Rift Valley Fever is an infection in Saharan Africa caused by a virus in the family Bunyaviridae and spread by mosquitoes. It usually causes a febrile illness, but a small percentage of patients may develop a fulminant disease with hemorrhage, hepatitis, renal failure and/or neurologic impairment. Adam et al developed a prognostic score which can help identify those patients at greatest risk for a fatal outcome.
|
Finding |
Description |
Points |
|
fever |
> 39°C |
2 |
|
gingival hemorrhage |
|
2 |
|
black vomit |
vomiting digested blood |
2 |
|
hematemesis |
vomiting fresh blood |
2 |
|
melena |
|
2 |
|
petechiae |
|
3 |
|
purpura |
|
3 |
|
"obnubilation" (French) |
? obsessive thoughts |
3 |
|
neurologic signs |
|
3 |
|
severe jaundice |
|
3 |
|
hepatocellular damage |
SGOT or SGPT > 800 U/L |
3 |
|
renal damage |
urea > 0.5 g/L (50 mg/dL), serum creatinine > 20 mg/L (2 mg/dL) |
3 |
|
isolation of virus |
in tissue culture |
3 |
|
oliguria |
|
2 |
|
hematuria |
|
2 |
prognostic score =
= SUM(points for parameters present)
Interpretation:
• minimum score: 0
• maximum score: 38
• The higher the score, the higher the mortality rate.
|
Prognostic Score |
mortality rate in patients with severe RVF |
mortality rate for all patients with RVF |
|
0 |
0.15 |
0.08 |
|
1 |
0.18 |
0.11 |
|
2 |
0.18 |
0.11 |
|
3 |
0.18 |
0.12 |
|
4 |
0.20 |
0.16 |
|
5 |
0.21 |
0.16 |
|
6 |
0.31 |
0.27 |
|
7 |
0.34 |
0.32 |
|
8 |
0.36 |
0.35 |
|
9 |
0.49 |
0.47 |
|
10 |
0.52 |
0.51 |
|
11 |
0.53 |
0.54 |
|
12 |
0.63 |
0.65 |
|
13 |
0.62 |
0.64 |
|
14 |
0.65 |
0.66 |
|
15 |
0.68 |
0.74 |
|
16 |
0.69 |
0.76 |
|
17 |
0.69 |
0.76 |
|
18 |
0.82 |
0.86 |
|
19 |
0.81 |
0.85 |
|
20 |
0.87 |
0.90 |
after Table 6, page 634
Purpose: To evaluate a patient with Rift Valley Fever using a prognostic score.
Specialty: Infectious Diseases
Objective: risk factors, severity, prognosis, stage, comorbid conditions
ICD-10: A92.4,
