Enteric Fever Flashcards
What is Enteric fever?
A common disease caused by gram -ve strains of typhoidal Salmonella species such as;
Salmonella typhi (75-90%)
Salmonella paratyphi (10-25%)
Explain enteric fever pathology.
Bacteria invade the intestinal mucosa.
There is dissemination that occurs without a primary diarrhoeal response.
The transmission is faecal-oral from contaminated water/food.
Incubation of enteric fever.
6-30d usually 10-20d
What distunguishes typhoidal from non-typhoidal salmonella?
Non-typhoidal causes D+V in primary response.
In typhoid there is a dissemination that occurs without a primary diarrhoeal response.
Presentation of enteric fever.
Fatigue, headache and anorexia.
There is a marked “stepwise” fever that is rising through each day with progressive peaks, this is however only in 20%.
There is abdo pain, relative bradycardia (Faget’s sign), cough, constipation.
Rose spots in 25%
Diarrhoea and hepatosplenomegaly in 2nd week.
Complications of enteric fever.
PRogressive toxicity and complicated disease in 10% of cases.
Intestinal haemorrhage and perforation.
Myocarditis
Hepatitis
Pneumonia
DIC
CNS involvement with delirium, meningism, encephalitis etc…
Eye complications
Diagnosis of enteric fever.
Isolation of S. typhi from blood (multiple cultures), bone marrow, intestinal secretions or stool.
This should preferably be 2 samples leading up to 80% sensitivity.
Serology is not sufficient as a sole diagnostic tool.
Increased LFTs
PCR however not routine.
Treatment of Enteric fever.
Azithromycin +/- IV ceftriaxone.
70% from Asia is resistant to fluoroquinolones.
Antipyretics, fluid management, nutrition.
Treatment of enteric fever with CNS disease.
Dexamethasone 3mg/kg IV then 1mg/kg/6h for 8 doses.
Why does it take the fever 5-7 days to respond to treatment?
Because of the intracellular niche of the organism.
Vaccinatio of enteric fever.
Ty21a or Vi.
50-80% effective for 3 years.
There is limited/no protection against paratyphoid.
Laboratory findings in Enteric fever
Leucopenia
Lymphopenia
Raised CRP and ESR
What is Faget’s sign?
Fever with a paradoxical slow pulse i.e. Fever with bradycardia instead of tachycardia.
