descriptive epidemiology of multiple sclerosis (ms) multiple sclerosis
TRANSCRIPT
Descriptive Epidemiology of
Multiple Sclerosis
(MS)
Course of DiseaseAcute - Very Rapid Course, Death in a
few monthsProgressive - Gradually becoming
worse, well defined remissions and exacerbations
Benign - Exacerbations with very long remissions
Subclinical - No Symptoms, identified at autopsy
ProgressiveAcute
Epidemiology: Incidence of MS in
Denmark
0
2
4
6
8
10
10 20 30 40 50 60
MalesFemales
Incidence of MS in Iceland
0
0.5
1
1.5
2
2.5
3
3.5
1900 1910 1920 1930 1940 1950 1960 1970
per
/100
,000
Incidence of MS in Faroe Islands
0
2
4
6
8
10
12
1935
1940
1945
1950
1955
1960
1965
1970
1975
1980
NativePost-war birth
Incidence of MS in Faroe Islands by age
0123456
Females
Males
Years since 1942:in Faroe Islands
0
2
4
6
8
per
100
,000
Incidence of MS in South Africa
0
2
4
6
8
10
12
10 20 30 40 50
Immigrants
SA Born AfricanSpeak
SA Born EnglishSpeak
All White SA
Prevalence of MS
0
20
40
60
80
100
120
140
0 10 20 30 40 50 60 70 80
Winnipeg
Boston
New Orleans
Unusual Occurrence of MS in
Tropical Island
0
1
2
3
4
5
6
60
62
64
66
68
70
72
74
76
78
80
82
84
Risk Factors:
Unusual Stress in 2 Yrs Before
Cases Controls p value
79% 54% <0.01
Risk factors:
Exposed to Animal Illness
Cases Controls
43% 19%
Risk Factors:
Exposed to Canine Distemper
Cases Control
17% 6%
Physical Activity and MS
Cases ControlsPhysicallyActive
50% 34%
MixedActivities
27% 24%
SedentaryHobbies
20% 36%
None 3% 6%
Immunologic Involvement
Autoantibodies Encephalomyelitis developing--Similar to the administration of rabies virus vaccine
Evidence for a superantigen?
Frequency of Viral Infection
Colds Flu Enteric Herpes
Controls 9% 9% 0% 3%
Cases 5% 2% 8% .03%
Concordance Rates in Twins
MZ DZ
31/107 13/101
0.29 0.13
Prevalence of MS in First Degree
Relatives
Sibs Parents Offspring125/10,682 41/6,521 9/1,521
0.0117 0.0063 0.0059
DZ Risk versus Sibling Risk
DZ Sibling
0.13 0.012
HLA Antigens and MS:
Northern EuropeansCases Controls RR
A3 32 21 1.8
B7 35 18 2.5
DR2 41 22 2.5
ConclusionsMS caused by environmental factors, but not clear what they are
For MS there is evidence for HLA associations, however, there is more than HLA
MS is a multiloci disease