This is a **Category II exposure** (minor abrasion/scratch) according to **WHO rabies classification**. With both the dog and person **fully immunized**, the recommended management is **immediate wound washing** with soap and water followed by **observation of the dog for 10 days**. - If the dog remains healthy during the 10-day observation period, no further rabies post-exposure prophylaxis is needed. The person's prior vaccination provides adequate protection. - **Prophylactic antibiotics are NOT routinely indicated** for minor abrasions in immunized individuals when the wound can be properly cleaned. The risk of significant bacterial infection in superficial wounds is low with proper wound care. - This approach follows **WHO and IAPSM guidelines** for rational dog bite management, avoiding unnecessary antibiotic use. *Amoxiclav* - Prophylactic antibiotics like **amoxicillin-clavulanate** are reserved for **high-risk wounds**: deep puncture wounds (Category III), wounds near bones/joints, hand/face wounds, delayed presentation (>8 hours), or immunocompromised patients. - A **small abrasion** in an immunized person does not meet criteria for routine antibiotic prophylaxis. Over-prescription contributes to **antimicrobial resistance**. - The primary concern in dog bite management is **rabies prevention**, not routine bacterial prophylaxis for minor wounds. *Metronidazole* - **Metronidazole** alone has limited coverage against common bite wound pathogens and would not be appropriate even if antibiotics were indicated. - It lacks activity against aerobic organisms like *Pasteurella* and *Staphylococcus* species commonly found in dog bites. *Ciprofloxacin* - **Ciprofloxacin** is not the first-line antibiotic for dog bites even when prophylaxis is indicated, due to limited anaerobic and Gram-positive coverage. - More importantly, antibiotics are **not routinely needed** for this Category II exposure with proper wound care and observation.

Question 258: SAFE strategy for trachoma includes all except?

A. Antibiotics
B. Surgery for trichiasis
C. Facial cleanliness
D. Evaluation of control program (Correct Answer)

Explanation: ***Evaluation of control program*** - **Evaluation** is a monitoring and assessment process used to measure the effectiveness of the SAFE strategy, but it is **not one of the four intervention components** of the strategy itself. - The SAFE strategy consists of: **S**urgery, **A**ntibiotics, **F**acial cleanliness, and **E**nvironmental improvement. *Surgery for trichiasis* - **Trichiasis** (in-turned eyelashes) is a blinding complication of trachoma requiring **surgical correction** to prevent corneal damage. - This is the "S" component of SAFE. *Antibiotics* - **Mass drug administration** with **azithromycin** (single oral dose) is used to reduce the community reservoir of *Chlamydia trachomatis*. - This is the "A" component of SAFE. *Facial cleanliness* - Promoting **facial hygiene**, especially in children, prevents transmission of *Chlamydia trachomatis* through contact and fly vectors. - This is the "F" component of SAFE. *Environmental improvement (Not listed as an option but part of SAFE)* - Improving **water supply**, **sanitation**, and **waste management** reduces breeding sites for flies and improves hygiene. - This is the "E" component of SAFE.

Question 259: What is the minimum percentage of partner notification required for effective STI control according to NACO guidelines?

A. 95%
B. 80% (Correct Answer)
C. 65%
D. 50%

Explanation: ***80%*** - NACO guidelines emphasize that a **minimum of 80% partner notification** is required for effective control of sexually transmitted infections (STIs). - Achieving this threshold helps in **breaking the chain of transmission** by identifying and treating exposed individuals. *95%* - While 95% is an aspirational target for some public health interventions, it is not the **minimum required percentage** specifically stated by NACO for effective STI partner notification. - This level of notification would provide even greater control but is often difficult to achieve in practice. *65%* - A 65% partner notification rate is considered **insufficient** by NACO guidelines to effectively control STI transmission within a population. - This rate would likely lead to a significant number of **untreated partners**, allowing the infection to continue spreading. *50%* - A 50% partner notification rate is **far below** the recommended minimum by NACO, making it largely ineffective for STI control. - Such a low rate would result in a substantial number of **missed cases** and ongoing transmission.

Question 260: Which of the following is NOT a core component of the WHO's global STI control strategy?

A. Case management
B. Universal mandatory screening (Correct Answer)
C. Strategic information systems
D. Prevention services

Explanation: ***Universal mandatory screening*** - While screening is part of STI control, **universal mandatory screening** for all STIs in the general population is not a core component of the WHO's strategy due to feasibility, cost, and ethical considerations. - The strategy emphasizes **targeted screening** for at-risk populations and opportunistic screening. *Case management* - **Case management**, including accurate diagnosis and effective treatment, is a critical component for managing current infections and preventing further transmission. - This involves syndromic or etiologic approaches to treatment and partner notification. *Strategic information systems* - **Strategic information systems** are essential for monitoring trends, evaluating interventions, and informing policy decisions related to STI control. - This includes surveillance data, program monitoring, and research. *Prevention services* - **Prevention services** are a cornerstone of the WHO's strategy, aiming to reduce the incidence of new infections. - These services encompass health education, condom promotion and distribution, vaccination, and pre-exposure prophylaxis (PrEP).

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Communicable Disease Control Principles

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Vector-Borne Diseases

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Water-Borne Diseases

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Air-Borne Diseases

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Zoonotic Diseases

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Sexually Transmitted Infections

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HIV/AIDS Control Program

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Tuberculosis Control

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Leprosy Elimination

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Emerging and Re-emerging Infections

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Hospital-Acquired Infections

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Integrated Disease Surveillance Project

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