Infectious Diseases Practice Questions

Q: The finding shown below is used for diagnosis of CNS parasitic lesion. Which of the following best describes the condition?

***Major criteria*** - The image likely depicts **multiple calcified cysts**, which in the context of CNS parasitic lesions (e.g., neurocysticercosis), would be considered a **major diagnostic criterion** for the disease. - Major criteria are significant findings, often radiographic evidence of **cysts or calcifications**, that strongly support a diagnosis of neurocysticercosis when combined with other criteria. *Minor criteria* - Minor criteria include less specific findings, such as **seizures** or headaches, or findings that support the diagnosis but are not definitive on their own. - While supportive, these findings are typically not sufficient for diagnosis without major or other criteria. *Absolute criteria* - Absolute criteria are definitive findings, such as a **histopathological demonstration of the parasite** or direct visualization of the scolex on imaging, which are direct proof of infection. - The image shows calcifications, which are strong evidence but not necessarily "absolute" proof of active parasitic presence without further context like a viable cyst with a scolex. *Epidemiological criteria* - Epidemiological criteria relate to the patient's **exposure history** or origin from areas endemic for the parasite. - These criteria help in narrowing down the differential diagnosis but do not provide direct evidence of the lesion itself.

Q: A patient undergone a Solid organ transplant is having the following lesions which are present on oral mucosa and sites shown below. Which of the following is incriminated in causing the same?

KSHV. ***KSHV*** - The image shows multiple **violaceous cutaneous lesions** which are characteristic of **Kaposi's sarcoma (KS)**. - In a solid organ transplant recipient, KS is commonly associated with **Kaposi's sarcoma-associated herpesvirus (KSHV)**, also known as HHV-8. Immunosuppression due to antirejection medications can reactivate latent KSHV infection. *HHV6* - HHV-6 is primarily associated with **roseola infantum** (exanthem subitum) in children. - While HHV-6 can cause complications in immunocompromised individuals, its typical manifestations do not involve the characteristic violaceous skin lesions seen in Kaposi's sarcoma. *HHV7* - HHV-7 is also associated with **roseola-like illnesses** and is generally considered a less pathogenic virus compared to other human herpesviruses. - It does not cause Kaposi's sarcoma, and its clinical manifestations in transplant patients are typically different from the lesions depicted. *CMV* - **Cytomegalovirus (CMV)** is a common opportunistic infection in solid organ transplant recipients, causing a variety of clinical syndromes. - While CMV can lead to numerous symptoms (e.g., fever, leukopenia, pneumonitis, colitis), it does not directly cause the characteristic skin lesions of Kaposi's sarcoma.

Q: Which of the following statements are correct regarding Weil's disease? I. It is caused by a virus named leptospira II. Acute kidney injury can lead to oliguria in this disease III. Microscopic agglutination is the investigation of choice IV. Ceftriaxone given parenterally is effective treatment Select the correct answer using the code given below :

II, III and IV. ***II, III and IV*** - **Weil's disease**, a severe form of leptospirosis, frequently causes **acute kidney injury (AKI)**, which can manifest as **oliguria** due to renal tubular damage and interstitial nephritis [2]. - The **microscopic agglutination test (MAT)** is considered the gold standard for diagnosing leptospirosis due to its high specificity and sensitivity in detecting specific antibodies against *Leptospira* serovars [2]. - **Ceftriaxone** is an effective parenteral antibiotic for treating severe leptospirosis, including Weil's disease, particularly when oral antibiotics are insufficient or the patient is critically ill. *I, II and III* - Statement I is incorrect because Weil's disease is caused by a **spirochete bacterium**, *Leptospira interrogans*, not a virus [1]. - While statements II and III are correct regarding **AKI and oliguria** and the utility of **MAT**, the incorrectness of statement I makes this option wrong. *I, III and IV* - Statement I is incorrect as Weil's disease is caused by a **bacterium** (*Leptospira*), not a virus [1]. - While statements III and IV are correct, the presence of an incorrect statement (I) makes this composite option incorrect. *I, II and IV* - Statement I is factually incorrect; Weil's disease is caused by the **bacterium *Leptospira***, not a virus [1]. - Although statements II and IV are correct—**AKI with oliguria** is a feature and **ceftriaxone** is a treatment—the fundamental error in statement I invalidates this option.

Q: Which one of the following conditions is a complication of bacterial pharyngitis involving extension of infection into the internal jugular veins leading to thrombosis and metastatic dispersal of the organism?

Lemierre syndrome. ***Lemierre syndrome*** - This syndrome is characterized by **bacterial pharyngitis** that extends to the **internal jugular vein**, leading to **thrombosis** and subsequent septic emboli [3]. - The most common causative organism is ***Fusobacterium necrophorum***, and it can result in metastatic infections in organs like the lungs. *Wegener's granulomatosis* - This is an **autoimmune vasculitis** affecting small to medium-sized vessels, primarily in the respiratory tract and kidneys [2]. - It is distinct from infection-related venous thrombosis and is characterized by **granulomatous inflammation** and **ANCA positivity**. *Chronic Pulmonary Aspergillosis* - This is a fungal infection of the lungs, typically occurring in individuals with pre-existing lung conditions or immunosuppression [1]. - It does not involve the initial presentation of bacterial pharyngitis followed by internal jugular vein thrombosis. *Cystic Fibrosis* - This is an **autosomal recessive genetic disorder** affecting exocrine glands, leading to thick, sticky mucus, primarily impacting the lungs and digestive system. - While it causes chronic respiratory infections, it is not initiated by bacterial pharyngitis leading to septic thrombophlebitis of the jugular vein.

Q: Which of the following statements are correct regarding Mantoux test for tuberculosis? 1. It entails injecting 1 TU (Tuberculin Unit) of PPD (Purified Protein Derivative) in 0.1 mL intradermally. 2. The injection should be given with the needle bevel facing downward. 3. When placed correctly, the injection should produce a pale wheal of the skin, 1 - 2 mm in diameter. 4. The injection should be given with a tuberculin syringe. Select the correct answer using the code given below:

1 and 4. **1 and 4** - Statement 1 is correct: The Mantoux test involves injecting **1 TU (Tuberculin Unit) of PPD (Purified Protein Derivative)** in **0.1 mL intradermally** into the forearm, which is the standard dose and administration route. - Statement 4 is correct: A **tuberculin syringe** is specifically designed for small, precise volume injections like the Mantoux test, ensuring accurate dosing and placement. *1 and 2* - Statement 1 is correct, but statement 2 is incorrect regarding the **Mantoux test procedure**. - The needle bevel should face **upward** during intradermal injection to ensure proper placement of the PPD and formation of the wheal. *2 and 3* - Statement 2 is incorrect because the needle bevel should face **upward** for intradermal injection. - Statement 3 is incorrect because a correctly placed Mantoux injection should produce a wheal of **6-10 mm in diameter**, not 1-2 mm, indicating the PPD is in the dermis. *2 and 4* - Statement 2 is incorrect as the needle bevel should be positioned **facing upward**. - While statement 4 correctly identifies the use of a tuberculin syringe, the incorrectness of statement 2 makes this option unsuitable.

Q: Which one of the following is the commonest extra-salivary gland manifestation of mumps in adults?

Orchitis. **Orchitis** - **Orchitis**, the inflammation of the testes, is the most common extra-salivary gland manifestation of mumps in **post-pubertal males** and can lead to **testicular atrophy** and infertility. - The incidence of orchitis in adult males with mumps can be as high as 30–50%. *Pancreatitis* - While mumps can cause **pancreatitis**, it is less common than orchitis, occurring in only about 2-5% of cases [1]. - Mumps-induced pancreatitis is usually mild and self-limiting [1]. *Polyarthritis* - **Polyarthritis** is a rare complication of mumps, typically resolving without long-term sequelae. - It is much less frequently observed compared to orchitis, especially in adults. *Hydrocephalus* - **Hydrocephalus** is an extremely rare and severe complication of mumps, often associated with mumps **meningoencephalitis**. - This complication involves an abnormal accumulation of cerebrospinal fluid, which is highly uncommon following mumps infection.

Q: Which of the following is NOT a complication of malaria in pregnancy?

Metabolic alkalosis. ***Metabolic alkalosis*** - **Metabolic alkalosis** is not typically associated with malaria in pregnancy. - Malaria complications usually lead to conditions like **metabolic acidosis** due to lactate production or kidney dysfunction. *Disseminated intravascular coagulation* - **Disseminated intravascular coagulation (DIC)** is a severe complication of malaria, particularly **severe P. falciparum infection**, leading to widespread clot formation and bleeding. - It occurs due to systemic inflammation and endothelial damage caused by malarial parasites. *Hypoglycemia* - **Hypoglycemia** is a common and serious complication of malaria in pregnancy, especially with **P. falciparum infection**. - It results from increased glucose consumption by parasites, impaired gluconeogenesis, and quinine treatment. *Thrombocytopenia* - **Thrombocytopenia** (low platelet count) is a very common complication in both pregnant and non-pregnant patients with malaria. - It is caused by platelet destruction, splenic sequestration, and bone marrow suppression.

Q: The complications of ascaris lumbricoides infestation include all of the following except :

peptic ulcer disease. ***Peptic ulcer disease*** - **Peptic ulcer disease** is not a commonly recognized direct complication of *Ascaris lumbricoides* infestation. - While *Ascaris* can cause gastrointestinal symptoms, it does not typically lead to the formation of peptic ulcers. *Lower gastrointestinal bleed* - Heavy worm burdens can cause irritation and inflammation of the intestinal lining, potentially leading to **mucosal erosions** and **lower gastrointestinal bleeding**. - In rare cases, worms might erode into blood vessels, contributing to bleeding. *Cholangitis and obstructive jaundice* - Adult worms can migrate from the small intestine into the **biliary tree**, obstructing bile flow and causing **cholangitis** or **obstructive jaundice**. - They can also enter the pancreatic duct, leading to **pancreatitis**. *Acute intestinal obstruction* - A large bolus of adult worms can form a tangled mass (bolus) within the small intestine, leading to **complete or partial acute intestinal obstruction**. - This is a serious surgical emergency, especially in children with heavy worm loads.

Q: The most common opportunistic infection observed in patients with AIDS is

Pneumocystis carinii. ***Pneumocystis carinii*** - **Pneumocystis pneumonia (PCP)**, caused by *Pneumocystis jirovecii* (formerly *P. carinii*), is the **most common opportunistic infection** and a leading cause of death in AIDS patients [1]. - It typically presents with **fever, cough, and dyspnea** in patients with a CD4 count below 200 cells/µL [1]. *Pseudomonas aeruginosa* - While *Pseudomonas aeruginosa* can cause serious infections in immunocompromised individuals, it is not the **most common opportunistic infection** seen in patients with AIDS. - Infections usually involve the **lungs (pneumonia)**, skin, urinary tract, or bacteremia, often in patients with **neutropenia** or hospitalized for other reasons. *Atypical mycobacteria* - **Mycobacterium avium complex (MAC)** is an important opportunistic pathogen in AIDS patients (CD4 < 50 cells/µL), causing disseminated disease, but it is not the **most common** overall [2]. - Symptoms include **fever, weight loss, night sweats, and diarrhea**, and diagnosis requires blood cultures or tissue biopsy [2]. *Haemophilus influenzae* - *Haemophilus influenzae* can cause **respiratory tract infections** (e.g., sinusitis, bronchitis, pneumonia) and invasive disease, particularly in children and individuals with underlying lung disease. - While patients with HIV may be more susceptible to bacterial infections, *H. influenzae* is **not classified as a classic opportunistic infection** in the same way as *Pneumocystis* or MAC in AIDS patients.

Question 1

The finding shown below is used for diagnosis of CNS parasitic lesion. Which of the following best describes the condition?

Answer

Minor criteria

Answer

Absolute criteria

Answer

Epidemiological criteria

Answer

Major criteria

Question 2

A patient undergone a Solid organ transplant is having the following lesions which are present on oral mucosa and sites shown below. Which of the following is incriminated in causing the same?

Accepted Answer

KSHV

Answer

HHV6

Answer

HHV7

Answer

CMV

Question 3

Which of the following statements are correct regarding Weil's disease?
I. It is caused by a virus named leptospira
II. Acute kidney injury can lead to oliguria in this disease
III. Microscopic agglutination is the investigation of choice
IV. Ceftriaxone given parenterally is effective treatment

Select the correct answer using the code given below :

Accepted Answer

II, III and IV

Answer

I, II and III

Answer

I, III and IV

Answer

I, II and IV

Question 4

Which one of the following conditions is a complication of bacterial pharyngitis involving extension of infection into the internal jugular veins leading to thrombosis and metastatic dispersal of the organism?

Accepted Answer

Lemierre syndrome

Answer

Wegener's granulomatosis

Answer

Chronic Pulmonary Aspergillosis

Answer

Cystic Fibrosis

Question 5

Which of the following statements are correct regarding Mantoux test for tuberculosis?

1. It entails injecting 1 TU (Tuberculin Unit) of PPD (Purified Protein Derivative) in 0.1 mL intradermally.
2. The injection should be given with the needle bevel facing downward.
3. When placed correctly, the injection should produce a pale wheal of the skin, 1 - 2 mm in diameter.
4. The injection should be given with a tuberculin syringe.

Select the correct answer using the code given below:

Accepted Answer

1 and 4

Answer

1 and 2

Answer

2 and 3

Answer

2 and 4

Question 6

Which one of the following is the commonest extra-salivary gland manifestation of mumps in adults?

Accepted Answer

Orchitis

Answer

Pancreatitis

Answer

Polyarthritis

Answer

Hydrocephalus

Question 7

Which of the following is NOT a complication of malaria in pregnancy?

Accepted Answer

Metabolic alkalosis

Answer

Disseminated intravascular coagulation

Answer

Hypoglycemia

Answer

Thrombocytopenia

Question 8

Match List-I with List-II and select the correct answer using the code given below the Lists:

Accepted Answer

A→1  B→2  C→4  D→3

Answer

A→1  B→4  C→2  D→3

Answer

A→4  B→3  C→2  D→1

Answer

A→1  B→2  C→3  D→4

Question 9

The complications of ascaris lumbricoides infestation include all of the following except :

Accepted Answer

peptic ulcer disease

Answer

lower gastro intestinal bleed

Answer

cholangitis and obstructive jaundice

Answer

acute intestinal obstruction

Question 10

The most common opportunistic infection observed in patients with AIDS is

Accepted Answer

Pneumocystis carinii

Answer

Pseudomonas aeruginosa

Answer

Atypical mycobacteria

Answer

Haemophilus influenzae

Infectious Diseases — MCQs

Infectious Diseases — MCQs

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