Infectious Diseases Practice Questions

Q: A 26-year-old male presented with fever and headache for 3 days. On 3rd day, his BP is $90 / 60 \mathrm{~mm} \mathrm{Hg}$ and examination revealed rashes on the legs as shown. What is the likely diagnosis?

Meningococcus. ***Meningococcus*** - The combination of **fever, headache, hypotension**, and a **purpuric rash** (as shown in the image, indicating petechiae and ecchymoses) is highly suggestive of **meningococcemia**, a severe systemic infection caused by *Neisseria meningitidis*. - This rapidly progressive infection can lead to **septic shock** and disseminated intravascular coagulation (DIC), often presenting with these characteristic skin lesions. *Dengue hemorrhagic fever* - While dengue can cause **fever** and **rash**, the rash is typically a maculopapular or scarlatiniform erythema, not the distinct **purpuric lesions** seen. - Though **hypotension** can occur in severe dengue, the overall clinical picture with extensive purpura points away from dengue without other classic features like **thrombocytopenia** and hemoconcentration. *Enteric fever* - Enteric fever (typhoid fever) presents with **prolonged fever**, headache, and often **bradycardia**. - The typical rash associated with enteric fever is **rose spots**, which are transient, faintly erythematous macules, distinct from the petechial/purpuric rash in the image. *Scrub typhus* - Scrub typhus is characterized by fever, headache, and a **maculopapular rash** that may later become purpuric, but also typically includes an **eschar** at the site of the chigger bite. - While **hypotension** can occur in severe cases, the absence of an eschar and the rapid progression with prominent purpura are less typical for scrub typhus compared to meningococcemia.

Q: The following cell type is seen in peripheral smear of a patient with membrane over the tonsils. All can be used in treatment except?

Acyclovir. ***Acyclovir*** - The image depicts an **atypical lymphocyte** (Downey cell), characteristic of **infectious mononucleosis**, commonly caused by the **Epstein-Barr virus (EBV)**. - Acyclovir is an **antiviral medication** primarily used for **herpes simplex virus (HSV)** and **varicella-zoster virus (VZV)** infections, and it is **not effective against EBV**. *Prednisolone* - **Corticosteroids** like prednisolone may be used in severe cases of infectious mononucleosis, especially when complications such as **airway obstruction** due to tonsillar hypertrophy, **hemolytic anemia**, or **thrombocytopenia** are present. - They help to **reduce inflammation** and suppress the immune response. *IVIG* - **Intravenous immunoglobulin (IVIG)** can be used in rare, severe, or complicated cases of infectious mononucleosis, particularly if there are significant **hematologic complications** (e.g., severe thrombocytopenia, severe hemolytic anemia) or in patients with **immunodeficiency**. - IVIG provides **passive immunity** and modulates the immune response. *Acetaminophen* - **Acetaminophen (paracetamol)** is a common **analgesic** and **antipyretic** used to manage symptomatic relief for fever, sore throat, and muscle aches associated with infectious mononucleosis. - It helps to **alleviate discomfort** and improve patient well-being during the acute phase of the illness.

Q: Which of the following will best describe this patient?

Fever, weight loss, night sweats and elevated ESR. ***Fever, weight loss, night sweats and elevated ESR*** - The CT scan shows numerous **small, diffuse nodules** throughout both lung fields, consistent with **miliary tuberculosis (TB)**. - The systemic symptoms of **fever, weight loss, night sweats**, and an **elevated ESR** are classic constitutional symptoms of disseminated TB. *Rusty sputum with gram positive diplococci* - This description is characteristic of **Streptococcus pneumoniae (pneumococcal pneumonia)**. - Pneumococcal pneumonia typically presents with lobar consolidation on imaging, not diffuse miliary nodules. *Acute dyspnea, elevated JVP and long history of air travel* - This constellation of symptoms (acute dyspnea, elevated JVP) and risk factor (long history of air travel) strongly suggests **pulmonary embolism (PE)**. - Imaging findings for PE would typically include a filling defect in the pulmonary arteries, rather than diffuse nodularity. *Acute dyspnea, pink frothy sputum and mid-diastolic rumble* - These symptoms point towards **left-sided heart failure (acute pulmonary edema)**, often associated with **mitral stenosis** (suggested by the mid-diastolic rumble). - Pulmonary edema on CT would show ground-glass opacities, septal thickening, and pleural effusions, not diffuse nodular infiltrates.

Q: Drug of choice for following infection (as shown in image) in a HIV patient: (NEET Pattern 2019)

Cotrimoxazole. ***Cotrimoxazole*** - The image shows numerous **dark-stained cysts** and **trophozoites** within lung tissue, characteristic of **Pneumocystis jirovecii pneumonia (PCP)**, a common opportunistic infection in HIV patients. - **Cotrimoxazole (trimethoprim-sulfamethoxazole)** is the drug of choice for the treatment and prophylaxis of PCP. *INH + Rifampicin* - This combination is used for the treatment of **tuberculosis**, characterized by **acid-fast bacilli** and granulomas, which are not seen in this image. - While TB is common in HIV patients, the morphology in the image is not consistent with Mycobacterium tuberculosis. *Doxycycline* - Doxycycline is a broad-spectrum antibiotic used for various bacterial infections, including atypical pneumonia, but it is not effective against **Pneumocystis jirovecii.** - It is also used for malaria prophylaxis and Rickettsial infections. *Azithromycin* - Azithromycin is an antibiotic primarily effective against atypical bacteria like **Mycoplasma** and **Chlamydia**, and it is used for **MAC (Mycobacterium avium complex)** prophylaxis in advanced HIV. - It has no role in the treatment of Pneumocystis jirovecii pneumonia.

Q: A 28-year-old female patient presents with abdominal pain, fever, night sweats, malaise, and intercostal tenderness. Past history of bloody diarrhea is present. USG liver of the patient is given. Which among the following statements is false?

Aspiration and culture is the investigation of choice. ***Aspiration and culture is the investigation of choice*** - This statement is **FALSE** - while aspiration may be performed, **culture often yields negative results** for *Entamoeba histolytica* as trophozoites are fragile and difficult to culture. - **Serology** (antibody detection), **imaging**, and **response to anti-amoebic therapy** are the preferred diagnostic approaches for amoebic liver abscess. *This condition is caused by an organism that spreads via fecal-oral route* - This statement is **TRUE** - *Entamoeba histolytica* causes amoebic liver abscess and spreads via **fecal-oral route**. - Transmission occurs through ingestion of **contaminated food or water** containing cysts. *Right lobe of the liver is most commonly affected* - This statement is **TRUE** - the **right lobe** is most commonly affected in amoebic liver abscess. - This occurs due to **preferential portal blood flow** and the right lobe's larger size. *Patient may present with pulmonary symptoms* - This statement is **TRUE** - amoebic liver abscesses can cause **pleuropulmonary complications**. - Abscess rupture into the **diaphragm or pleural cavity** can lead to cough, chest pain, and dyspnea.

Q: Which of the following infections in most commonly seen in this transfusion dependant child shown below?

Yersinia enterocolitica. ***Yersinia enterocolitica*** - Transfusion-dependent patients, especially those with **iron overload** (common in thalassemia), are particularly susceptible to **Yersinia enterocolitica** infections because *Yersinia* thrives in iron-rich environments. - The image shows a child with marked hepatosplenomegaly (outlined on the abdomen), which is characteristic of conditions leading to transfusion dependence and subsequent iron overload, such as **thalassemia major**. *Listeria monocytogenes* - While *Listeria* can cause serious infections, particularly in immunocompromised individuals and neonates, its association with **iron overload** from transfusions is not as prominent as *Yersinia*. - **Listeriosis** typically presents as meningitis, sepsis, or febrile gastroenteritis. *Acinetobacter* - *Acinetobacter* species are often associated with **nosocomial infections**, affecting critically ill or immunocompromised patients in hospital settings, but not specifically linked to iron overload or transfusion dependence as a primary risk factor like *Yersinia*. - Infections commonly include pneumonia, urinary tract infections, and wound infections. *Pneumococcus* - **Pneumococcal infections** are common in children, especially those with asplenia or functional asplenia (which can occur in thalassemia due to splenic sequestration), but a direct link to **transfusion-associated iron overload** as a specific risk factor for severe pneumococcal disease is not the primary association like *Yersinia*. - These infections typically manifest as pneumonia, meningitis, and otitis media.

Q: The image shows cigar-shaped soft tissue calcification/rice grain calcification in muscles, which is characteristic of cysticercosis. This finding in a patient with neurocysticercosis is categorized as:

Minor criteria. ***Minor criteria*** - **Extraparenchymal cysticercosis** (e.g., subcutaneous, intramuscular, or ocular cysts) is classified as a minor criterion in the diagnostic criteria for neurocysticercosis (NCC). - While supportive, these findings alone are usually insufficient for a definitive NCC diagnosis without other major or epidemiological criteria. *Major criteria* - Major criteria for NCC diagnosis include definitive findings like **histological evidence** of *Taenia solium* cysticerci or **neuroimaging evidence** of intraparenchymal cysts, often showing scolex or characteristic calcifications. - The calcified muscle lesions are not considered major criteria as they are outside the central nervous system. *Absolute criteria* - **Absolute criteria** for NCC are typically histological confirmation of the parasite or unambiguous demonstration of the scolex within a cyst on imaging. - While strongly indicative of *Taenia solium* infection, soft tissue calcifications alone do not meet this level of certainty for a CNS diagnosis. *Confirmatory criteria* - **Confirmatory criteria** often imply a definitive diagnosis based on highly specific findings, such as parasitic identification, or resolution of lesions upon anti-parasitic treatment. - Calcifications in soft tissues, while highly suggestive of cysticercosis, do not directly confirm neurocysticercosis without evidence of CNS involvement.

Q: A 48-year-old intravenous drug abuser presents with vomiting, jaundice and right hypochondrium pain. USG abdomen shows presence of:

Amebic liver abscess. ***Amebic liver abscess*** - The image provided clearly labels "a. Amebic liver abscess" and the clinical presentation of **vomiting**, **jaundice**, **right hypochondrium pain**, and particularly **intravenous drug abuse** (a risk factor for infections, including those that can lead to abscesses) are consistent with a liver abscess. - The ultrasound image (left panel) likely shows a **hypoechoic lesion** within the liver, characteristic of an abscess. The MR image (right panel, likely an MRCP or similar sequence) also shows features consistent with an intrahepatic lesion. *Acute viral hepatitis* - While intravenous drug abuse is a risk factor for **viral hepatitis** (e.g., HBV, HCV), acute viral hepatitis typically presents with diffuse liver inflammation, which would appear as **hepatomegaly** and altered parenchymal echogenicity on ultrasound, rather than a focal lesion like an abscess. - The imaging for acute viral hepatitis usually doesn't show a well-defined **focal lesion** as depicted. *Acute cholecystitis* - **Acute cholecystitis** involves inflammation of the gallbladder, often due to gallstones, presenting with right hypochondrium pain. - The provided images focus on the liver parenchyma and do not specifically show signs like **gallbladder wall thickening**, pericholecystic fluid, or gallstones within the gallbladder, which are characteristic of cholecystitis. *Hepatocellular carcinoma* - **Hepatocellular carcinoma (HCC)** is a primary liver cancer, often seen in patients with chronic liver disease (e.g., from chronic viral hepatitis or alcoholism). - While HCC can present as a focal liver lesion, the clinical context of **acute symptoms** (vomiting, jaundice, pain) and intravenous drug abuse points more towards an infectious process like an abscess rather than a typically more indolent malignant lesion unless there's a specific acute complication.

Q: A 45-year-old alcoholic presents with severe respiratory distress. On examination bronchial breathing was heard in right infraclavicular and inframammary areas. The X-ray chest was performed. The best antibiotic to be given to the patient is:

Cefotaxime plus amikacin. ***Cefotaxime plus amikacin*** - This combination provides broad-spectrum coverage, essential for severe pneumonia in an alcoholic patient, particularly against **Gram-negative bacilli** and potentially **anaerobes** if aspiration is suspected. - Alcoholics are prone to infections with atypical organisms like *Klebsiella pneumoniae*, which can cause severe, cavitating pneumonia, requiring aggressive antibiotic therapy. *Azithromycin* - Azithromycin is primarily effective against **atypical pathogens** (e.g., Mycoplasma, Chlamydia, Legionella) and some Gram-positive bacteria. - It lacks sufficient coverage for the broad range of pathogens, especially Gram-negative rods, that are common in aspiration pneumonia or severe community-acquired pneumonia in alcoholics. *Penicillin* - Penicillin has a relatively narrow spectrum, primarily covering **Gram-positive cocci** (like some Streptococcus strains) and some anaerobes. - It would be insufficient against common Gram-negative pathogens and lacks efficacy for severe pneumonia where multi-drug resistance or unusual pathogens are a concern. *Aztreonam plus meropenem* - This combination is extremely broad-spectrum and typically reserved for very severe, often **nosocomial infections** or cases with documented multidrug-resistant organisms. - While meropenem offers excellent broad-spectrum coverage, including against Gram-negative bacteria and anaerobes, aztreonam is specific to Gram-negative aerobes. This combination may be overtreatment for initial empiric therapy and carries a higher risk of C.difficile infection.

Question 1

A 26-year-old male presented with fever and headache for 3 days. On 3rd day, his BP is $90 / 60 \mathrm{~mm} \mathrm{Hg}$ and examination revealed rashes on the legs as shown. What is the likely diagnosis?

Accepted Answer

Meningococcus

Answer

Dengue hemorrhagic fever

Answer

Enteric fever

Answer

Scrub typhus

Question 2

The following cell type is seen in peripheral smear of a patient with membrane over the tonsils. All can be used in treatment except?

Accepted Answer

Acyclovir

Answer

Prednisolone

Answer

IVIG

Answer

Acetaminophen

Question 3

Which of the following will best describe this patient?

Accepted Answer

Fever, weight loss, night sweats and elevated ESR

Answer

Rusty sputum with gram positive diplococci

Answer

Acute dyspnea, elevated JVP and long history of air travel

Answer

Acute dyspnea, pink frothy sputum and mid-diastolic rumble

Question 4

Drug of choice for following infection (as shown in image) in a HIV patient: (NEET Pattern 2019)

Accepted Answer

Cotrimoxazole

Answer

INH+ Rifampicin

Answer

Doxycycline

Answer

Azithromycin

Question 5

A 28-year-old female patient presents with abdominal pain, fever, night sweats, malaise, and intercostal tenderness. Past history of bloody diarrhea is present. USG liver of the patient is given. Which among the following statements is false?

Accepted Answer

Aspiration and culture is the investigation of choice

Answer

This condition is caused by an organism that spreads via fecal-oral route

Answer

Right lobe of the liver is most commonly affected

Answer

Patient may present with pulmonary symptoms

Question 6

Which of the following infections in most commonly seen in this transfusion dependant child shown below?

Accepted Answer

Yersinia enterocolitica

Answer

Listeria monocytogenes

Answer

Acinetobacter

Answer

Pneumococcus

Question 7

The image shows cigar-shaped soft tissue calcification/rice grain calcification in muscles, which is characteristic of cysticercosis. This finding in a patient with neurocysticercosis is categorized as:

Accepted Answer

Minor criteria

Answer

Major criteria

Answer

Absolute criteria

Answer

Confirmatory criteria

Question 8

A 48-year-old intravenous drug abuser presents with vomiting, jaundice and right hypochondrium pain. USG abdomen shows presence of:

Accepted Answer

Amebic liver abscess

Answer

Acute viral hepatitis

Answer

Acute cholecystitis

Answer

Hepatocellular carcinoma

Question 9

A 45-year-old alcoholic presents with severe respiratory distress. On examination bronchial breathing was heard in right infraclavicular and inframammary areas. The X-ray chest was performed. The best antibiotic to be given to the patient is:

Accepted Answer

Cefotaxime plus amikacin

Answer

Azithromycin

Answer

Penicillin

Answer

Aztreonam plus meropenem

Question 10

A 30-year-old patient has suffered from multiple episodes of GTCS for the last one week. MRI was performed. All are true about the condition except:

Accepted Answer

Steroids must be given in the racemose form

Answer

MRI shows colloidal stage of NCC

Answer

CSF eosinophilia

Answer

Enzyme-linked immune-electrotransfer blot assay is more sensitive than CSF ELISA

Infectious Diseases — MCQs

Infectious Diseases — MCQs

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