Infectious Diseases — MCQs

Infectious Diseases Indian Medical PG Practice Questions and MCQs

Question 131: Intravascular hemolysis is not associated with:

A. Clostridium tetani (Correct Answer)
B. Plasmodium falciparum
C. Babesia microti
D. Bartonella bacilliformis

Explanation: ***Clostridium tetani*** - *Clostridium tetani* causes **tetanus**, a neurological disorder characterized by muscle spasms and paralysis, primarily due to the **tetanospasmin neurotoxin**. - It does not produce toxins that directly lyse red blood cells, thus it is not associated with **intravascular hemolysis**. *Bartonella bacilliformis* - *Bartonella bacilliformis* causes **Carrion's disease (Bartonellosis)**, which includes an acute phase known as Oroya fever. - This bacterium invades and proliferates within **red blood cells**, leading to their destruction and severe **hemolytic anemia**. *Plasmodium falciparum* - *Plasmodium falciparum* is a parasite responsible for the most severe form of **malaria**. - It infects and replicates within **red blood cells**, causing them to rupture and leading to significant **intravascular hemolysis** and anemia. *Babesia microti* - *Babesia microti* is an intraerythrocytic parasite that causes **babesiosis**, transmitted by ticks. - It replicates within **red blood cells**, leading to their destruction and causing **hemolytic anemia**, similar to malaria.

Question 132: All of the following statements are true regarding central nervous system infections, except:

A. Prions infection causes spongiform encephalopathy
B. JC virus is causative agent for progressive multifocal leucoencephalopathy
C. Cytomegalovirus is a common cause of bilateral temporal lobe hemorrhagic infarction (Correct Answer)
D. Measles virus is the causative agent for subacute sclerosing pan encephalitis (SSPE)

Explanation: ***Cytomegalovirus is a common cause of bilateral temporal lobe hemorrhagic infarction.*** - **Cytomegalovirus (CMV)** typically causes **ventriculoencephalitis or periventricular necrosis** and microglial nodules in immunocompromised patients, not bilateral temporal lobe hemorrhagic infarction. - **Herpes simplex virus type 1 (HSV-1)** is the classic infectious cause of **bilateral temporal lobe hemorrhagic infarction (necrotizing encephalitis)**. *Prions infection causes spongiform encephalopathy* - **Prions** are misfolded proteins that cause transmissible spongiform encephalopathies (TSEs), such as Creutzfeldt-Jakob disease, characterized by **neuronal loss** and vacuolation (spongiform changes). - These diseases are invariably fatal and lead to rapid neurological deterioration. *JC virus is causative agent for progressive multifocal leucoencephalopathy* - The **JC virus** specifically targets and destroys **oligodendrocytes**, the myelin-producing cells of the central nervous system. - This leads to **demyelination** in multiple areas of the brain, causing the characteristic lesions seen in progressive multifocal leukoencephalopathy (PML). *Measles virus is the causative agent for subacute sclerosing pan encephalitis (SSPE).* - **Subacute sclerosing panencephalitis (SSPE)** is a rare, fatal, progressive neurodegenerative disease caused by a persistent and defective **measles virus infection** in the brain. - It occurs years after the initial measles infection, leading to cognitive decline, seizures, and motor dysfunction.

Question 133: Which of the following prion diseases is most commonly associated with cattle and has been linked to variant Creutzfeldt-Jakob disease in humans?

A. Scrapie
B. Transmissible mink encephalopathy
C. Progressive multifocal leucoencephalopathy
D. Bovine spongiform encephalopathy (Correct Answer)

Explanation: ***Bovine spongiform encephalopathy*** - **Bovine spongiform encephalopathy (BSE)**, also known as **"mad cow disease,"** is a prion disease of cattle strongly linked to the development of **variant Creutzfeldt-Jakob disease (vCJD)** in humans through consumption of contaminated beef products. - The disease causes **neurodegeneration** in cattle, leading to **neurological symptoms** such as incoordination, behavioral changes, and aggression. *Transmissible mink encephalopathy* - This is a rare **prion disease** affecting farm-raised **mink**, known to be transmissible among mink. - It is **not associated with cattle** as its primary host, nor has it been linked to human prion diseases like vCJD. *Scrapie* - **Scrapie** is a **prion disease** specific to **sheep and goats**, and it is not known to be transmissible to humans or to cause human disease. - While it was one of the earliest recognized prion diseases, it does not affect cattle or cause vCJD. *Progressive multifocal leucoencephalopathy* - This is a **demyelinating disease** of the central nervous system caused by the **JC virus**, not a prion. - It primarily affects individuals with **compromised immune systems** and is unrelated to cattle and variant CJD.

Practice by Chapter

Respiratory Tract Infections

Practice Questions

Urinary Tract Infections

Practice Questions

Gastrointestinal Infections

Practice Questions

Skin and Soft Tissue Infections

Practice Questions

Central Nervous System Infections

Practice Questions

Bone and Joint Infections

Practice Questions

Cardiovascular Infections

Practice Questions

Sexually Transmitted Infections

Practice Questions

Zoonotic Infections

Practice Questions

Bloodstream Infections and Sepsis

Practice Questions

Fever of Unknown Origin

Practice Questions

Infections in Immunocompromised Host

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free