Biology Reference
In-Depth Information
Table 2.3
KFD Virus Isolation from Questing Ticks Collected by Hand picking and
Dragging (1961
1972)
Species
Number of Ticks
Number of Isolations
Larvae
Nymphs
Adults
Larvae
Nymphs
Adults
H. spinigera
19
253,946
88,624
0
479
359
1
a
H. turturis
41
123,738
53,645
431
265
2
a
H. kinneari
81
12,597
26,646
26
49
1
a
H. kyasanurensis
21
14,712
629
41
4
H. wellingtoni
0
11,754
401
0
17
1
H. bispinosa
1
2,907
702
0
11
0
H. minuta
a
0
2,113
104
0
6
0
H. cuspidata
a
0
1,517
509
0
11
2
H. aculeata
a
0
220
10
0
0
0
H. intermedia
a
0
0
181
0
0
0
H. cornigera
a
0
0
136
0
0
0
H. mixed species
18108
13,386
928
0
30
0
Total
18271
436,890
172,515
4
1,052
680
a
KFD virus had been isolated from these species after 1972.
Disease Relationship
7,23,109,130,132,134,135,145
This is the most predominant species among Haemaphysalis in the KFD area with
the maximum number of KFD isolations. As many as 479 isolations from nymphs
and 359 isolations from adults have been recorded during the period from 1961 to
1972 from the KFD area. There is no report of KFD isolation from larva.
132,135,145
Under laboratory studies, the transstadial as well as transovarial transmission of
KFD virus by H. spinigera ticks has been proved.
130
In addition to KFD, another
arbovirus called Kaisodi has also been isolated from this species. From 1965 to
1970, as many as 77 and 52 isolates of Kaisodi virus have been reported from
nymphs and adults, respectively.
5,109,125
In another laboratory study, unfed H. spinigera was infected by parenteral inoc-
ulation of Ganjam virus. H. spinigera distinctly supported the multiplication of the
virus as progressively rising titers were observed in ticks at various intervals.
Changes in the Ecosystem and Spread of H. spinigera
16,20
Boshell (1969) reported the possible emergence of KFD in the forest biotope in
Shimoga district, Karnataka, India, due to ecologic changes. Formation of inter-
phases due to clearance of forest patches is said to have triggered the multiplication
of tick vector, H. spinigera, resulting in the outbreak of KFD for the first time in
this forest. Out of thousands of tick specimens belonging to 15 species of
Haemaphysalis collected from KFD area for two decades,
1977 in
connection with different ecological studies, H. spinigera has been found to be the
i.e., 1957
