Viral Hemorrhagic Fevers — MCQs
All are transmitted by blood except -
In a patient presented with a fever and a positive filarial antigen test, what is the next appropriate method of management?
Crimean-Congo Hemorrhagic Fever is transmitted by?
Which of the following viral infections is transmitted by tick?
The tick-borne hemorrhagic fever found in Karnataka state is:
Which of the following statements regarding dengue fever is false?
An elderly man who had been in several military conflicts during the early 1980s and received blood transfusions for injuries recently consulted his physician for a diagnosis of cryoglobulinemia and glomerulonephritis. Additional testing revealed that he was infected with a virus transmitted through blood. Which virus was involved in this infection?
A 25-year-old woman presents with a sudden onset of high fever, chills, and rigors. Blood cultures are pending. What is the next appropriate step in her management?
Dengue hemorrhagic fever on Day 5: Which investigation is most appropriate?
What is the most likely diagnosis for a patient presenting with sudden onset headache and neck rigidity?
Viral Hemorrhagic Fevers Indian Medical PG Practice Questions and MCQs
Question 1: All are transmitted by blood except -
- A. Parvovirus B-19
- B. Cytomegalovirus
- C. Hepatitis G
- D. Epstein-Barr virus (Correct Answer)
Explanation: **Epstein-Barr virus** - While Epstein-Barr virus can be detected in blood, its primary mode of transmission is through **saliva** (e.g., kissing, sharing utensils), leading to infectious mononucleosis. - **Blood transfusion transmission** of EBV is rare and not considered a major route of spread in otherwise healthy individuals. *Parvovirus B-19* - **Parvovirus B-19** is well-known to be transmitted via **blood products** and can cause transient aplastic crisis, especially in patients with chronic hemolytic anemias. - It can also be transmitted via **respiratory droplets** and vertically from mother to fetus. *Cytomegalovirus* - **Cytomegalovirus (CMV)** is frequently transmitted through **blood transfusions**, especially to immunocompromised patients. - It can also be transmitted through other bodily fluids, organ transplantation, and congenitally. *Hepatitis G* - **Hepatitis G virus (HGV)**, now renamed **GB virus C (GBV-C)**, is primarily transmitted through **blood** and blood products. - It is often found as a co-infection with hepatitis C virus but its pathogenicity remains controversial.
Question 2: In a patient presented with a fever and a positive filarial antigen test, what is the next appropriate method of management?
- A. Bone marrow biopsy
- B. DEC provocation test
- C. Detection of microfilariae in the blood smear (Correct Answer)
- D. Ultrasound of the scrotum
Explanation: ***Detection of microfilariae in the blood smear*** - A positive **filarial antigen test** indicates the presence of adult worms, and the next step is to confirm active infection by identifying **microfilariae**. [1] - **Nocturnal blood samples** are crucial because microfilariae of *Wuchereria bancrofti* and *Brugia malayi* exhibit **nocturnal periodicity**, meaning they are most abundant in peripheral blood between 10 PM and 2 AM. [1] *Bone marrow biopsy* - This procedure is typically used to diagnose **hematological disorders**, such as leukemia or lymphoma, or investigate causes of unexplained fever, but it is not indicated for filariasis. - While filariasis can rarely lead to **eosinophilia**, a bone marrow biopsy is not a diagnostic tool for filarial infection itself. *DEC provocation test* - The **diethylcarbamazine (DEC) provocation test** is used to bring out microfilariae into the peripheral blood during the daytime for species that exhibit nocturnal periodicity. [1] - However, it carries a risk of severe adverse reactions due to rapid killing of microfilariae, especially in cases of heavy infection, and is generally avoided when antigen tests are positive. [1] *Ultrasound of the scrotum* - Scrotal ultrasound can detect the characteristic "filarial dance sign" (motile adult worms) in the **lymphatic vessels of the scrotum and epididymis**, confirming lymphatic filariasis. [2] - While useful for assessing advanced disease manifestations like **hydrocele**, it does not quantify microfilaremia or replace the need for microscopic confirmation of circulating microfilariae to guide treatment.
Question 3: Crimean-Congo Hemorrhagic Fever is transmitted by?
- A. Catfish
- B. Mosquitoes
- C. Ticks (Correct Answer)
- D. Mites
Explanation: ***Ticks*** - Crimean-Congo Hemorrhagic Fever (CCHF) is primarily transmitted to humans through the bite of infected **Hyalomma ticks**. - Transmission can also occur through contact with infected animal blood or tissues, or through contact with infected human body fluids. *Cat fish* - **Catfish** are aquatic animals and are not known vectors for the transmission of viral diseases like CCHF. - Their habitat and interaction with humans do not facilitate the spread of tick-borne illnesses. *Mosquitoes* - **Mosquitoes** are vectors for diseases like dengue, malaria, and Zika, but not for CCHF. - CCHF is caused by a Nairovirus, which typically requires a tick vector for its lifecycle and transmission to humans. *Mites* - While some **mites** can transmit diseases (e.g., scrub typhus), they are not the primary or significant vector for Crimean-Congo Hemorrhagic Fever. - The main vector for CCHF is specified as ticks, particularly the Hyalomma genus.
Question 4: Which of the following viral infections is transmitted by tick?
- A. Ehrlichiosis
- B. Lyme disease
- C. Rocky Mountain spotted fever
- D. Kyasanur forest disease (KFD) (Correct Answer)
Explanation: ***Kyasanur forest disease (KFD)*** - KFD is a **viral hemorrhagic fever** caused by the Kyasanur Forest disease virus, a member of the *Flaviviridae* family. - It is primarily transmitted to humans through the bite of infected **ticks**, especially *Haemaphysalis spinigera*. *Ehrlichiosis* - Ehrlichiosis is a **bacterial infection** caused by *Ehrlichia* species, not a viral infection. - It is transmitted by **ticks**, primarily the **lone star tick** (*Amblyomma americanum*). *Lyme disease* - Lyme disease is a **bacterial infection** caused by *Borrelia burgdorferi*, not a viral infection. - It is transmitted by **ticks**, notably the **black-legged tick** (*Ixodes scapularis*). *Rocky Mountain spotted fever* - Rocky Mountain spotted fever (RMSF) is a **bacterial infection** caused by *Rickettsia rickettsii*, not a viral infection. - It is transmitted by **ticks**, such as the **American dog tick**, **Rocky Mountain wood tick**, and **brown dog tick**.
Question 5: The tick-borne hemorrhagic fever found in Karnataka state is:
- A. Japanese encephalitis
- B. Kyasanur forest disease (Correct Answer)
- C. Epidemic nephrosonephritis
- D. Lassa fever
Explanation: Kyasanur forest disease - **Kyasanur Forest Disease (KFD)** is a **tick-borne hemorrhagic fever** endemic to **Karnataka, India**, particularly in the Shivamogga district. - The disease is caused by the **Kyasanur Forest Disease virus (KFDV)**, a member of the *Flaviviridae* family, transmitted to humans through the bite of infected ticks, primarily *Haemaphysalis spinigera*. *Japanese encephalitis* - **Japanese encephalitis** is a **mosquito-borne viral disease** that can cause encephalitis, but it is not typically characterized as a hemorrhagic fever and is not specifically linked to ticks in Karnataka. - While it can cause neurological symptoms, the primary vector is **mosquitoes**, not ticks, and its epidemiology differs from KFD. *Epidemic nephrosonephritis* - **Epidemic nephrosonephritis** (also known as **Hemorrhagic Fever with Renal Syndrome - HFRS**) is caused by **Hantaviruses** and is typically transmitted through contact with rodent urine, feces, or saliva. - It primarily affects the kidneys and can cause hemorrhagic manifestations, but it is **not tick-borne** and is not the specific hemorrhagic fever found in Karnataka. *Lassa fever* - **Lassa fever** is an **acute viral hemorrhagic illness** caused by the Lassa virus, which is endemic to West Africa and is primarily transmitted to humans through contact with food or household items contaminated with the urine and feces of **multimammate rats (Mastomys natalensis)**. - It is **not found in India** and is not transmitted by ticks.
Question 6: Which of the following statements regarding dengue fever is false?
- A. Common in south Asian region
- B. Transmitted by Aedes aegypti
- C. Thrombocytopenia
- D. Subclinical cases never occur (Correct Answer)
Explanation: **Subclinical cases never occur** - This statement is false because **subclinical** or **asymptomatic infections** are common in dengue fever, meaning many infected individuals do not develop noticeable symptoms but can still transmit the virus. - Studies indicate that the ratio of asymptomatic to symptomatic cases can be as high as 4:1, playing a significant role in **virus transmission** and **herd immunity**. *Common in south Asian region* - This statement is true; **dengue fever** is highly **endemic** in South Asian regions, including countries like India, Bangladesh, and Pakistan, due to suitable climatic conditions for the **Aedes mosquito** and high population density. - The region experiences annual outbreaks, particularly during **monsoon seasons**, leading to a substantial public health burden. *Transmitted by Aedes aegypti* - This statement is true. Dengue fever is primarily transmitted to humans through the bite of infected female **Aedes aegypti mosquitoes**. - **Aedes albopictus** can also act as a vector, but **Aedes aegypti** is considered the main vector in most urban areas. *Thrombocytopenia* - This statement is true. **Thrombocytopenia** (low platelet count) is a hallmark of dengue fever, often correlating with disease severity and risk of **hemorrhage**. - As platelet counts drop, patients are at higher risk of **bleeding complications**, especially in **severe dengue**.
Question 7: An elderly man who had been in several military conflicts during the early 1980s and received blood transfusions for injuries recently consulted his physician for a diagnosis of cryoglobulinemia and glomerulonephritis. Additional testing revealed that he was infected with a virus transmitted through blood. Which virus was involved in this infection?
- A. Hepatitis A Virus (HAV)
- B. Hepatitis B Virus (HBV)
- C. Hepatitis C Virus (HCV) (Correct Answer)
- D. Hepatitis D Virus (HDV)
Explanation: ***Hepatitis C Virus (HCV)*** - HCV infection is a common cause of **mixed cryoglobulinemia** and can lead to **glomerulonephritis**, particularly membranoproliferative glomerulonephritis. - Before widespread screening of the blood supply, HCV was a significant risk from **blood transfusions**, especially for individuals who received them in the early 1980s [1]. *Hepatitis A Virus (HAV)* - HAV is primarily transmitted via the **fecal-oral route** and does not typically cause chronic infection or lead to cryoglobulinemia or glomerulonephritis. - It causes **acute, self-limiting hepatitis** and is not associated with blood transfusions in the context described. *Hepatitis B Virus (HBV)* - While HBV can be transmitted through blood and can cause glomerulonephritis (e.g., membranous nephropathy), it is less commonly associated with **cryoglobulinemia** in comparison to HCV. - The constellation of cryoglobulinemia and glomerulonephritis, especially with a history of transfusions in the 1980s, points more strongly to HCV. *Hepatitis D Virus (HDV)* - HDV is a **defective virus** that requires co-infection with HBV to replicate. - While it can cause severe liver disease, it is not primarily associated with **cryoglobulinemia** or glomerulonephritis as a direct cause, but rather exacerbates HBV-related complications.
Question 8: A 25-year-old woman presents with a sudden onset of high fever, chills, and rigors. Blood cultures are pending. What is the next appropriate step in her management?
- A. Administer broad-spectrum antibiotics (Correct Answer)
- B. Wait for blood culture results
- C. Start antipyretic therapy only
- D. Order a CT scan
Explanation: ***Administer broad-spectrum antibiotics*** - The patient presents with classic signs of **sepsis** (high fever, chills, rigors), which is a medical emergency requiring prompt intervention [2]. - **Early administration of broad-spectrum antibiotics** is crucial to improve outcomes and reduce mortality in suspected sepsis, even before culture results are available [1]. *Wait for blood culture results* - Delaying antibiotic treatment in a patient with suspected sepsis can lead to rapid clinical deterioration and increased mortality [1]. - While blood cultures are essential to guide definitive therapy, initial empiric broad-spectrum antibiotics should not be withheld [3]. *Start antipyretic therapy only* - Antipyretics only address the symptom of fever and do not treat the underlying infection causing the fever and chills. - This approach would leave the potentially life-threatening infection untreated, leading to worsening patient condition. *Order a CT scan* - A CT scan is not the immediate priority in a patient presenting with acute signs of systemic infection and suspected sepsis. - While it may be useful later to identify a source of infection, controlling the infection with antibiotics is the most urgent step.
Question 9: Dengue hemorrhagic fever on Day 5: Which investigation is most appropriate?
- A. RT PCR
- B. Viral culture
- C. IgM ELISA (Correct Answer)
- D. NS1 Antigen
Explanation: ***IgM ELISA*** - From day 4-5 onwards in dengue infection, **IgM antibodies** start to become detectable and their levels rise significantly towards the end of the first week and into the second week. - An **IgM ELISA** (Enzyme-Linked Immunosorbent Assay) is a highly sensitive and specific method for detecting these antibodies, making it the most appropriate test on Day 5. *RT PCR* - **Reverse transcriptase polymerase chain reaction (RT-PCR)** detects viral RNA and is most useful in the early stages of dengue infection (first 1-5 days) when viremia is high. - By Day 5, viral load may be decreasing, making RT-PCR less sensitive compared to antibody detection. *Viral culture* - **Viral culture** is generally labor-intensive, time-consuming, and has low sensitivity for dengue virus detection in clinical practice. - It is not commonly used for routine diagnosis and is usually reserved for research purposes. *NS1 Antigen* - **NS1 antigen** detection is most useful in the very early acute phase of dengue infection, typically within the first 0-5 days. - While it might still be detectable on Day 5, its sensitivity tends to decrease after the first few days, whereas IgM antibodies are increasing, making IgM ELISA a better choice for that time point [1]. *Clinical Course* - The period 3–7 days after onset of fever is termed the ‘critical’ phase, during which signs of Dengue Hemorrhagic Fever (DHF) may develop [1].
Question 10: What is the most likely diagnosis for a patient presenting with sudden onset headache and neck rigidity?
- A. Intraparenchymal hemorrhage
- B. Meningitis
- C. Subarachnoid Hemorrhage (Correct Answer)
- D. None of the options
Explanation: ***Subarachnoid Hemorrhage*** - A **sudden onset headache**, often described as the **"worst headache of my life,"** [1] combined with **neck rigidity (nuchal rigidity)**, [1] is highly characteristic of a subarachnoid hemorrhage. - This condition results from bleeding into the **subarachnoid space**, typically due to a ruptured aneurysm, [2] leading to meningeal irritation. *Intraparenchymal hemorrhage* - While an intraparenchymal hemorrhage can cause a sudden headache, **neck rigidity** is less common unless the hemorrhage is very large or extends into the ventricular system, irritating the meninges. - Neurological deficits are often more prominent and specific to the affected brain region, such as **hemiparesis** or **aphasia**. *Meningitis* - Meningitis also presents with **headache** and **neck rigidity**, [1] but the onset is usually more gradual, developing over hours to days, unlike the abrupt onset seen in this case. - Additionally, fever, photophobia, and altered mental status are common accompanying symptoms in meningitis. *None of the options* - This option is incorrect because **subarachnoid hemorrhage** is a strong and plausible diagnosis given the presented symptoms.
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