Figure 1Detection of chikungunya virus (CHIKV) from a patient’s serum by duplex reverse transcription-polymerase chain reaction targeting both CHIKV and dengue virus (DENV). Lane 1, patient code 09-B09; lane 2, patient code 09-B36; lane 3, positive control (DENV), lane M, 1kb DNA ladder. The expected size of CHIKV and DENV fragment was 205 and 511 bp, respectively.
Figure 2The alignment of amino-acid sequences of the E1 gene of chikungunya viruses. Amino-acid sequence substitution from alanine (A) to valine (V) was shown at the position 226. Country and isolation year are described in the parentheses of each virus name. SAR = South African Republic.
Figure 3Phylogenetic analysis of the chikungunya virus based on the partial E1 gene (1044 nt) from 21 isolates. The tree was constructed by the neighbor-joining method (substitution model: maximum composite likelihood) using MEGA (version 5.1). The o'nyong-nyong virus (ONN, GenBank ID: AF079456) was used as out-group in the tree. The percentage of bootstrap values is shown at each node (2000 replications). CESA = Central/East/South African; DRC = Democratic Republic of Congo; SAR = South African Republic.
Table 1Result of laboratory testing for Chikungunya
Patient ID |
Age |
Days after
|
Dengue
|
Chikungunya
|
Travel destination |
Onset∗
|
ELISA |
RT-PCR |
ELISA |
RT-PCR |
09-A37 |
IU†
|
IU |
– |
– |
+ |
– |
Philippines |
09-A63 |
33 |
7 |
– |
– |
+ |
– |
Indonesia |
09-A73 |
34 |
IU |
– |
– |
+ |
– |
Indonesia |
09-B08 |
70 |
32 |
– |
– |
+ |
– |
Malaysia |
09-B09 |
IU |
IU |
– |
– |
– |
+ |
IU |
09-B36‡
|
57 |
26 |
–– |
–– |
–+ |
+– |
Malaysia/Singapore |
09-C54 |
38 |
IU |
– |
– |
+ |
– |
IU |
09-C77 |
IU |
6 |
– |
– |
+ |
– |
Vietnam |
09-D14 |
22 |
9 |
– |
– |
+ |
– |
IU |
10-D052 |
11 |
IU |
– |
– |
+ |
– |
IU |
10-D062 |
40 |
IU |
– |
– |
+ |
– |
IU |
10-D094 |
IU |
IU |
– |
– |
+ |
– |
IU |
10-D100 |
36 |
IU |
– |
– |
+ |
– |
IU |
10-D220 |
19 |
12 |
+ |
– |
+ |
– |
Indonesia |
10-D226 |
56 |
IU |
– |
– |
+ |
– |
IU |
10-D234 |
32 |
4 |
+ |
– |
+ |
– |
Philippines |
10-D328 |
IU |
IU |
+ |
– |
+ |
– |
East Timor |
10-D342 |
33 |
6 |
– |
– |
+ |
– |
IU |
10-D375 |
32 |
IU |
+ |
– |
+ |
– |
Philippines |
10-D445 |
12 |
IU |
– |
– |
+ |
– |
IU |
10-D497 |
IU |
IU |
+ |
– |
+ |
– |
Vietnam |
Table 2Details of the chikungunya viruses used for phylogenetic analysis