SALMONELA/TYPHOID

Question 1

The mean incubation period for S. Typhi

Answer 1

10-14 days

• but ranges from 5-21 days

Question 2

The most prominent symptom in typhoid fever?

Answer 2

prolonged fever

Question 3

Faint, salmon-colored, blanching, maculopapular rash located primarily on the trunk and chest evident at the end of the first week and resolves without a trace after 2–5 days in 30% of patients?

Answer 3

Rose spots

Question 4

Complication of typhoid fever that most commonly occur in the third and fourth weeks of illness

Answer 4

Gastrointestinal bleeding (6%) and intestinal perforation (1%)

Question 5

Chronic carriage is more common among

Answer 5

• Women
• Infants
• Persons who have biliary abnormalities or concurrent bladder infection with Schistosoma haematobium.

Question 6

TRUE OR FALSE: Chronic carriage is associated with an increased risk of gallbladder cancer

Answer 6

TRUE

Question 7

Stool cultures can become positive during what week of infection in untreated patients.

Answer 7

3rd week

Question 8

The definitive diagnosis of enteric fever requires

Answer 8

isolation of S. Typhi or S. Paratyphi from blood, bone marrow, other sterile sites, rose spots, stool, or intestinal secretions

Question 9

Patients who develop chronic carriage of Salmonella can be treated for _ weeks

Answer 9

4 weeks (28 days)

Question 10

It is an oral live attenuated S. Typhi vaccine given on days 1, 3, 5, and 7

Answer 10

Ty21a

Question 11

The most effective class of agents for the treatment of drug-susceptible typhoid fever

Answer 11

fluoroquinolones

Question 12

gram-negative, non-spore-forming, facultatively anaerobic bacilli

Answer 12

Salmonella

Question 13

Infectious dose of salmonella

Answer 13

200 CFU to 10^6 CFU

Question 14

Empiric antibiotic therapy for Enterif fever?

Answer 14

Ceftriaxone 2g IV OD for 10-14 days
Azithromycin 1g tab OD x 5 days

Question 15

Ceftriaxone-resistant S. Typhi infection should be treated empirically with

Answer 15

Meropenem 1g IV q8 for 10-14 days or
Azithromycin 1g tab OD x 5 days

Question 16

Drug of choice for eradication of carriage?

Answer 16

Ciprofloxacin 500-750mg BID x 28 days

Question 17

If the patient is a chronic carrier but susceptibility studies showed fluoroquinolone resistance, what is the alternative treatment option?

Answer 17

Amoxicillin 2g tab PO x 28-42 days

Question 18

TRUE OR FALSE: Severe enteric fever remains one of the few indications for glucocorticoid treatment of an acute bacterial infection

Answer 18

TRUE

Question 19

It is a parenteral vaccine consisting of purified Vi polysaccharide from the bacterial capsule

Answer 19

Vi CPS
* given in a single dose
* with a booster every 2 years
* minimal age for vaccination is 2 years for Vi CPS

Question 20

What is the treatment of enteric fever in cases where anatomic abnormality (e.g., biliary or kidney stones) is present?

Answer 20

both antibiotic therapy and surgical correction.

Question 21

Which of the following organisms cause enteric (typhoid) fever?
A) Salmonella Typhi and Salmonella Paratyphi
B) Salmonella Enteritidis and Salmonella Typhimurium
C) Escherichia coli and Vibrio cholerae
D) Shigella dysenteriae and Campylobacter jejuni

Answer 21

Answer: A
Rationale: Salmonella Typhi and Salmonella Paratyphi are restricted to human hosts and cause enteric (typhoid) fever.

Question 22

How is typhoid fever most commonly transmitted?
A) Inhalation of contaminated droplets
B) Mosquito bites
C) Fecal-oral route through contaminated food and water
D) Direct skin contact

Answer 22

Answer: C
Rationale: Typhoid fever is primarily transmitted via the fecal-oral route, through ingestion of contaminated food or water.

Question 23

What is the most prominent symptom of enteric fever?
A) Jaundice
B) Prolonged high fever
C) Severe vomiting
D) Hemoptysis (coughing up blood)

Answer 23

Answer: B
Rationale: The most prominent symptom of enteric fever is prolonged fever (38.8°C–40.5°C or 101.8–104.9°F).

Question 24

What is the characteristic rash associated with typhoid fever?
A) Erythema nodosum
B) Petechial rash
C) Rose spots
D) Bullous rash

Answer 24

Answer: C
Rationale: Rose spots are faint, salmon-colored, blanching maculopapular rashes that appear primarily on the trunk and chest.

Question 25

What is the most sensitive diagnostic test for enteric fever?
A) Blood culture
B) Stool culture
C) Bone marrow culture
D) Urine culture

Answer 25

Answer: C
Rationale: Bone marrow culture has the highest sensitivity (>80%) and is not affected by prior antibiotic use.

Question 26

Which of the following complications is most commonly associated with the third and fourth weeks of typhoid fever?
A) Gastrointestinal bleeding and intestinal perforation
B) Severe dehydration
C) Liver abscess
D) Hemoptysis

Answer 26

Answer: A
Rationale: Gastrointestinal bleeding (6%) and intestinal perforation (1%) occur most commonly in the third and fourth weeks of illness.

Question 27

What is the first-line treatment for drug-susceptible typhoid fever?
A) Fluoroquinolones (e.g., ciprofloxacin)
B) Doxycycline
C) Vancomycin
D) Metronidazole

Answer 27

Answer: A
Rationale: Fluoroquinolones (such as ciprofloxacin) are the most effective treatment for drug-susceptible typhoid fever.

Question 28

What is the recommended empirical treatment for enteric fever in regions with high fluoroquinolone resistance (e.g., Indian subcontinent, Nepal, and some parts of Africa)?
A) Ciprofloxacin
B) Ceftriaxone or azithromycin
C) Amoxicillin
D) Amphotericin B

Answer 28

Answer: B
Rationale: In areas with high fluoroquinolone resistance, treatment should be with ceftriaxone or azithromycin.

Question 29

Which vaccine is an oral live attenuated S. Typhi vaccine?
A) Vi CPS
B) Ty21a
C) BCG
D) Hepatitis B vaccine

Answer 29

Answer: B
Rationale: Ty21a is the oral live attenuated S. Typhi vaccine.

Question 30

How often should the Vi CPS typhoid vaccine be boosted?
A) Every 6 months
B) Every year
C) Every 2 years
D) Every 5 years

Answer 30

Answer: C
Rationale: The Vi CPS (purified polysaccharide) vaccine requires a booster every 2 years.