Volume 14, Number 5—May 2008
Dispatch
Increase in West Nile Neuroinvasive Disease after Hurricane Katrina
Table 2
Incidence rate ratios of West Nile neuroinvasive disease (WNND) in 2002–2005 and 2006 in Louisiana parishes and Mississippi counties*
State, area | West Nile neuroinvasive disease incidence rate† |
Incidence rate ratio (95% CI) | |||||
---|---|---|---|---|---|---|---|
2002‡ | 2003‡ | 2004‡ | 2005‡ | 2002–2005§ | 2006¶ | ||
Louisiana | |||||||
Affected | 5.6 | 1.3 | 0.2 | 1.4 | 2.1 | 4.4 | 2.09 (1.48–2.94) |
Unaffected |
4.1 |
2.7 |
2.7 |
3.2 |
3.2 |
1.5 |
0.47 (0.35–0.64) |
Mississippi | |||||||
Affected | 6.1 | 2.1 | 0.8 | 1.5 | 2.6 | 6.5 | 2.45 (1.77–3.47) |
Unaffected | 5.5 | 1.7 | 1.2 | 1.3 | 2.4 | 1.7 | 0.71 (0.55–1.03) |
*WNND incidence rates increased 2-fold in the hurricane-affected regions of both states. The unaffected regions showed a decrease in WNND incidence rates (Louisiana) and no change in incidence (Mississippi). CI, confidence interval.
†No. cases/100,000.
‡Population estimate based on 2000 US Census (8).
§Cumulative WNND incidence = (no. WNND cases 2002 + 2003 + 2004 + 2005) / cumulative population (Census 2000 [8] × 100,000).
¶Population estimate based on 2006 US Census estimate (7).
References
- Lehman JA, Hinckley AF, Kniss KL, Nasci RS, Smith TL, Campbell GL, Effect of Hurricane Katrina on arboviral disease transmission. Emerg Infect Dis. 2007;13:1273–5.PubMedGoogle Scholar
- Centers for Disease Control and Prevention. Neuroinvasive and non-neuroinvasive domestic arboviral diseases (includes diseases caused by California serogroup viruses; eastern and western equine encephalitis viruses; and Powassan, St. Louis encephalitis, and West Nile viruses). 2004 [cited 2007 Oct 23]. Available from http://www.cdc.gov/ncidod/dvbid/westnile/surv&control.htm#casedefinition
- Knabb RD, Rhome JR, Brown DP. Tropical cyclone report: Hurricane Katrina, August 23–30, 2005 [cited 2008 Feb 19]. Available from http://www.nhc.noaa.gov/pdf/TCR-AL122005_Katrina.pdf
- Final evacuation of New Orleans completed. Reuters [International Herald Tribune]. 2005 Sep 4.
- Hayes EB, Komar N, Nasci RS, Montgomery SP, O’Leary DR, Campbell GL. Epidemiology and transmission dynamics of West Nile virus disease. Emerg Infect Dis. 2005;11:1167–73.PubMedGoogle Scholar
- US Census Bureau. Special population estimates for impacted counties in the Gulf Coast area. 2007 [cited 2008 Feb 19]. Available from http://www.census.gov/Press-Release/www/emergencies/impacted_gulf_estimates.html
- US Census Bureau. US census 2000 [cited 2008 Feb 19]. Available from http://www.census.gov/main/www/cen2000.html
- Breidenbach M, Haagsma K, Olson S, Teig D, Spears B, McHugh C, Air Force aerial spray operations to control adult mosquitoes following Hurricanes Katrina and Rita. Wing Beats. 2006;Summer:7–15.