ENTERIC FEVER Flashcards
What is enteric fever?
A communicable disease encompassing typhoid and paratyphoid fevers caused by Salmonella typhi and Salmonella paratyphi A B
What are typhoidal Salmonella species?
Salmonella typhi and Salmonella paratyphi A B
What are non-typhoidal Salmonella species?
Other serotypes of Salmonella enterica such as Salmonella typhimurium
What is the reservoir of infection for enteric fever?
Humans are the only reservoir except for S. paratyphi C
How is enteric fever transmitted?
Fecal-oral route often through contaminated food and water; rarely person-to-person.
What is the incubation period of enteric fever?
10-14 days but it can range from 6 to 30 days depending on dose and host factors.
What is the infective dose of Salmonella typhi?
Usually 10^7 but it can be as low as 10^3 in vulnerable hosts.
What are the systemic features of enteric fever?
Involves the reticuloendothelial system intestinal lymphoid tissue
What are the clinical stages of enteric fever?
First week: Fever headache
What are key complications of enteric fever?
Intestinal hemorrhage and perforation jaundice
What are the risk factors for enteric fever?
Age (school-age children young adults)
What are the main diagnostic methods for enteric fever?
Clinical suspicion blood culture (1st week)
What is the Widal test?
A serological test detecting O and H antibodies to S. typhi widely used but with poor specificity and sensitivity.
What is the IDL Tubex test?
An immunochromatographic test detecting IgM to S. typhi O antigens providing early diagnosis with ~90% sensitivity.
What is the gold standard for diagnosing enteric fever?
Blood culture despite its low sensitivity due to low bacteremia and prior antibiotics.
What are the first-line treatments for enteric fever?
Fluoroquinolones like ciprofloxacin with ceftriaxone and azithromycin as alternatives.
Why is chloramphenicol no longer used for enteric fever?
Widespread resistance has rendered it obsolete as a first-line therapy.
What is the role of cholecystectomy in chronic carriers of S. typhi?
Considered if antibiotics fail to eradicate gallbladder colonization.
What are preventive measures for enteric fever?
Safe water proper sanitation
What are the two types of vaccines for typhoid fever?
Injectable polysaccharide vaccine (Typhim Vi) and live oral vaccine (Typhoral).
What is the efficacy of injectable typhoid vaccine (Typhim Vi)?
50-70% with protection lasting 2 years.
What is the efficacy of the live oral typhoid vaccine (Typhoral)?
50-70% with immunity starting 2-3 weeks after administration and lasting 7 years.
Who should receive the live oral typhoid vaccine?
Recommended for travelers to high-risk areas but contraindicated in children under 5 and immunocompromised individuals.
What are common differential diagnoses of enteric fever?
Malaria dengue
What is the case fatality rate of enteric fever?
Reduced to ~2% globally with antibiotic use but it remains higher in endemic areas.
What are the epidemiological hotspots for enteric fever?
South Asia sub-Saharan Africa (1000/100
What is the significance of rose spots in enteric fever?
A rash observed in light-skinned individuals during the second week indicative of S. typhi infection.
What is the importance of bone marrow culture in enteric fever?
Has the highest sensitivity (>90%) but is rarely used due to associated risks.
