Typhoid Fever Flashcards
Typhoid Fever
Bacteria causing enteric fever
- Salmonella typhi
- Salmonella paratyphi A,B,C
Typhoid Fever
Bacteria causing typhoid
Salmonella typhi
Typhoid Fever
non typhoid salmonella bacteria causes
gastroenteritis
Typhoid Fever
Mode of transmission
feco- oral
Typhoid Fever
Source of transmission
humans
Typhoid Fever
Infective dose
10^5 organisms
Typhoid Fever
3 main antigenic factors of salmonella paratyphi
- O- Somatic Ag
- Vi- encapsulation Ag
- H- flagellar Ag
Typhoid Fever
Incubation period
5-21 days
Typhoid Fever
Pathogenesis
- Bacteria enters through oral route
- Escape the acidic stomach barrier
- Invade the ileum mucosa
- Phagocytosed but survive the phagocytosis
- Crried to Lymph nodes and multiply there
- Enter the blood stream and cause primary bacteremia
- Reach- liver, GB, Spleen, Kidney, Bone marrow
- Multiply and cause Secondary bacteremia
Typhoid Fever
Invading site in human
ileum
Typhoid Fever
Sx during the 1st week
- Slow rising temp w relative bradycardia
- Malaise
- headache (mainly frontal)
- cough
- Coated tongue
- constipation
- blood culture
Typhoid Fever
Sx during the second week
- High fever ( Step ladder)
- Diarrhea
- rose spots in lower chest and abdomen
- Hepatosplenomegaly
Typhoid Fever
Sx during the third week
- intestinal hemorrhage
- Intestinal perforation and septicemia
- Diffuse peritonitis
- Encephalitis
- Metastatic abscess
- cholecystitis
- Endocarditis
Typhoid Fever
Labs during first, second, third week
- First week- blood culture +
- Second week - Stool culture +, widal + for O and H Ab
- Third week- Urine culture +
Typhoid Fever
Test done irrespective of the time
Blood culture
Typhoid Fever
DDs
Appendicitis
Typhoid Fever
Similarities with appenidicits
- RIF Pain
- Coated tongue
- Fever
Typhoid Fever
Step ladder fever is seen during
Mainly second week but can be seen during the first week as well
Typhoid Fever
Complications
- Some become chronic carriers
- Intestinal perforation
- Intestinal hemorrhage
- Rarely Periosteitis, myocarditis, pneumonia
- Bone marrow suppression
Typhoid Fever
Chronic carriers carry the bacteria in the
Mainly the GB, sometimes the Kidney
Typhoid Fever
How does the carriers spread the disease
Through excreta time to time
Typhoid Fever
Best Ix
Bone marrow culture, Not done though
Typhoid Fever
FBC
Can be normal. WBC reduced. Mainly neutrophils
Typhoid Fever
Serology tests
SAT ( Standard agglutination tes, Widal test)
Typhoid Fever
SAT
- NOt done because of the low sensitivity and specificity
- Targets O and H Ag
Typhoid Fever
SAT test samples are best taken during
Acute and convalescent phases
Typhoid Fever
Rx
- Cefotaxime/ ceftriaxone
- Ciprofloxacin
- Co- amoxiclav
Typhoid Fever
Why is chloramphenicol not given anymore
can further cause bone marrow suppression. Disease itself can cause BM suppression
Typhoid Fever
Chronic carriers impose a problem in careers such as
Food handlers
Typhoid Fever
Groups more prone to become chronic carriers
- Female
- Biliary abnormalities
- Co- existing bladder schistosomiasis
Typhoid Fever
How does chronic carriers spread the illness
Through urine and fecal excreta for >1 year
Typhoid Fever
Why does chronic carriers carry the bacteria for more than one year in urine and feces
Due to the persistent infection in the GB and Kidney
Typhoid Fever
Relative bradycardia
Usually in a fever, increase in body temp by one degree will increase the heart rate by 8- 10 bpm. But in typhoid fever HR will increase by ~ 5-6 bpm
Typhoid Fever
One difference which sets Typhoid fever sets apart from lepto and typhus
Typhoid will have altered bowel habits. First week will have constipation and then second week will have diarrhea
