Enteric fever: Difference between revisions

Latest revision as of 09:57, 27 January 2022

Background

Microbiology

Caused by Salmonella enterica subspecies enterica serotypes Typhi and Paratyphi
Virulence is related to Vi antigen and invasin protein

Epidemiology

Fecal-oral transmission acquired from contaminated food, milk, or water
Less than 5% of infected people become chronic carriers, with bacteria remaining in the gallbladder despite adequate antibiotic treatment

Pathophysiology

Induction of pH-shock proteins and other adaptions allow ingested bacteria to pass through the stomach and into the small intestine
There, they penetrate the intestinal mucosa followed by mononuclear cells, which transport them to lymph nodes
They multiple within the reticuloendothelial system during the incubation period
After a threshold is reached, they disseminate to blood

Clinical Manifestations

Most commonly presents as fever in the returned traveller
Incubation period 5 to 21 days
Symptoms progress over weeks
- First week: fever, chills, bacteremia, relative bradycardia, headache
- Second week: abdominal pain, and a blanchable papular rash ("rose spots") may appear
- Third week: can progress to gastrointestinal perforation, hepatosplenomegaly, GI bleed, secondary bacteremia
Constipation is more common in adults, while diarrhea is more common in children and people with HIV
CBC shows leukopenia and anemia
Extraintestinal manifestations are myriad
- Myelitis, psychosis, ataxia, parkinsonism
- Meningoencephalopathy
- Abscess or empyema
- Endocarditis, myocarditis, and pericarditis
- Pneumonia
- Hepatitis, cholestasis, liver abscess
- Osteomyelitis, rarely

Diagnosis

Blood cultures (large volume, like x4), stool cultures, bone marrow
Biopsy (most sensitive)

Management

Treatment with third-generation cephalosporins like ceftriaxone, stepped down to oral when improving and susceptibility data are available
- Alternatives are azithromycin, followed by ampicillin, TMP-SMX, chloramphenicol
- Avoid fluoroquinolones due to high resistance rate
Duration 10 to 14 days
- Can take 4 to 6 days to defervesce, even with treatment
Monitor for relapse 2 to 3 weeks after treatment ends

@@ Line 2: / Line 2: @@
 ===Microbiology===
-*Caused by ''[[Salmonella enterica]]'' subsp. ''typii'' and ''paratyphii''
+*Caused by ''[[Salmonella enterica]]'' subspecies ''enterica'' serotypes Typhi and Paratyphi
 *Virulence is related to Vi antigen and invasin protein
@@ Line 12: / Line 12: @@
 ===Pathophysiology===
-*Induction of pH-shock proteins and other adaptions allow ingested bacteria to pass through the stomch and into the small intestine
+*Induction of pH-shock proteins and other adaptions allow ingested bacteria to pass through the stomach and into the small intestine
-*There, they penetrate the intestinal mucosa followed by mononuclear cells, which transport them to lypmh nodes
+*There, they penetrate the intestinal mucosa followed by mononuclear cells, which transport them to lymph nodes
 *They multiple within the reticuloendothelial system during the incubation period
 *After a threshold is reached, they disseminate to blood
@@ Line 30: / Line 30: @@
 **[[Myelitis]], [[psychosis]], [[ataxia]], [[parkinsonism]]
 **[[Meningoencephalopathy]]
-**[[abscess]] or [[empyema]]
+**[[Abscess]] or [[empyema]]
 **[[Endocarditis]], [[myocarditis]], and [[pericarditis]]
 **[[Pneumonia]]
@@ Line 45: / Line 45: @@
 *Treatment with third-generation cephalosporins like [[Is treated by::ceftriaxone]], stepped down to oral when improving and susceptibility data are available
 **Alternatives are [[Is treated by::azithromycin]], followed by [[ampicillin]], [[TMP-SMX]], [[chloramphenicol]]
-**Avoid fluoroquinolones due to high resistance rate
+**Avoid [[fluoroquinolones]] due to high resistance rate
 *Duration 10 to 14 days
 **Can take 4 to 6 days to defervesce, even with treatment