Table 2.
Incidence Rate Estimates Among Acute Gastroenteritis Case Patients (Inpatients and Outpatients), by Pathogen and Overall, July 2016 to June 2018
| Setting | Rate per 100 000 Population (95% CI)a |
||||||
|---|---|---|---|---|---|---|---|
| AGE | Ciostridioides difficile | Norovirus | Campylobacter | Shigeiia/EIEC | Saimoneiia | Rotavirus | |
|
| |||||||
| Inpatients | |||||||
| Overall | 380 (363–396) | 71.3 (61.3–82.3) | 19.4 (13.9–26.2) | 14.7 (9.4–20.4) | 8.4 (4.7–12.6) | 6.8 (3.7–10.5) | 5.8 (2.6–9.4) |
| Attributable Fraction (AF)b | ... | 43 (41.5–44.7) | 13.8 (10.7–14.8) | 12.8 (0–15.8) | 8.4 (4.7–12.6) | 5.9 (0–76) | 5.8 (2.6–9.4) |
| Age group | |||||||
| <65 y | 315 (293–334) | 56.2 (44.5–68.8) | 14.3 (76–21.8) | 10.1 (5–15.9) | 10.1 (5–15.9) | 5.9 (1.7–10.1) | 5.0 (1.7–9.2) |
| ≥65 y | 459 (433–484) | 90.6 (70.9–110) | 26.3 (15.8–38.1) | 21 (11.8–32.8) | 5.3 (1.3–11.8) | 79 (2.6–14.4) | 6.6 (1.3–11.8) |
| Exposure setting | |||||||
| Community onset | 218 (207–230) | 55.6 (45.6–64) | 18.3 (12.3–23.9) | 13.6 (8.9–18.3) | 79 (4.2–11.5) | 6.8 (3.1–11) | 5.8 (2.6–9.4) |
| Hospital onset | 388 (347–430) | 114 (79.6–145) | 76 (0–19) | 76 (0–19) | 3.8 (0–11.4) | 0 (0–0) | 0 (0–0) |
| Season | |||||||
| Winter (November-April) | 504 (474–532) | 84.8 (673–101) | 29 (18.6–39.5) | 12.8 (5.8–19.7) | 10.4 (4.2–16.6) | 5.8 (1.2–11.6) | 11.6 (5.8–19.7) |
| Summer (May-October) | 375 (351–402) | 65.4 (50.9–80.0) | 12.5 (6.2–19.7) | 177 (9.3–26) | 7 (2.3–12.8) | 8.3 (3.1–14.5) | 1.0 (0–3.1) |
| Surveillance year | |||||||
| July 2016 to June 2017 | 268 (249–288) | 46 (34.0–58.1) | 15 (8–23) | 10 (4.6–16.4) | 6.4 (1.8–11.8) | 4.6 (.9–9.1) | 8.0 (3.0–14) |
| July 2017 to June 2018 | 479 (453–503) | 94.6 (76.7–111) | 23.1 (14.7–32.6) | 16.3 (9.6–24.9) | 8.6 (3.8–15.3) | 76 (2.9–13.4) | 3.2 (0–74) |
| Outpatients | |||||||
| Overall | 2715 (2674–2755) | 285 (207–361) | 291 (226–366) | 140 (91.6–194) | 80.8 (43.1–121) | 32.3 (10.8–59.2) | 80.8 (48.5–119) |
| Age group | |||||||
| <65 y | 3100 (3041–3158) | 272 (188–371) | 329 (225–441) | 169 (93.9–254) | 112.7 (56.4–178) | 28.2 (0–65.7) | 103 (47–159) |
| ≥65 y | 2247 (2192–2302) | 310 (207–426) | 245 (155–349) | 103 (38.7–181) | 38.7 (0–775) | 38.7 (0–90.4) | 51.7 (12.9–103) |
| Season | |||||||
| Winter (November-April) | 3369 (3321–3417) | 455 (313–611) | 542 (381–703) | 147 (73.2–234) | 128 (56.9–213) | 28.4 (0–71.1) | 142 (56.9–227) |
| Summer (May-October) | 2854 (2810–2899) | 225 (139–321) | 253 (149–372) | 238 (133–357) | 64.1 (21.4–117) | 42.8 (5.3–85.5) | 53.5 (10.7–102) |
| Surveillance year | |||||||
| July 2016 to June 2017 | 2517 (2460–2574) | 306 (178–428) | 242 (129–354) | 113 (48.4–202) | 48.4 (0–112) | 16.1 (0–48.4) | 145 (56.5–242) |
| July 2017 to June 2018 | 2892 (2835–2950) | 283 (200–374) | 324 (233–420) | 158 (91.4–224) | 99.7 (49.9–157) | 41.6 (8.3–83.1) | 49.9 (16.6–91.4) |
Abbreviations: AGE, acute gastroenteritis; CI, confidence interval; EIEC, enteroinvasive Escherichia coli.
CIs for AGE outpatient estimates and inpatient community and hospital-onset inpatient estimates were calculated assuming Poisson distribution. Remaining estimates including pathogen-specific CIs calculated using bootstrapping.
The attributable fraction (AF) was calculated for inpatient pathogens based on the odds ratio (OR) of that pathogen’s prevalence among case patients and controls, using the following formula: (OR −1)/OR. The AF is an estimate of the percentage of AGE cases that can be attributed to infection with the pathogen of interest. (The AF was not calculated for other inpatient variables, owing to the small sample size for controls after stratification.)