Table 4. The regression equations of the relationship between a cumulative number of WNV positive pools, mosquito infection rate in a six-week period early and mid-summer and human West Nile virus illnesses for the year for Cook and DuPage counties from 2004–2014.

Week	Regression equation	R-square
28	30.1 + 0.445 * Number of positive pools	0.721
29	21.2 + 0.278 * Number of positive pools	0.825
30	11.8 + 0.194 * Number of positive pools	0.895
31	2.33 + 0.144 * Number of positive pools	0.931
32	- 6.0 + 0.118 * Number of positive pools	0.917
33	- 16.5 + 0.103 * Number of positive pools	0.901
34	- 23.7 + 0.0938 * Number of positive pools	0.863
35	- 29.5 + 0.0861 * Number of positive pools	0.813
Early summer (22–27)	13.7 + 162 * average MIR of week 22–27	0.833
Mid-summer (28–33)	- 16.7 + 14.7 * average MIR of week 28–33	0.936