The population-based burden of influenza-associated hospitalization in rural western Kenya, 2007–2009
Daniel R Feikin, Maurice O Ope, Barrack Aura, James A Fuller, Stella Gikunju, John Vulule, Zipporah Ng’ang’a, M Kariuki Njenga, Robert F Breiman & Mark Katz
Volume 90, Number 4, April 2012, 256-263A
Table 5. Annual hospitalizations (per 100 000 population) associated with respiratory illness and influenza by age group, Bondo district, Kenya, June 2007–May 2009
| Illness and age group | Year 1a |
Year 2b |
Both years |
|||||
|---|---|---|---|---|---|---|---|---|
| Unadjusted |
Adjustedc |
Unadjusted |
Adjustedc |
Unadjusted |
Adjustedc |
|||
| No. (95% CI) | No. (95% CI) | No. (95% CI) | No. (95% CI) | No. (95% CI) | No. (95% CI) | |||
| All age groups | ||||||||
| Respiratory illness | 722.3 | NA | 677.6 | NA | 699.8 | NA | ||
| (690.8–753.8) | (647.4–707.9) | (678.0–721.6) | ||||||
| Influenza, A virus | 29.9 | 53.5 | 33.2 | 47.1 | 31.6 | 50.3 | ||
| (23.4–36.3) | (44.9–62.1) | (26.5–39.9) | (39.1–55.1) | (26.9–36.2) | (44.4–56.1) | |||
| Influenza, B virus | 1.4 | 2.4 | 8.5 | 9.8 | 5.0 | 6.1 | ||
| (0.0–2.9) | (0.6–4.2) | (5.1–11.9) | (6.2–13.4) | (3.1–6.8) | (4.1–8.2) | |||
| Influenza, A virus, B virus or both | 31.3 | 55.8 | 41.4 | 56.5 | 36.4 | 56.2 | ||
| (24.7–37.9) | (47.0–64.6) | (33.9–48.9) | (47.7–65.3) | (31.4–41.4) | (50.0–62.4) | |||
| Influenza-associated hospitalizations (A, B or both virus types) | ||||||||
| < 1 year | 93.8 | 105.5 | 122.8 | 169.5 | 108.4 | 137.8 | ||
| (40.7–146.8) | (49.3–161.8) | (62.7–182.9) | (98.9–240.1) | (68.3–148.5) | (92.6–183.0) | |||
| 1 year | 204.0 | 406.3 | 100.2 | 122.5 | 151.6 | 263.1 | ||
| (109.9–298.1) | (273.6–539.0) | (34.8–165.6) | (50.1–194.8) | (94.5–208.8) | (187.9–338.3) | |||
| 2 years | 58.5 | 145.3 | 68.9 | 84.7 | 63.8 | 114.7 | ||
| (7.2–109.8) | (64.5–226.0) | (13.8–124.1) | (23.6–145.9) | (26.1–101.4) | (64.2–165.2) | |||
| 3 years | 60.6 | 163.9 | 59.5 | 67.0 | 60.1 | 115.0 | ||
| (7.5–113.7) | (76.6–251.2) | (7.4–111.7) | (11.6–122.3) | (22.9–97.3) | (63.5–166.5) | |||
| 4 years | 58.2 | 124.2 | 22.9 | 29.1 | 40.4 | 76.2 | ||
| (7.2–109.3) | (49.7–198.7) | (0.0–54.6) | (0.0–64.8) | (10.5–70.3) | (35.1–117.3) | |||
| < 5 years | 95.7 | 182.4 | 79.4 | 105.6 | 87.5 | 143.7 | ||
| (67.8–123.7) | (143.8–221.0) | (54.2–104.6) | (76.5–134.7) | (68.7–106.3) | (119.6–167.8) | |||
| 5–19 years | 9.7 | 16.8 | 18.1 | 20.7 | 13.9 | 18.8 | ||
| (4.0–15.4) | (9.3–24.4) | (10.4–25.9) | (12.5–29.0) | (9.1–18.7) | (13.1–24.4) | |||
| 20–34 years | 28.1 | 33.6 | 58.9 | 76.5 | 43.6 | 55.2 | ||
| (13.9–42.3) | (18.0–49.1) | (38.5–79.3) | (53.2–99.7) | (31.2–56.1) | (41.2–69.2) | |||
| 35–49 years | 33.0 | 49.7 | 48.6 | 80.3 | 40.9 | 65.1 | ||
| (12.6–53.5) | (24.6–74.8) | (24.0–73.2) | (48.7–111.9) | (24.9–56.9) | (44.9–85.3) | |||
| ≥ 50 years | 19.2 | 55.0 | 34.6 | 59.5 | 27.0 | 57.3 | ||
| (3.8–34.6) | (29.0–81.1) | (14.2–55.0) | (32.7–86.3) | (14.2–39.8) | (38.6–76.0) | |||
CI, confidence interval; NA, not applicable.
a June 2007–May 2008.
b June 2008–May 2009.
c Adjusted for the number of hospitalized patients meeting case definitions who did not have swabs tested. Adjustment was made separately for each age group, health facility and influenza season.