Volume 18, Number 4—April 2012
Dispatch
Neuroinvasive Disease and West Nile Virus Infection, North Dakota, USA, 1999–2008
Table
Sex and age group, y | No. donors | Seroprevalence, % (95% CI) | Seropositivity, RR (95% CI) | Total population† | WNV-infected population‡ | No. WNND cases§ | Ratio of WNND cases to WNV infections (95% CI) | WNND, RR (95% CI) | Inverse of ratio¶ |
---|---|---|---|---|---|---|---|---|---|
Male | 2,349 | 9.2 (6.1–8.3) | 279,252 | 26,122 | 119 | 0.0045 (0.0038–0.0054) | 220 | ||
16–24 | 321 | 12.8 (9.1–16.4) | Referent | 56,156 | 7,188 | 10 | 0.0014 (0.0008–0.0026) | Referent | 719 |
25–44 | 562 | 8.7 (6.4–11.1) | 0.7 (0.5–1.0) | 89,968 | 7,827 | 22 | 0.0028 (0.0018–0.0042) | 2.0 (1.0–4.2) | 356 |
45–64 | 1,132 | 9.3 (7.6–11.0) | 0.7 (0.5–1.0) | 90,701 | 8,435 | 34 | 0.0040 (0.0029–0.0056) | 2.9 (1.4–5.9) | 248 |
≥65 | 334 | 6.3 (3.7–8.9) | 0.5 (0.3–0.8) | 42.427 | 2,672 | 53 | 0.0198 (0.0152–0.0258) | 14.3 (7.3–28.0) | 50 |
Female | 2,165 | 7.2 (6.2–8.3) | 271,968 | 18,353 | 63 | 0.0034 (0.0027–0.0044) | 291 | ||
16–24 | 316 | 9.8 (6.5–13.1) | Referent | 50,274 | 4,926 | 4 | 0.0008 (0.0003–0.09) | Referent | 1,231 |
25–44 | 600 | 6.7 (4.7–8.7) | 0.7 (0.4–1.1) | 78,869 | 5,284 | 16 | 0.0030 (0.0018–0.0049) | 3.7 (1.2–11.1) | 330 |
45–64 | 1,010 | 7.5 (5.9–9.2) | 0.8 (0.5–1.1) | 87,775 | 6,583 | 17 | 0.0026 (0.0016–0.0042) | 3.2 (1.1–9.4) | 387 |
≥65 | 239 | 2.9 (0.8–5.1) | 0.3 (0.1–0.7) | 55,050 | 1,596 | 26 | 0.0163 (0.0111–0.0241) | 20.1 (7.0–57.4) | 61 |
Total | 4,514 | 8.2 (7.4–9.0) | 551,220 | 44,511 | 182 | 0.0041 (0.0035–0.0047) | 244 |
*WNV, West Nile virus; WNND, WNV neuroinvasive disease; RR, relative risk.
†Source: US Census Bureau, 2010.
‡Seroprevalence × population.
§Data from Centers for Disease Control and Prevention; ArboNET.
¶No. WNV infections/no. WNND cases.
Page created: March 14, 2012
Page updated: March 14, 2012
Page reviewed: March 14, 2012
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