Table 1 Cyanobacteria harmful algal exposure case characteristics by medical outcome, US, 2010–2022 (n = 4260)
Known outcomes | Unknown outcomes | ||||||||
|---|---|---|---|---|---|---|---|---|---|
Characteristics | No effect (N = 1163, 27.3%) | Minor effect (N = 856, 20.1%) | Moderate effect (N = 98, 2.3%) | Major effect (N = 4, 0.1%) | Not followed, nontoxic exposure† (N = 137, 3.2%) | Not followed, minimal clinical effects possible (N = 1453, 34.1%) | Unable to follow, potentially toxic exposure (N = 128, 3.0%) | Effect probably unrelated to exposure (N = 421, 9.9%) | Total§ (N = 4260) |
Age group in years, N(%) | |||||||||
0–5 | 191 (16.4) | 184 (21.5) | 13 (13.3) | 0 | 33 (24.1) | 313 (21.5) | 22 (17.2) | 87 (20.7) | 843 (19.8) |
6–12 | 187 (16.1) | 155 (18.1) | 21 (21.4) | 0 | 16 (11.7) | 279 (19.2) | 22 (17.2) | 86 (20.4) | 766 (18.0) |
13–19 | 127 (10.9) | 103 (12.0) | 11 (11.2) | 2 (50.0) | 4 (2.9) | 139 (9.6) | 10 (7.8) | 40 (9.5) | 436 (10.2) |
20–49 | 270 (23.2) | 281 (32.8) | 30 (30.6) | 0 | 24 (17.5) | 374 (25.7) | 43 (33.6) | 122 (29.0) | 1144 (26.9) |
50 and over | 47 (4.0) | 60 (7.0) | 18 (18.4) | 2 (50.0) | 6 (4.4) | 132 (9.1) | 8 (6.3) | 51 (12.1) | 324 (7.6) |
Unknown adult (≥ 20 years) | 137 (11.8) | 52 (6.1) | 5 (5.1) | 0 | 18 (13.1) | 125 (8.6) | 16 (12.5) | 32 (7.6) | 385 (9.0) |
Unknown child (≤ 19 years) | 82 (7.1) | 6 (0.7) | 0 | 0 | 1 (0.7) | 33 (2.3) | 5 (3.9) | 3 (0.7) | 130 (3.1) |
Unknown age | 122 (10.5) | 15 (1.8) | 0 | 0 | 35 (25.5) | 58 (4.0) | 2 (1.6) | 0 | 232 (5.4) |
Gender, N(%) | |||||||||
Male | 440 (37.8) | 403 (47.1) | 51 (52.0) | 2 (50.0) | 47 (34.3) | 689 (47.4) | 52 (40.6) | 204 (48.5) | 1888 (44.3) |
Female | 478 (41.1) | 428 (50.0) | 47 (48.0) | 2 (50.0) | 56 (40.9) | 669 (46.0) | 68 (53.1) | 215 (51.1) | 1963 (46.1) |
Unknown | 245 (21.1) | 25 (2.9) | 0 | 0 | 34 (24.8) | 95 (6.5) | 8 (6.3) | 2 (0.5) | 409 (9.6) |
Exposure site, N(%) | |||||||||
Own residence | 168 (14.4) | 207 (24.2) | 31 (31.6) | 0 | 46 (33.6) | 490 (33.7) | 67 (52.3) | 116 (27.6) | 1125 (26.4) |
Public area | 968 (83.2) | 584 (68.2) | 57 (58.2) | 3 (75.0) | 88 (64.2) | 878 (60.4) | 50 (39.1) | 274 (65.1) | 2902 (68.1) |
Other/Unknown | 27 (2.3) | 65 (7.6) | 10 (10.2) | 1 (25.0) | 3 (2.2) | 85 (5.8) | 11 (8.6) | 31 (7.4) | 233 (5.5) |
Route of exposure, N(%)* | |||||||||
Dermal | 1045 (89.9) | 645 (75.4) | 56 (57.1) | 2 (50.0) | 99 (72.3) | 989 (68.1) | 76 (59.4) | 282 (67.0) | 3194 (75.0) |
Ingestion | 478 (41.1) | 504 (58.9) | 58 (59.2) | 2 (50.0) | 83 (60.6) | 863 (59.4) | 87 (68.0) | 208 (49.4) | 2283 (53.6) |
Inhalation nasal | 34 (2.9) | 81 (9.5) | 18 (18.4) | 1 (25.0) | 2 (1.5) | 144 (9.9) | 14 (10.9) | 41 (9.7) | 335 (7.9) |
Other/Unknown | 16 (1.4) | 63 (7.4) | 17 (17.3) | 1 (25.0) | 14 (10.2) | 67 (4.6) | 9 (7.0) | 37 (8.8) | 224 (5.3) |
Chronicity, N(%)‡ | |||||||||
Acute | 1085 (93.3) | 770 (90.0) | 76 (77.6) | 4 (100.0) | 130 (94.9) | 1297 (89.3) | 106 (82.8) | 356 (84.6) | 3824 (89.8) |
Acute-on-chronic | 25 (2.1) | 27 (3.2) | 9 (9.2) | 0 | 2 (1.5) | 50 (3.4) | 6 (4.7) | 19 (4.5) | 138 (3.2) |
Chronic | 53 (4.6) | 48 (5.6) | 12 (12.2) | 0 | 4 (2.9) | 96 (6.6) | 15 (11.7) | 37 (8.8) | 265 (6.2) |
Unknown | 0 | 11 (1.3) | 1 (1.0) | 0 | 1 (0.7) | 10 (0.7) | 1 (0.8) | 9 (2.1) | 33 (0.8) |