Which of the following is the primary mode of transmission of typhoid fever?

BTSC Staff Nurse 30July-2025

Applied Microbiology & Infection control

Easy

Appeared in: BTSC Staff Nurse 30July-2025

Explanation

Typhoid fever is an enteric (gastrointestinal) infection caused by the bacterium Salmonella enterica serovar Typhi.
The primary mode of transmission is the fecal-oral route, which occurs through the ingestion of food or water contaminated with the feces of an infected person.
The bacteria can survive for weeks in contaminated water and foods, making sanitation and hygiene crucial for prevention.
Humans are the only reservoir for S. Typhi, meaning the infection spreads from person to person, often through asymptomatic carriers.

Option B: Mosquito bites are a form of vector-borne transmission. Mosquitoes transmit pathogens for diseases like malaria, dengue, chikungunya, and Zika virus, not bacterial infections like typhoid.
Option C: While direct person-to-person contact can theoretically transmit the bacteria if hygiene is extremely poor, it is not the primary or most common mode of transmission. The main pathway is indirect, via contaminated food and water.
Option D: Airborne transmission involves inhaling droplets expelled by an infected person's cough or sneeze. This is characteristic of respiratory infections, not enteric infections like typhoid.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Mode of transmission for Typhoid Fever as background academic context rather than a clinical decision trigger.
Nurses are at the forefront of patient and community education on preventive measures for typhoid, emphasizing the WASH (Water, Sanitation, and Hygiene) strategy.
In a hospital setting, nurses must implement contact precautions for patients with typhoid fever to prevent nosocomial (hospital-acquired) spread, paying strict attention to the safe disposal of feces and urine.
A key nursing assessment is to inquire about recent travel history, especially to regions where typhoid is endemic, for any patient presenting with sustained high fever and gastrointestinal symptoms.

How to Approach the Question

First, identify the key terms in the question: "primary mode of transmission" and "typhoid fever".
Recall or deduce the nature of typhoid fever. It is an enteric disease, meaning it affects the gastrointestinal tract.
Associate enteric diseases with their most common transmission route: the fecal-oral route. This route involves pathogens from feces entering the mouth.
Evaluate the options in this context. 'Contaminated food and water' is the classic description of the fecal-oral route.
Eliminate the other options by categorizing their transmission types: mosquito bites (vector-borne), direct contact (common for skin/saliva-transmitted diseases), and airborne droplets (respiratory diseases).
Conclude that contaminated food and water is the only option that fits the profile of an enteric disease like typhoid.

Concept Tested & Keywords

Q0aZoyswCga4UH0B_TjekN

E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart B (pp 202-403 of 604) pp. 91-93, 161-163

E6 Medicine Harrison 22e Part 1 p. 1360-1362