Infectious Diseases Practice Questions

Q: Which hepatitis infection is most commonly associated with immune thrombocytopenic purpura?

Hepatitis C infection. ***Hepatitis C infection*** - **Hepatitis C** is well-established for causing various **extrahepatic manifestations**, including mixed cryoglobulinemia, membranoproliferative glomerulonephritis, and **immune thrombocytopenic purpura (ITP)**. - The mechanism involves chronic viral stimulation leading to the production of **autoantibodies** against platelets and megakaryocytes, or direct viral effects on bone marrow. *Hepatitis A infection* - **Hepatitis A** is an **acute, self-limiting viral infection** [1] that typically does not lead to chronic liver disease or significant extrahepatic manifestations like ITP. - There are rare reports of transient thrombocytopenia in acute hepatitis A, but it is not commonly associated with chronic ITP. *Hepatitis B infection* - While **Hepatitis B** can cause extrahepatic manifestations such as polyarteritis nodosa and glomerulonephritis, its association with **immune thrombocytopenic purpura (ITP)** is less frequent and not as strong as with Hepatitis C. - HBV-associated thrombocytopenia is more often related to **hypersplenism** in cirrhotics or direct viral bone marrow suppression, rather than immune-mediated destruction. *Hepatitis D infection* - **Hepatitis D (HDV)** is a **defective virus** that requires co-infection with Hepatitis B virus (HBV) to replicate. - Its extrahepatic manifestations are primarily linked to the underlying **HBV infection**, and there is no strong, independent association with immune thrombocytopenic purpura.

Q: Which tool objectively assesses the risk of adverse outcomes in a patient with pneumonia?

CURB - 65 criteria. ***CURB - 65 criteria*** - The **CURB-65 criteria** is a validated tool for assessing the **severity of pneumonia** and predicting adverse outcomes such as mortality, need for intensive care, and length of hospital stay [1]. - It assesses **Confusion, Urea >7 mmol/L, Respiratory rate ≥30 breaths/min, Blood pressure <90 mmHg systolic or ≤60 mmHg diastolic**, and **age ≥65 years**, assigning points that correlate with increasing risk [1]. *Pneumonia severity index [PSI]* - The **Pneumonia Severity Index (PSI)** is another widely used tool, but it is a **more complex** - It involves 20 variables, making it more cumbersome for rapid clinical use compared to CURB-65. *APACHE Score* - The **APACHE (Acute Physiology and Chronic Health Evaluation) Score** is a general measure of disease severity used in **critically ill patients**, not specific to pneumonia. - It predicts **mortality risk** in intensive care unit (ICU) patients across various conditions. *Glasgow scale* - The **Glasgow Coma Scale (GCS)** is used to **assess the level of consciousness** in patients. - It is not a tool for specifically assessing the risk of adverse outcomes in pneumonia, but rather a component that may contribute to a pneumonia severity score.

Q: Which of the following is an ocular complication associated with Zika virus infection?

Eye inflammation. ***Eye inflammation*** - **Ocular manifestations** are recognized complications of **Zika virus infection**, ranging from conjunctivitis to more severe conditions like **uveitis** and **optic neuritis**. - Specifically, **chorioretinal scars** and **optic nerve abnormalities** have been observed in infants with congenital Zika syndrome. *Liver inflammation* - **Hepatitis**, or liver inflammation, is not a common or specific complication directly associated with Zika virus infection. - While some viral infections can affect the liver, **Zika** primarily targets **neural tissues** and has specific ocular and neurological complications. *Heart inflammation* - **Myocarditis**, or heart inflammation, is not a frequently reported or characteristic complication of **Zika virus infection**. - The primary systemic manifestations of **Zika** typically involve **mild fever**, **rash**, **arthralgia**, and **conjunctivitis**, with severe outcomes usually being neurological. *None of the options* - This option is incorrect because **eye inflammation** is a well-documented and significant ocular complication of **Zika virus infection**. - The virus is known to have **tropism for ocular tissues**, leading to various visual impairments.

Q: CCR5 mutation is related to which condition ?

Resistance to HIV infection. ***Resistance to HIV infection*** - A specific mutation, **CCR5-delta32**, leads to a non-functional **CCR5 receptor** on the surface of immune cells. - Since **HIV** primarily uses the **CCR5 receptor** to enter target cells, individuals with this mutation are highly resistant to HIV infection. *Susceptibility to HIV infection* - A functional **CCR5 receptor** is required for most **HIV** strains (R5 strains) to enter human cells. - Mutations leading to a non-functional **CCR5 receptor** decrease, rather than increase, susceptibility to HIV. *Resistance to HBV infection* - The **hepatitis B virus (HBV)** uses different cellular receptors for entry, primarily the **sodium taurocholate co-transporting polypeptide (NTCP)**. - **CCR5** mutations have no known effect on susceptibility or resistance to **HBV infection**. *Susceptibility to HBV infection* - Susceptibility to **HBV** infection is determined by the presence and functionality of its specific entry receptors, such as NTCP. - **CCR5** mutations do not impact these pathways and therefore do not influence susceptibility to **HBV**.

Q: Bloody diarrhea in HIV infected patient is mostly due to ?

CMV. ***CMV*** - **Cytomegalovirus (CMV) colitis** is a common opportunistic infection in advanced HIV, causing **bloody diarrhea**, abdominal pain, and fever. - CMV infection can lead to **ulcerations** and inflammation of the colonic mucosa, resulting in blood in the stool. *Cryptosporidium* - **Cryptosporidiosis** causes profuse, **watery diarrhea** in HIV patients, not typically bloody [1]. - While it can be severe and persistent, it primarily affects the small intestine, leading to malabsorption. *Isospora* - **Isosporiasis** (caused by *Isospora belli*) primarily presents as **unrelenting watery diarrhea** in immunocompromised individuals [1]. - It affects the small bowel and does not commonly result in bloody stools. *Salmonella* - **Salmonella gastroenteritis** can cause bloody diarrhea, but in HIV patients, it is often associated with **bacteremia** and systemic infection. - While possible, **CMV colitis** is a more classic and frequent cause of bloody diarrhea in advanced HIV in the absence of other focal symptoms.

Q: Which of the following is NOT an extrahepatic manifestation of Hepatitis C?

Celiac Disease. ***Celiac Disease*** - Celiac disease is an **autoimmune disorder** triggered by gluten, not associated with Hepatitis C. [1] - Extrahepatic manifestations of Hepatitis C typically include **dermatological and rheumatological conditions**, which are absent in celiac disease. *Cryoglobulinemia* - Cryoglobulinemia is a common **extrahepatic manifestation** of Hepatitis C, often leading to **vasculitis**. - It presents with **skin rashes**, arthralgia, and renal issues, significantly associated with chronic Hepatitis C infection [2]. *Lichen Planus* - Lichen Planus is another **dermatological condition** frequently linked with Hepatitis C, manifesting with **itchy lesions** on skin and mucous membranes. - The exact mechanism is unclear, but it shows a significant correlation with the virus. *Glomerulonephritis* - Glomerulonephritis is also recognized as a potential **extrahepatic complication** of Hepatitis C, often resulting from **cryoglobulinemic vasculitis**. - It can lead to symptoms of **nephritis**, such as hematuria and proteinuria, reflecting kidney involvement [2].

Q: Which of the following is NOT a characteristic of Dengue shock syndrome?

Decreased haemoglobin. ***Decreased haemoglobin*** - **Decreased hemoglobin** is *not* a characteristic feature of Dengue shock syndrome; rather, **hemoconcentration**, indicated by an *increased* hematocrit, is a hallmark due to plasma leakage. - While bleeding can occur in dengue, leading to decreased hemoglobin, **hemoconcentration** is a more direct and consistent sign of severe plasma leakage in Dengue Shock Syndrome [1]. *Hepatomegaly* - **Hepatomegaly** (enlarged liver) is a common finding in severe dengue, including Dengue Shock Syndrome, due to hepatic inflammation and dysfunction [1]. - This symptom reflects the systemic nature of the infection and can contribute to abdominal pain and tenderness. *Pleural effusion* - **Pleural effusion** is a key indicator of **plasma leakage**, a defining characteristic of severe dengue and Dengue Shock Syndrome [1]. - The effusion results from fluid transudation into the pleural space, often accompanied by ascites. *Thrombocytopenia* - **Thrombocytopenia** (low platelet count) is a consistent and serious finding in dengue, particularly in severe forms like Dengue Shock Syndrome [1]. - A significant drop in platelet count often precedes or accompanies the onset of shock and increases the risk of bleeding.

Q: A 60-year-old farmer presents with swelling on the sole of the foot accompanied by discharging yellow granules. What is the most likely diagnosis?

Actinomycosis. ***Actinomycosis*** - The presentation of a **slowly progressive swelling** with **draining sinuses** that exude **"sulfur granules" (yellow granules)** is highly characteristic of actinomycosis. - While often associated with the cervicofacial region, actinomycosis can affect other sites such as the foot, especially after **trauma** or through direct inoculation from soil, consistent with a farmer's occupation. *Fungal mycetoma* - While fungal mycetoma also presents with **swelling, draining sinuses**, and **granules**, these granules are typically **black or white** from fungal elements, not yellow [1]. - The causative agents are true fungi, and the clinical course might differ subtly, but the **color of the granules** is a key differentiator [1]. *Actinomycetoma* - Actinomycetoma is caused by **filamentous bacteria** (like *Nocardia* or *Actinomadura*), which are a type of bacterial mycetoma. It presents similarly to fungal mycetoma with **granules**, but these are usually **white, red, or yellow-brown**, and less commonly the bright yellow "sulfur granules" seen in classical actinomycosis. - It’s important to distinguish actinomycetoma (bacterial mycetoma) from actinomycosis, which is caused by *Actinomyces* species and is characterized specifically by the classic sulfur granules. *Candidiasis* - **Candidiasis** (yeast infection) typically presents as **mucocutaneous lesions, thrush, or invasive systemic infections**, not localized swelling with discharging yellow granules on the sole of the foot. - It does not involve the formation of granules or sinuses in this manner.

Q: Pulmonary eosinophilia is found in infection with ?

Strongyloides. ***Strongyloides*** - **Strongyloides stercoralis** can cause **pulmonary eosinophilia** (Löffler's syndrome) as larvae migrate through the lungs [1]. - This migration is part of the parasite's life cycle, leading to an inflammatory response with eosinophil infiltration [1]. *Babesia* - **Babesia** species primarily infect **red blood cells** and cause **hemolytic anemia**, resembling malaria. - They are transmitted by ticks and do not typically cause pulmonary eosinophilia. *Malaria* - **Malaria**, caused by Plasmodium parasites, is known for infecting **red blood cells** and causing cyclical fevers, chills, and anemia. - It does not typically present with pulmonary eosinophilia as a characteristic feature. *Trypanosoma* - **Trypanosoma** species cause **sleeping sickness** (African trypanosomiasis) and **Chagas disease** (American trypanosomiasis). - These infections affect the bloodstream, lymphatic system, and various organs, but pulmonary eosinophilia is not a hallmark.

Question 1

Which hepatitis infection is most commonly associated with immune thrombocytopenic purpura?

Accepted Answer

Hepatitis C infection

Answer

Hepatitis A infection

Answer

Hepatitis B infection

Answer

Hepatitis D infection

Question 2

Which tool objectively assesses the risk of adverse outcomes in a patient with pneumonia?

Accepted Answer

CURB - 65 criteria

Answer

Glasgow scale

Answer

APACHE Score

Answer

Pneumonia severity index [PSI]

Question 3

Which of the following is an ocular complication associated with Zika virus infection?

Accepted Answer

Eye inflammation

Answer

Liver inflammation

Answer

Heart inflammation

Answer

None of the options

Question 4

CCR5 mutation is related to which condition ?

Accepted Answer

Resistance to HIV infection

Answer

Susceptibility to HIV infection

Answer

Resistance to HBV infection

Answer

Susceptibility to HBV infection

Question 5

Bloody diarrhea in HIV infected patient is mostly due to ?

Accepted Answer

CMV

Answer

Cryptosporidium

Answer

Isospora

Answer

Salmonella

Question 6

Major criteria for infective endocarditis include which of the following

Accepted Answer

Isolation of a typical organism from two separate blood cultures

Answer

History of injection drug use

Answer

Presence of Osler's nodes

Answer

Persistent fever for more than 4 days

Question 7

Which of the following is NOT an extrahepatic manifestation of Hepatitis C?

Accepted Answer

Celiac Disease

Answer

Glomerulonephritis

Answer

Cryoglobulinemia

Answer

Lichen Planus

Question 8

Which of the following is NOT a characteristic of Dengue shock syndrome?

Accepted Answer

Decreased haemoglobin

Answer

Pleural effusion

Answer

Thrombocytopenia

Answer

Hepatomegaly

Question 9

A 60-year-old farmer presents with swelling on the sole of the foot accompanied by discharging yellow granules. What is the most likely diagnosis?

Accepted Answer

Actinomycosis

Answer

Fungal mycetoma

Answer

Candidiasis

Answer

Actinomycetoma

Question 10

Pulmonary eosinophilia is found in infection with ?

Accepted Answer

Strongyloides

Answer

Babesia

Answer

Malaria

Answer

Trypanosoma

Infectious Diseases — MCQs

Infectious Diseases — MCQs

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