Khan et al developed a prognostic staging system for patients with Salmonella bacteremia associated with typhoid fever. This can help identify patients at risk for complications. The authors are from the University of Natal and King Edward VIII Hospital in Durban, South Africa.
Blood cultures: positive for Salmonella typhi
Exclusion criteria:
(1) HIV infection
(2) concurrent conditions with increased risk for Salmonella infection (hemolytic anemia, diabetes mellitus, collagen vascular disease, neoplastic disease, immunodeficiency, schistosomiasis, chronic renal failure, chronic liver disease, history of gastrectomy or gastroenterostomy, history of regular antacid use, use of immunosuppressive therapy)
Parameters:
(1) abdominal pain
(2) systolic blood pressure
(3) serum albumin
(4) laboratory evidence of DIC (disseminated intravascular coagulopathy)
Laboratory criteria for DIC (page 202)
(1) platelet count < 150,000 per µL plus
(2) 2 or more of the following:
(2a) PT > 15 seconds (upper limit of reference range);
(2b) aPTT > 44 seconds (upper limit of reference range);
(2c) serum fibrinogen < 150 mg/dL (lower limit of normal)
(2d) while not listed in paper, I would also include increased fibrin degradation products
|
Parameter
|
Finding
|
Points
|
|
abdominal pain
|
absent
|
0
|
|
|
present
|
1
|
|
systolic blood pressure
|
>= 100 mm Hg
|
0
|
|
|
< 100 mm Hg
|
1
|
|
serum albumin
|
>= 3.2 g/dL
|
0
|
|
|
< 3.2 g/dL (hypoalbuminemia)
|
1
|
|
evidence of DIC
|
absent
|
0
|
|
|
present
|
1
|
prognostic score =
= SUM(points for all 4 parameters)
Interpretation:
• minimum score: 0
• maximum score: 4
• The higher the score, the more serious the infection and the more likely complications are to occur.
|
Prognostic Score
|
Risk Group (Prognostic Stage)
|
Probability of Complications (95% CI)
|
|
0
|
low (I)
|
2% (0 – 15%)
|
|
1
|
intermediate (II)
|
38% (22 – 58%)
|
|
>= 2
|
high (III)
|
95% (69 - 99%)
|
from Table III, page 204.
