Reservoir of salmonella typhi is-

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2024

Explanation

Humans are the only known natural host and reservoir for Salmonella Typhi, the causative agent of typhoid fever.
The bacterium is maintained in the population through either acutely infected individuals (cases) or asymptomatic chronic carriers.
Transmission occurs via the fecal-oral route, through ingestion of food or water contaminated by an infected person.
Unlike other Salmonella serotypes that have animal reservoirs (zoonotic), S. typhi is exclusively adapted to humans.

Option A: Mosquitoes are arthropod vectors, not reservoirs for bacterial infections like typhoid. They transmit pathogens like protozoa (malaria) and viruses (dengue).
Option C: Pigs are not reservoirs for S. typhi. They can, however, be reservoirs for other non-typhoidal Salmonella serotypes (e.g., S. cholera-suis) which cause salmonellosis (food poisoning).
Option D: Rats are reservoirs for different pathogens, such as Yersinia pestis (plague) and Rickettsia typhi (murine typhus), but not Salmonella Typhi.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Reservoir of infection for Salmonella typhi as background academic context rather than a clinical decision trigger.
Understanding that humans are the only reservoir is critical for public health interventions, focusing on sanitation, safe water supply, and food hygiene to break the chain of transmission.
In a clinical setting, this knowledge reinforces the need for strict contact precautions and meticulous hand hygiene when caring for a patient with typhoid fever to prevent nosocomial spread.
Public health efforts must include the identification and treatment of chronic carriers to prevent community outbreaks, as they are a persistent source of infection.

How to Approach the Question

First, identify the key terms in the question: 'Reservoir' and 'salmonella typhi'.
This is a factual recall question from microbiology and community health nursing.
Recall the specific epidemiology of Salmonella typhi. A key distinguishing feature is its host specificity.
Differentiate S. typhi (which causes typhoid fever) from non-typhoidal salmonellae (which cause gastroenteritis and have animal reservoirs).
Evaluate the options. Eliminate the options that are known reservoirs or vectors for other diseases (mosquitoes, rats, pigs).
Select the option that correctly identifies the exclusive reservoir for S. typhi, which is humans.

Concept Tested & Keywords

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

Practise the full RUHS, Jaipur, PB B.Sc Nursing Entrance-2024

Attempt every question from this paper in a timed mock, then review the full solution for each one.