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Submenu
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The percentage of
dengue cases in different areas of Viet Nam
|
year
|
North
|
Central
|
Highland
|
South
|
|
1998
|
13
|
30
|
6
|
51
|
|
1999
|
8
|
35
|
3
|
54
|
Serologic
confirmation of dengue cases
|
year
|
no
of specimen
|
no of
positive tests
|
%
positive
|
|
1991
|
1,905
|
933
|
51.7
|
|
1992
|
1,060
|
259
|
24.4
|
|
1993
|
1,507
|
560
|
37.2
|
|
1994
|
537
|
160
|
29.8
|
|
1995
|
617
|
167
|
27.1
|
|
1996
|
1,156
|
139
|
12.0
|
|
1997
|
448
|
185
|
43.7
|
|
1998
|
1,299
|
525
|
40.4
|
|
1999
|
6,003
|
1,620
|
26.99
|
00000000In
Southern Viet Nam during the year from 1987 through
1999, the
virologic surveillance offered knowledge of epidemic
serotypes of dengue viruses. The activity cycle of DEN
1 started in 1990 and remained active into 1995. The
DEN 2 activity cycle began in 1987 and continued through
1997; while DEN 3 first appeared in 1995 has become
the predominant serotype of the biggest 1998 DHF epidemic
and currently this serotype in continuing to be active.
In addition to 1999, there was strong resurgence of
DEN 4. This emerging trend will likely continue in the
future. Genomic structure of the DEN2/Vietnam/1987 are
somewhat different in comparison with many topotypes
of the world, but closely related to the Den 2 topotype
of Jamaica 1983. Another close relationship has been
demonstrated between DEN 3/Vietnam/1997-98 and the DEN
3/Thailand/1987. Cases of DHF were always confirmed
through virologic surveillance in the first quarter
of every year. Therefore, active surveillance of DHF
and its control programme must be implemented within
this limited period.
Viral isolation in
Viet Nam
|
year
|
DEN
1
(%)
|
DEN
2
(%)
|
DEN
3
(%)
|
DEN
4
(%)
|
total
|
|
1991
|
21
(25.9)
|
53
(65.4)
|
4
(4.9)
|
3
(3.7)
|
81
|
|
1992
|
16
(48.5)
|
17
(51.5)
|
0
|
0
|
33
|
|
1993
|
22
(71.0)
|
9
(29.0)
|
0
|
0
|
31
|
|
1994
|
24
(54.6)
|
15
(34.1)
|
5
(11.4)
|
0
|
44
|
|
1995
|
96
(59.3)
|
50
(30.9)
|
16
(9.9)
|
0
|
162
|
|
1996
|
20
(14.4)
|
78
(56.1)
|
41
(29.5)
|
0
|
139
|
|
1997
|
0
|
5
(18.5)
|
22
(81.5)
|
0
|
27
|
|
1998
|
77
(12.9)
|
56
(9.4)
|
453
(76.1)
|
8
(1.3)
|
594
|
|
1999
|
24
(27.0)
|
18
(20.2)
|
24
(27.0)
|
23
(25.8)
|
89
|
|
Total
|
300
(25.0)
|
301
(25.1)
|
565
(47.1)
|
34
(2.8)
|
1,200
|
Data from Professor
Dao Dinh Duc and Professor Do Quang Ha (Pasteur Institute,
Ho Chi Minh City)
 
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