Table 3.
Characteristics of ZIP Codes in Contiguous Groups with High Burden of Reported West Nile Virus Disease Cases Compared with All Other ZIP Codes in Nine California Counties (Los Angeles, Orange, Riverside, San Bernardino, Stanislaus, Kern, Fresno, Butte, and Tulare)
| Characteristic | High-burden ZIP codes (IQR) [N = 151] | Low-burden ZIP codes (IQR) [N = 607] | pa | ||
|---|---|---|---|---|---|
| Total population | 6,468,241 | 14,818,550 | |||
| Mean population | 42,836 | 27,233–55,869 | 25,245 | 3962–38,304 | <0.001 |
| Population density per km2 | 2369 | 1140–3379 | 1756 | 43–2725 | 0.004 |
| Median age in years | 36 years | 32–39 | 39 years | 32–43 | <0.001 |
| Proportion aged ≥60 years | 18% | 14–20 | 21% | 14–25 | <0.001 |
| Average elevation | 160 meters | 39–249 | 421 meters | 65–583 | <0.001 |
| Proportion of developed land cover | 71% | 56–95 | 43% | 38–88 | <0.001 |
| Proportion with vector control agency | 99% | 88% | <0.001 | ||
| Proportion of White non-Hispanic residents | 37% | 20–51 | 42% | 16–66 | 0.01 |
| Median household income | $67,436 | 51,961–84,714 | $63,558 | 41,276–80,230 | 0.08 |
| Proportion of medically insured people | 89% | 86–92 | 88% | 85–94 | 0.61 |
Bold text indicates statistical significance.
a
Due to making 10 comparisons, the Bonferroni adjustment was applied, resulting in statistical significance at p ≤ 0.005.