Infectious Diseases — MCQs
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The most common ophthalmic affection of diphtheria is –
Fever and haemorrhagic rash are seen in all except which of the following?
Which of the following is a chronic complication of malaria?
Fecal leucocytes are absent in all of the following, except:
A most common cause of nongonococcal septic arthritis is
An 34-year-old male HIV patient on c-A presents with seizures and a unilateral facial nerve palsy. The CT scan shows a ring-enhancing lesion. What is the best treatment?
Which of the following is a characteristic symptom of Bacillus cereus food poisoning?
Risk of pneumococcal meningitis is seen in whom?
Not typically associated with Ludwig's angina is
Maximum infection of CMV is seen after what duration post-transplantation?
Infectious Diseases Indian Medical PG Practice Questions and MCQs
Question 1261: The most common ophthalmic affection of diphtheria is –
- A. Ptosis
- B. Total ophthalmoplegia
- C. Isolated ocular palsies (Correct Answer)
- D. Ophthalmoplegia externa
Explanation: ***Isolated ocular palsies*** - Diphtheria exotoxin can lead to localized neuropathies, and **ocular muscle palsies** are common, often affecting individual extraocular muscles rather than generalized paralysis. - Involvement typically presents as problems with **accommodation** or specific ocular movements due to cranial nerve involvement. *Ptosis* - While ptosis can occur due to **oculomotor nerve dysfunction**, it is less common as an isolated, primary ophthalmic manifestation of diphtheria compared to other ocular palsies. - It usually indicates more widespread **Cranial Nerve III involvement**, which is not the most frequent initial or isolated ocular finding. *Total ophthalmoplegia* - This involves paralysis of **all extraocular muscles**, which is a severe and less common manifestation of diphtheria. - Diphtheria typically causes more **localized and incomplete palsies** rather than affecting all eye movements universally. *Ophthalmoplegia externa* - This involves paralysis of the **extraocular muscles** but spares the **intrinsic eye muscles** (pupil and accommodation). - While diphtheria *can* cause external ophthalmoplegia, **isolated ocular palsies** (which include external ophthalmoplegia) more accurately describe the common presentation of affecting specific muscles or nerves.
Question 1262: Fever and haemorrhagic rash are seen in all except which of the following?
- A. Dengue fever
- B. Rift Valley fever
- C. Sand fly fever (Correct Answer)
- D. Lassa fever
Explanation: ***Sand fly fever*** - **Sand fly fever**, also known as phlebotomus fever, is typically characterized by an acute onset of fever, headache, myalgia, and malaise. - While it can cause a rash, it is generally **non-hemorrhagic** and petechiae or purpura are uncommon. *Dengue fever* - **Dengue fever** is well-known for causing **hemorrhagic manifestations**, ranging from petechiae and purpura to severe bleeding [1]. - The classic presentation includes high fever, severe headache, retro-orbital pain, and a generalized rash which can become hemorrhagic [1]. *Lassa fever* - **Lassa fever** is a severe viral hemorrhagic fever caused by the Lassa virus [2]. - It often progresses to include a **hemorrhagic rash** along with organ damage and generalized bleeding tendencies [2]. *Rift Valley fever* - **Rift Valley fever** is another viral hemorrhagic fever that can cause a spectrum of symptoms including fever and, in severe cases, **hemorrhagic manifestations** such as petechiae, ecchymoses, and epistaxis. - Ocular and neurological complications are also characteristic of severe disease.
Question 1263: Which of the following is a chronic complication of malaria?
- A. Nephrotic syndrome
- B. Pneumonia
- C. Hodgkin's disease
- D. Splenomegaly (Correct Answer)
Explanation: Splenomegaly - Chronic malaria, especially Plasmodium falciparum infections, leads to persistent erythrocytic sequestration in the spleen. - This prolonged immune response and destruction of infected red blood cells contribute to significant and often palpable enlargement of the spleen [1]. Nephrotic syndrome - While malaria can cause kidney complications, nephrotic syndrome is more commonly associated with specific types of malaria, particularly Plasmodium malariae, and is often considered a direct acute or subacute complication rather than a widespread chronic sequela of all malaria types. - The primary chronic complication that affects a broader range of malaria cases is splenomegaly. Pneumonia - Pneumonia is an acute respiratory infection that can occur as a co-infection or complication in severely ill malaria patients. - It is not considered a chronic complication of malaria itself, but rather an acute opportunistic infection or secondary issue. Hodgkin's disease - There is no direct, established link between chronic malaria infection and the development of Hodgkin's disease [2]. - While other infections (e.g., EBV) are associated with certain lymphomas, malaria is not known to be a direct causative agent or chronic complication leading to Hodgkin's lymphoma [2].
Question 1264: Fecal leucocytes are absent in all of the following, except:
- A. Cryptosporidiosis
- B. Clostridium perfringes infection
- C. Giardiasis
- D. Campylobacter infection (Correct Answer)
Explanation: ***Campylobacter infection*** - This infection causes **inflammatory diarrhea**, leading to the presence of **fecal leucocytes** as a response to intestinal tissue invasion. - The inflammatory process results in disruption of the intestinal mucosa, attracting **neutrophils** and other inflammatory cells to the stool. *Giardiasis* - **Giardia lamblia** infection typically causes **non-inflammatory diarrhea** by interfering with nutrient absorption in the small intestine. - Due to the non-invasive nature of the pathogen, **fecal leucocytes** are generally **absent** in the stool. *Cryptosporidiosis* - **Cryptosporidium parvum** primarily causes **non-inflammatory watery diarrhea** by adhering to and damaging the microvilli of the intestinal epithelium. - While it can cause flattening of the villi, it does not typically lead to significant tissue invasion or the presence of **fecal leucocytes**. *Clostridium perfringens infection* - This bacterium causes **food poisoning** mainly through the production of **toxins** that affect the intestinal lining. - The diarrhea is typically **non-inflammatory**, and **fecal leucocytes** are usually **absent** because there is no significant host immune cell invasion.
Question 1265: A most common cause of nongonococcal septic arthritis is
- A. Staphylococcus aureus (Correct Answer)
- B. Pseudomonas aeruginosa
- C. Streptococcus species
- D. Haemophilus influenzae
Explanation: ***Staphylococcus aureus*** - **_Staphylococcus aureus_** is the most common cause of **nongonococcal septic arthritis** in adults and children [1]. - This organism can invade joints via **hematogenous spread** or direct inoculation following trauma or surgery [1]. *Pseudomonas aeruginosa* - **_Pseudomonas aeruginosa_** is a common cause of septic arthritis in **IV drug users** and individuals with **puncture wounds** through shoes [1]. - It is not the most common overall cause of nongonococcal septic arthritis. *Streptococcus species* - Various **_Streptococcus species_** (e.g., *S. pyogenes*, *S. pneumoniae*) can cause septic arthritis, particularly in elderly individuals or those with underlying conditions [1]. - However, they are **less frequent** causes compared to *Staphylococcus aureus* [1]. *Haemophilus influenzae* - **_Haemophilus influenzae_** was a common cause of septic arthritis in **children** before the widespread introduction of the hib vaccine. - Its incidence has significantly decreased in vaccinated populations and is now rare in adults.
Question 1266: An 34-year-old male HIV patient on c-A presents with seizures and a unilateral facial nerve palsy. The CT scan shows a ring-enhancing lesion. What is the best treatment?
- A. Albendazole with dexamethasone
- B. Amphotericin B
- C. ATT with steroids
- D. Sulphadiazine, pyrimethamine and Leucovorin (Correct Answer)
Explanation: ***Sulphadiazine, pyrimethamine and Leucovorin*** - This combination is the standard **first-line treatment for cerebral toxoplasmosis**, which is strongly suggested by the clinical presentation (HIV patient, seizures, facial nerve palsy) and the imaging findings of **multiple ring-enhancing lesions**. - **Leucovorin** is added to prevent bone marrow suppression caused by pyrimethamine. *Albendazole with dexamethasone* - **Albendazole** is primarily used for **neurocysticercosis**, which typically presents with cystic lesions, not necessarily ring-enhancing, and the patient's HIV status makes toxoplasmosis more likely. - While **dexamethasone** may be used to reduce brain edema, it's adjunctive and not the primary antimicrobial treatment for toxoplasmosis. *Amphotericin B* - **Amphotericin B** is the mainstay treatment for **cryptococcal meningitis** and other severe fungal infections, which usually present with symptoms of meningitis and different imaging findings (e.g., hydrocephalus, gelatinous pseudocysts). - It is not effective against **Toxoplasma gondii**. *ATT with steroids* - **ATT (Anti-Tubercular Therapy)** with steroids is the treatment for **CNS tuberculosis**, which can present with ring-enhancing lesions. - However, the typical presentation for CNS tuberculosis in HIV patients often includes basilar meningitis, multiple tuberculomas, or abscesses, and toxoplasmosis is a far more common cause of ring-enhancing lesions in HIV patients with CD4 counts < 100 cells/µL.
Question 1267: Which of the following is a characteristic symptom of Bacillus cereus food poisoning?
- A. Abdominal cramps
- B. Vomiting (emetic type) (Correct Answer)
- C. Fever (uncommon)
- D. Diarrhea (diarrheal type)
Explanation: ***Vomiting (emetic type)*** - The **emetic type** of *Bacillus cereus* food poisoning is characterized by prominent **nausea and vomiting** with a rapid onset (within 1-5 hours) after consuming food, particularly rice [1],[2]. - This is caused by the preformed **cereulide toxin**, a heat-stable cyclic depsipeptide [2]. *Abdominal cramps* - While *Bacillus cereus* food poisoning can include abdominal cramps, they are a more general symptom and not as specifically characteristic or defining as the emetic or diarrheal presentations [1],[2]. - Abdominal cramps are often present in both the emetic and diarrheal forms, but the distinctive feature lies in the primary gastrointestinal manifestation [3]. *Fever (uncommon)* - Fever is **rarely a prominent symptom** in *Bacillus cereus* food poisoning, distinguishing it from many other bacterial foodborne illnesses. - The disease is primarily mediated by toxins, leading to localized GI symptoms rather than systemic inflammatory responses that cause fever. *Diarrhea (diarrheal type)* - *Bacillus cereus* also causes a **diarrheal type** of food poisoning, characterized by diarrhea and abdominal pain, but typically with a longer incubation period (6-15 hours) and is caused by different toxins (**hemolysin BL and non-hemolytic enterotoxin**) [2]. - While diarrhea is a characteristic symptom of *Bacillus cereus* diarrheal type, the question lists vomiting as the emetic type, focusing on the specific emetic presentation which is distinct [3].
Question 1268: Risk of pneumococcal meningitis is seen in whom?
- A. Post splenectomy patient (Correct Answer)
- B. Patient undergone neurosurgical intervention
- C. Patient following cardiac surgery
- D. Patient with hypoplasia of lung
Explanation: ***Post splenectomy patient*** - Patients who have undergone a **splenectomy** are at a significantly increased risk of developing severe infections, particularly by **encapsulated bacteria** like *Streptococcus pneumoniae*. - The **spleen plays a crucial role** in filtering bacteria from the blood and producing antibodies. Without it, the body's ability to clear pneumococci is severely impaired, leading to a higher risk of systemic infections, including meningitis. *Patient undergone neurosurgical intervention* - Neurosurgical interventions can increase the risk of meningitis, but usually it involves **nosocomial infections** or organisms introduced during the procedure (e.g., *Staphylococcus aureus*, gram-negative rods). - While possible, the risk of **pneumococcal meningitis** specifically is not as uniquely or significantly elevated as in splenectomized patients due to an underlying immune deficiency related to bacterial clearance. *Patient following cardiac surgery* - Patients undergoing cardiac surgery are at risk for various postoperative complications, including infections (e.g., **surgical site infections**, **endocarditis**). - However, routine cardiac surgery does not inherently predispose patients to a significantly increased risk of **pneumococcal meningitis** specifically, as their immune response to encapsulated bacteria is generally intact. *Patient with hypoplasia of lung* - **Hypoplasia of the lung** refers to incomplete development of the lung tissue, leading to reduced lung function. - While it may increase susceptibility to **respiratory infections** due to compromised lung mechanics, it does not directly impair the systemic immune response to encapsulated bacteria like *Streptococcus pneumoniae* in a way that specifically elevates the risk of meningitis to the same extent as asplenia.
Question 1269: Not typically associated with Ludwig's angina is
- A. It is caused by anaerobic organisms
- B. Cellulitis in the floor of mouth
- C. Aphthous ulcer in pharynx (Correct Answer)
- D. Glottal edema, may require tracheostomy
Explanation: ***Aphthous ulcer in pharynx*** - **Aphthous ulcers** are discrete, painful oral lesions typically associated with trauma, stress, or certain systemic conditions, and are **not a feature** of the infection and inflammation seen in Ludwig's angina [1]. - Ludwig's angina is a severe **bacterial infection** of the submandibular, sublingual, and submental spaces, characterized by aggressive cellulitis rather than ulcerative lesions. *It is caused by anaerobic organisms* - **Mixed flora**, including **anaerobic bacteria** (e.g., Peptostreptococcus, Bacteroides, Fusobacterium), are commonly implicated in Ludwig's angina, often originating from odontogenic infections [2]. - The presence of anaerobes contributes to the rapid progression and extensive tissue destruction characteristic of this severe infection [2]. *Cellulitis in the floor of mouth* - Ludwig's angina is specifically defined as a **rapidly spreading cellulitis** that involves the **submandibular, sublingual, and submental spaces** of the floor of the mouth. - This cellulitis is non-suppurative but causes significant edema and induration, which can displace the tongue superiorly and posteriorly. *Glottal edema, may require tracheostomy* - The extensive edema in the floor of the mouth can extend rapidly to the **larynx**, leading to **glottal edema** and **airway obstruction**. - Due to the critical risk of airway compromise, an emergency **tracheostomy** or **cricothyrotomy** may be necessary to secure the airway in advanced cases.
Question 1270: Maximum infection of CMV is seen after what duration post-transplantation?
- A. Immediate
- B. < 1 month
- C. 1-4 months (Correct Answer)
- D. > 6 months
Explanation: ***1-4 months*** - The period of **1 to 4 months post-transplantation** is considered the peak risk period for **cytomegalovirus (CMV) infection** and disease due to a combination of intense immunosuppression and viral reactivation/transmission dynamics during this time [1]. - This window allows sufficient time for the transplanted organ to establish itself and for immunosuppressive regimens to reach their full effect, which then creates an environment highly susceptible to opportunistic viral infections like CMV [1]. *Immediate* - **Immediate post-transplant** (first few days) complications are usually related to surgery, organ function, or hyperacute rejection. - While viral exposure can occur, clinically significant CMV infection usually requires a longer incubation period. *< 1 month* - Though CMV infection can occur within the first month, the **incidence typically rises significantly after the first few weeks**, peaking later. - Early infections (<1 month) may be seen in cases of very high viral load in the donor organ or severe initial immunosuppression, but are not the overall maximum. *> 6 months* - After 6 months, while CMV infection can still occur (late-onset CMV disease), the **overall risk is generally lower** compared to the 1-4 month period. - This is because immunosuppression regimens are often tapered, and the recipient's immune system may have partially recovered or developed some anamnestic response by this time.
Practice by Chapter
Principles of Antimicrobial Therapy
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Fever of Unknown Origin
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HIV/AIDS and Related Infections
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Tuberculosis and Mycobacterial Diseases
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Tropical and Parasitic Infections
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Viral Infections (Hepatitis, Herpes, etc.)
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Healthcare-Associated Infections
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Fungal Infections
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Sepsis and Septic Shock
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Infection in Immunocompromised Hosts
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Emerging and Re-emerging Infections
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Antimicrobial Resistance
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Vaccination Principles
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