TABLE 1. Number and percentage of reported cases of West Nile virus and other arboviral diseases (N = 884), by virus type and selected patient characteristics — United States, 2020.
| Characteristic | Virus type,* no. (%) of cases |
|||||
|---|---|---|---|---|---|---|
| West Nile (n = 731) | La Crosse (n = 88) | Powassan (n = 21) | St. Louis encephalitis (n = 16) | Eastern equine encephalitis (n = 13) | Jamestown Canyon (n = 13) | |
|
Age group, yrs
| ||||||
| <18 |
16 (2) |
83 (94) |
3 (14) |
0 (—) |
3 (23) |
0 (—) |
| 18–59 |
302 (41) |
3 (3) |
6 (29) |
5 (31) |
2 (15) |
6 (46) |
| ≥60 |
413 (56) |
2 (2) |
12 (57) |
11 (69) |
8 (62) |
7 (54) |
|
Sex
| ||||||
| Male |
459 (63) |
52 (59) |
14 (67) |
12 (75) |
7 (54) |
10 (77) |
| Female |
272 (37) |
36 (41) |
7 (33) |
4 (25) |
6 (46) |
3 (23) |
|
Period of illness onset
| ||||||
| Jan–Mar |
5 (1) |
1 (1) |
1 (5) |
1 (6) |
0 (—) |
0 (—) |
| Apr–Jun |
38 (5) |
7 (8) |
10 (48) |
2 (13) |
0 (—) |
7 (54) |
| Jul–Sep |
607 (83) |
76 (86) |
4 (19) |
10 (63) |
12 (92) |
6 (46) |
| Oct–Dec |
81 (11) |
4 (5) |
6 (29) |
3 (19) |
1 (8) |
0 (—) |
|
Clinical syndrome
| ||||||
| Nonneuroinvasive |
172 (24) |
4 (5) |
1 (5) |
2 (13) |
0 (—) |
3 (23) |
| Neuroinvasive |
559 (76) |
84 (95) |
20 (95) |
14 (88) |
13 (100) |
10 (77) |
| Encephalitis† |
343 (61) |
66 (79) |
13 (65) |
8 (57) |
12 (92) |
9 (90) |
| Meningitis† |
150 (27) |
16 (19) |
5 (25) |
3 (21) |
1 (8) |
0 (—) |
| AFP†,§ |
26 (5) |
0 (—) |
1 (5) |
0 (—) |
0 (—) |
0 (—) |
| Unspecified† |
40 (7) |
2 (2) |
1 (5) |
3 (21) |
0 (—) |
1 (10) |
|
Outcome
| ||||||
| Hospitalization |
583 (80) |
83 (94) |
17 (81) |
15 (94) |
13 (100) |
10 (77) |
| Death | 66 (9) | 0 (—) | 1 (5) | 3 (19) | 4 (31) | 0 (—) |
Abbreviation: AFP = acute flaccid paralysis.
* Two unspecified California serogroup virus cases were also reported.
† Percentages of cases of encephalitis, meningitis, AFP, and unspecified neurologic signs or symptoms are percentages of neuroinvasive cases.
§ Among the 26 West Nile virus disease cases with AFP, six persons (23%) also had encephalitis or meningitis.