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Dr.Niraj Mahajan
Dr.Niraj Mahajan
Dr.Niraj Mahajan


Infectious Diseases

By AdminPosted On 05-Oct-2016

1. “Pastia” lines are seen in

a) Kawasaki disease

b) Scarlet fever

c) Staphylococcal Toxic shock Syndrome

d) Syphillis

Correct Answer: b) Scarlet fever. Scarlet fever results from group A streptococcal infection. Underarm, elbow and groin skin creases may become brighter red than the rest of the rash. These are called Pastia’s lines. It occurs prior to the appearance of the rash and persists as pigmented lines after desquamation.

2. Slapped-Cheek Appearance

A 7-year-old girl developed a rash that appeared 3 days ago. Her temperature is 37.2°C (99°F) and her face has an intense rash with a “slapped-cheek” appearance. The most likely etiologic agent is

a) Adenovirus

b) Rotavirus

c) Parvovirus

d) Coxsackievirus

e) Echovirus

Correct Answer: c) Parvovirus. Erythema infectiosum (also known as fifth disease) is usually a benign childhood condition characterized by a classic slapped-cheek appearance and lacy exanthem. It results from infection with human parvovirus (PV) B19, an erythrovirus.

3. The diagnosis of rota virus is made by

a) Demonstration of Antibody in stool

b) Demonstration of antigen in stool

c) Direct visualization

d) Stool culture

Correct Answer: b) Diagnosis may be made by rapid detection of rotavirus antigen in stool specimens. Strains may be further characterized by enzyme immunoassay or reverse transcriptase polymerase chain reaction, but such testing is not commonly done.

4. What is the incubation period for Hepatitis B?

a) 3 days

b) 7 days

c) 15 days

d) 30 days

e) 90 days

Correct Answer: e) 90 days. Symptoms begin an average of 90 days (range: 60–150 days) after exposure to HBV.

5. HBsAg-Positive

How long does (average) it take for blood to test HBsAg-positive after exposure to HBV?

a) 1 week

b) 4 weeks

c) 9 weeks

d) 12 weeks

e) 15 weeks

Correct Answer: b) 4 week. HBsAg will be detected in an infected person’s blood an average of 4 weeks (range: 1–9 weeks) after exposure to the virus. About 1 of 2 patients will no longer be infectious by 7 weeks after onset of symptoms, and all patients who do not remain chronically infected will be HBsAg-negative by 15 weeks after onset of symptoms.

6. Acute CMV Infection

Which white blood cell type is elevated in an acute cytomegalovirus infection?

a) Basophils

b) Eosinophils

c) Lymphocytes

d) Monocytes

e) Neutrophils

Correct Answer: c) Lymphocytes. Classically, lymphocytes are elevated in a viral infection.

7. Vector Born Infectious Disease

Arthropods are the vectors transmitting the following diseases. The vectors transmitting these diseases are found in India, yet one of the disease is not found here. Which is it?

a) Kyasanaur forest disease

b) Japanese encephalitis

c) Dengue fever

d) Sandfly fever

e) Yellow fever

Correct Answer: e) Yellow fever. There is no risk of yellow fever in India. The government of India requires proof of yellow fever vaccination only if you are arriving from a country with risk of yellow fever. This does not include the US. Yellow fever virus is mainly transmitted through Aedes aegypti mosquito. India is a yellow–fever “Receptive” area, that is, “An area in which yellow fever does not exist, but where conditions would permit its development if introduced.”

8. All of the following diseases are transmitted by louse EXCEPT

a) Epidemic typhus

b) Trench fever

c) Epidemic relapsing fever

d) Endemic typhus

Correct Answer: d) Endemic typhus. Several of the infectious diseases associated with human lice are life-threatening, including epidemic typhus, relapsing fever, and trench fever, which are caused by Rickettsia prowazekii, Borrelia recurrentis, and Bartonella quintana, respectively. Endemic typhus fever is spread by rat fleas and cat fleas.

9. CMV

What proportion of cytomegalovirus (CMV) infections is asymptomatic in immune-competent patients?

a) 10%

b) 40%

c) 60%

d) 80%

e) 90%

Correct Answer: e) 90%. CMV infection in adults is asymptomatic in 90% of cases. If primary infection occurs in pregnancy, then there is a 40–50% risk of fetal transmission. Between 22% and 38% of the infected fetuses will develop symptoms.

10. Which group of viruses cause chicken pox?

a) Adenovirus

b) Herpes virus

c) Papovavirus

d) Parvovirus

e) Pox virus

Correct Answer: b) Herpes virus. Chicken pox is caused by varicella zoster virus, which is one of eight herpes viruses. The other viruses in the Herpes virus group are herpes simplex virus 1, herpes simplex virus 2, Epstein-Barr virus, cytomegalovirus, roseolovirus, pityriasis rosea, Kaposi's sarcoma-associated herpes virus.

11. What is the incubation period for varicella infection?

a) 5–7 days

b) 7–10 days

c) 10–14 days

d) 10–20 days

e) 14–21 days

CorrectAnswer: d) 10–20 days. The infectious period lasts from about 5 days before the rash develops until all of the lesions have crusted over.

12. Animal reservoir for swine influenza virus is

a) Field mice

b) Urban rats

c) Pigs

d) Calomys callosus

e) Rhesus monkey

Correct Answer: c) Pigs. Swine influenza/ pig influenza/ swine flu is an infection caused by any one of several types of swine influenza viruses that is endemic in pigs. The retention of influenza strains in pigs after these strains have disappeared from the human population make pigs a reservoir where influenza viruses could persist, later emerging to reinfect humans once human immunity to these strains has waned.

13. Syphilis

Gummas can occur in various locations with syphilis infection. In what stage of the infection are gummas first found?

a) Cardiovascular quaternary syphilis

b) Neurological quaternary syphilis

c) Primary syphilis

d) Secondary syphilis

e) Tertiary syphilis

Correct Answer: e) Tertiary syphilis. Gummas are the defining characteristic of tertiary syphilis. There is usually a latency period between secondary and tertiary syphilis of 2–20 years.

14. Stage of Syphilis

A patient presents with condyloma lata. At what stage of syphilis does this feature occur?

a) Neurosyphilis

b) Primary

c) Quaternary

d) Secondary

e) Tertiary

Correct Answer: d) Secondary. Condyloma lata are specific for secondary syphilis.

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MD- Gynecologist, Laparoscopic Surgeon, Uro-gynecologist , Infertility specialist & Cosmetic Gynecologist.

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