Volume 15, Number 3—March 2009
Research
Prevalence and Seasonality of Influenza-like Illness in Children, Nicaragua, 2005–2007
Table 2
Incidence of influenza-like illness in cohort of children 2–11 years of age, Managua, Nicaragua, 2005–2007*
Characteristic | Person-years, %† | ILI episodes‡ | Incidence/100 person-years | 95% CI |
---|---|---|---|---|
All participants | 7,449.4 | 2,596 | 34.8 | 33.5–36.2 |
Year | ||||
2005–2006§ | 3,704.5 | 1,106 | 29.9 | 28.1–31.7 |
2006–2007¶ |
3,745.0 |
1,490 |
39.8 |
37.8–41.9 |
Sex | ||||
M | 3,778.7 | 1,280 | 33.9 | 32.1–35.8 |
F |
3,670.7 |
1,316 |
35.9 |
34.0–37.8 |
Age, y | ||||
2 | 339.2 | 285 | 84.0 | 74.8–94.4 |
3 | 721.8 | 475 | 65.8 | 60.2–72.0 |
4 | 871.1 | 418 | 48.0 | 43.6–52.8 |
5 | 931.6 | 342 | 36.7 | 33.0–40.8 |
6 | 916.3 | 287 | 31.3 | 27.9–35.2 |
7 | 854.2 | 252 | 29.5 | 26.1–33.4 |
8 | 852.7 | 181 | 21.2 | 18.3–24.6 |
9 | 815.0 | 172 | 21.1 | 18.2–24.5 |
10 | 709.5 | 122 | 17.2 | 14.4–20.5 |
11 |
438.0 |
62 |
14.2 |
11.0–18.2 |
Asthma | ||||
Yes | 447.8 | 322 | 71.9 | 64.5–80.2 |
No | 7,001.7 | 2,274 | 32.5 | 31.2–33.8 |
*ILI, influenza-like illness; CI, confidence interval.
†Person-years were determined by dividing the total number of person-weeks by 52.
‡ILI was defined as an acute fever >37.8°C with cough or sore throat.
§April 16, 2005–April 15, 2006.
¶April 16, 2006–April 15, 2007.